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Stringing or Oozing | Simplify3D Software

Stringing or Oozing

Stringing (otherwise known as oozing, whiskers, or “hairy” prints) occurs when small strings of plastic are left behind on a 3D printed model. This is typically due to plastic oozing out of the nozzle while the extruder is moving to a new location. Thankfully, there are several settings within Simplify3D that can help with this issue. The most common setting that is used to combat excessive stringing is something that is known as retraction. If retraction is enabled, when the extruder is done printing one section of your model, the filament will be pulled backwards into the nozzle to act as a countermeasure against oozing. When it is time to begin printing again, the filament will be pushed back into the nozzle so that plastic once again begins extruding from the tip. To ensure retraction is enabled, click “Edit Process Settings” and click on the Extruder tab. Ensure that the retraction option is enabled for each of your extruders. In the sections below, we will discuss the important retraction settings as well as several other settings that can be used to combat stringing, such as the extruder temperature settings.

Common Solutions

Retraction distance

The most important retraction setting is the retraction distance. This determines how much plastic is pulled out of the nozzle. In general, the more plastic that is retracted from the nozzle, the less likely the nozzle is to ooze while moving. Most direct-drive extruders only require a retraction distance of 0.5-2.0mm, while some Bowden extruders may require a retraction distance as high as 15mm due to the longer distance between the extruder drive gear and the heated nozzle. If you encounter stringing with your prints, try increasing the retraction distance by 1mm and test again to see if the performance improves.

Retraction speed

The next retraction setting that you should check is the retraction speed. This determines how fast the filament is retracted from the nozzle. If you retract too slowly, the plastic will slowly ooze down through the nozzle and may start leaking before the extruder is done moving to its new destination. If you retract too quickly, the filament may separate from the hot plastic inside the nozzle, or the quick movement of the drive gear may even grind away pieces of your filament. There is usually a sweet spot somewhere between 1200-6000 mm/min (20-100 mm/s) where retraction performs best. Thankfully, Simplify3D has already provided many pre-configured profiles that can give you a starting point for what retraction speed works best, but the ideal value can vary depending on the material that you are using, so you may want to experiment to see if different speeds decrease the amount of stringing that you see.

Temperature is too high

Once you have checked your retraction settings, the next most common cause for excessive stringing is the extruder temperature. If the temperature is too high, the plastic inside the nozzle will become less viscous and will leak out of the nozzle much more easily. However, if the temperature is too low, the plastic will still be somewhat solid and will have difficulty extruding from the nozzle. If you feel you have the correct retraction settings, but you are still encountering these issues, try decreasing your extruder temperature by 5-10 degrees. This can have a significant impact on the final print quality. You can adjust these settings by clicking “Edit Process Settings” and selecting the Temperature tab. Select your extruder from the list on the left, and then double-click on the temperature setpoint you wish to edit.

Long movements over open spaces

As we discussed above, stringing occurs when the extruder is moving between two different locations, and during that move, plastic starts to ooze out of the nozzle. The length of this movement can have a large impact on how much oozing takes place. Short moves may be quick enough that the plastic does not have time to ooze out of the nozzle. However, long movements are much more likely to create strings. Thankfully, Simplify3D includes an extremely useful feature that can help minimize the length of these movements. The software is smart enough that it can automatically adjust the travel path to make sure that nozzle has a very short distance to travel over an open space. In fact, in many cases, the software may be able to find a travel path that avoids crossing an open space all together! This means that there is no possibility to create a string, because the nozzle will always be on top of the solid plastic and will never travel outside the part. To use this feature, click on the Advanced tab and enable the “Avoid crossing outline for travel movement” option.

Movement Speed

Finally, you may also find that increasing the movement speed of your machine can also reduce the amount of time that the extruder can ooze when moving between parts. You can verify what movement speeds your machine is using by clicking on the Speeds tab of your process settings. The X/Y Axis Movement Speed represents the side-to-side travel speed, and is frequently directly related to the amount of time your extruder spends moving over open air. If your machine can handle moving at higher speeds, you may find that increasing this settings can also reduce stringing between parts.

Related Topics

5 Ways How to Fix Stringing & Oozing in Your 3D Prints – 3D Printerly

If you’re in the field of 3D printing, you might have come across an issue of strings of melted plastic or plastic oozing from your 3D prints. This is called stringing and oozing, which fits perfectly.

Fixing stringing and oozing is best done by having good retraction settings, where a good retraction length is 3mm and a good retraction speed is 50mm/s. You can also decrease your printing temperature to help filament be less runny, which reduces the instance of stringing and oozing.

It’s a fairly common problem that people experience which leads to poor quality prints, so you definitely want to get this fixed.

There are more details to know about so keep on reading the article to find out why this happens in the first place, and how to fix it once and for all.

Here’s an example of stringing in a 3D print.

What to do against this stringing? from 3Dprinting

What Causes 3D Prints to Have Stringing & Oozing?

Sometimes users try to print an object in which the nozzle has to move through an open area to reach the next point.

Stringing and oozing is the problem in which the nozzle extrudes the melted plastic while moving from an open space.

The melted plastic sticks between two points and look like attached strings or threads. To prevent or solve the problem, the first step is to find out the actual cause of the issue.

