To see this working, head to your live site.

Play in the gearboxes of all step motors

Hi everyone,

I mailed Chris about this issue and he told me that it is normal for these low-cost motors to have some play in the gearbox. The question is - are there any better quality motors that I can mount on the arm without big modifications? Please see this video and tell me if it is normal to have this amount of play: https://photos.app.goo.gl/JbkGkzq95JAdzVzVA

I would like to have approx. 0,3 mm repeatability and I'm not even close to that, even with the fine calibration and keeping the arm under constant weight. I checked all connections with the shafts, belt and chain tensions, everything is really nice and tight, on every axis.

Thanks in advance

David

1 answer2 replies

Comments (3)

Chris Annin

Mar 23, 2020

from the pic it looks like movement is coming from J1, 3 & 5. After some break in I would try increasing belt and chain tension. I cant tell how much force is being exerted or if the movement is gear backlash or belt stretch but keep in mind max lift is around 4lbs.

David Šinko

Mar 23, 2020

Replying to

Thanks for the reply. The belts and chain are quite tense. There is also a lot of play at J2. By "constant weight" I meant that the arm is never perpendicular to the table - the gravity pulls it constantly downwards. I want to move some PCBs with the robot, so I'm far from 4 lbs. I'm 99.9% sure the play is coming from the gearboxes. Is there no other stepper alternative?

Trond Bentzen

Mar 25, 2020

Replying to

@David Šinko Maybe you will have better luck with gearboxes from Nanotec

ANNIN ROBOTICS

Play in the gearboxes of all step motors