dob dual axis platform.

[dwayne dias]

Hie folks,

Wanted a mount for astrophotographt, but buying one for my 8" dob is really expensive. Nearly 3000$. I recently came across a dob dual axis eq platform. What would be your suggestions on this. ???It is a motorised dual axis dob platform with hand controls and costs about 550$. Yes il b using an autoguider to keep the object i want centered. Any suggestions...?? Please feel free to share youe thoughts.

[ronin]

This all somewhat guesswork, so bits will I suspect be wrong.

Equitorial Platforms have never "caught on" here and I suspect that the reason is they do a partial job. They are I believe intended to put your dobsonian on, and they rotate and so the scope follows the object without you needing to nudge it.

However the nature of a dobsonian means one person is looking down and using it so nudging the scope tends to be no great problem and many find it an integral part of the experience of using one. So in effect a platform removes that interaction.

I am not sure how "equitorial" they actually are. From the design I cannot see them being a good/perfect equitorial tracker.

The drive will be 2 (?) motors and will not I would say take an autoguider, they will simply drive the platform horizontally and vertically. I suppose if "equitorial" there need only be one motor. I would suggest that you looked into this aspect as my thought is that an autoguider will not function with one. Put it another way: I would be somewhat surprised if one did.

It will be better for astrophotography then a "simple" dobsonian but it is not an astrophotography set up. Not sure of the overall accuracy, I also think that you can "track" for a limited period before you have to reposition and restart over again. Not really a great problem as all it means is that every so often you need to get up and play with the equipment a bit.

Hopefully someone that has one or has had one will come along with more experienced answers or input.

If you have a link to the platform you are considering it would be useful as the manufacturer may well supply greater detail.

[dwayne dias]

5 hours ago, ronin said:

This all somewhat guesswork, so bits will I suspect be wrong.

Equitorial Platforms have never "caught on" here and I suspect that the reason is they do a partial job. They are I believe intended to put your dobsonian on, and they rotate and so the scope follows the object without you needing to nudge it.

However the nature of a dobsonian means one person is looking down and using it so nudging the scope tends to be no great problem and many find it an integral part of the experience of using one. So in effect a platform removes that interaction.

I am not sure how "equitorial" they actually are. From the design I cannot see them being a good/perfect equitorial tracker.

The drive will be 2 (?) motors and will not I would say take an autoguider, they will simply drive the platform horizontally and vertically. I suppose if "equitorial" there need only be one motor. I would suggest that you looked into this aspect as my thought is that an autoguider will not function with one. Put it another way: I would be somewhat surprised if one did.

It will be better for astrophotography then a "simple" dobsonian but it is not an astrophotography set up. Not sure of the overall accuracy, I also think that you can "track" for a limited period before you have to reposition and restart over again. Not really a great problem as all it means is that every so often you need to get up and play with the equipment a bit.

Hopefully someone that has one or has had one will come along with more experienced answers or input.

If you have a link to the platform you are considering it would be useful as the manufacturer may well supply greater detail.

http://pw1.netcom.com/~tlsystem/cablet4.html

 

This is the link. And i think its pretty good for somewhat longer exposures. And it tracks just like an eq mount. Just that u need an autoguider to ease off tracking for deep space photography. It has an RA and declination moror. Somewhat like an eq mount. May be not that accurate though. But it does the job. 

[dwayne dias]

This seemed pretty good. Even if u can take like 10 min exposures. It is good enough to take multipke shots and stack them. Just that this mount wont have any database so it cant automatically track DSOs. Thats one drawback. But its better i get some experience before moving on to very faint DSOs. So till then i can make do with this mount. Atleast till i can finally afford a goto mount for my OTA. Although a colleague and me are working  and trying to develope our own database with the help of a few other friends who are good programmers and good at making circuits. 

 

[Louis D]

I built one of TL System's equatorial kit platforms 18 years ago, and I never could get it to work right.  It didn't use proper rollers or sectors back then, just furniture sliders on Formica, so it jumped and skipped and was very unstable with a dob on it.  I substituted skateboard wheels and bearings which improved things, but that still left the single point pivot as a problem.

Perhaps the new design fixes these issues.  I'm still out over $250 1998 dollars for the original kit, so I'm not willing to bite again.

[Stu]

I have an Equatorial Platform which I use for visual observing and have been surprised how accurate it is. Even with only basic levelling and pointing north it keeps the sun and moon fairly well centred at high mag. I can easily see how with better setup and a variable control on the powered axis that good perfrormance could be achieved.

This link might be of interest

http://www.equatorial-platforms-uk.co.uk/photogrpahy-with-a-platform/some-of-our-early-results