Some of the major causes behind the stringing and oozing problem include:

  • Retraction settings not being used
  • Retraction speed or distance too low
  • Printing with a temperature too high
  • Using filament which has absorbed too much moisture
  • Using a clogged or jammed nozzle without cleaning

Knowing the causes is a good way to start before getting into the solutions. The section below will take you through a number of ways how to fix stringing & oozing in your 3D prints.

Once you’ve gone through the list and tried them out, your problem should hopefully be solved.

How to Fix Stringing and Oozing in 3D Prints

Just like there are various reasons that cause stringing and oozing problems, there are also plenty of solutions that can help you fix and avoid it.

Most of the time this type of problem can be fixed just by changing some settings in the 3D printer such as extruder speed, temperature, distance, etc. It’s not ideal when your 3D prints are stringy so you want to get this sorted out quickly.

Below are some of the simplest and easiest solutions that can be implemented without requiring any major tools or techniques.

The methods that will help you to get rid of the problem for once and for all includes:

1. Print at a Lower Temperature

The chances of stringing and oozing increase if you are printing at a high temperature. The very first thing that you should do is to reduce the temperature and check for the results.

Reducing the temperature will help you because it will extrude less liquid material reducing the chances of stinging and oozing.

Those higher temperature materials are more prone to stringing because of the effects of higher heat on the viscosity or liquidity of filament.

Although PLA is a relatively low temperature material, it doesn’t mean it’s safe from stringing and oozing.

  • Reduce the temperature step by step and check if there are any improvements.
  • Make sure that the temperature is within the range required for the type of filament being used (should be on the filament packaging)
  • Try to use a filament that melts at lower temperatures efficiently like PLA
  • While reducing the printing temperature, you may have to lower down the extrusion speed because the filament material will take time to melt at low temperatures.
  • Do test prints of little objects to get an idea about the perfect temperature because different materials print well on different temperatures.
  • Some people will print their first layer 10°C hotter for good adhesion, then lower the printing temperature for the rest of the print.

2. Activate or Increase Retraction Settings

3D printers include a mechanism that works as a pullback gear called retraction, as explained in the video above. Enable retraction settings to pull back the semi-solid filament that is pushing the liquid to extrude from the nozzle.

According to experts, activating the retraction settings usually work to fix the stringing problems. What it does is relieve the pressure of the melted filament so it will not drip while moving from one point to another.

  • Retraction settings are activated by default but check for the settings if you are experiencing stringing or oozing.
  • Enable the retraction settings so that the filament can be pulled back every time the nozzle reaches an open space where printing is not designed or required.
  • A good retraction setting start-point is a retraction speed of 50mm/s (adjust in 5-10mm/s adjustments until good) and retraction distance of 3mm (1mm adjustments until good).
  • You can also implement a setting called ‘Combing Mode’ so it only travels where you have already printed, rather than in the middle of your 3D print.

I’d advise you to download and use this Retraction Test on Thingiverse, created by deltapenguin. It’s a great way to quickly test out how well in-tune your retraction settings are dialed in.

It really is hit or miss, high retraction settings of 70mm/s retraction speed and 7mm retraction distance works well, while others get good results with much lower.

One user who was experiencing some pretty bad stringing said that he fixed it by using a retraction distance of 8mm and retraction speed of 55mm. He also shortened his Bowden tube by 6 inches since he replaced the stock one with some Capricorn PTFE Tubing.

The results does depend on what 3D printer you have, your hotend, and other factors, so it’s good to test out some values with a test.

3. Adjust Print Speed

Adjusting the print speed is a common factor to fix stringing, especially if you have reduced the printing temperature.

Reducing speed is necessary because with the reduced temperature the nozzle can start under extruding. After all, the filament will take more time to melt and become ready to extrude since it’s less runny.

If the nozzle is moving at a high speed, with a high temperature, and no retraction settings, you can bet you’ll experience stringing and oozing at the end of your 3D print.

  • Reduce the printing speed because this will mitigate the chances of leaking filament and causing stringing.
  • A good starting speed ranges from 40-60mm/s
  • A good travel speed setting is anywhere from 150-200mm/s
  • As different filaments take different time periods to melt, you should test the material by reducing the speed before starting your printing process.
  • Make sure that the printing speed is optimal because both too fast and too slow speed can cause problems.

4. Protect Your Filament from Moisture

Most 3D printer users knows that moisture affects the filament badly. Filaments absorb moisture in the open air and this moisture turns into bubbles when heated.

The bubbles usually keep on bursting and this process forces the dripping of the filament from the nozzle causing stringing and oozing problems.

The moisture can also become steam and will increase the chances of the stringing problems when mixed with the plastic material.

Some filaments are worse than others such as Nylon and HIPS.

  • Keep your filament stored and protected in a box or something that is totally airtight, with desiccant and has the ability to stop moisture from reaching the filament.
  • If suitable, try to use a filament which absorbs less moisture like PLA

I’d recommend going for something like the SUNLU Upgraded Filament Dryer from Amazon. You can even dry filament while you’re 3D printing since it has a hole that can feed through. It has an adjustable temperature range of 35-55°C and a timer that goes up to 24 hours.

5. Clean the Printing Nozzle

Whenever you print an object some particles of the plastic are left behind in the nozzle and with time get stuck in it.

This happens more so when you print with a high temperature material, then switch to a lower temperature material like from ABS to PLA.

You don’t want any kind of blockage in the way of your nozzle, since this is a very significant area for creating successful prints without imperfections.

