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CGE surgical proceedures...

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#1 CounterWeight

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Posted 15 July 2009 - 04:03 PM

OK, last night was in the catagory of nightmare with this thing... Id' got the thing aligned once and the slews weere way off, tried to re-align and variously couldn't find switches it the dec or ra... whacky I tell you! Symptoms didn't follow cable swaps... :( After several sets of cables and trial and error, and verifying input power and connexs and everything else one can do on their patio = I had to call it a night...

So today I am going into the guts on the heads and may very well make the modifications to the cable connex I've been considering, anything to avoid yet another night ruined by this mount (and it's still not a year old).

:tonofbricks:

#2 LLEEGE

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Posted 15 July 2009 - 04:11 PM

:(
I had to adjust the micro-switch on mine once to get it to find the home position. I wouldn't make any mods until the warranty is up.

#3 David Pavlich

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Posted 15 July 2009 - 06:11 PM

Here's What I ended up doing to repair the runaway Dec axis slews and the Error 17 message.

If you're having problems in Dec AND RA, I'd go to the Celestron site and download the latest firmware. It may be a hand controller problem.

David

#4 CounterWeight

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Posted 15 July 2009 - 07:43 PM

Hi David and Luke,

I did the updates as soon s they came out, and continue to wonder if (having a clear view of Polaris) I should... :) not trying to start a debate on that - but I think they've done a great job either way...

The horrible thing last night was that I finally had started taking test exposure of the Dumbell (no - not me, the M object...) and was going Wow! great! cool! and had to do a meridian flip before going for the real shots... well it didn't survive the flip, ended up pointing more towards the Eagle and thats not even close....

--------------------------------------------

Ok. I've got all the stuff out of the 'pier' and have covers of RA and DEC assys... the works is on the table and have meters, soldering equip, spare wire and cabling at the ready...

Am inpressed at how modular and easy this all is to fool with :)

#5 LLEEGE

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Posted 15 July 2009 - 09:09 PM

If the mount homes out when initializing, the micro switches are OK. As for GOTO's being off after a meridian flip, that could just be poor polar alignment. I use to do a 2 star align followed by a 4 star calibration. Then the PA routine followed by another 2/4 star. I was able to get 5-6 min unguided at 700mm FL and the GT's were spot on.

#6 CounterWeight

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Posted 16 July 2009 - 03:49 AM

Thanks Luke,
Well that's what I do also, I think it works amazingly well, "when it works" but this thing has just gone sort of what an old tech friend of mine would call 'catywompus'... As I said, last night before the meltdown it had M27 'center chip'.

I have the RA assy working reliably now after several hours of playing with the switches and thought the dec was working too... the find switches routine was working just fine... went 3 or 4 times on he test bech no problem... until I tried to do an actual 2*4 alignment about 2 hours ago... started ok, then again the dec started 'swirling'... then seems ok, then looking for stars below my patio :( I suppose the inital estimates on the align stars weren't up to par either, but it seemed to take the slew/correction well enough.

Interestingly, all the switches check out though both a Fluke and analog VOM's... when it's (now the dec only) doing the 'whirl-o-matic' bit I had it removed from the cam assy and was manually actuating it and 'nada'... Certainly the cabling is suspect, but I've 4 or 5 sets and problems seem to change a little, but they arent fixing it this time.

I've let it suck the life and fun out of this hobby enough for one day, oops, make that 2 days (and nights....) will try again tomorrow. I've had problems with mount a-plenty and from what I hear about C's after sales suppor I am not chomping at the bit to send it to them and after 2 months hear again that I dont know how to plug cables in.

#7 LLEEGE

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Posted 16 July 2009 - 06:51 AM

If you have to send it back for the same problem multiple times, I believe they are obligated to replace it under the lemon law.??

#8 CounterWeight

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Posted 16 July 2009 - 05:45 PM

That may be true. But I'll be mountless for ages... in the intervals... we'll see what comes of my tune=up and checking stuff.


Well there is some progress... the main input 12vdc to both male and female portions were 'less than good', I know I'd slight jacked the pin once or twice but the plug always seemed to fit. Ohm/voltage checking reveals problems on both sides!?!?! Well one of many things done today was to replace the power conx from both sides w/ some HD teflon 4-pin jobbys...

Too much to type... and gotta run... but I think the input power may be why symptoms seemed to move around?

Lots more testing to go through... Oh and one last thig, don't know if this is normal but the MC interconnect / interface board was just loose in the pier, it has standoffs, I see screw holes on the upper and lower tube plates, assuming it must go on one as both have holes at correct spacing...


see ya...

#9 CounterWeight

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Posted 16 July 2009 - 10:00 PM

Ok, I've also run a 2nd 'pin 9' to both RJ housing and the common foil on the boards... appeard on the interconnect boards this is used for both motors and the 'cam' switches ground?... have had 10+ successfuly find switch routines in a row. I've been looking at the switch actuation both resistively and voltaically to see if there's something borderline and they appear fine.

But still it seems that the interconnect cable seating is a problem...I'd like to remove the jack from the board and stress the spring wires more 'out' to try and better contact...

Looks like another great night here... we'll see if I got it?

#10 CounterWeight

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Posted 17 July 2009 - 01:05 AM

Hmmm... clouds rolled in... possibly a good sign?

#11 David Pavlich

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Posted 17 July 2009 - 09:51 PM

Hmmm... clouds rolled in... possibly a good sign?


