Gearless mount

kochu · Post by **kochu** » Wed May 16, 2007 1:46 pm

This mount has no gears . Stepper motors are directly connected to shaft spindles.

The French thread is here with some really nice pics:
http://www.astrosurf.com/ubb/Forum3/HTML/014525.html
And a simply amazing video, showing the mount pointing at its max
speed with a Celestron C11:
http://www.astrosurf.com/sguisard/Video ... er_sec.avi

Kochu/16-5-07

jermng · Post by **jermng** » Wed May 16, 2007 2:27 pm

'Crayford' Mount?

aquillae · Post by **aquillae** » Wed May 16, 2007 2:35 pm

whoah.....max speed...max acceleration...
/drool

Post by **rcj** » Wed May 16, 2007 3:01 pm

super cool! looks like pro observatory technology. Astelco makes professional truss scopes as well!

Post by **acc** » Wed May 16, 2007 8:31 pm

I can foresee after a long tiring night, a couple of Naglers or Pentaxes going into low-earth orbit...

Its kinda dangerous to stand near this beast??

Post by **weixing** » Wed May 16, 2007 8:58 pm

Hi,

Stepper motors are directly connected to shaft spindles.

Sound and look like a DC motors to me... stepper motor will stall if load is too heavy or moving too fast, so I think it is a DC motors.

Its kinda dangerous to stand near this beast??

Totally agree!! A electronics/electrical fault or a software bug may cause the scope to... watch out for that counter-weight "flying" towards someone near it!! Touch wood...

Have a nice day.

Post by **acc** » Wed May 16, 2007 9:00 pm

It can also give you a black-eye if you happen to accidentally punch the GOTO button while peering into the eyepiece!!

river · Post by **river** » Thu May 17, 2007 10:15 am

Good design. I think it can track smoothly than any other mount with gear.

Safe or not is depend on how you use it, a simple plastic bag can kill if one dont know how to use it.

kochu · Post by **kochu** » Thu May 17, 2007 10:35 am

The video may be showing the speed at max setting of 100 degrees /sec.

The motors of this reference mount NTM 502 are stepper motors as per spec
---------------

- direct drive steppers resulting in absolutely NO periodic error
(because there is no gears at all)
- pointing at 100°/sec with 5" accuracy, thanks to direct drive system
- can use many stars (30 for example) to make an accurate "flexure
model" of the scope pointing position in the sky
- really accurate and fast polar alignment process, made possible
thanks to the previous multi stars model: you have to recenter a star
with ALT/AZ bolts and mount is polar aligned!
- it can carry up to 50kg, and 70kg for the new NTM502.
-----------------------------------

Kochu/17-5-07

Post by **weixing** » Thu May 17, 2007 7:52 pm

Hi,

Safe or not is depend on how you use it, a simple plastic bag can kill if one dont know how to use it.

Yap... Agree, but you won't get injure by standing too close to a plastic bag... hee hee

- direct drive steppers resulting in absolutely NO periodic error
(because there is no gears at all)

IMHO, you can also get no periodic error with gears on a computerize mount... the key is to mount your encoders on the final axis of the mount and not on the motor axis.

Anyway, just wonder at max slew speed, how long will the scope hold it's collimation??

Have a nice day.