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Celestron Electronic Focus Motor For SCT and EdgeHD

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#151 golfgti

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Posted 18 February 2019 - 10:13 AM

Yes I agree. The 2 screws that mount the focus motor does not carry the weight of the focuser. They just hold the focuser in place so that it doesn't rotate when focusing. Are you convinced the the 1/2'' diameter of the brass sleeve can be inserted into the clamp?



#152 HenrikH

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Posted 18 February 2019 - 01:57 PM

Mike do you specifically where the "Updating Celestron Firmware with macOS is located it's not showing up in any of the searches and everything else is for windows which I've no luck at all with .. Thanks Carl

Here you go:

https://www.cloudyni...are-with-macos/



#153 lwool

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Posted 18 February 2019 - 03:16 PM

Yes I agree. The 2 screws that mount the focus motor does not carry the weight of the focuser. They just hold the focuser in place so that it doesn't rotate when focusing. Are you convinced the the 1/2'' diameter of the brass sleeve can be inserted into the clamp?

I am sure about the diameter of my focus shaft but I don't know what size split bushing's come with the focuser, it looks like there is a large one in the focuser and a smaller converter bushing that fits in it for smaller focus shafts.  I went ahead and ordered the focuser thinking I could make an adapter or something if it doesn't fit.  



#154 vlxjim

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Posted 18 February 2019 - 07:18 PM

The shaft diameter on my 8 Edge (2018) .504". The split bushing was about .514". I took aluminum foil and wrapped it one time around to shim the shaft. If not by the time the collar was compressed enough to grip the shaft it would be off-center. Shimming took care of most of the problem.


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#155 BrushyCanyon

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Posted 19 February 2019 - 12:03 AM

I also have a Celestron 80's vintage 8" SCT OTA, now deforked and riding on a CGEM II.  Please sign me up for any updates on plates, bushings, etc that would make it possible to fit up this focuser.

 

I have some good mechanical and machining skills, and are happy to DYI some basic adaptors.

 

Thanks

 

bc


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#156 golfgti

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Posted 19 February 2019 - 04:04 AM

The shaft diameter on my 8 Edge (2018) .504". The split bushing was about .514". I took aluminum foil and wrapped it one time around to shim the shaft. If not by the time the collar was compressed enough to grip the shaft it would be off-center. Shimming took care of most of the problem.

Many thanks. This is a great help. It makes me wonder why Celestron havn't designed an adapter to fit the older scopes, seeing that the shaft size fits.


Edited by golfgti, 19 February 2019 - 04:06 AM.


#157 vlxjim

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Posted 19 February 2019 - 11:41 PM

It looks to me as tho most older scopes can be adapted to work. It maybe that Celestron did not have older scopes to try a test fit on.

CH75-64-16031-DC.jpg



#158 mclewis1

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Posted 20 February 2019 - 09:19 AM

bigshock.gif Eeeeeewwwwww.  lol.gif

 

I'm sure Celestron could find some older examples but I'll bet it's more a case of cost (more variables in mounting, different couplers, testing, ongoing support, and general push to newer products) vs the simpler setup just for the newer scopes that drove the product decisions. 


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#159 vlxjim

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Posted 20 February 2019 - 01:30 PM

Not my scope, found it on the net. But looking at this photo it would not surprise me if it mounted up with little to know modification. I think the shaft is the right size and the only question would be the the hole pattern. Adding a new hole pattern to one of the mounting rings if needed would be no big deal.



#160 Michael_Swanson

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Posted 20 February 2019 - 08:10 PM

bigshock.gif Eeeeeewwwwww.  lol.gif

 

I'm sure Celestron could find some older examples but I'll bet it's more a case of cost (more variables in mounting, different couplers, testing, ongoing support, and general push to newer products) vs the simpler setup just for the newer scopes that drove the product decisions. 

Yep, there have been so many slight variations through the years and I expect no one at Celestron has every design drawing for the dozens of variations that they most likely just decided to draw a line.  The internal conversation probably went something like - "we know if works with these, everything else is suspect so rather than upset customers with older gear, let's say it is only compatible with the new stuff."  Consider the fact that they didn't determine their first design wasn't compatible with the current 9.25" with focal reducer until an owner pointed it out...

 

So, it will be up to owners of older gear to discover whether it is compatible or not.



#161 saguaro

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Posted 21 February 2019 - 11:21 AM

The shaft diameter on my 8 Edge (2018) .504". The split bushing was about .514". I took aluminum foil and wrapped it one time around to shim the shaft. If not by the time the collar was compressed enough to grip the shaft it would be off-center. Shimming took care of most of the problem.

