1 Topic by Cammy

  • Cammy
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  • Registered: 2020-09-29
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Topic: Geeetech A30t pulley issue

I bought the A30t from Geeetech, and it's been alright, except for the fact that the models tend to drift in the middle of printing on occasion. After some experimentation and watching, I think I narrowed it down to the drive belt for the extruder- or, more precisely, the fact that there's little tension on the belt and that the side opposite the drive motor is a toothless pulley for some reason. As of now, I've replaced the pulley with a printed gear that seems to be working far better, though it does cause different (though much more minor) printing issues as the hole in the gear is a little too big for the bolt that serves as an axle and thus it shifts around a little during operation.

I've been trying to adjust the gear through iterations, trying to compromise between size (putting tension on the belt) and how tightly it holds to the axle, but I can't seem to hit just the right balance. Is there a better solution for this problem other than trial and error? Failing that, is there a program that could allow me to shrink the hole without reducing the overall size of the gear?

2 Reply by justsomeguy

  • justsomeguy
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Re: Geeetech A30t pulley issue

I'm no engineer but I don't see why teeth vs. no teeth matters on a pulley that does not drive the belt.

It sounds to me like you are saying the x axis belt seems loose. You might try something like this as an update: https://www.thingiverse.com/thing:3903803. I think a lot of Ender 3 mods will work for your printer without too much fuss.

Also, Geetech makes and uses really cheap parts and their quality control is not the greatest. I have an A10M which I am quite happy with. However, out of the box, the y axis stepper driver would lose steps. I swapped it out with the Z driver while troubleshooting the problem and since then both axes have worked flawlessly. I was expecting to have to replace that driver.

If you want to continue down the road you've already started on, this openscad geared pulley might help, https://www.thingiverse.com/thing:2758711. I would suggest looking into the belt tensioners for X and Y though.

Hope you find something helpful in my post. Cheers.

3 Reply by Cammy

  • Cammy
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Re: Geeetech A30t pulley issue

justsomeguy wrote:

I'm no engineer but I don't see why teeth vs. no teeth matters on a pulley that does not drive the belt.

It sounds to me like you are saying the x axis belt seems loose. You might try something like this as an update: https://www.thingiverse.com/thing:3903803. I think a lot of Ender 3 mods will work for your printer without too much fuss.

Also, Geetech makes and uses really cheap parts and their quality control is not the greatest. I have an A10M which I am quite happy with. However, out of the box, the y axis stepper driver would lose steps. I swapped it out with the Z driver while troubleshooting the problem and since then both axes have worked flawlessly. I was expecting to have to replace that driver.

If you want to continue down the road you've already started on, this openscad geared pulley might help, https://www.thingiverse.com/thing:2758711. I would suggest looking into the belt tensioners for X and Y though.

Hope you find something helpful in my post. Cheers.

Installed and tested, and the tensioner seems to fix the problem! Many thanks you! Thought I was gonna have to send this one back and find another large printer.