Jump to content

1565608528_ReflectionNebulositybanner.jpg.5b3647faf258fca0cd9c62694d6e7b71.jpg

Harmonic Drive mounts such as the RST-135e - question on total payloads for AP


Jonny_H
 Share

Recommended Posts

Hi all,

A quick question re: harmonic drive mounts such as the Rainbow RST-135e, 300 etc.... do the typical payload rules apply to these as they do for traditional worm drive mounts for astrophotogrpahy?

E.g. there is a general rule for the latter to take the manufacturers total payload for AP and then take 60-75 (ish) % of that figure to get the true viable magic number. Is this also true for harmonic drive mounts? Taking the 13.5kg payload (without counterweights) for the RST-135e for example, does this infact mean it can realistically support just 8.5kg (ish) for AP use (without counterweights)?

I am curious is all :)

Thanks,

Jon

 

Edited by Jonny_H
  • Like 1
Link to comment
Share on other sites

  • Jonny_H changed the title to Harmonic Drive mounts such as the RST-135e - question on total payloads for AP
  • 2 weeks later...

The answer seems to be yes. I had about 6-7kg of an imaging train on it (with a fairly long scope, mind you) and it did not have any issues. I was getting about 0.7" RMS guided on my RST-135.

Most people with a 7kg-class imaging scope (FSQ-106 for example) seems to use a counterweight though, not because the mount can't handle it but because they worry the tripod might fall over. So with a 8.5kg payload you might want to have the counterweight.

  • Thanks 1
Link to comment
Share on other sites

  • 8 months later...

Hi Jon,

I have been testing my new RST-135E with various scopes that I have. In summary: with a fully loaded Takahashi FSQ-85EDP, at 11kG total weight, I use the mount without counterweight ad the mount operates flawlessly with a total guiding error in the range 0.2" to 0.4". With a heavier fully loaded Takahashi FSQ-106EDX4 scope, at 16kg, I use the small RST counterweight and I get similarly small guiding errors. Under windy conditions, the guiding errors change little going up to 0.3"-0.4" only, as the mount motors have a very large torque and handle the lod firmly.

This is a fabulous mount.

Best regards,

Jose

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.