Author Topic: 3D Printing Tips and Techniques  (Read 24263 times)

Offline robunos

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3D Printing Tips and Techniques
« on: July 29, 2021, 04:53:26 AM »
Otherwise known as the 'pick Frank3K's brains' thread, as it says in the title, this is a thread for asking questions about, and exchanging information on the techniques of using 3D printers, especially for newbies like me . . .   :-[
I'll be posting some questions in due course, but for now, here's a link to a post about 3D resin printing made by Frank previously :-


https://beyondthesprues.com/Forum/index.php?topic=8451.0


Would it be too much to make this thread sticky ?


cheers,
Robin.
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Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #1 on: July 30, 2021, 11:16:37 AM »
Overview

The most popular 3D resin printers are made by Elegoo, Anycubic and EPAX. These printers (and several others) use a common controller made by Chitu Systems. They work by shining a 405nm UV light through an LCD screen into a vat of UV sensitive resin.

The vat has a film of FEP, tautly stretched  across the bottom. The FEP is in direct contact with the LCD screen, so images displayed on the LCD are transferred to the resin without distortion.
When an object is printed, very thin slices (10-100 microns thick, typically 50 microns) are displayed in sequence on the LCD.
  • At the start of the printing process, a metal plate (the build plate) comes to within a layer thickness of the FEP
  • The LCD displays a slice and the UV light is turned on for a few seconds.
  • Under ideal conditions, the cured resin sticks to the build plate (and not the FEP.) The UV is turned off and the build plate moves up another layer height
  • A new slice is displayed, the UV light is turned on for a few seconds, which should cause the resin to cure to the previously printed layer... and so on, until the object is printed.




Before an object can be printed, it has to be oriented on the build plate to minimize overhangs and excessive force on the FEP (which is thin and relatively delicate). The object will also need to be supported and finally the object and its supports have to be sliced into layers.

Slicing and Verification
There's software to slice your 3D file. Chitubox is the standard slicer program. There are others, like Lychee and PrusaSlicer.

The slicer program will slice your 3D object into cross-sections spaced by the layer thickness you've selected (10-100 microns) and will produce a file for the printer chosen. In a perfect world, you put this file on a USB stick, take it to the printer, and the object prints. Unfortunately, without doing a file verification check chances are good that parts of the model will not print properly and the cured bits will float in the uncured resin. This is a bad thing; cured resin can puncture the FEP which in turn can cause the resin to leak out of the vat, making a mess out of the printer or worse, leaking under or into the printer.

There are several ways of verifying a file: via manually inspection, prayer (never works) or by using a program like UVTools

I've settled on PrusaSlicer and Chitubox as my slicing programs and UVTools as the verification program. UVTools has printer settings to import into PrusaSlicer to allow it to produce slice files for non-Prusa printers.

Design Software
Unless you're downloading and printing other people's 3D files from Thingiverse or similar repositories, you'll want to create the 3D objects on your own. This is a whole different universe with a learning curve, often steep.

Blender This is a free program and can be used for 3D animations as well as static, 3D objects. It use to have a very confusing interface and steep learning curve, but it's greatly improved in the last few years. The Blender organization has tutorials, but they're not great; find a beginner's series on Youtube and follow it.

Fusion 360 Free for personal/hobbyist use.

Rhino 3D Not free, but they have a 30 day demo. This is what I've used over the years.

Meshmixer This is more of a 3D mesh editing tool.

Netfabb standard. This program was bought by Autodesk and is free. It will check and fix your 3D object for printability. Then you slice it.

3DBuilder - comes with Microsoft Windows 10. It will also let you check and fix 3D models and works as well as Netfabb

There's also Sketchup... but it doesn't do a great job at creating printable 3D objects.

Resins
There's a wide variety of resins; soft and squishy, ABS-like, clear or translucent, resin that can be tapped and machined (without shattering) and even dental resins. Most resins are brittle (as brittle or more so than the common resin used in resin kits)
Many "Clear" resins usually aren't - they can yellow over time when exposed to UV, even after they're fully cured.
Elegoo and AnyCubic sell a a wide variety, including plant based and water washable resins. Siraya Tech makes some of the best resin around and they're my favorite resin manufacturers .

Resin exposure and test
All resin manufacturers will list recommended exposures for their resins and for different printers, but it's a good idea to dial in the best exposure. There's the Resin exposure finder, which I find difficult to interpret at times.
The Amerlabs town will test the limits of the printer.

Other sources for help or instruction

Both reddit groups are very helpful:
https://www.reddit.com/r/AnycubicPhoton/
https://www.reddit.com/r/ElegooMars/

These two Youtube channels are also very helpful:
https://www.youtube.com/c/3DPrintFarm
3D Printing Pro

I avoid "Uncle Jessy"'s channel - I haven't found his ideas to be helpful or useful.

Offline Buzzbomb

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Re: 3D Printing Tips and Techniques
« Reply #2 on: July 30, 2021, 12:03:10 PM »
Excellent Frank, great overview.

Personally I still use the original type 3D FDM printer (Up 3D Plus) with the spools of ABS or PLA plastic. For actual models, these are now terribly passe as the build texture is awfully hard to get rid of. But they still have a place.
Typically I am using the printer more and  more for producing gadgets, where detail texture is not important.
As described by Frank, using available software and fairly simple shapes enable you to produce your own stuff.

Having a drawer section full of collets from various tools rattling around, led me to design the Collet Holder in 3D Builder provided free as part of Windows 10
Simple cube shape sized to fit the drawer section, then other shapes were used to remove parts of the shape, to leave the finished item



Using this software, it is also possible to edit other models from elsewhere, such as thingiverse to suit your own needs.
This Airbrush holder was modified to change the angle of the holders to suit my workshop, buy cutting all off and keeping one. Get the position right then simply copy/paste and move into position. Again using 3D Builder in Windows 10


Really the possibilities are endless, but the key is have a go at designing your own stuff, that is where the satisfaction lies

Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #3 on: July 31, 2021, 01:09:21 AM »
FDM printers still have a place in modelling, especially if it's capable of printing in ABS. You can use Acetone vapors (or just Acetone on a rag) to smooth out the surface. It will obliterate most details, but for things like wings, frames and hulls (ships or planes) etc., they're very handy.

Plus as Brian said, they're really handy for making non-model "things". I'm working on n LED strip and battery holder for my Donegal visor.

Offline robunos

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Re: 3D Printing Tips and Techniques
« Reply #4 on: July 31, 2021, 01:58:20 AM »

Thanks, Frank, for the useful post, a lot of good information there.
@Buzzbomb, I made a few simple tools myself, designed them with Tinkercad, then had them printed by Shapeways.
A set of small squares, AFAIK you can't buy them this small . . .





a centre finder for marking the axle holes in replacement cast resin wheels,





and finally a 'Square Checker', for making sure eg. ARV hull parts are square to each other, also tailplanes and fins.





cheers,
Robin.

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Offline robunos

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Re: 3D Printing Tips and Techniques
« Reply #5 on: July 31, 2021, 02:06:14 AM »
Okay, so my first question.
Where is best to site a 3D printer, both in terms of position in the room, for access, ventilation, etc. and what it stands on, furniture wise.
The Elegoo manual, I have a Mars 2 Pro, is less than useful here, it mentions that the printer should not be subjected to 'shaking', I assume that means vibration, and I also see that the unit has levelling feet. I also assume therefore, that the printer has to be set level horizontally, in order to print properly.


cheers,
Robin.
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Offline Buzzbomb

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Re: 3D Printing Tips and Techniques
« Reply #6 on: July 31, 2021, 07:06:52 AM »
Okay, so my first question.
Where is best to site a 3D printer, both in terms of position in the room, for access, ventilation, etc. and what it stands on, furniture wise.
The Elegoo manual, I have a Mars 2 Pro, is less than useful here, it mentions that the printer should not be subjected to 'shaking', I assume that means vibration, and I also see that the unit has levelling feet. I also assume therefore, that the printer has to be set level horizontally, in order to print properly.
cheers,
Robin.

No clear direct answer from my point of view, but you are correct about being level as a base starting point. Most printers have a leveling procedure as part of the manual. FDM printers also relied on heat, so advice was to keep out of draughts or in a box to keep a stable environment. Where it goes will typically rely on space. Resin printers for instance, seem to need two units, the printer and the washing/curing station for optimum use. Washing can be done elsewhere likewise, curing can be done outside, but I have heard mixed reports on the efficiency of both those options. Resin printing does also appear to be somewhat messier than FDM because of the multistep process of printing, washing and curing.

