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Advice on RCX or ASF 20" from meade

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11 replies to this topic

#1 wargrafix

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Posted 13 July 2020 - 07:24 AM

Hey all, my group received a complete unit thats in a bit of rough shape. The optics are miraculously good and the mount is excellent. But is there any advice for restoration of this thing?

 

 

Guess the first beast to tackle is the collimation system

Then the electronics.

 

 

Any advice about this scope would be appreciated



#2 Supernova74

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Posted 13 July 2020 - 07:58 AM

hi there well It cannot be the Meade ACF as thay simperly don,t manufacture one.so from your very brief description it sounds like the 20”RCX possibly which came with the Meade max mount.and sorry to say it was a major flop on Meades behalf as it was simperly not pratical to manufacture and produce.and unfortunately I’ve never seen one come up for sale on the preowned market.the retail price at the time was around £35,000 a very exspense research grade telescope when thay worked thay was most probably the best optical designed telescope of its kind.the electronics are very sophisticated and there was only one qualified Meade engineer in the whole uk that could work on them.the scope itself has electronically controlled collomation system for the secondary mirror also motor focus.and due to the electronics I’ve also heard thay like to be used on a regular basis.so sorry to say depending on the nature in how much the scope needs to be reburshed you just maybe have a serious  never ending money pit on your hands to get it up and running again so my advice would be is very much doubtful you be able to puchase any spare parts due to the scopes age.or it might be possible to sort out the OTA and have to find a rather large mount which it would be suitable for however if you can be so kind a sent a picture of the scope I might have a better idea what I’m dealing with.



#3 555aaa

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Posted 13 July 2020 - 10:09 AM

There was recently another person posting on the Meade forum here about refurbushing a meade 16 RCX in their club observatory. You should message that person also as it has the moving corrector focus system. You could of course simply fix the corrector and secondary in place and add a conventional focuser.

Edited by 555aaa, 13 July 2020 - 10:12 AM.


#4 wargrafix

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Posted 13 July 2020 - 02:34 PM

The mount looks physically fine. The collimation system looks like it needs help.

#5 Hobby Astronomer

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Posted 13 July 2020 - 03:32 PM

Congratulations



#6 n2dpsky

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Posted 13 July 2020 - 06:26 PM

The mount looks physically fine. The collimation system looks like it needs help.

Collimation and focusing is all electronic and must be done through the hand controller.    



#7 carolinaskies

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Posted 13 July 2020 - 07:19 PM

There was a fellow Charlie Trump who made a replacement focus/colimation retrofit for the RCX scopes.  Don't know if those are still available(or if they directly work with the 20") or not as that was a number of years ago.  Google search "Charlie Trump RCX" and you'll find some Youtube videos he did on the board and his email is contained in the videos.  

The RCX uses carbon fiber rods attached to the floating corrector to adjust colimation and focus.  I believe they used a high torque stepper motor system which for colimation would set each individual stepper motor to a set-point then for focus the group of motors would act in unison to move the corrector toward or away from the primary mirror.  The system was ingenious, sadly this was developed at a point where Meade corporate leadership was questionable and like any major product if you lose leadership in a shakeup programs/products can suffer.  

The RCX line had a USB hub as well, well ahead of most everyone else... something that would likely have made it to the other Meade products if things had remained solid. 

I think the RCX has some great design features and with a board like Charlie Trump designed you likely would regain the control you're having issues with. 

Dr Clay Sherrod probably can also provide excellent advice as he is probably the goto guy for understanding repairing of most any Meade SCT. 

 


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#8 wargrafix

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Posted 14 July 2020 - 02:34 PM

Thank you very much! 

 

The thinking is to change out the board and go with another Arduino solution and retrofit the OTA electronics.

 

Meade if had been managed better, could have run circles around Celestron. (and I have Celestron gear).

 

The team I am apart of, I think is more than up to the challenge.

 

 

I gotta say, Meade mount was very very well engineered. After 20 years-ish locked in an observatory in the tropics, that Max mount looks fresh as a daisy



#9 Supernova74

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Posted 14 July 2020 - 06:08 PM

let us know how you get on a send some pics please of the end result it was truly one of the best sct cassagrain ever made I very nearly brought a preowned 12”RCX 400 a little while back it just put me off that only one guy in the uk could service or fix it if anything went wrong I’m a very keen observer not an electrician unfortunately



#10 wargrafix

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Posted 16 July 2020 - 05:25 AM

med_gallery_218407_302_66707.jpg


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#11 Supernova74

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Posted 16 July 2020 - 12:09 PM

quite a project you got on your hands then 



#12 wargrafix

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Posted 16 July 2020 - 12:42 PM

If we can get this sorted out....duddeeeeee




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