Harmonic Drive Technology mounts

[Hans Tucker (Hans)]

Anyone remember the Chronos Mounts available back around 2010?

Remember how expensive these mounts were?

The Chronos HD32HPO Mount retailed around $33,000 USD.

These Harmonic Drive Technology mounts claimed to have zero backlash and high torque.

Here is an offering from Crux:

https://www.hobym.net/crux170hd

Chinese clone??

[Wavytone]

The text on that page is Korean, not Chinese.

There’s another range of mounts with harmonic drives made in Korea as well - by Rainbow Astro, costing roughly AU$11k if you factor in GST.

This one looks like it uses the same harmonic drive components as the Rainbow unit - the specs are very similar.

I’ve seen harmonic drives used on machinery and indeed they do have zero backlash, extremely high torque and stiffness. If money was no object sure I’d buy one.

There was a video taken at the 2017 eclipse using one of the Rainbow mounts where the camera traces a neat circle around the suns perimeter mid-eclipse... very smooth, no backlash. https://vimeo.com/231484786

[AndrewJ]

Gday Hans
They dont mention anything re encoders and "appear" to quote the PE as around +/-2 arcsecs. Also max speed is only about 6deg/sec.
As such, i suspect they merely count microsteps to control position, vs the Chronos that uses precision encoders and massively more powerful/faster motors.
( If only counting microsteps, they cant account for errors in the gearing )

Ya get what you pay for, but they do look an interesting mid point.
Andrew