  • Clean your nozzle thoroughly before printing to make it free from the residues and dirt particles.
  • Use a brush with metal wires to clean the nozzle, sometimes the common brush can also work well.
  • It will be better if you clean the nozzle every time you complete a print because it becomes easier to remove the heated liquid residues.
  • Clean your nozzle using acetone if you are printing after a long time.
  • Keep in mind that cleaning the nozzle is considered essential whenever you switch from one material to another.

After going through the above solutions, you should be in the clear for getting rid of that stringing and oozing problem that you have been experiencing.

It may be a quick fix, or it can require some trial and testing, but at the end of it, you know you’ll come out with some print quality you can be proud of.

Happy printing!

50 3D Printing Ideas

It looks like we'll soon be drowning in useless stuff made for 3D printing projects. But you can do something that will really be useful! If you're running out of ideas, here's a list of 50 3D printable items you're unlikely to throw away.

Bag clip with screw cap

Now the bag clip will have a new feature - a hole with a lid for quick access, as in the photo. This clip is easy to print and convenient to use. Strange that no one thought of this before.

Author: Minkix

Download: Thingiverse

Modular Furniture Connector

This connector allows you to quickly assemble modular furniture. The default model is designed for 17×17 mm wood, but the size and material can be changed to suit your needs using a parametric file for customization.

Author: LeFabShop

Where to download: Cults

Sealant cap

No more throwing open sealant tubes away. The screw cap for the nozzle presses the o-ring tightly against the body of the tube and closes the access of air to the solvents inside.

Author: The-Mechanic

Where to download: Thingiverse

Laptop niche

Now the laptop will always be at hand, but hidden from prying eyes in a special niche that is attached to the bottom of any coffee table.

Author: Too Snide

Download: Thingiverse

Phone holder - Candice

Elegant and simple, perhaps the easiest thing you can print on a 3D printer.

Author: Clem.C2

Where to download: Cults

Polypanels

The idea for Polypanels came from Devin Montes. A polypanel is a series of three-dimensional building blocks. The individual elements of a Polypanel look simple, but if you print a lot of them and different types, you can create all sorts of complex designs. Something like LEGO where you can design each brick.

Author: MakeAnything

Where to download: MyMiniFactory

Coat Hook

This coat hook is designed as an E3D attachment and can be printed multiple times to fit all your clothes.

Author: Filar3D

Where to download: Cults

Plant Pot

This anatomical brain flower pot is easier to print than it looks, creator DrFemPop says. For assembly, it is only necessary to glue the parts after printing. It turns out an original house for plants.

Author: DrFemPop

Where to download: Cults

Door Holder

This is a simple solution for holding a door. Double-sided adhesive tape is sufficient for surface mounting.

Author: Akiraraiser

Where to download: Thingiverse

Piggy bank

A simple piggy bank for beginners, no complicated settings.

Author: lecaramel

Where to download: Thingiverse

Cable ties

This tie is perhaps the simplest and most ingenious of all devices. Clips are printed as a whole sheet at once, and then the required amount can be cut off from it.

Author: Sunshine

Where to download: Cults

Roller ruler

An indispensable device if you need to measure the length of something non-linear: a piece of rope, a curved line, a perimeter with bends, etc. The ruler is called Geneva and has step 5 mm.

Author: MechEngineerMike

Where to download: Thingiverse

Pliers

This small, solid piece of plastic can easily replace your pliers / pliers. These forceps take the force to the handles and redistribute it at the end of the grip. It's definitely pliers. Just smarter.

Author: BYU CMR

Where to download: Thingiverse

Cylindrical textured box

Beautiful tube from Syboulette decorated with hexagons. Well suited as a kitchen utensil for storing oatmeal, rice and other crumbly substances.

Author: Syboulette

Where to download: Cults

Door stopper

This stopper is modeled after the Guyer Anderson cat statue in the British Museum. The design is hollow, which allows you to fill the limiter with something for additional weight.

Author: Duaneindeed

Where to download: Cults

Plague Doctor Mask

Not exactly the most useful item on the list since bubonic plague is a thing of the past. But a mask can come in handy, for example, when you need to clean up after your pet. And you can also go to the carnival in it.

Author: Odrivious

Download: Cults

Universal Spool Holder

This adjustable spool holder uses a spring and an adjustable rewind clutch. It's the perfect place to store those pesky wires.

Who made it: Vincent Goenhuis

Where to download: Thingiverse

Sturdy waterproof box

This tight-fitting box will keep things from getting wet. Print it in PLA or PETG, add a flexible TPU seal and M3 screws for the spring hinge, and you're done.

Author: ZX82

Where to download: Cults

Dice

This dice is suitable for flat 3D printing and has a face size of 16mm.

Author: Devin Montes (MakeAnything)

Where to download: MyMiniFactory

Collapsible Coat Rack

Really cool coat rack. That's all there is to say about her.

Author: Komaru

Where to download: Thingiverse

Business Card Holder

Great for showing off your new business cards to your Wall Street friends. What could be more delightful than this Zippo card holder with flip-top lid.

Author: PentlandDesigns

Where to download: Cults

Pencil and pen holder

Iceberg or melting beehive? Be that as it may, this is a handy pen and pencil holder that is cheaper to print than to buy.

Author: BeeVeryCreative

Where to download: Cults

Groovi Monster Audio Amplifier

This is a passive smartphone audio amplifier that looks stylish and does the job well. It's called Groovi Monster for a reason.

