Author Topic: CGEM DX Optical Encoder-broken  (Read 876 times)

Fred Lafever

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CGEM DX Optical Encoder-broken
« on: December 27, 2017, 11:57:02 AM »
I now have a trashed DEC motor...the optical encoder broke.  Are the encoders available anywhere? Replaceable? Cost effective? or should I just change out the motor all together?
Thanks for your feedback...



nepaletha

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Re: CGEM DX Optical Encoder-broken
« Reply #1 on: December 30, 2017, 10:04:48 PM »
Looks like it's a Motor/Encoder Assembly.

Mike

Seth Mamidi

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Re: CGEM DX Optical Encoder-broken
« Reply #2 on: December 31, 2017, 12:55:41 AM »
When my DEC encoder took a dive on my CGE, I went searching through the CGE Y! forum and found a place that sold the encoder circuit and optical wheel. It cost me $56 instead of the nearly $400 to replace the whole motor/encoder. Are you getting No Response 16/17 errors on the handset? Does the motor move with button pushes or is the motor dead as well? You can go into the DEC/RA position settings on the handset and slew the scope around on the axis in question, if you aren't getting any counts, then it's possible it's the encoder. The electronics for it are underneath the black cap on the back side of the motor-encoder assembly. There is nothing serviceable that I could find on the encoder, I just replaced the everything with an E4T driver PCB, a 256CPR wheel (4mm bore), and a spacer kit from USDigital. There is a chance that the CGEM DX uses the same encoder, but verify first. I'm cheap, but very resourceful and good at taking things apart and fixing them. Your skills may be different and if you do have to replace the entire motor/encoder, it's a lot cheaper than for the CGE. You should make sure the motor control board isn't the culprit before doing anything else, otherwise you may be needlessly spending money on the wrong repair.

malralilin

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Re: CGEM DX Optical Encoder-broken
« Reply #3 on: January 04, 2018, 03:37:18 AM »
The encoder wheel is split in half..Im replacing the entire assembly but I like to tinker too so am looking to repair and replace as well. I'll have to check the DX ygroup as to where I can obtain the items.  Where did you get the parts for the CGE?

behelphyri

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Re: CGEM DX Optical Encoder-broken
« Reply #4 on: January 08, 2018, 05:10:39 AM »
Quote
The encoder wheel is split in half..Im replacing the entire assembly but I like to tinker too so am looking to repair and replace as well. I'll have to check the DX ygroup as to where I can obtain the items.  Where did you get the parts for the CGE?

I got the parts from USDigital.

Below is a pic of the parts list. It was an easy install and worked perfectly. Good luck!Attached Thumbnails


xenjavabve

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Re: CGEM DX Optical Encoder-broken
« Reply #5 on: January 08, 2018, 06:57:04 PM »
This is great, thanks. I off to US Digital to check it out...clear skies!!

Eric Hayes

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Re: CGEM DX Optical Encoder-broken
« Reply #6 on: January 10, 2018, 09:36:51 PM »
I have a problem with my decoders for the CGEM DX, at times when slewing they just do not resond to the HC input and run away, i do not want to buy the whole motor assy. just the encoder . I can get pulse movements on the HC, but if i press down longer there is no response-I have tried 3 diff. HC's SS, GEM And AVX HC all with more or less the same result.
 Can anyone help me out on this , as there seems to be a common problem with runaway motors/encoders. Thank You, Ernest

Jomega Ceo

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Re: CGEM DX Optical Encoder-broken
« Reply #7 on: January 11, 2018, 09:10:31 AM »
The runaway slew on my CGE was on one axis and it was accompanied by a No Response 17/16 error. Checking the handset showed no ticks being registered in DEC. Swapping the motors resulted in the issue, but on the RA axis. This led me to deduce that the problem was generated from within the motor encoder instead of a control board. Make sure that the encoder is bad and not something else before attempting repairs.

Calvin Dolla

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Re: CGEM DX Optical Encoder-broken
« Reply #8 on: January 12, 2018, 01:10:50 AM »
@ Mariner 2  was the part for a CGEM DX ? or for the more expensive CGE Pro ? I have the cgem dx ----I checked the RA/DEC settings and when i slewed they also changed, i can get a (pulse + movement) from the HC but if i press too long it seems to stick and keeps going, sometimes stopping soon and sometimes later , i dont want to order anything unnessesary, but i need to get the mount operable, bought it used....i guess thats what you get buying used things-----

neaubigvapec

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Re: CGEM DX Optical Encoder-broken
« Reply #9 on: January 16, 2018, 11:25:21 PM »
Merged this topic with another very similar one.

David Reynolds

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Re: CGEM DX Optical Encoder-broken
« Reply #10 on: January 18, 2018, 02:21:50 AM »
Hi, All. Anyone know if the the E4T driver PCB, a 256CPR wheel (4mm bore), and a spacer kit from USDigital. fit CGEM DX motors.

Thanlks

mellidonde

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Re: CGEM DX Optical Encoder-broken
« Reply #11 on: January 22, 2018, 10:18:55 PM »
Based on what Ive learned the 4mm bore is too big as the shaft measures out at 2.3mm That said US Dig is not making the 2.3mm(091) any more. Im seeing some are making adapter to compensate for the difference but I lack the ability, so unless I get lucky I'll buy the complete motor from Deep Sky Products (159$)

Ryan Hernandez

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Re: CGEM DX Optical Encoder-broken
« Reply #12 on: January 25, 2018, 03:48:13 PM »
Thanks for the reply ccard, That`s what i thought too, so on the 25th i ordered the 4ET 256 098 s d d2 with the wire kit from us digital it came Friday. The wiring was tricky from J 1 on the celestron board was placed wrong as to the 4ET J 1 was placed in the right place, celestron sure makes it hard to do this, as i am an tech i manged to figure it out as not to blow the encoder so i followed the leads on the celestron chip and code on the wires to find how it should be installed opposite that of the celestron chip. Well it worked Pleased to say the right 4ET encoder chip will work for celestron mounts. That said the reason these encoders blow a lot in celestron mounts is mainly do to unbalanced mount/the disc spinning over the encoder in all to much vibration, and the encoder lets go on 1 or more of it`s legs and that`s lights out. In ten years i have had 4 encoders go on me, in spite all my efforts to keep those factors to a minimum. I am sick of dishing out $270 CAD. to get a motor to Canada. So i went this route and it works, also you stated the shaft is 2.3 mm and the 098 is 2.5mm and the 2.3mm is no longer available, WHY IS THIS? i think some of us know why! I used lock tight and very carefully gaped and centered the disc, i have the Cgem DX and the GT Adv Cg5 goto and it happens to both of them, always the encoder, i have 3 motors where the encoder went bad and now i can fix them all at a fraction of the price. I think celestron is way over rated, over priced junk toy encoders, where as the 4ET encoder is coated in a clear epoxy or something like that, this add more strength to the chip, i suspect they will last longer, only time will tell, and oh yeh i will never buy there product again, I`m going to sell off my mounts and go EQ8

Aaron Romano

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Re: CGEM DX Optical Encoder-broken
« Reply #13 on: January 31, 2018, 09:18:23 AM »
Funny how I am just now finding out my bore size on the encoder I received in Sept is too big and wondering what to. Also RLF55, can you be more specific on the wiring, that had me worried also if it was just a matched cut and splice.

cicacating

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Re: CGEM DX Optical Encoder-broken
« Reply #14 on: February 04, 2018, 11:49:38 AM »
@Sparkyht
It probably is the wiring from the RA sensor-I had the same problem and the yellow insulation was intact but the wire inside was defective f- ixed that and everything was fine. Ernest