My personal solution was to put it in a cupboard, so I have a printer cupboard in my workshop, which because I have the environment to do that, works. It keeps the printer, setup and level, warm when in operation, quieter and more to the point, very out of the way when not being used.


I have thought many times about getting a 3D Resin printer, but as quite a number of my modelling buddies have them, I thought what's the point, I can use their gear and pay them for the small amount of Resin printing I might ever need to get done.

BTW, great gadgets. Really like the wheel Centre device. Much sleeker than the one I found.
How legal is resin money  ;D
« Last Edit: July 31, 2021, 07:26:12 AM by Buzzbomb »

Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #7 on: July 31, 2021, 08:28:30 AM »
Unlike FDM printers, the Elegoo itself doesn't shake when printing; it only has one motor that moves vertically (in the Z axis). You do want the printer level (you don't want the resin to slop over an edge) but more importantly, you want the build plate to be parallel to the FEP and screen.

As far as location, a sturdy table that doesn't vibrate every time someone walks by should work.

You want it near a window or near good ventilation, since some resins can have a strong smell.

You also want the resin temperature to stay constant and above 68F/20C

If you place the printer near a window, make sure it doesn't get sunlight or any UV on it. The clear plastic cover will block much but not all UV light. If you get a few hours of Sun on the printer, it may start curing the resin in the vat.
An opaque box over the printer or a darkened room should be enough.
You can see my "lab" setup here. The resin printer is in the black enclosure... which has a clear window in the flap. I covered it up.
Brian's setup with the doors would work well with a resin printer.

You can leave the resin in the vat for a few days, as long as it doesn't get ambient UV exposure.

Use a "waste" container for resin that was in the vat, and strain it; never pour it back in the original container. Keep it in a dark place and reuse it.


Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #8 on: August 01, 2021, 12:59:28 AM »

Offline GTX_Admin

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Re: 3D Printing Tips and Techniques
« Reply #9 on: August 01, 2021, 01:03:03 AM »
Great thread guys. :smiley:
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Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #10 on: August 01, 2021, 02:38:46 AM »
Robin - how do you use the "square checker"? sounds handy.

Offline robunos

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Re: 3D Printing Tips and Techniques
« Reply #11 on: August 01, 2021, 04:51:21 AM »



Like this . . .








Also with things like tailplanes and fins, basically anywhere you have two parts that need to be at a true right angle . . .


cheers,
Robin.
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Offline robunos

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Re: 3D Printing Tips and Techniques
« Reply #12 on: August 01, 2021, 04:53:24 AM »
Unlike FDM printers, the Elegoo itself doesn't shake when printing; it only has one motor that moves vertically (in the Z axis). You do want the printer level (you don't want the resin to slop over an edge) but more importantly, you want the build plate to be parallel to the FEP and screen.
[SNIP}



Thank for this, most useful.


cheers,
Robin.
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Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #13 on: August 02, 2021, 04:08:56 AM »
The square checker looks handy!

Offline robunos

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Re: 3D Printing Tips and Techniques
« Reply #14 on: August 02, 2021, 05:15:52 AM »
That's why I developed it !    8)
If you don't get the pieces square, when building those AFV kits with the hull made from separate plates, the model never comes out right . . .


cheers,
Robin.
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Offline apophenia

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Re: 3D Printing Tips and Techniques
« Reply #15 on: August 02, 2021, 07:28:03 AM »
... I made a few simple tools myself ...

Dang those are clever  :smiley:
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Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #16 on: August 05, 2021, 04:21:55 AM »
A video by Scale-a-ton where he uses Blender and his new printer to print some model parts. He doesn't go into details, but it's worth watching.

Offline robunos

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Re: 3D Printing Tips and Techniques
« Reply #17 on: August 26, 2021, 03:08:42 AM »





Okay, so I've managed to get my printer set up and try using it, with shall we say 'mixed' results . . .
After having levelled the machine (or so I thought), and then levelled the build plate, I made my first test print, the 'Rook' model included with the printer's software. The results weren't bad, for a first attempt.








There's some roughness and white deposits around the base, which I understand to be due to not washing off all of the uncured resin / not drying the piece completely before curing. Also this test print does not have supports with it, and is printed directly on to the  Build Plate. This made them difficult to remove, and I did crack one while doing so, although you can't see it unless you look closely. I also discovered that the machine was not properly levelled after all.
I levelled the printer properly this time.  A 'problem' I've found is that the adjustable feet have no locknuts, so there's nothing to retain the setting once you've made it . . .
I decided to add supports this time, so I used the supplied 'rook .stl' file and addded the supports and sliced it myself using the supplied Chitubox software. This was the result . . .