Author: 3DShook

Where to download: Cults

Cup holder

Can be used not only as a cup holder, but also as a coaster for hot dishes. The dimensions of the template are easily adjusted to suit any size cookware.

Author: jmdbcool

Where to download: Thingiverse

Clamp

Designed for fixing various materials, including the ends of the wire in the coil. Also great as a clothespin replacement.

Author: Med

Where to download: Cults

Pencil Box

Suitable for storing all your desk trivia and trinkets (memory cards, rubber bands, pencils, paper clips, etc.).

Author: Monkey3D

Where to download: Cults

Headphone holder

This is a duck. Yes, you can hang headphones on it.

Author: Toshi_TNE

Download: Thingiverse

Polyhedral Succulent Pot

Unusual geometric pots for your growing succulent collection. These small pots can be configured to be connected together.

Author: PrintFutura

Download: Cults

Survival Whistle

This is a survival whistle with original design. It is durable, easy to make and very loud (118 dB is more than enough to be heard in an emergency).

Author: Joe Zisa

Where to download: Thingiverse

Measuring Cube

Simple and original measuring cube for the kitchen. On each side there are recesses for measuring the volume of ingredients (in cups - according to the American system, and in metric units for everyone else). It is best to print with PETG material, it is the safest for products.

Author: iomaa

Download: Thingiverse

Hinge

This is a parametric hinge that can be sized to fit your needs.

Written by Rohin Gosling

Download: Thingiverse

Car Eyeglass Holder

Attaches to your car's sun visor. Glasses will always be at hand.

Author: Trevor Long

Download: Thingiverse

Opener

The simplest things are usually the most useful. Convenient and easy to print opener. Covers the sharp edges of the cork as much as possible, protecting you from injury.

Author: Jeremy Peterson

Download: Thingiverse

Superhero Keychains

Sometimes you need to remind yourself of your hidden superpowers. Stylish and cool keyrings are well suited as a small gift.

Author: Formbyte

Where to download: Cults

Headphone stand

It will be useful for music lovers and gamers who use headphones a lot and often. After all, now they will no longer roll around anywhere.

Author: MakerBot

Where to download: Thingiverse

Bag Clip

The model consists of two printed parts. Allows you to keep packages closed and keep food fresh longer.

Author: Walter Hsiao

Download: Thingiverse

Plastic wrench

Handy wrench, but don't choose soft plastic to make it.

Author: Daniel Noree

Where to download: Cults

Sliding Decal

No more worrying about whether cups are clean or dirty right now in the dishwasher! With the help of a special mechanism, the slider easily changes the inscription on the plate.

Who made it: MiddleFingerBoss

Where to download: Thingiverse

Collapsible basket

Cool picnic item. A folding square basket with five sections is printed from several parts and then glued together. For product safety, it is recommended to use PETG plastic.

Author: PatternToPrint

Where to download: Cults

Self-watering plant pot

Houseplants are dying from your forgetfulness? This will not happen again! This pot will water them by itself, and your conscience will be clear.

Author: Parallel Goods

Where to download: Cults

Maze Gift Box

Cash is not the most original gift. But if you present them in such a gift box, your friend will surely like it. The lucky recipient will have to work hard to get to the prize, because there is only one right way.

Author: Robert

Download: Thingiverse

Wired headphone holder

The headphones will now be protected from tangling and breakage.

Author: Robert

Where to download: Thingiverse

Tube Squeezer

Will help squeeze out the contents of the tube to the last drop. Wide enough to fit most tubes on the market. Printed in three separate parts.

Author: Justin Otten

Where to download: Thingiverse

Webcam Shutter

The best thing for the paranoid and just for those who are uncomfortable being under the gun of a webcam. Instead of sticking tape or sticky tape over the lens, attach a slider shutter to the body and open it when you need a video call.

Author: Horizon Lab

Where to download: Cults

Hexagonal Prefabricated Drawers

Useful to free your desk from the noodles of cables, wires and just every little thing. The design can be easily expanded if necessary.

Created by Dan O'Connell

Where to download: Cults

Wall Phone Shelf

Attach the shelf to a power outlet and place your phone on it while charging. The model also has a corner slot that holds your smartphone or tablet upright for watching videos.

Author: Tosh Sayama

Where to download: Cults

Card Shuffle Machine

Awesome item for poker lovers. This device will help to shuffle the cards and deal them during the game.

Author: LarsRb

Where to download: MyMiniFactory

Box with a secret lock

Box for storing things in a place inaccessible to prying eyes with a secret multi-stage opening mechanism.

Author: 3DPrintingWorld

Where to download: Thingiverse

Digital Sundial

Yes, your eyes don't deceive you. This is a digital sundial and it really works. They are designed to pass only the right beams at the right time and at the right angle to display the actual time in 20-minute intervals. Only works during daylight hours, of course.

Author: Mojoptix

Where to download: Thingiverse

Keyring

Designed in the shape of a stylish Swiss Army knife, it looks amazing. Printed from two plates and the keys are held in place with standard hex nuts and bolts.

Author: Craig Blanchette

Where to download: Thingiverse

Translation of the article “50 Cool Things to 3D Print in June 2019”

Printed circuit boards using a photopolymer 3D printer / Sudo Null IT News And in the last year or two, thanks to a strong reduction in cost, their photopolymer subspecies is also flourishing.

Now such a printer is already available to almost everyone, and the number of their models on the market is multiplying every month.

