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Goto mount with manual control?

Started by skygeezer59, 06/17/2010 05:15PM
Posted 06/17/2010 05:15PM | Edited 06/17/2010 05:17PM Opening Post
As much as I enjoy waltzing the night away with my big Dob, I am getting the bug to try a goto scope. After watching a friend go through months of frustration with an ETX 125, I have one primary requirement; the mount must be usable in manual mode if no power is available. And this doesn't mean untightening the clutches, it means access to the gearing with a good old fasioned plastic knob. I am disappointed that the current generation of goto equatorials have no manual control at all. I find this truly stupid. Older goto equatorials did have facility for manual control. Isn't that the whole point in having a GEM?

After a farily intensive survey of the major dealers and a long hunt through Astromart, I think I am hooped. Mounts like the iOptron cube and all the various Meade, Celestron and Orion fork mounts are strictly power only. I really like the Borg single arm mount. It has the potential to be motorized but is too small for my application. Does anybody know of anything out there that could be used goto and manual? Maybe a bunch of ATM'ers should get together and invent it for us.
Posted 06/17/2010 06:59PM #1
Don McDonald said:

As much as I enjoy waltzing the night away with my big Dob, I am getting the bug to try a goto scope. After watching a friend go through months of frustration with an ETX 125, I have one primary requirement; the mount must be usable in manual mode if no power is available. And this doesn't mean untightening the clutches, it means access to the gearing with a good old fasioned plastic knob. I am disappointed that the current generation of goto equatorials have no manual control at all. I find this truly stupid. Older goto equatorials did have facility for manual control. Isn't that the whole point in having a GEM?

After a farily intensive survey of the major dealers and a long hunt through Astromart, I think I am hooped. Mounts like the iOptron cube and all the various Meade, Celestron and Orion fork mounts are strictly power only. I really like the Borg single arm mount. It has the potential to be motorized but is too small for my application. Does anybody know of anything out there that could be used goto and manual? Maybe a bunch of ATM'ers should get together and invent it for us.

Don: I understand where you are coming from... It would be nice. Unfortunately, the problem of clutching and declutching the drives in order to use the manual controls is not an easy one...

About all I can offer is that I own a CG-5 ASGT which I use with an 8 inch F/5 Newtonian. I don't use it as a GOTO scope, I use it as an EQ mount with nice, responsive drives and indeed I am dependent on there being power for it to work... I guess with these sorts of mounts, one could remove the drives and add slo-mo nobs if power was lost. Then you could take the drives, the controllers, the batteries and the cables and well... put them in a box...

My own dream is an EQ mount with an RA drive and slo motion controls in both axises, not just the Dec Axis.

Jon
Posted 06/17/2010 10:13PM #2
Don McDonald said:

As much as I enjoy waltzing the night away with my big Dob, I am getting the bug to try a goto scope. After watching a friend go through months of frustration with an ETX 125, I have one primary requirement; the mount must be usable in manual mode if no power is available. And this doesn't mean untightening the clutches, it means access to the gearing with a good old fasioned plastic knob. I am disappointed that the current generation of goto equatorials have no manual control at all. I find this truly stupid. Older goto equatorials did have facility for manual control. Isn't that the whole point in having a GEM?

After a farily intensive survey of the major dealers and a long hunt through Astromart, I think I am hooped. Mounts like the iOptron cube and all the various Meade, Celestron and Orion fork mounts are strictly power only. I really like the Borg single arm mount. It has the potential to be motorized but is too small for my application. Does anybody know of anything out there that could be used goto and manual? Maybe a bunch of ATM'ers should get together and invent it for us.


Having completely disassembled and re-assembled my own Goto CG5, it does not look all that difficult to add clutch mechanism to the stepper motors. The only thing that I could foresee as being an issue is if you are concerned about cosmetics. The plastic covers for the electroguts leave very little room internally, so they would have to be modified to add an accessible component between the stepper and the worm. the plastic covers should not be completely removed, IMO, as they support and protect the circuit boards and switches/connectors. As the worm shaft does not extend beyond the bearing on the opposite side of the motor, one would either have to add another spur gear mechanism to the motor side, or machine the worm shaft end (opposite the motor) so that one could attach an extension that could engage a slowmo cable.

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