I made sure I washed this one completely before curing, so no  roughness or white deposits this time, but the print came out wonky. I put this down to having not re-homed the Build Plate when I levelled the whole machine. So I levelled and zeroed the Build Plate once more. The other major problem was this . . .





the size was completely different to the first print. I have absolutely no idea why this should be . . .
So for my next attempt I decided to use an object I'd designed myself. After letting the printer do it's stuff, I was presented with . . . nothing, a clean build plate. Another attempt gave the same result. A third go, and now the printer is producing loud grinding noises when the Build Plate goes to the Home position to start printing. Googling informs me that this is due to the Home position not being correctly set. After two attempts at re-homing with no change I decided to give up for the day. After emptying the resin vat I find the reason for the grinding noise . . .





The 'missing' prints were in fact stuck to the FEP, and not the Build Plate !  :o
So today's questions are :-

How do I get the prints to stick to the Build Plate, and not to the FEP ?

How do I get the print to come out at the correct size ?
and finally, I've managed to lose on of the screws that secures the resin vat.   :o   :-[   >:D

Are replacements available, or if not, what size is the screw, so I can get a substitute ?


cheers,
Robin.
« Last Edit: August 26, 2021, 03:11:22 AM by robunos »
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Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #18 on: August 26, 2021, 04:14:13 AM »
Leveling the machine is important to keep the resin from sloshing out one side of the tank, but not critical.

Leveling the build plate so it's parallel to the FEP is critical. Not doing so can lead to print failures. Follow the leveling instructions carefully - the build plate bolts have to be adjusted in the sequence they recommend, or the build plate can get twisted out of level.

In your failed print, how many base layers did you use? You'll have to carefully remove the stuck on resin. Don't use a metal spatula! A silicone scraper should work and won't scratch the FEP. I've used denatured alcohol to help remove stuck on bits and some will come off by picking at them (carefully) with your fingernail (through a glove).

When all clean, check the FEP for tears, deep scratches or holes. Make sure the build plate is clean, too.

If you poured the resin back into the bottle without filtering it first, use a filter before you pour the resin in the vat again to catch any bits of cured resin.

The screws are metric; M4 0.7 x 12mm for the Mars 2 Pro. Contact Elegoo and see if they'll send or sell you a replacement. They're pretty large - how did you lose one?

3D Printing Pro has really helpful videos on printing.

Leveling the Plate for Resin 3d printing - Flint Read v Paper method!
How many bottom layers should you actually use for resin 3d printing?!?
Base layer exposure
How to clean the resin vat

Offline robunos

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Re: 3D Printing Tips and Techniques
« Reply #19 on: August 26, 2021, 04:55:20 AM »
Frank3k said :- Leveling the machine is important to keep the resin from sloshing out one side of the tank, but not critical.


That's how I found out the machine was not level, I could see that the resin level was deeper at one end of the tank than the other . . .


Frank3k said :- Leveling the build plate so it's parallel to the FEP is critical. Not doing so can lead to print failures. Follow the leveling instructions carefully - the build plate bolts have to be adjusted in the sequence they recommend, or the build plate can get twisted out of level.


I've done that, and I'm satisfied that level is good, I've even used a square to make sure that the edges of the Build Plate are parallel to the sides of the printer.


Frank3k said :- In your failed print, how many base layers did you use?


I used the software default; 5 layers of 0.05mm thickness, with an exposure time of 35 seconds.


Frank3k said :- You'll have to carefully remove the stuck on resin. Don't use a metal spatula! A silicone scraper should work and won't scratch the FEP.


I'm using water washable resin, so after I emptied the tank I left it filled with water for about 30 minutes, then emptied and dried it. The stuck on prints came off with a bit of work. There are some dents in the FEP, but no tears or holes. I only have one spare, so I'd like to try and get a bit more life out of this one, if I can.


Frank3k said :- Make sure the build plate is clean, too.


I've cleaned it thoroughly with water, and now I have some IPA, i will clean it with that too. Or would cellulose (lacquer) thinners be better ?


I decided to dispose of the unused resin, as it had been hanging around while I was messing about. How long can the resin be left exposed to light before it starts to cure and is unusable for printing ?


