Equatorial platform: any experiences?

  • #1
sophiecentaur
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I was trawling the net and came across an equatorial platform that you can put a Dobsonian on. It claims to give you about an hour of tracking and then you have to start again.
The geometry of it looks clever as you never need to be actually tilting the Dobs base by more than a few degrees.
The firm seems to have stopped trading so they clearly weren't selling enough of the platforms (which were fairly expensive). Have any PFstronomers ever used one or owned one?
 

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  • #2
davenn
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I was trawling the net and came across an equatorial platform that you can put a Dobsonian on. It claims to give you about an hour of tracking and then you have to start again.
The geometry of it looks clever as you never need to be actually tilting the Dobs base by more than a few degrees.
Yes, it's being tilted to an angle that is the same as your latitude and you are doing a rough polar alignment
you dobbo isn't really a dobbo any more, now its a scope on a fork mounted equatorial mount

I could do a similar thing with my fork mounted Al/Az mount scope. There are wedge units available to make it an equatorial mount
here's a www pic of the scope I have on its standard mount ......

ImageGen.ashx?image=%2Fmedia%2F647864%2F11074_CPC_925_GPS_1.jpg



and here's the wedge for it that goes between the base of the mount and the top of the tripod ....

C93664-2T.gif


to give the final result of ......

CELESTRON_CPC_925_HD_WEDGE.png




you could always build your own wedge, not horrifically difficult if your are mechanically minded and have a reasonable workshop or access to one


Dave
 
  • #3
sophiecentaur
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The equatorial platform I refer to is not like that at all . I did consider doing the 'obvious' myself and concluded that the Dob's base would fall over unless it was bolted down and the azimuth bearing would be subjected to an asymmetrical load.
This mount is Actively Driven and follows a star position for about an hour. It tilts by only about 5 degrees. If you look at the link you will see it holding massive Dobs models. It doesn't need to tilt much because it only provides 'correction' and the Dobs bearing operates as it was designed.
[Actually, I gave the wrong link. There seem to be two companies; the US one seems to be functioning still but the UK one has stopped selling them. - too cheap to be making a profit, probably]
 
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  • #4
davenn
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This mount is Actively Driven and follows a star position for about an hour. It tilts by only about 5 degrees. If you look at the link you will see it holding massive Dobs models. It doesn't need to tilt much because it only provides 'correction' and the Dobs bearing operates as it was designed.
yeah OK, after looking at this page ...
http://www.equatorialplatforms.com/about.our.platforms.shtml

I see what they are doing ... interesting idea


Dave
 
  • #5
sophiecentaur
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It looks an expensive system and hardly worth it for a 'little' 8" Dobs. An ordinary heavy duty EQ mount would only cost a few hundred quid with Go-to thrown in.
The U.K. Site for those platforms gives a simple description of the principle. The back and front of the platform move in different diameter (counter rotating?) circles to keep the scope locked on target.
Some nifty sums there, I think.
 

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