Chinese Harmonic 4th axis

[Chaz]

When can we expect your review?

Me? Nothing yet, need to finish Thor first.

[Rey8801]

Me? Nothing yet, need to finish Thor first.

Hi! Did you ended up using hte 4th axis harmonic drive? I just got one and wired up. It looks ok but i notice the chuck has this huge play. Do you also have it? I thought it should be gapless with not backlash. I am confused. :-)

Here the video showing it.
https://www.youtube.com/watch?v=uSB-UlZzBjQ

Thanks for the help!

[Chaz]

Hi! Did you ended up using hte 4th axis harmonic drive? I just got one and wired up. It looks ok but i notice the chuck has this huge play. Do you also have it? I thought it should be gapless with not backlash. I am confused. :-)

Here the video showing it.
https://www.youtube.com/watch?v=uSB-UlZzBjQ

Thanks for the help!

Hi, nope - didnt look at it.

[Rey8801]

Ah ok. Well if you will have justa minute maybe try to replicate what I have shown in the video. In my drive the front can move without turning the stepper motor. I thought harmonic should be backlash free or gapless as the seller mentioned in the product title. Thanks! :-)

[johnsattuk]

Harmonic drives have very low backlash, that looks like something loose inside where it is attached to the gear, bad key-way, loose bolts ??

[Rey8801]

Harmonic drives have very low backlash, that looks like something loose inside where it is attached to the gear, bad key-way, loose bolts ??

Not sure how it is connected inside but it is strange to me too. I might try to open it up in front. The runout is not measurable so will be really a pity if that can no be solved.

[Rey8801]

Harmonic drives have very low backlash, that looks like something loose inside where it is attached to the gear, bad key-way, loose bolts ??

Report here as well.
I made a video yesterday during the disassemble, just a random talk late at night, but it's useful to actually show how it is made. The backlash it's really from what I would call harmonic drive, but I am not an expert. What surprise me is that there are other users from this forum with the same drive and they claim almost ZERO backlash, so can be that I got a faulty one with maybe components out of tollerance. It seems the mesh inside the gearbox has a play before lock in place.

https://youtu.be/qgmcX7lL5zw