Frank3k said :- The screws are metric; M4 0.7 x 12mm for the Mars 2 Pro. Contact Elegoo and see if they'll send or sell you a replacement. They're pretty large - how did you lose one?


When I loosened it to take the resin tank out, I overdid it, and dropped it in the resin tank. I took into the kitchen to clean it in the sink. then dried it, then put it down to dry completely while i went to fetch the Build Plate. When I returned I couldn't find It . . .


Thanks for the video links, that's my evening entertainment sorted . . .


cheers,
Robin.


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Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #20 on: August 26, 2021, 05:32:35 AM »
I've cleaned it thoroughly with water, and now I have some IPA, i will clean it with that too. Or would cellulose (lacquer) thinners be better ?

IPA or any alcohol should be more than enough. You don't want any high spots that can puncture the FEP.

Quote from: robunos
I decided to dispose of the unused resin, as it had been hanging around while I was messing about. How long can the resin be left exposed to light before it starts to cure and is unusable for printing ?

Resin will cure slowly and will form a skin as it cures. If you're going to get rid of it, the best way is to cure it (leave it in the sun until it solidifies completely) then dispose of the solid resin.

Quote
When I loosened it to take the resin tank out, I overdid it, and dropped it in the resin tank. I took into the kitchen to clean it in the sink. then dried it, then put it down to dry completely while i went to fetch the Build Plate. When I returned I couldn't find It . . .

could it be in the sink trap?

Quote
Thanks for the video links, that's my evening entertainment sorted . . .

You can play it at a slightly higher speed or skip a bit. He does tend to go on... but it's top notch info.

Offline robunos

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Re: 3D Printing Tips and Techniques
« Reply #21 on: August 26, 2021, 06:05:29 AM »
I poured the resin into an empty small clear yoghurt pot, then put it in my wash/cure machine, then let it cure in there. When it was solid, I binned it.
I definitely put in on the worktop, away from the sink. The knob on the bolt head is too big for the holes in the sink drain anyway. I've taken a break from video watching, you're right, those videos are excellent, and just been on Amazon to order some more FEPs, and also some replacement screws, will be here tomorrow (isn't Prime a truly wonderful thing . . .  ;D  )


cheers,
Robin.
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Offline robunos

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Re: 3D Printing Tips and Techniques
« Reply #22 on: August 31, 2021, 05:03:25 AM »

Okay, today I had the chance to try some printing again. The parts I ordered had arrived last Friday, the replacement FEP films, in a nice pack, to keep them safe from damage,





and a packet of bolts to replace the one I somehow managed to lose . . .





The original bolt is on the left, a replacement on the right, effectively identical . . .


This time I decided to print some parts that I had CADed myself, to check that the way I had done things, design, build plate layout, supports, slicing, etc, were correct, and also to see if the scaling issue I had previously was still present.
After 30 minutes or so, success !





After removal from the build plate, washing and curing,





and finally after removal of the raft and cleaning up.





So to today's questions. I had some trouble with the machine not recognising the Chitubox files at print time. After some messing about, I did get things to work. Have you experienced this ? Also, a new version of Chitubox is available, but in order to use it, I have to update the machine's firmware. Have you ever done this ?


cheers,
Robin.
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Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #23 on: August 31, 2021, 12:01:46 PM »
Don't print from the USB stick that came with the printer; they aren't always the best. Buy a good quality USB stick and print from that instead. That may be causing the issues with Chitubox. Also, make sure it was saved properly.

I updated the firmware on my two Elegoo printers since it fixed some minor issues on the Saturn; I'm still using Chitubox 1.18. I do most of the supports, slicing and file checking with PrusaSlicer and UVTools. These days, I use Chitubox mainly for playing with supports and checking files.

Offline robunos

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Re: 3D Printing Tips and Techniques
« Reply #24 on: September 01, 2021, 05:07:55 AM »
Don't print from the USB stick that came with the printer; they aren't always the best. Buy a good quality USB stick and print from that instead.

I read about that when I was trying to figure out what was going on, so I ordered one from Dr Evil Amazon. Arrived today via Prime, but I haven't tried it in the printer yet.
[/size]
Quote
I do most of the supports, slicing and file checking with PrusaSlicer and UVTools.
I tried Prusa slicer, but I wasn't really sure what to do = . . . haven't tried UVTools, will have to investigate further.


cheers,
Robin.
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Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #25 on: September 01, 2021, 10:08:41 AM »
It isn't obvious how to use the PrusaSlicer. This blog post covers some of the basics. There's an online knowledge base as well.