Even when I just learned about the appearance of a new type of photopolymer printers a few years ago - in which the image of the layer for illumination is formed by an LCD, the thought flashed through me already then: "Hmm, what if we substitute a photoresist on a textolite?". But then it was a purely theoretical question - the prices for them were considerable, and the resolution and display area left much to be desired. However, today these printers can already boast of a decent resolution - from 30 microns per pixel, and a completely normal display area.

And as it turned out, with the help of an inexpensive modern photopolymer printer, it is quite possible to make boards with tracks / gaps from 0.15 mm.

I apologize in advance for such voluminous graphomania, I didn't expect the note to get so fat...

I foresee the question "But why? In China, they will make normal boards with a mask and silk-screen printing for a penny!". I answer: now, most likely, there will be several iterations of finishing the board to a satisfactory state. I made a board - tested it - made corrections. And so several times. Waiting every time for 2-3 weeks from China is not an option :) But when the final design of the board is determined - then, of course, normal production in China or on Rezonit.

Now let's get down to business.

Who does not know - here is a brief principle of operation of such a printer

The main part of such a printer is an LCD display. Below this display is a 405 nm UV source. Above the display is a bath of photopolymer, which has a thin transparent FEP film as a bottom. A platform is lowered into the bath, on which the model is “grown”. At the beginning of printing, the platform lowers to the height of one layer from the film, the image of the first layer is displayed on the display, and UV illumination is turned on for a specified time. Illumination, getting through the "open" pixels of the display and the film onto the photopolymer, hardens it, so a hardened layer is obtained. The first layer sticks to the platform. Then the illumination is turned off, the platform rises to the height of the next layer, the image of this layer is displayed on the display, and the illumination is turned on. The second layer is cured by welding with the previous layer. And this is repeated over and over until the entire model is printed.

The idea to try to make a printed circuit board using such a printer came to me again about three years ago, when I bought myself an Anycubic Photon S printer. , then I just forgot about this idea, because and there was no need to make boards. But the other day, the need arose for the manufacture of several small boards, and with a high probability that as tests are made, changes will be made to these boards and it will be necessary to go through several iterations of "manufactured-checked-changed" in a short time. And the idea resurfaced.

To be honest, I thought that by now the Internet would be filled with the results of such experiments, the idea lies on the surface :) But to my surprise I found that the Internet is almost completely silent on this issue. There are separate notes, but there is no integrity and completeness in them. That's why I decided to publish this post - maybe it will help someone go all the way faster than me, and with less rakes :)

Well, the most important thing is that you don't need film and you don't have to struggle with increasing the contrast of the template. You also do not need a separate UV source with a place for its installation. And, of course, it is stylish, fashionable, youthful.

There are also disadvantages - the resolution of most modern 3D printers still does not cause much enthusiasm yet - the pixel size of all fluctuates around 0.05 mm. But this is already enough for confident manufacturing of boards with tracks from 0.2 mm and rather high chances of success with tracks from 0.15 mm. Due to the raster nature of such a template output, the position and size of elements on it can vary + -1 pixel, so I think it’s not even worth counting on tracks of 0.1 mm or less.

Let's go in order.

Task

It is necessary to make a printed circuit board at home using photoresist. Instead of templates and illumination lamps, use a photopolymer 3D printer that will serve both at the same time.

Let's divide the problem into separate steps-solutions for each moment.

  1. PCB development

  2. Printer-friendly output of layers

  3. Preparation of textolite with photoresist

  4. Printer flare

  5. Photoresist development, board etching

1. PCB development

Well, there are no questions. Whoever prefers to work in what program - in that one makes boards. The main thing is that the program should be able to display the result in some commonly used form. The easiest way I've come up with is outputting board layers to gerber files that can be fed to an online service. But you can also output to PDF or images.

2. Converting the CAD output to a printer-readable form

This is where the trouble begins. If almost all CADs can output to generally accepted formats - gerberas, DXF, printing to PDF, then 3D printer manufacturers so far categorically refuse to accept any file standard. Everyone is perverted as they can. The situation is largely saved by the fact that many manufacturers use motherboards from one Chinese company, Chitu Systems, in their printers. Thanks to this, many printers on such boards are able to understand one of the basic formats developed by the same company. And even often, if a file has some unique extension, then in fact it has the same basic format, just with a different extension. But it may differ in some details.

In any case, there is a free UVtools utility known among photopolymerists that can open files in one format and convert them to another format. It understands almost all formats on the market :)

I have tried two ways of preparing files with layers for the printer and I will describe both.

2.1 Gerber output and conversion to .
photon

The .photon file format is understood by the old Anycubic printers - Photon and Photon S. This is exactly the case when the printer manufacturer took the format from Chitu and changed its extension. In the original, this is the Chituvian .cbddlp format, so you can safely change the extensions of these file types among themselves and the printers will devour them like native ones.

Since I have a printer that understands this format, this method suited me perfectly. The limitations of this method are that the printer must understand .photon or .cbddlp files and have a standard display for most non-monochrome printers with a resolution of 2560x1440 and a diagonal of 5.5". manuals on how to do this for any CAD that can, in principle, mirror layers or not - it makes no difference, they can be mirrored in the utility during the conversion process.0003

Now open the online utility for converting gerber files - https://pcbprint.online/ and load the gerberas into it. By the way, this is a utility from a Russian developer who lives here.

