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Probably lost some part of counterweight - iOptron - Any ideas?

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#1 tsk1979

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Posted 06 July 2020 - 02:34 AM

I have the GEM45, and the counterweight no longer tightens on to the shaft. 

I see just 2 parts, and the screw seems too short to hit the ring inside. So I think something which comes between the screw and ring has fallen out? 

 

Any ideas?

 

Pictures attached

1.JPG

 

2.JPG

 



#2 junomike

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Posted 06 July 2020 - 03:04 AM

Looks like there's a "pin" missing.  I'd try to find something similar to replace it


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#3 OldManSky

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Posted 06 July 2020 - 07:51 AM

Mike's right -- the iOptron CWs have a two-step tapered pin that goes into the CW ahead of the locking bolt.  That's what presses against the CW shaft.  It won't fall out into the center hole, it will only fall out if you unscrew the locking bolt all the way.  See if you can find yours, or ask iOptron for a replacement...

 

 

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  • ioptron_cwpin.jpg

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#4 tsk1979

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Posted 06 July 2020 - 11:57 AM

Thanks fellas. I tried using a similar sized narrow screw bit, and after inserting that the outer turning screw does not fully go in. I guess I will try to find something shorter. Looks like time to hit an auto parts store or something



#5 tsk1979

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Posted 06 July 2020 - 12:03 PM

Mike's right -- the iOptron CWs have a two-step tapered pin that goes into the CW ahead of the locking bolt.  That's what presses against the CW shaft.  It won't fall out into the center hole, it will only fall out if you unscrew the locking bolt all the way.  See if you can find yours, or ask iOptron for a replacement...

Can you measure narrow and wide diameter for the same

 

https://www.amazon.c...1&rps=1&sr=8-32 and am just worried about them being too thick



#6 OldManSky

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Posted 06 July 2020 - 12:19 PM

Can you measure narrow and wide diameter for the same

 

https://www.amazon.c...1&rps=1&sr=8-32 and am just worried about them being too thick

I don't have my calipers, but to the best I can measure:

narrow:  5mm

Wide: 7mm

 

Note: that's from a counterweight for a CEM25P.  Your mileage may vary...


Edited by OldManSky, 06 July 2020 - 12:19 PM.


#7 tsk1979

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Posted 06 July 2020 - 02:08 PM

I don't have my calipers, but to the best I can measure:

narrow:  5mm

Wide: 7mm

 

Note: that's from a counterweight for a CEM25P.  Your mileage may vary...

Thanks! Just wondering if the shaft is 1.01 inches same as GEM45 and the CEM40Ps or narrower?



#8 kfiscus

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Posted 06 July 2020 - 02:30 PM

You can use a piece of wooden dowel to get back up and running.


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#9 Michael Covington

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Posted 06 July 2020 - 02:32 PM

The GEM45 shaft is 28 mm, which is more than 1.01 inches.  Maybe slightly more than 1.1.



#10 Michael Covington

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Posted 06 July 2020 - 06:20 PM

OK, here are the dimensions of the brass peg in the 5-kg counterweight that came with my GEM45:

 

Length 34 mm

First 8mm of it are 8mm in diameter

Rest is 6mm in diameter

 

There is also a spring somewhere in the hole that makes the brass peg retract when the knob is loosened.  However, other iOptron counterweights, including the 2.5-kg one that I bought for the same mount, lack the spring.  I may try to add it.  Off to the workshop now :)

For a substitute, you might try a 6mm bolt, 35mm long, whose head is less than 8mm in diameter or can be filed down.


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#11 kfiscus

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Posted 06 July 2020 - 06:42 PM

A spring explains why that brass pin has a shoulder.  Makes sense.


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#12 lphilpot

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Posted 07 July 2020 - 09:39 PM

Brass (or steel, in a pinch) rod stock can usually be found at hardware stores and home centers. A minute with a hacksaw and a file will make a perfect workable replacement. Plus, since it's rarely found in lengths shorter than about 36" (sometimes 24"), there's lots of opportunity to redo if the finished length isn't quite right!



#13 ThatsMyCoffee

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Posted 08 July 2020 - 12:53 AM

Just make sure that material is SOFT or you'll be damaging your counterweight shaft.


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#14 csrlice12

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Posted 08 July 2020 - 01:00 AM

Duct tape and extension cords....




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