MakerGear Forum

Hi all,

I bought my M2 from Amazon back in January and have been having a blast with it ever since. I have been lurking on the old board and would like to thank all of you because that saved me from lots of headaches and trauma associated with the learning curve. I have been using ABS almost exclusively and am ready to try PET. I am not happy with the shrinkage and warping with the ABS.

Anyway, since I have a new toy, my father has asked me to make him some parts for his model trains that are no longer available. I will attach a few pics of the part. So I drew it up using Sketchup as two pieces. One hollow cylinder and the gear. The diameter of the gear is approximately 7mm and it has 12 teeth. When I tried to print it I realized right away that there is no way I'm going to be able to achieve that kind of resolution with a .35 nozzle. I tried it with telling the slicer that the nozzle was .10 and no luck.

Do I need to buy a .25 nozzle in order to make this part? Is it possible to make parts this small?

Thanks in advance for any advice.

Megan

That's pretty small, but I wouldn't completely give up on a .35 mm nozzle. I'm printing parts now where I need accuracy on .8 mm thick walls that curve and twist. I use an extrusion width of .4mm and it works fine. The key is slowing the print way down. I'm at 25 mm/sec, or 1500 mm/min in S3D

If you like, post the stl of the part and I'll check it out.

with the extrusion width of a .35 nozzle i would bet that your slicer is going to say no way. a .25 will certainly help. if you get it to slice and print your going to have to print it with something else that is large so each layer can cool. to print just that gear by itself isnt going to happen.

Toby wrote:That's pretty small, but I wouldn't completely give up on a .35 mm nozzle. I'm printing parts now where I need accuracy on .8 mm thick walls that curve and twist. I use an extrusion width of .4mm and it works fine. The key is slowing the print way down. I'm at 25 mm/sec, or 1500 mm/min in S3D

If you like, post the stl of the part and I'll check it out.

Thanks Toby. What do you set the nozzle diameter at? Here's the .STL - nevermind, it won't let me attach an .STL

jimc wrote:with the extrusion width of a .35 nozzle i would bet that your slicer is going to say no way. a .25 will certainly help. if you get it to slice and print your going to have to print it with something else that is large so each layer can cool. to print just that gear by itself isnt going to happen.

Thanks Jim. I would have never thought of printing something else with it to slow it down. Great! I'm using simplify 3d and it didn't complain a bit!

The nozzle dia should be set to what your nozzle actually is then you can move the extrusion width up or down. Your width should not technically get lower than maybe .05 above your nozzle dia. You can drop it lower and it certainly does work but infill can be broken and you can have other issues. If you drop below i suggest you do 100% infill. You will have better luck. To really do detailed stuff though a .25 nozzle is the way to go.

Is this a job for Taulman bridge nylon? They claim it is good for small parts like gears, but I don't know about this tiny one, which looks more like it needs the level of detail claimed by laser sintering printers.

Yeah tim i have a roll of it but haven broken into it yet. Im interested to compare to the 618 but i havent really had a need for a nylon part

You can post an stl on this forum by putting it in a zip file. Or you can post it on the old Google Groups and we can find it there.

It sounds like the base of each prong is about 1mm. I think that's printable with a .35 mm nozzle, though I'm not sure how accurate the tip will be. But depending on the geometry it may be possible to tune the extrusion width to it.

Just for kicks I tried to print a small part like that in PLA. Hard to say if it worked or if it didn't. The print is clean but it's not the exact shape of the CAD model. Here's the model:
And here's the printed part on the bed, with a skirt around it to give the layers a chance to cool while printing. The scale on the ruler is in mm.
Here's a sharper close up showing the printing paths:
It feels stronger than it looks, but the teeth aren't the same shape as the CAD model so it might not function well as a gear.