It is easy to understand, although it does not contain any information or help. But here is a short guide:

For a single-sided board

Upload your gerbera in the main window with the "Upload file" button:

We made sure that everything is fine and the image meets expectations, if necessary, make a negative or mirror the image with the buttons in the top center, and press the button " Render layout":

Now press "Lauout" at the top right and get into another screen:

Here you first need to go to the settings (gear button at the top right) and there select the format of the output file "photon":

The time in "Exposition" can be left at default and change it to the desired one directly in the printer. But you can immediately put the right one if its value is already known :)

Close the settings and return to the previous screen. Here the output image is on a black space showing the working field of the printer. The image can be moved, aligned. When everything suits, we first press "Render", and when the "Download result" button next to it becomes active, we also press it. And save the proposed .photon file to a convenient location on your computer :)

For double-sided boards, things are a little more complicated due to the need to match them. Therefore, it is necessary to know very exactly the position of the image displayed on the printer's display in order to place the board on the display very accurately in accordance with it.

I had several options for solving this issue, but in the end I decided on the simplest of them, which did not require any mechanical conductors. To do this, I still in CAD in a separate layer (it is possible in the border layer or in any other "unnecessary" layer) I draw a frame around the board with a line of 0.15 mm and indented from the edges of the board by 0.25 mm. As a result, I get three gerberas - the top layer, the bottom layer and a separate empty frame.

I upload all three gerberas to the above site and then in a few steps I get three files for the printer.

Double-sided board in pcbprint.online/

So, all three gerberas have been loaded. All of them are mixed together, but it's not scary:

Now hide the top and bottom layers, leaving only the frame (by clicking on the eyes in the names of the gerberas).

Click "Render layout" and go to the "Layout" screen with the button in the upper right corner. We see an empty frame, drag it to the desired position on the black field of the display, click "Render" and "Download". The first file for the printer is ready.

Switch back to the gerber screen with the "PCB comose" button. Redisplay the first layer (the frame layer still remains visible), mirror if necessary, and click "Render layout" again. Again we go to the output screen and now there are two pictures hanging on the display field - a separate frame and the first layer with a frame. The frame remained in the same place where we pulled it last time. And now our task is to exactly combine the frame of the first layer and the empty frame:

Click "Increase" and combine in one of the corners. In this case, in no case should you move the empty frame that we set in the last step!

Combined, click "Render" and "Download", and we have a second file for the printer. Before returning to the gerbera screen, we delete the render layer with the frame, we should again have an empty frame. And now we return to the gerberas, hide the first layer and display the second one, look at the need to mirror, click "Render layout" and go to this screen again. In the same way, we combine the layer frame with an empty frame (which cannot be moved!), then "Render" and "Download".

Everything, all three necessary files for the printer are ready.

All this hemorrhoids allows you to generate for the printer files of an empty frame and layers with a frame in the same place on the printer display with high accuracy. The empty frame serves to aim the board, more on that below.

If necessary, the resulting .photon files can be converted to the desired format using UVtools :)

2.2 Output layers to PDF or images

The second method is perhaps more confusing, but its great advantage is versatility, it is suitable for any printers, whose formats are supported by UVtools. I will describe it only in general terms, because. There are quite a lot of tools and specific ways to implement it, and everyone can choose them according to their preferences.

So, the goal of the first step is to get a picture with a size equal to the resolution of the printer's display, preferably in a lossless compression format. In this case, the image of the layer in the picture must correspond to the real size in the scale of the display.

If CAD allows you to output directly to the picture - great, output to it. If the resolution of the output image is configurable - specify the resolution of the printer display. It is elementary to calculate it - we divide the number of pixels across the width of the display by the width of the working area in mm and multiply the result by 25. 4, we get the resolution in pixels per inch. If the resolution is not set, then set the image size as large as possible so that there are at least 15-20 pixels per 1 mm of the board.

If output to image in CAD is not available, then output to PDF. This PDF will need to be opened in another program and converted to an image. Photoshop, Corel, maybe other programs can do this... The requirements for image resolution are the same. For example, in Photoshop, when importing a PDF, you can immediately specify with what resolution to convert to an image. For example, for common displays with a resolution of 2560x1440 and a diagonal of 5.5 "the resolution is approximately 537.566 PPI (pixel size - 0.04725 mm).

The resulting image will need to be changed in some image editor, bringing its size to the resolution of the printer's display. In this case, the layer image must be scaled to the real one (taking into account the pixel size of the printer display) or saved without scaling if the PPI of the display was specified when importing the image.

UPD: in the comments @0x3f00 gave a link to his converter of PNG images to files for the .photon printer - https://github.com/0x3f00/PhotonCpp/releases/tag/v1.0.0 . There is also an instruction for using it just for the purpose of manufacturing boards - https://github.com/borelg/PhotonPCB.

2.3 There is another way, but it is very resource-intensive

You can output layers to PDF, then open this PDF in Corel, convert it, save it in DXF, extract a three-dimensional object from this DXF, which you can push into the printer's slicer.

Necessary transformations in the vector editor:

  1. Connect all curves.

  2. Convert outlines to objects.

  3. Merge intersecting objects.

You can extract a three-dimensional object from DXF, for example, SolidWorks. Fusion360 also seems to be able to. Who else is capable of this - I honestly don't know, but in theory any CAD that can import DXF as a sketch.

Thus, for example, I made a model for determining the exposure time of the photoresist.