UVTools is also not obvious, but it does an amazing job at fixing print files and can open most printer file formats.

UVTools comes with printer profiles for PrusaSlicer that have to be installed before you try to slice your file in PrusaSlicer.

There's a UVTools workflow that is helpful... but you'll have to mouse around to find the menu commands in the program.
There's also a series of videos on UVTools, but they aren't tutorials.
« Last Edit: September 01, 2021, 10:12:31 AM by Frank3k »

Offline LemonJello

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Re: 3D Printing Tips and Techniques
« Reply #26 on: October 13, 2021, 09:27:43 PM »
I may have convinced the Lady LemonJello to acquire a 3D printer for my Christmas gift this year.

I was thinking of going with the Mars 2 Pro, seems like a good starting size for what I think I'll be printing (1/48 and 1/35 bits-n-bobs).

Is the Mercury Plus washing/curing machine a "must have" or more of a "nice to have"?

Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #27 on: October 13, 2021, 11:31:20 PM »
The Mars 2 Pro is a good printer and has a monochrome screen, so it will print much faster and the screen will last longer than the older RGB screens.

Washing and curing is probably one of the most annoying parts of 3D resin printing. You can make your own curing station with UV LEDs or a nail curing UV station (or even putting the print in the Sun) and you can manually wash the part in isopropyl or put it in an ultrasonic bath.

I thought wash & cure stations were just "nice to have" but even though I had streamlined the way I washed and cured parts, it was getting tedious. I bought an Anycubic wash and cure station (at the time it was both cheaper than the Elegoo and in stock) and it really made a huge difference. Now I print, drip of the excess resin, put the part in the wash tank, give it a few minutes wash and depending on the part, either cut off the supports and cure or just cure with the supports. The machine does an even cure and I don't get pockets of partly cured resin.

Offline LemonJello

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Re: 3D Printing Tips and Techniques
« Reply #28 on: October 14, 2021, 03:54:58 AM »
Excellent! I shall send the links to both to the interested parties and hope to find both under the tree this year.

Also, Blender will be downloaded/installed on the home laptop so I can get ahead of the designing curve. 

Thanks!

Offline robunos

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Re: 3D Printing Tips and Techniques
« Reply #29 on: October 14, 2021, 04:46:54 AM »
I can only second what Frank says about the Mercury Plus, with the qualifier that as I've been using the water-soluble resin, I tend to wash my prints in the sink . . .


cheers,
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Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #30 on: October 14, 2021, 11:00:10 AM »
Uncured resin down the sink isn't a great idea... just wash it in a container of water and set it outside in the Sun to cure the resin.

@LemonJello - there are some excellent tutorials for Blender on Youtube. Make sure they're recent (for version 2.8 or higher).

The Blender Foundation videos are good, up to the chapter where they introduce armatures and they don't mention how to get the test files, or load them. Truly infuriating.

Offline arkon

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Re: 3D Printing Tips and Techniques
« Reply #31 on: December 08, 2021, 09:52:13 AM »
when you draw/design things  will it print them out solid or do you have to design them with thinish walls so your not printing a big chunk of plastic? or is there a progam that will take your big chunky shape and only print the outer most part?

« Last Edit: December 08, 2021, 09:53:57 AM by arkon »
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Re: 3D Printing Tips and Techniques
« Reply #32 on: December 08, 2021, 12:28:59 PM »
It's really up to you. If you draw/design an object and it passes all the printablilty tests, in most cases it's going to be a solid object. This can make an object expensive (if you send it to a place like Shapeways) or expensive and heavy if you print it yourself. A heavy object can cause issues during printing as well.

Most slicing programs have the option to hollow out a solid object. Depending on the object, you may need to add drain holes to allow the resin to flow out during printing.

I design my objects with a wall thickness - 0.75mm is OK for medium sized objects (but can be fragile), 1mm is a good compromise between cost and strength. Bigger objects may need slightly thicker walls.

Offline LemonJello

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Re: 3D Printing Tips and Techniques
« Reply #33 on: December 28, 2021, 06:07:40 AM »
My Mars Pro 2 is set up and running a test print as I type this. 