If I understand you correctly, you are saying that the split bushing on the Celestron Focus Motor is .514-inch inside diameter, right?

 

The outside diameter of the brass focus shaft on my early 1980's C8 is exactly .5-inch. So it would seem that the Focus Motor would fit, with a bit of shimming as you suggested, assuming that there are no clearance issues between the Focus Motor housing and the visual back. There's also the question of whether a custom cover plate would be needed.

 

C8 focus knob half inch OD.jpg

 

Just found these on Celestron's site:

Focus Motor dimensions: https://celestron-si...ions 012219.PDF

Focus Motor Installation: https://celestron-si...ng_BookletF.pdf


Edited by saguaro, 21 February 2019 - 11:39 AM.


#162 vlxjim

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Posted 21 February 2019 - 02:49 PM

If I understand you correctly, you are saying that the split bushing on the Celestron Focus Motor is .514-inch inside diameter, right?

 

The outside diameter of the brass focus shaft on my early 1980's C8 is exactly .5-inch. So it would seem that the Focus Motor would fit, with a bit of shimming as you suggested, assuming that there are no clearance issues between the Focus Motor housing and the visual back. There's also the question of whether a custom cover plate would be needed.

 

attachicon.gif C8 focus knob half inch OD.jpg

 

Just found these on Celestron's site:

Focus Motor dimensions: https://celestron-si...ions 012219.PDF

Focus Motor Installation: https://celestron-si...ng_BookletF.pdf

I would thing that it should fit, possibly a modification to the hole pattern on one of the two included mounting rings. I don't see any clearance problems as this focuser also fits the C6. The mounting ring would need to be installed on top of the bearing housing. This would shorten the length of the brass focuser knob by about an .125. This would not pose a problem as there Is plenty of hight to clamp to.


Edited by vlxjim, 21 February 2019 - 02:53 PM.

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#163 Brian Risley

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Posted 22 February 2019 - 10:44 AM

There are probably issues with the size of the focuser assembly is and how big a flat area there is.  On older C-8's I have seen the original large focuser (have one), the smaller focuser that has the smaller diameter covering plate/tube that sticks up about  1/2" and the styles that lay flat on the back but have either the larger or smaller hole pattern.  There may not be enough room from where the tube comes through the thread (there were multiple big ridges on some of the older ones, see post 161) to the focus assembly for it to fit.

They may be looking into these issues with the new model, as they realized that the space between the focus knob and the back port had some issues.

The post 2006 models all seem to have a larger flat area on the back from the threads to the focus knob and the area around the focus knob.The  pre1976 focusers (the real dirty one above) were different than the later ones and this was a known issue with some previous focus motors.

Brian



#164 saguaro

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Posted 22 February 2019 - 10:56 AM

There are probably issues with the size of the focuser assembly is and how big a flat area there is.  On older C-8's I have seen the original large focuser (have one), the smaller focuser that has the smaller diameter covering plate/tube that sticks up about  1/2" and the styles that lay flat on the back but have either the larger or smaller hole pattern.  There may not be enough room from where the tube comes through the thread (there were multiple big ridges on some of the older ones, see post 161) to the focus assembly for it to fit.

They may be looking into these issues with the new model, as they realized that the space between the focus knob and the back port had some issues.

The post 2006 models all seem to have a larger flat area on the back from the threads to the focus knob and the area around the focus knob.The  pre1976 focusers (the real dirty one above) were different than the later ones and this was a known issue with some previous focus motors.

Brian

This is why I will wait for the re-designed focus motor before ordering one. Even if I wanted one now, they are currently on back-order everywhere I checked.



#165 geothomas

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Posted 22 February 2019 - 11:25 AM

Can this be plugged into a powered usb hub or does it have to be plugged straight into a usb slot on a computer? If not usb powered, would I have to purchase a separate DC power cable if I don't have a celestron mount?



#166 davidparks

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Posted 22 February 2019 - 11:45 AM

Yes, the focuser will be powered by a USB Hub  (or any USB connection with sufficient power).

From Celestrons product page:

 

Power Options

There are three options for powering your Celestron Focus Motor:
1.When using a Celestron computerized mount, you can power and control the focus motor through the mount using the supplied AUX cable. This allows control from the mount’s hand controller (NexStar+ or StarSense) or a computer.
2.If you are not using a Celestron mount, you can power and control the focus motor from a computer USB port. You will need a user supplied USB A-to-B cable.
3.You may also opt to use an external 12V DC power source which plugs into the motor’s power jack. 12V DC, 1A, 5.5mm/2.1mm tip positive plug

 

And just for confirmation:  I've actually done the 30ft active (powered) usb cable with a non-powered 4 port hub scope-side, and the focuser took power through the hub from the active cable.  Focuser worked great.


