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Scott2526
super member
Reged: 04/16/09
Posts: 174
Loc: Cincinnati
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Hello:
I am breaking a new (to me) ETX 90 and I have a couple questions.
1) In higher magnifications the OTA drifts upwards. It does not doe this in low mags. The DEC knob is tight. The funny this is the lower mag EPs are heavier. Any thoughts?
2) Is the a DIY or for sale focuser attachment to increase the size and placement of the focuser knob?
Thanks
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LX 200 10'' (Classic)
AR-6
AR-5
8'' Hardin Dob
ETX 90
More EPs than I need
Telrads!
Therma-Cell
A bunch of nicks and knacks
______________________________________________
Make everything as simple as possible, but not simpler. - A. Einstein
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brianb11213
Carpal Tunnel
Reged: 02/25/09
Posts: 2105
Loc: 55.215N 6.554W
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Quote:
1) In higher magnifications the OTA drifts upwards. It does not doe this in low mags. The DEC knob is tight. The funny this is the lower mag EPs are heavier. Any thoughts?
2) Is the a DIY or for sale focuser attachment to increase the size and placement of the focuser knob?
1. Are you sure it isn't just the higher mag which makes it appear to drift at high but not low magnifications?
Did you try training the drives? (Setup menu)
2. You used to be able to get a flexible stalk for the focuser, Focusmate by Scopetronix, but I think Scopetronix went out of business. Try eBay. Actually it was pretty straightforward, just a coupling to fit over the focus shaft end (the knob is fixed using a small recessed hex bolt), a thickish nylon shaft (the Scopetronix one was approx. 4" long by 0.1" diameter) and a knob on the end. DIY is a real possibility.
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Treehopper
professor emeritus
Reged: 07/29/08
Posts: 582
Loc: Upstate NY
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Assuming the focusing mechanism is similar on the 90 compared to the 125, there is a flexible cable focus extender on ebay. They run around $10 +S/H. As brianb described, you remove the focus knob with a small hex wrench (provided with the cable), slide the coupler sleeve over the focus shaft and tighten it, then replace the original focus knob on the other end of the cable. I suppose it's possible you could find a larger diameter knob, so long as the inner shaft diameter mated properly.
I didn't want any extra weight dangling off the end of my scope, so I just use the same knob the scope came with on my cable. It performs quite well, actually... the cable is about 8" long, is stiff enough to transmit fine adjustments while dampening the "jitters" that often accompany trying to manually focus these scopes.
Just checked...trying doing a search on ebay with "extendflex" as your search.
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Tim
Champion of small aperture scopes everywhere!
Meade ETX-125PE
Meade ETX-80
Celestron FirstScope 76mm Mini-dob
 Updated: 09/16/2009
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1_old_dog
sage
Reged: 09/07/07
Posts: 435
Loc: Smoky Mnts
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Hi
I think brianb has your answer, re-train and re-calibrate your drives. As for the flex focus cable, yup these work very well.
od
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old stuff but good stuff
http://chu65nang67.us/nam/vietnam.html
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JT5
professor emeritus
Reged: 11/08/07
Posts: 582
Loc: Ozarks of Missouri
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Be sure an read the entire manual carefully. You probably need to do a RESET and then go though all of the procedures in the CORRECT order to accomplish the kind of tracking that your scope is capable of giving.
Be extremely careful that you follow the procedure for calibrating the drives and do NOT repeat a calibration step (this is easy to have happen since the procedure is not clear on how to get out of the loop.
If you have not done so already get familiar with Mike Weasner's Mighty ETX website. It will be a tremendous help to anyone not already fully aware of the capabilities and idiosyncracies of the ETX family.
John 
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My wife shares my love of the night skies and tolerates all of my other hobbies.
Televue Pronto w/Starbeam pointer and Televue tripod
Meade 2045D, ETX-125PE, 12" Lightbridge
Celestron: 7Amp PowerTank, 15X70mm binoculars
Meade, Swan and Televue Lenses (33, 26, 20, 15 & 9mm), Televue Barlow
Catsperch Observing Chair
Member: Astronomical Society of Eastern Missouri
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Scott2526
super member
Reged: 04/16/09
Posts: 174
Loc: Cincinnati
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Thanks
I'll do a reset and go through things from th start.
Has anyone had success with the electronic focuser that are sold for the ETX?
Scott
--------------------
LX 200 10'' (Classic)
AR-6
AR-5
8'' Hardin Dob
ETX 90
More EPs than I need
Telrads!
Therma-Cell
A bunch of nicks and knacks
______________________________________________
Make everything as simple as possible, but not simpler. - A. Einstein
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