My laptop is running Win7, Blender requires at least 8...so I'll be using my work computer and AutoCAD for my first few designs, but Chitubox and UVTools had no issues installing.

Excited to see if my test print comes out ok.

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Re: 3D Printing Tips and Techniques
« Reply #34 on: December 28, 2021, 06:37:57 AM »
Great! The latest (2.7, now 3) versions of Blender are a great improvement, especially in the interface.

Chitubox is OK, but get PrusaSlicer as well; UVTools will install the correct printer profiles as well. UVTools finds fewer issues with Prusa sliced objects vs Chitubox. Also, resin is sensitive to temperature - if it's cooler than 68F, you're going to have a lot of issues getting a good print. 70F-78F is better (at least around the printer)

Offline LemonJello

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Re: 3D Printing Tips and Techniques
« Reply #35 on: December 28, 2021, 10:20:47 AM »
Test print was successful. I washed them in Isopropyl alcohol and will have to let them cure in the sun tomorrow. (I won't know if I got the wash/cure station until New Years). 

My son got me three bottles of Elegoo's resin; clear red, clear green, and grey.


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Re: 3D Printing Tips and Techniques
« Reply #36 on: December 28, 2021, 10:43:27 AM »
Counterintuitively, black resin will produce the best details, clear resins will be slightly fuzzier because the UV will spread further in clear resins than dark. Gray is a good compromise and parts come out looking primed. You'll want to do an exposure print (UVTools has one) for each of the resins, because one exposure definitely doesn't fit all.

Offline arkon

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Re: 3D Printing Tips and Techniques
« Reply #37 on: December 29, 2021, 08:37:10 AM »
are stl files specific to resin or extruder  3d machines?
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Re: 3D Printing Tips and Techniques
« Reply #38 on: January 04, 2022, 09:48:30 PM »
The Mercury Wash & Cure station has arrived.  Haven't had a chance to play with my new toys with family here over the New Year's holiday, and dealing with 15 inches of snow dropped on us yesterday.  Lost power for most of the day, restored around 7pm local time.

Weather has us socked in right now, lots of downed trees and unplowed roads, so maybe today I'll get to play?


Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #39 on: January 04, 2022, 11:44:02 PM »
are stl files specific to resin or extruder  3d machines?

STL is just a file format that's commonly used with 3D printers. It defines the 3D geometry of an object. To make the object printable, you have to process the file in a slicer that knows about the printer you're going to use (resin or FDM). The slicer cuts the object into layers for the printer, adds supports, etc. and generates a file that the printer understands. Most FDM printers understand a language called G-Code, which is common to CNC machines and just tells the print head where to move, plus the thickness of each slice.

Most hobbyist resin printers are different - the slicer just generates images that are slices of the object (and added supports) from the STL, with each slice separated by a layer thickness - much like an MRI or CT scan. This is one reason they're often faster than FDM printers; each layer is printed in one go. The resin printers also use G-Code to move the build plate and for setting parameters.

Another type of resin printer uses a UV laser that shines on a mirror and the mirror is moved in XY very quickly by galvos; these are closer to FDM printers in that the slices describe the motion of the laser spot. They're still very fast, since the mirror is much lighter than the printhead on an FDM printer.

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Re: 3D Printing Tips and Techniques
« Reply #40 on: January 08, 2022, 02:07:44 AM »
This is a very technical page - Jan Mrázek does some serious experimenting with resin printers and shows all his steps - but his results are understandable and applicable to most resin printers: https://blog.honzamrazek.cz/category/3d-priting/

Offline LemonJello

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Re: 3D Printing Tips and Techniques
« Reply #41 on: January 19, 2022, 09:34:45 AM »
Update from LemonJello Heavy Industries, 3D Printing Division:

Had some free time to play and found a canoe and mens/womens bicycles that looked useful. 

1st attempt: my scale calculations were off, plus I didn't account for scaling in all 3 dimensions, so the prints were wonky, not usable, but they did print.
2nd attempt: much better results. The bikes are a little tall for 1/35, but could be added to a truck bed or strapped to a vehicle to add interest. The canoe is usable, but a tad underscale and fragile.  but, again, successful prints!

I have an assortment of weapons curing right now: pump shotgun, Saiga 12, AA-12, lever action rifle; again, my scaling may be slightly off/need refining, but they all look usable.