3. Preparation of textolite with photoresist

The Internet is simply littered with articles on this topic, but for the sake of integrity and for the sake of some specific points, I will also describe such well-known stages as the preparation and etching of textolite.

My first experience with such a fabrication was a couple of days ago with a domestic photoresist PF-VShch. Taking into account the last yesterday's experience, I categorically advise not to waste time on this photoresist, but immediately take a decent one - Ordyl Alpha 350(330) :) They say that Kolon is also decent, but I have not tried it. With Ordyl photoresist, the results are much more stable and accurate, it is easier to develop and adheres much better to the foil. And he can forgive those mistakes that will be critical for the PF-VSC. And what is important - it is sold in a bunch of places quite inexpensively.

3.1 Preparing the PCB

To begin with, the PCB should be smooth, preferably with a smooth foil without scratches or dents. Otherwise, the chances of success are reduced.

If a double-sided board is being made, then you need to immediately cut the board out of the PCB exactly to size. If there is any CNC router, then you can drill all the holes and cut along the contour in one installation, as I do. If not, then it is better to leave the drilling for later, when the board is etched.

After this, the textolite blank must be very carefully cleaned and degreased. This can be done with a kitchen abrasive sponge (but not used for washing dishes on which fats have already accumulated) and a scouring powder like Pemolux. Very carefully, slowly three every square millimeter of foil, without touching it with your fingers. In general, I categorically do not advise touching the foil with your fingers after the start of cleaning, there should not be the slightest even the faintest greasy spot on it. After cleaning, rinse thoroughly in running water, shake off excess water and allow to dry. I do not advise blotting or wiping with anything, because. grease can be applied, even from a new napkin.

3.2 Applying the photoresist

Also a fairly common topic on the Internet, so I'll go over it briefly.

Photoresist usually comes in sheets or rolls. It consists of three layers - two protective films and the photoresist itself between them. A piece is cut off from the photoresist according to the size of the board + 5 mm in length and width, then a matte (polyethylene) protective film is removed from it.

the second, glossy (lavsan) must remain on it until the etching stage.

The easiest way to remove the film is with a piece of tape. It is glued with its edge to the corner of the photoresist and then folded back, pulling the protective film along with it.

After removing the matt film, the photoresist is applied to the edge of the board and smoothed along this edge with a finger. The rest of the photoresist is supported by weight, without tension, but in such a way that as little as possible of its area lies on the foil.

Please note that if the Ordyl photoresist falls on a well-prepared textolite, then it can firmly stick to it, and without bubbles it can no longer be rolled. You have to scrape it off and do it all over again. And PF-VShch can fall as much as you like - it definitely won't stick :)

Now the knurling itself. If you have a laminator, in which the textolite will crawl through the thickness, then it's just wonderful. We make an envelope-type strip of paper folded in half, put a textolite with a sticky edge of the photoresist in it, and serve this sandwich into a laminator heated to 100-110 degrees. At the same time, we continue to hold the photoresist so that it comes into contact with the textolite foil only directly at the inlet of the laminator.

That's all for Ordyl, for PF-VShch it will be harmless to roll a couple more times.

If there is no laminator, then smooth the photoresist to the textolite with your finger from edge to edge, gradually lowering it onto the textolite. The main thing is not to catch the bubbles. After all the photoresist lay on the foil, we take a hair dryer and heat the textolite to 70 degrees, after which we iron the entire photoresist once again.

After knurling, let the textolite with photoresist lie down for 15-20 minutes, or at least until they cool down to room temperature - according to the recommendation of the photoresist manufacturer.

And now everything is ready to highlight the layer pattern :)

4. Printer highlights

I want to warn you right away: looking directly into the glowing display of a photopolymer printer may not be very good for the eyes. Although not true UV (405 nm), the brightness is quite noticeable and can be harmful to the eyes. Therefore, I recommend using colored or tinted goggles. I think even sunscreen will do.

First, you need to remove the bath and platform from the printer, they are completely unnecessary for this business and even interfere. This completes the preparation of the printer :)

Lighting also has different options. If you have a one-sided board and the blank is larger than the size required for the board, then everything is simple - throw the file obtained at the preparation stage into the printer and, knowing the approximate place for displaying the image on the display, put a textolite with photoresist in this place. Then start printing the file and wait until it is completed. Everything, the photoresist is exposed, it is possible to develop.

If the workpiece is equal in size to the board being made and the error with the position of the workpiece on the display is unacceptable, then in this case it is necessary to remove the frame during preparation, as is the case for a double-sided board. Illumination also occurs using a frame, similar to a double-sided board, only without the second side and the second layer.

So, the illumination of the double-sided board. We throw all three files into the printer - with a frame, with the first layer and with the second layer. We put the workpiece next to the printer in quick accessibility. If it is already pre-drilled, it will be useful to make sure that it lies in the correct position so that you can quickly take it and immediately put it on the display. To do this, we run a file with a layer planned for exposure, and compare the layer pattern on the display and the orientation of the board next to the printer.

Printing a file with one frame. As soon as the frame lights up on the printer display, we take the workpiece and put it approximately inside the frame. While the frame is being illuminated, we align the workpiece so that it is exactly in the frame, with the same indentation of the frame from the edges of the workpiece on all sides.