Edited by davidparks, 22 February 2019 - 11:48 AM.


#167 mitaccio

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Posted 22 February 2019 - 05:44 PM

I currently am using the JMI motofocuser and have the Nexstar remote (not Nexstar+). I do visual only for now. What improvement does this focuser offer over my JMI unit?  I'd have to buy the focuser plus a Nexstar+ remote, right?



#168 geothomas

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Posted 22 February 2019 - 06:30 PM

FYI,   I just ordered the Focus Motor from HighPoint Scientific and they said it will be April before the next delivery.



#169 carlm01

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Posted 22 February 2019 - 06:48 PM

I saw one up for sale on astromart for 160.00



#170 davidparks

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Posted 22 February 2019 - 10:45 PM

I currently am using the JMI motofocuser and have the Nexstar remote (not Nexstar+). I do visual only for now. What improvement does this focuser offer over my JMI unit?  I'd have to buy the focuser plus a Nexstar+ remote, right?

I believe the focuser is only compatible with the Nexstar+ and Starsense controllers (and PC/ASCOM).  I think the Celestron product page has updated and current information regarding compatibility.

 

I had the JMI Motofocus on my 6se, and I can tell you the differences I found.

  1. With the 3 speed settings, Celestron’s focuser handles large movements easily, while JMI was painfully slow even at it’s fastest rate.  Very noticeable when changing eyepieces, and especially when changing focal length with a reducer or Barlow.
  2. Celestrons focuser will take power from AUX or USB,  no batteries required.
  3. In my opinion I like having focus control on the same hand controller as mount control, less hand held items to juggle.

For me, the high speed makes the biggest difference (the low speed fine adjustments are great on both JMI and Celestron).

 

I think there are other advantages for imagers, but that’s my take for visual.  Hope it helps 



#171 De Lorme

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Posted 23 February 2019 - 07:10 PM

Has anybody tried using the Celestron Focus Motor on a Sky Watcher 7" Mak Cass? I have a AVX mount and this would be absolutely great

if it would work with my SW Mac Cass!


Edited by De Lorme, 23 February 2019 - 07:14 PM.


#172 Taylor

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Posted 23 February 2019 - 10:06 PM

My favorite aspect of the JMI unit is how easy it is to slip on and off. I also have a fine focus, large knurled knob from ScopeStuff that I like to use when observing with folks who don't want to bother with the electronic unit. 

 

I use velcro to attach the JMI unit, it works perfectly with no slippage. When I want it off, it slides right off.

 

The Celestron OEM unit looks more complicated than that. Not sure I am going to replace the JMI unit with the Celestron one.

 

 

Attached Thumbnails

  • focuser2.jpg
  • focuser1.jpg


#173 De Lorme

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Posted 23 February 2019 - 10:58 PM

To be able too slew at fast speeds, use one controller, and takes no batteries would be great.   It cost the same as the JMI but is much more user friendly.

 

Looking at the measurement on their dimensions and taking a few off my 7 Sky Watcher Mak Cass I'm sure the Celestron electric controller

back plate will match up the SW.


Edited by De Lorme, 23 February 2019 - 11:32 PM.


#174 vlxjim

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Posted 25 February 2019 - 07:09 PM

My favorite aspect of the JMI unit is how easy it is to slip on and off. I also have a fine focus, large knurled knob from ScopeStuff that I like to use when observing with folks who don't want to bother with the electronic unit. 

 

I use velcro to attach the JMI unit, it works perfectly with no slippage. When I want it off, it slides right off.

 

The Celestron OEM unit looks more complicated than that. Not sure I am going to replace the JMI unit with the Celestron one.

The Celestron one is more feature rich. It is a servomotor with an encoder. Once you preform the auto calibration it alway knows the position and reports back with and numeric value. So you can record the value for different eyepieces or camera, FR and barlow setups and return to that position as a goto. Its very good and accurate.



#175 vlxjim

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Posted 25 February 2019 - 07:14 PM

FYI,   I just ordered the Focus Motor from HighPoint Scientific and they said it will be April before the next delivery.

Yes April is the new date. And it well be the same unit that they have been shipping. This it a great focuser as long as you don't have the C9.25 with a FR. The one for the 9.25 is going to have a different part number on it.




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