Offline arkon

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Re: 3D Printing Tips and Techniques
« Reply #42 on: January 28, 2022, 10:54:52 AM »
got a crealty halot-one resin printer from the kiddos this christmas. resin has already arrived now just waiting on the respirator.have watched all recommended videos and read all info provided so far from Frank3k.
new territory here so this shall be fun.
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Offline LemonJello

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Re: 3D Printing Tips and Techniques
« Reply #43 on: February 14, 2022, 04:36:31 AM »
Here's a couple photos of my first run of prints,  I've got a batch of kegs, weber grills and milk crates washing right now, and a batch of crates and barrels printing.

More photos to come.




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Re: 3D Printing Tips and Techniques
« Reply #44 on: February 14, 2022, 08:59:47 AM »
Nice job! If you can't account for all the missing pieces, make sure they're not stuck to the FEP or the build plate or you'll have a Bad Time. How did you print the rifles? parallel to the build plate?

I'm having some difficulty "dialing in" my Saturn. The larger vat and FEP are a bitch to work with.

Offline LemonJello

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Re: 3D Printing Tips and Techniques
« Reply #45 on: February 14, 2022, 10:46:39 PM »
Thanks! It was pretty fun to get some time with the printer.  At one point I had a batch of prints in washing while another batch was printing. 

Any missing parts are lost to the carpet monster as they flew off as I was removing the supports.

I let PrusaSlicer determine best position for details on the rifles, and they all printed at odd angles with a lot of supports.  I think I'll try it again with more vertical orientation and see what happens.

I give the FEP a good inspection for cured bits at the end of my printing time and a rinse of Isopropyl before closing up shop.

Offline robunos

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Re: 3D Printing Tips and Techniques
« Reply #46 on: February 15, 2022, 01:49:22 AM »
I'm having some difficulty "dialing in" my Saturn. The larger vat and FEP are a bitch to work with.


I was recommended to view this blog, and it does seem to have some good advice, might be worth you looking at it . . .


https://blog.honzamrazek.cz/category/3d-printing/




cheers,
Robin.
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Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #47 on: February 15, 2022, 01:57:46 AM »
Robin,
 I'm using some of Jans' ettings! His latest settings and script for UVTools are great. I'm having issues dialing in the best exposure.

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Re: 3D Printing Tips and Techniques
« Reply #48 on: February 17, 2022, 07:00:18 AM »
I should follow my own advice...

I was having weird print failures, even on basic prints like exposure checks. Half would be stuck to the FEP and half to the build plate; it didn't make sense. After many attempts and many re-levels - I took the build plate off, cleaned it well and took a good look at the surface. I gave it a quick pass with a 600 grit sanding pad and a shiny spot appeared. It was a tiny sliver of resin, no more than 5mm x 3mm and much, much less than 1mm thick (maybe only 1-2 layers thick, so around 100 microns) near the edge of the build plate. It was smooth and almost invisible and I could only feel it by its smoothness.

I scraped the build plate several times, gave it a couple of passes with a 400 then 600 sanding pad, cleaned it off, re-leveled and it started printing like a champ.

Offline Story

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Re: 3D Printing Tips and Techniques
« Reply #49 on: September 19, 2022, 03:50:06 PM »
What do you guys do with your misprints?

Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #50 on: September 20, 2022, 12:16:04 AM »
Send them to you or Jeff or anyone who wants them. I keep some of the supports  to use as a "pull tab" when cleaning the FEP (the clear film at the bottom of the tank) - I hold one down near a corner of the tank, run the "tank clean" function (which lights up the whole screen for a few seconds).I then take the partially exposed sheet outside to fully cure - although this is extremely exothermic in direct sunlight.

I usually print many copies if the parts are small enough to fit multiples on the build plate. They get cured and go into the spares box.

The rest (all cured) goes into the recycling bin.

Offline Frank3k

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Re: 3D Printing Tips and Techniques
« Reply #51 on: September 25, 2022, 03:25:55 AM »
HackSpace has a pretty good free PDF book on 3D design and printing FreeCAD for Makers They're using FreeCAD a Free 3D CAD program - its a parametric design CAD program, but it will work with meshes and can output STL files. It's also (as it says on the tin) free.

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Re: 3D Printing Tips and Techniques
« Reply #52 on: November 20, 2022, 01:52:01 AM »
Another one with 3D STL files for purchase:  https://www.gambody.com
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