Timing belt for huxley

I am trying to get hold of a replacement belt for my reprap pro Huxley.

I think it is a MXL timing belt, but not 100% certain, and I can't seem to see it on the site. Anyone able to point me in the right direction - and possibly where to buy a length.

If you search ebay for Huxley belt there should be a number of results turning up.

The only belts that pop up are T2.5, T5 (sometimes GT2), but I think the default is a MXL belt, hence the question.

Can't tell you what it is as I have never seen a reprappro, but if this is indeed an MXL, you can get it there :

[www.econobelt.com] (check the nice drawings with dimension to verify against your own belt)

or : [sdp-si.com]

(I have only tried the later personally - quite slow regarding delivery time).

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

I doubt they use MXL as it isn't metric and that would be apparent in the firmware configuration.

Why not ask RepRap Pro? Their designs are all open source so there will be a bill of materials somewhere public, most likely on their github account.

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[www.hydraraptor.blogspot.com]

Current RepRapPro Huxley and Mendels use a kevlar-reinforced black rubber MXL belt, 1/4" (6.35mm) wide, on a printed 17-tooth pulley, giving 92.635 steps per mm.

Older machines, pre March 2013, use a steel wire-reinforced polyurethane T2.5 belt, 5mm wide, on a printed 14-tooth pulley, giving 91.429 steps per mm.

We changed over to the MXL belt because it is quieter, lighter, just as strong, and cheaper!

Ian
RepRapPro tech support

Jezz
Now so confused.
Will you new MXL belts work with 16teeth aluminum pulleys which are the same as printed pulley???

@Suljo: Our MXL belts will work with MXL pulleys. If the pulley has 16 teeth, rather than 17 teeth like our printed one, you will need to change the steps per mm of the X and Y axis. The new steps per mm will be 98.52 (using [calculator.josefprusa.cz] ). So, when you change your pulleys over, send the following commands:

M92 X98.52 Y98.52
M500

This will set the steps per mm correctly for X and Y axis.

Ian
RepRapPro tech support

droftarts Wrote:
-------------------------------------------------------
> @Suljo: Our MXL belts will work with MXL pulleys.
> If the pulley has 16 teeth, rather than 17 teeth
> like our printed one, you will need to change the
> steps per mm of the X and Y axis. The new steps
> per mm will be 98.52 (using
> [calculator.josefprusa.cz] ). So, when you
> change your pulleys over, send the following
> commands:
>
> M92 X98.52 Y98.52
> M500
>
> This will set the steps per mm correctly for X and

> Y axis.
>
> Ian
> RepRapPro tech support

When my Aluminum pulleys arrived...
Is it same thing if I send command M92 X98.52 Y98.52 and save it with M500 in Pronterface or it is better if I change X/Y values in firmware under audrino C_tab?

Another question
What is purpose of reset jumper connector on right side of Melzi board?
Seam to me that from pronter face I can reprogramed some parts of Melzi bios with some commands without connecting this jumper on Melzi board, but eg. if I want to update firmware from audrino seams that I must connect this jumper...

@Suljo: Yes, you can set the steps per mm either way. But it's easier to do it with M92 than editing and flashing the firmware.

If you want to do it in firmware, the steps per mm are set in the configuration.h tab; look for the line that currently says:

#define DEFAULT_AXIS_STEPS_PER_UNIT {92.635, 92.635, 4000, 660}

And change both '92.635' numbers to the numbers I gave you above. Full instructions on flashing firmware are here: [reprappro.com]

That's exactly what the auto-reset jumper is for! In normal running, remove it, as it says in the instructions here: [reprappro.com]

When flashing firmware, it's generally better to put it back on, as it says in the instructions here: [reprappro.com]

Ian
RepRapPro tech support

16 teeth Aluminum pulleys has arrived but teeths are 12.2 mm in diameter and original printed pulleys are 10mm in diameter.
For now I changed only X pulley.
When I enter in pronter face new X value 98.52 as you suggest and leave Y value as default when I print 50x50mm square base I got 63x50mm.

When I turn back original X value 92.635 for 50x50mm square base I got 59x50mm in print.

Seams that I must enter lover value than default for X axis for that bigger pulley in diameter.
I try reciprocity formula (92.635 x 50) / 59 = 78.504
With 78.504 for x in pronterface For 50x50mm square I got 50.05 x 50mm in print. Iam to close but...

Do you know formula for axis steps where diameter of pulley is involved too?

Forget this post above. This pulley bigger in diameter just dont work fine with MXL belt. It works only with too much tension but this is not purpose of the pulley nor the belt.
Maybe it will works for Mendel if I print it in few weeks but for now forgot this post again.

Can you post the link of original X/Y pulleys or link where to buy same in diameter and teeth aluminum ones?

Edited 4 time(s). Last edit at 07/17/2013 06:22PM by Suljo.

@Suljo: It sounds like you got T2.5 pulleys.

Our printed pulley are here: [github.com]

We print them with a 0.3mm nozzle, 0.2mm layer height. Send me an email if you want me to send you a couple of fresh ones.

I trust this place for pulleys: [www.beltingonline.com]
You want a 16-tooth MXL pulley, with one grub screw hole and 5mm bore. 18-tooth should fit, 20-tooth is too big. You can, at your own risk, find something similar on ebay.

Ian
RepRapPro tech support

Hi, I'm looking to change the pulleys on my huxley to alloy ones,my huxley was pruchased from reprap pro in june this year and has definately got mxl belts, but the printed pulleys I'm pretty sure have 18 teeth on them (though it is quite difficult to count them in situe on the machine!) I guess going to 16 teeth will slightly increase the accuracy - more turns / mm.
Tom