:funny:

David

#12 CounterWeight

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Posted 18 July 2009 - 06:30 AM

The patient survived... though with the mods it currently looks like 'frankenmount' but hey I'm glad I've survived this too :)

Knew right away when slew after slew on the initial 2*4 align was getting them into the reticle ep field of view... whew! I thought... then the polar aling on Nunki... then the realign 2by 4 and a quick slew to M57 and "yeah Baby!" it's dead center - turned off the illum in the reticle ep and it was actually behind the double crosshairs... Wahooo! Miller Time..

Then i thought... well let's shut it down and wait half an hour and do it all over... just to be sure. And again (only a bit better having PA'd previously) they all showed up just fine :) re-pa'd re 2 by 4'd and spent some time looking at Jup (it slewed dead center) before slapping the imager on the thing and 'snapping away' on the ring and the dumbell.

This is the CGE that wowd me when I got it! I am happy... sorta...

I should predicate all this acivity with the fact that although the CSC and our local weather say 'clear' there is a patchy high overcast that made some things a bit more difficult than easy... but bottom line "It's Back"... :refractor: :woohoo: :fingerscrossed:

#13 DaveJ

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Posted 18 July 2009 - 07:35 AM

Great news, CounterWeight! I'm thrilled to hear your success story. I've got a box of parts here to make similar mods to mine but haven't found the courage to do so. Your success is an inspiration. Great job!

#14 David Pavlich

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Posted 18 July 2009 - 12:57 PM

Happiness is a purring CGE. :grin: Congratulations.

David

#15 CounterWeight

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Posted 18 July 2009 - 02:48 PM

well... as it took the big dump while trying for M27... here's 'the puddin'... [EDIT a crop of the center] I continue to be amazed by this scope - and mount when working! This was taken through the overcast and towards dawn - included some shots I normally wouldn't in the stack to get enough, so here's about 9 240 sec exposeures tracked with the guider/SSAG, I may try again tonite if I don't go for the Veil...

I'll be posting some pics of the mods - I need to see what I took picks of in the melee.

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#16 CounterWeight

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Posted 18 July 2009 - 02:55 PM

And what the full frame looked like. This was a 'blind center' meaning I did nothing to orient the target on the chip.

As far as the GOTO and slew issues, I'm feeling the mount is 'back to normal' and I am pretty darn happy and seems the slews and tracking are indeed back to what I expect from this mount.

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#17 CounterWeight

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Posted 18 July 2009 - 02:58 PM

Dave,
I'd be glad to answer any questions...

#18 CounterWeight

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Posted 18 July 2009 - 08:55 PM

Here is a shot of an assy under test using a vom or multimeter and two set of leads, one in place for measuring resistive open close and the other for measuring voltage, lead ends swapped out at the meter to read. The proceedure is identical for each of the 3 swithces - 2 in the RA head and one in the DEC head assy.

The resistive test is done without power and manually actuating the switch.

On the DEC head assy it is easier to do if you remove the dovetail mounting plate from the dec head, I think they are 3/8 allen head?

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#19 CounterWeight

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Posted 18 July 2009 - 09:03 PM

Detail of the interconnect board (as on mount new) in the RA and DEC heads... the board for both is identical, the RA board populates all connections, the DE head only 2... on both boards the connector J5 is the interst. The metal housing that is the 'pin 9' is held on the circuit board with 2 solder connections (one each side)

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#20 CounterWeight

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Posted 18 July 2009 - 09:13 PM

And here is a shot of my added wiring, from some cat 5 cabling leftover from other days, using twisted pair I attached one wire to the 'mounting through hole of the connector and the other directly to the shield housing (electrically these are the same) - this is the connect to the onboard foil run used by the switch and motor circuitry...

This was done on the corresponding connector on the control interconnect board in the electronics pier. That board can be removed easily by removing all at the same time. Altogether there are 4 connectors to mod. Using different color wirring pairs help make it easy to keep from cross wiring the grounds. BE AWARE on all these solder jobs that you dont solder to the metal housing too close to the 'exposed face' as these are a tight fit when installed in place and you risk creating another short or ground path... leave at least 1/4 "... and as a safety cover with electrical tape when done before re-installing the board.

Another thing to note, on the electronics pier (outside) these connections are labelled RA and DEC.... on the board the are labelled ALT and AZ...

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#21 CounterWeight

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Posted 18 July 2009 - 09:15 PM

and from another angle

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#22 CounterWeight

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Posted 18 July 2009 - 09:29 PM

These are the connections that need the mod in the electronics pier(the reason you have to remove the boards from the pier)... this is a shot after the mods from the outside... if you look carefully you can see the electrical tape I used on the l/h side of the connectors

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#23 CounterWeight

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Posted 18 July 2009 - 09:33 PM

I popped out the pier power switch and used this as a routing path for the 'pin 9' mod wires (the blu/wht and grn/wht twisted pairs) and the new power connection wiring...

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#24 CounterWeight

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Posted 18 July 2009 - 09:35 PM

and here is the new power connection, a connector used in most computer power supplies. I used all 4 wires 2 each for hot and ground...

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#25 CounterWeight

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Posted 18 July 2009 - 09:51 PM

All said and done with testing on each end this took the better part of a day to do, and I was being very careful. Clean work area and all the basics AND

put all small screws in cups or an empty egg container to keep from losing...

use electrical tape and label all connectors clearly BEFORE you disconnect them...

have a sheet of paper to note work activity and progress

use rosin core solder, makes the job of soldering the copper wire to the tin? metal connector housing a breeze.

observe all standard safety practices with electricity and hot soldering iron :)

If in doubt keep wire lengths much longer than you think you need - it's always easy to take more off than 'MORE-ON' :foreheadslap:

DISCLAIMER This will certainly invalidate any warranty on the mount. If you are handy with electronics it's really a breeze. If not, get a friend who is to help get it done?

If curious about the power mod please PM me.






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