SoliForum - 3D Printing Community — replace every belt and pulley with GT2?

Re: replace every belt and pulley with GT2?

null@example.com (TickTock) — Fri, 20 Mar 2015 02:56:56 +0000

Yup. I added both holes for the mount and resized it a bit so the original 3mm screw would reach all the way through and engage the lock nuts properly. I had a bunch of F623zz bearings (3X10X4) I needed to use so I made it work with that.

I just uploaded it to TV (http://www.thingiverse.com/thing:731769) if anyone wants it.

Re: replace every belt and pulley with GT2?

null@example.com (redbarret) — Thu, 19 Mar 2015 19:25:57 +0000

TickTock wrote:

Direct drive is probably even better but I thought I'd try the belt upgrade first.

I'm not really a fan. Ultimaker has a similar non direct driven Y axis and it works fine. Many printers work that way.
The reason I'm not a fan, the relatively weak break prone ABS printed part aside, and the general ugliness aside, is how much it flexes the 1mm Solidoodle frame. Not a good sign in my opinion.

I figure the long open belts connecting to the carriage would eventually wear out as well but they didn't seem to have any backlash, yet, that I could detect. I replaced them anyway, though, as long as I had the printer open. Probably will do the X axis, too, some day.

The issue to me is not the belts wearing out (they do if you don't align the pulleys well and the sides of the belts rub on them and delaminate), but the MXL belt teeth deforming at high tension, as the Reprap wiki mentions.
There's not much tension on the sides in Solidoodle, but quite a bit like you said on the Y motor belt. But probably enough tension will build up on all of them if you try printing fast enough.

I also replaced the two pulleys and pulley holders on the front with a modified version of this (had to change the bearing surface to match the bearings I had on hand). These are much stronger that the original and prone to less flex.

What have you modified? A nut slot and two holes for fastening instead of 1 (Solidoodle 3 ) would be nice.

Re: replace every belt and pulley with GT2?

null@example.com (TickTock) — Thu, 19 Mar 2015 14:00:48 +0000

redbarret wrote:

There we go
I'm willing to bet the looped belt and and 2 pulleys its on is all that's making the difference. Thought that might not be true if you try to print faster now.

Are you talking about the short continuous belt from the stepper to the 6mm shaft? If so, I agree. I could feel noticeable backlash when I grabbed the stepper pulley and wiggled the top pulley. I could feel the belt moving back and forth between the front teeth and back teeth despite having quite a bit of tension in it. This is what prompted me to look for something better. Direct drive is probably even better but I thought I'd try the belt upgrade first. I figure the long open belts connecting to the carriage would eventually wear out as well but they didn't seem to have any backlash, yet, that I could detect. I replaced them anyway, though, as long as I had the printer open. Probably will do the X axis, too, some day.

I also replaced the two pulleys and pulley holders on the front with a modified version of this (had to change the bearing surface to match the bearings I had on hand). These are much stronger that the original and prone to less flex.

Re: replace every belt and pulley with GT2?

null@example.com (redbarret) — Thu, 19 Mar 2015 10:39:22 +0000

There we go

I'm willing to bet the looped belt and and 2 pulleys its on is all that's making the difference. Thought that might not be true if you try to print faster now.

Re: replace every belt and pulley with GT2?

null@example.com (grob) — Tue, 17 Mar 2015 22:59:57 +0000

Bam. Nice work!

Re: replace every belt and pulley with GT2?

null@example.com (TickTock) — Tue, 17 Mar 2015 05:05:11 +0000

Circles

Re: replace every belt and pulley with GT2?

null@example.com (TickTock) — Tue, 17 Mar 2015 00:53:41 +0000

Will do. BTW, I bought all my gears and belts (they *are* reinforced) from speedmart on eBay. The 202mm GT2 was perfect for the 20T+40T combo but too big for 20T+20T and I couldn't find a 40T GT2 with a 6mm bore so I bought one with a 5mm bore and drill it out myself to 6mm (drilled with a 15/64th bit chucked into the tailstock on the lathe and used an adjustable reamer to take it the rest of the way since I don't own a set of metric bits). I also had to knock down the rims a bit to keep it from rubbing on the back panel.

Re: replace every belt and pulley with GT2?

null@example.com (redbarret) — Mon, 16 Mar 2015 14:23:33 +0000

Good to hear.
Please try this circle test and post a top down photo http://www.thingiverse.com/thing:532915

As for me, nothing has been delivered yet. Not the gt2 belt and pulleys, nor the Mk2 heatbeds I ordered. And the dial indicator I ordered in december.
I wonder whats up.

Re: replace every belt and pulley with GT2?

null@example.com (TickTock) — Mon, 16 Mar 2015 12:39:40 +0000

Here's the first print (http://www.thingiverse.com/thing:528775) after the GT2 upgrade. My banding on the front and back planes are back to as good as I ever had although there is still some room for improvement.

Re: replace every belt and pulley with GT2?

null@example.com (TickTock) — Sun, 15 Mar 2015 22:51:58 +0000

I just finished replacing all my Y gears and belts with GT2. I also added a 1:2 reduction by means of a 20 tooth on the stepper and a 40 tooth on the 6mm drive rod. The 40 tooth gear just barely clears the back wall but it does clear. Since it was the short belt that wore out causing the backlash, I figured reducing the strain on it via reduction could help the belt last longer (and the extra resolution couldn't hurt either). All I give up is speed which I have never been close to maxing out on. After calibration, my steps per mm for the Y axis in the eeprom config went from 88 to 159.5.

I can see why the GT2 is better wrt backlash. The teeth are deeper than the stock belts and I suspect don't fully bottom out in the GT2 pulleys so as the belt wears you just need to re-tighten to take up the backlash. I also like that the gears are solid metal instead of the plastic on metal that came stock. The backlash I could feel does appear to be eliminated.

Re: replace every belt and pulley with GT2?

null@example.com (redbarret) — Thu, 05 Feb 2015 18:07:23 +0000

I've asked mdrVB6 to order the two GT2 pulleys and belt and resend it to me because the seller was ignoring my every attempt to contact him. Thanks again, mdrVB6.
Hopefully I'll have them in few days and will test this theory.

Re: replace every belt and pulley with GT2?

null@example.com (redbarret) — Sat, 31 Jan 2015 15:43:42 +0000

Thanks mate. I'll send you a pm shortly.

Re: replace every belt and pulley with GT2?

null@example.com (mdrVB6) — Sat, 31 Jan 2015 12:57:37 +0000

Speed mart got two orders with 6mm bore pulleys thru to me in about 7 days, no issues. So if it is a last resort, PM me and I will order more and send them to you anywhere at cost. What country are you in?

Re: replace every belt and pulley with GT2?

null@example.com (redbarret) — Sat, 31 Jan 2015 09:18:05 +0000

I just doubt being able to cut a perfect straight and centered hole with just a dremel...

Re: replace every belt and pulley with GT2?

null@example.com (jagowilson) — Fri, 30 Jan 2015 22:26:34 +0000

... You're going to need 5mm bore for the motors. So what are your concerns? A fresh sharp drill bit will go right through aluminum.