Lead Screw

Hi there, I have a diy 3d printer which is an i3 clone i assume, I use 2 motors to elevate the z-axis, I used to have 2 standard m8 threaded rods there and had a bit of wobble but worked fine. Decided to replace those with t8 Lead screws, When I auto-home my machine, one of the z motors is having hard time rotating near the micro-switch. Why might that be ?

Check for interference with other parts.

The leadscrews are probably not parallel enough and are less tolerant to it than your m8 rods were. You could investigate attaching the leadscrews to the carriages with something that holds firmly in z but allows slight x/y tolerance, this is meant to reduce z wobble too.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

So my usage of lead screws is screwed ?

No it just needs tweaking, if they're not really parallel then as they are stiffer than threaded rods they bind and it becomes hard to turn them. The pitch is often longer ie more travel/revolution , so if you had to reduce your z steps /mm then you might need more motor current.

Edited 1 time(s). Last edit at 10/04/2017 03:55PM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

so I can overpower the fact that they are not %100 parallel ? what way should I follow I'm lost tbh

It depends on how non parallel they are if it's very slight you might just have slight bind at a certain point so slightly higher current can overcome it. What I mean is that if you only just had enough motor current and therefore torque to turn a threaded rod with a finer pitch then you won't be able to turn an 8mm pitch leadscrew it needs more torque.

If you can turn it by hand all the way up and down fully assembled with little resistance it's should work with appropriate motor torque.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions