Slicing My STL File for 3D Printing

3D Fabrication
#1

Hello all. I have been working on a project in fusion 360 (my first time using design software), and after a week I have finally finished my design. See below

This evening I will be taking it up to DMS to slice and print the design. It’s a very small piece (38mm OD x 33mm ID) with very small numbers. (Only hav our 4mm in height and 2mm in depth). Any recommendations for slicing this to make it come out the best?

Ps. For you watch lovers this will be used to make an antique style Bakelite bezel insert.

image
image1512×2016 1.18 MB
image
image1512×2016 1.13 MB
image
image1512×2016 1.16 MB

1 Like
#2

How small are the details like the triangle inside the 4 and the little peninsulas that go into the top of the 5 and 6?

My first instinct is that a standard .4mm nozzle will struggle to print those details but I’m thinking about my own slightly crappy home printer.

#3

This was also a concern of mine but I haven’t considered the small details within the numbers themselves. The circles are 1.5mm in diameter so that gives a decent reference on size so I would guess between .5 and 1 mm.

#4

Why not use the resin printer? I’d expect it to have no issues with that level of detail.

#5

Thanks for the reply! I have no experience with 3D design . I found an article on how to make your own bezel insert and that is what prompted this project. Is there a separate training for the resin printer that I can complete to learn how to operate it?

And would you might a brief explanation on why the resin printer would be a better option? Thanks again!!!

#6

You’d need resin printer training to use the resin printer.

There’s a bunch of different types of printers and they all have their tradeoffs.

“Standard” printers printing in PLA or ABS (or PTFE, ninjaflex, etc etc) are all using FDM (Fused Deposition Modeling) which means the printer is essentially a fancy hot glue gun with some motors driving it around to drop off the hot glue layer by layer. This type of printer has some max accuracy constraints such as how small of movements the motors can move accurately and how much the hot glue gun can spit out accurately. Roughly, 0.1mm is about where you’re at for both, which is plenty accurate for “most things”.

The resin print type is a SLA (Stereolithography Equipment) which means it uses some sort of light beam to expose some “liquid” medium layer by layer. After that you cure the part in a UV for a while and it becomes a solid part made from a previously liquid resin material. Watch some youtube videos it’s pretty cool. The nice thing about this type is you can have the accuracy of the beam size of your laser assembly, the downside is the resin is eicky and expensive.

My personal rule of thumb is, do I need small “jewelry level precision”? Then Resin. Otherwise more standard FDM.

TLDR: Lasers!

1 Like
#7

Wow that is very helpful. Thank you! It definitely sounds like resin is the way to go.

Is the training virtual or does it require an in person training?

#8

Pre-COVID it was in person only, not sure if it has an online class.

@Team_3D_Fab Is the resin printer operational and do we have a class coming up for it?

1 Like
#9

While there may be laser SLA printers, the current generation of cost effective, cheap ones are a UV LED, gated by cell phone LCD displays. Keeps the parts count and costs down, and the resolution is still better than FDM printing.

2 Likes
#10

Shapeways.com is another printing option, and one which is reasonably priced (especially for small parts). They have several materials options, including sintered metal powders and various plastics with varied strength, detail, and flexibility properties.

3 Likes
#11

3dhubs.com is (or used to be) another option - connects you with local 3d printing services. I haven’t used them in a few years though.

2 Likes
#12

I can’t quite tell from your rendering … is the part solid?

#13

Yes, so I decided to give it a shot a print it on the poly printer. The result was not bad, but the small numbers did not come out as clean as I need. Then I realized that my model was actually about 2 mm too large in diameter.

I have since updated the file and now the numbers are on 1.75mm in height and 1mm in depth ( 2 mm shorter than the model I originally posted.

I might have to seek out a printing service to get the level of detail I need for this project. Unless the sla resin printer would be able to capture this amount of detail.

image
image1512×2016 1.56 MB
image
image1512×2016 1.87 MB

#14

I would definitely try it on the resin printer. It is probably capable of the features you want.

online training: learn.dallasmakerspace.org

(1) If the sizing must be precise, account for resin shrinkage. X and Y (as printed) scale up about 1.0156 (i.e., 1.56%). Z scale up about 6%. Fusion has a non-uniform scale feature.

(2) Make sure your Fusion model is in millimeters before you export to STL. Sometimes the Chitubox slicer just flat freaks out on the size conversion it if didn’t start in mm.

(3) IIWY, my first attempt would be to print it flat against the build plate. The biggest challenge is going to be getting it off the build plate without shattering it. Put several copies onto the same print and print them all at once. Use a single-edge razor blade to very delicately lift it off the build plate. You’ll have to bring your own blade. It’s so thin that it’s going to print real fast. Print time is dependent solely upon the number of layers, so having more parts on the layer isn’t going to impact that.

(4) If you can’t get it off the build plate without shattering it, then tilt it at about 45 degrees, and use supports. Lots of supports. Make your supports nearly touching each other especially at the “leading edge” (i.e., lowest corner) of the print. Your part is so thin that it’s going to want to sag. Make the Z distance off the plate 7-8 mm.

(5) The resin profiles we have set up use a default of 0.05mm layer thickness. If you print on an angle, consider reducing your layer thickness to 0.025mm. It seems to be more stable that way. If you do that, reduce the exposure time per layer by 25%.

8 Likes
#15

This is all very helpful. Thank you!

1 Like
#16

Ran into a hiccup here. In the training there was mention of the app “chitubox” to convert the stl file into a useable layered file for print.

None of the computers in the 3D lab have this program installed. I found the Mars usb, but it contains the install file and not the actually program. How can I access this program?

#17

Regarding small or delicate parts. You can raft it and set it up on thin supports at an angle (35-45). This will reduce the peeling force when the platform resets for the next layer.

1 Like