Problem printing GT2 pulleys

I'm having a problem printing out 2mm pitch GT2 pulleys, via the OpenSCAD script below:

[www.thingiverse.com]

My printer is calibrated pretty well, but the pulley teeth aren't as defined as they should be. The root circle (teeth bottom land), pitch circle, and outside diameter (teeth top land) are all so close together that the belt slips. I'm using an eMaker Huxley with a 0.5mm tip, slic3r 1.00 RC3 with pretty average feedrates and settings, nothing else special worth noting. My firmware is pretty old and maybe should be upgraded but I haven't had a reason to yet. I think it's Sprinter, and I'm printing from an SD card.

So on one hand, I could assume printing a 2mm pitch pulley is "borderline" too fine of a detail to print with a 0.5mm nozzle. But on the other hand I see that other people have done it, so I'm wondering is the slicer screwing it up? Or is there some other OpenSCAD parameter I should have tweaked to get the gears to print a bit better?

I will post a picture tonight.

Thanks,

Neil

Edited 3 time(s). Last edit at 03/10/2014 02:25PM by FlyingLotus1983.

The peak of the tooth on a small GT2 2mm pulley is only ~0.4mm wide. This makes it pretty difficult to print with a 0.5mm nozzle, especially if you let Slic3r pick an extrusion width, as it will usually pick something a bit wider than your nozzle size. You could try defining the extrusion width as 0.5mm to get a bit better resolution, but that still won't quite get you there. Have you tried any other slicers, such as Cura?

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Haven't tried other slicers yet. Like I said I thought it was going to be difficult but I have seen others do it and I'm wondering what their secret is.

I might just pull the trigger and get an 0.3mm nozzle and try it with that.


If anyone else has successfully printed GT2 2mm please let me know how you did it

Quote
FlyingLotus1983
If anyone else has successfully printed GT2 2mm please let me know how you did it

I had one printed on a Uprint SE at work and it was great! I dont know the DIA of the tip but im sure its in the .3mm range.

I dont think I could do it at home with a .4 tip... Although I didnt try.

So I emailed Brian Reifsnyder at hotends.com about getting a 0.3mm J-Head made (they only list 0.5, 0.4, and 0.35 on the site). He said that he can definitely make a 0.3mm, but that it is considered more of "experimental nature" and can be easily clogged. So he recommends a 0.35 mm tip. I already ordered a 0.4mm tip from him for a scratch-built Prusa i2 that I still need to finish... and it doesn't make a whole lot of sense to have a 0.4mm and a 0.35mm, with only 0.05mm difference between them.

So I'm thinking about getting the 0.3mm anyway and going for broke. I'm not really worried about contamination, since I'm using good virgin PLA from PushPlastics (I don't work for them or get any money from them but I'm definitely a fan for their good value and high quality plastic). If I only use it for printing timing pulleys and such, I don't think it will be much of a problem.