Re: [ATM] Small Dob Question: Alignment features needed for accurate encoder GOTO's?

[Scott Carson <scottcarson@austin.rr.com>]

First, thanks for responding to my initial email.  Guess I should have 
anticipated your question. 

Given my limited expertise in this area, let me see if I can provide any 
intelligent parameters.
 
For the encooders and interface, I was considering using  David Ek's DIY 
interface including the recommended US Digital S1 or S2 encoders (4000 
to 10000 tic encoders recommended?) or possibly purchase a Nova MG5 
interface.   Have also considered going ahead and getting Scope II plus 
the Sidereal Tech interface which I would eventually migrate to a 
larger, motorized Dob. 

Would appreciate suggestions / recommendations regarding these systems 
or others that might be a better solution for my 8" scope.

Now, for my "stab" at the performance parameters.  Ideally I would like 
the GOTO accuracy to place any selected object within the FOV of a 24mm 
Panoptic eyepiece for an 8" f6 Dob.  And of course 100% success rate 
would be great.  But I suspect that's not realistic for the average 
"wooden" Dob mount?  So an acceptable compromise (which I hope is not 
unrealistic?) might be 95% successful positioning within 75% off-center 
of any object located within 90 degrees of the last DSC sync/calibration?

Hopefully the above parameters provide enough info so those with more 
hands-on experience can give me some realistic expectations.  Plus I'd 
appreciate any suggestions / recommedations for Dob mount "enhancements" 
(alignment features) that I should consider.

Thanks again.

Scott

 




Mel Bartels wrote:

>>(perpendicular to the azimuth axis) with careful building (approx. 1/32"
>>tolerance?) for successful encoder use?  Or should I consider adding
>>    
>>
>
>Please define successful.  What resolution encoders, how far off-center in
>the eyepiece, what percent misses are you willing to tolerate?
>
>Mel Bartels
>
>
>_______________________________________________
>ATM mailing list http://www.atmlist.net/
>
>  
>
_______________________________________________
ATM mailing list http://www.atmlist.net/