In the photo, I gave an example with a ready-made board, because I did not take pictures during the manufacturing process. Well, reflections interfere quite strongly, alas... But I think it's understandable :)

That's it, the position of the workpiece is verified, printing of the frame file can be interrupted or wait for it to finish. Without moving the workpiece, run the file with the first layer and wait for it to finish. We illuminate the second layer (the second side) in the same way - we launch the frame, place and align the workpiece, without moving it, we launch the second layer. Before this, just in case, you can make sure that the workpiece will lie in the correct orientation, as before the first layer.

If the workpiece is not completely flat and does not fit the entire area of ​​the display, then you can press it down from above with some heavy flat piece of iron. You just need to make sure that this piece of iron does not interfere with the platform lever, which will go down with the start of printing - the printer thinks that this is a normal photopolymer print and you need to lower the platform to the bottom of the bath :)

Illumination time can be different from printer to printer . It depends on the power of the emitter, and on the optical illumination system, and on what type of display is worth - monochrome or RGB. Here already it is necessary to select each individually. For orientation, I can say that I got the best result with the Ordyl photoresist at an exposure time of about 90-110 seconds. With photoresist PF-VShch - about 10-13 minutes. Printer with paraled, illumination power slightly less than 50 watts.

After exposure, the workpiece should be allowed to rest for 15 minutes - this is according to the recommendation of the photoresist manufacturer. Ordyl changes the color of the highlights quite noticeably, so it's pretty easy to control the highlights. Unfortunately, the photo did not convey it well, it can be seen better with the eyes.

5. Development, etching

Everything here is according to the recommendation of the photoresist manufacturer and according to the classics of the Internet.

All necessary chemicals were purchased inexpensively from Auchan. Even hydrogen peroxide 6% - this was a surprise for me, I had never seen it in hypermarkets before, and even in liter bottles.

For one session you need:

  • Soda ash - 1.5 grams

  • Hydrogen peroxide - 150 ml for 3% (or 75 ml for 6% + 75 ml of water)

    • Citric acid

  • Salt - 7.5 grams

  • Alkali (caustic soda, sodium hydroxide) 5-7% - 100 ml

    With the cheapness and ease of buying all the components around the corner, I am in favor of preparing a new solution for each board. Although the etching solution, as they say, is not stored anyway. A solution of soda ash noticeably "poorer" in the process of development. Unless caustic soda can be reused, but is it worth it to keep another bottle ...

    Both Ordyl and PF-VSH appear in a weak solution of soda ash. For PF-VShch - 1-2%, for Ordyl - 0.8-1.2%. For Ordyl, we take 150 ml of water and dilute 1.5 grams of soda in it. The solution can be heated up to 30 degrees, this will speed up the development, but it is important not to overdo it, otherwise the illuminated areas may begin to be damaged.

    Ordyl appears rather quickly. Already after 10-15 seconds, the illuminated pattern begins to become more and more contrasty, the unexposed areas gradually dissolve, become thinner and become paler.

    To speed up the process, it is recommended to shake the bath so that the reaction products are washed off the surface of the workpiece. For this I adapted my old 3D printer, its table and shook and heated the bath with the solution during development and etching :) Two minutes passed before there were at least some signs that development had begun. In addition, if Ordyl does dissolve, then PF-VShch first swelled like gelatin and discolored, and only then began to slowly dissolve.

    At the end of development, you can go over the boards with a hard paintbrush (or soft toothbrush) several times in different directions to help flush out any remaining photoresist from tight spots. Ordyl holds on tight, this procedure should not disrupt it, but with PF-VShch you need to be very gentle, even without a brush it strives to exfoliate on thin paths.

    After etching, the workpiece must be rinsed in cold water so that the soda residues do not continue to attack the photoresist and so as not to clog the etching solution with them.

    The result should be something like this, maybe even better :)

    More details

    Scale of the grid square - 0.2 mm:

    The scale is the same. Here you can see the raster component of the illumination, the pixels stick out:

    Etching was also done according to the traditional recipe, popular on the net:

    It is better to heat the solution to 40-50 degrees, then the etching goes much faster. This is my first experience with this solution. I used to poison with ammonium perchlorate, and even earlier - with classic ferric chloride. To be honest, I can't really express how I feel about this solution. On the one hand, it poisons rather quickly, is transparent, does not get dirty, and is relatively safe. On the other hand, it seemed to me that it was easing quite a lot ... But maybe it just seemed, I haven’t been making boards for 10 years and I forgot how it all worked when the trees were big :)

    After etching, the exposed photoresist must be removed from the workpiece, and this is done in caustic soda. On my bottle of cleaner it says "at least 5% but not more than 15%" and it takes 5-8% to remove the photoresist. I diluted the product 1:1 with water and this solution did the job perfectly. The photoresist does not dissolve in it, it simply peels off the foil after 2-3 minutes and begins to float in tatters in the solution.

    After that, the board is thoroughly rinsed under the tap and... The board is ready!

    Results of my experience

    Overall I am satisfied. I did not expect to get tracks / gaps of 0.1 mm and I did not get them. Here, the capabilities of the printer are severely limited (pixel size), and in general, good experience is needed for such results. But I was hoping to get at least 0.2 mm, and if I'm lucky, then 0.15 mm - and I got it. 0.2 mm confidently, 0.15 mm - well, so-so... If you try, you can achieve :)

    There were some flaws - it was not pickled in some areas, and imperfect alignment of layers and holes. But neither is critical. As for the non-mordant - I think that I just hurried to take it out of the developer, I was afraid after PF-VShch that thin paths would begin to peel off.

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