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First light with a Ioptron MiniTower

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#1 DonBoy

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Posted 25 April 2009 - 05:02 PM

Well after a lot of soul searching about the MT I decided to go to the NEAF show and see one in person and ask whether I would get jitter free imaging for short exposures. Well I was assured by the Ioptron people at their booth and also a well known dealer/ supporter of the MT that imaging is no problem. In fact this dealer pointed to two large DSO pictures taken using the MiniTower hanging on the back wall of his booth. We liked what we heard and saw and bought one.

After several nights of poor weather we finally had a clear night. I was feeling real good cause I just sold the alt/az mount I had been using for several years and the MT was it's replacement. I was finally able to unpack my new MT and learn how to use it. It took me about 20 minutes by the time I got everything percolating. It took another 10 minutes to really get the hang of things and to get a reasonable alignment.

Feeling confident that I would be able to image, I slapped in my Stellacam video camera that has a maximum 8.5sec. integration time, refocused and started to image M13.

Everything so far had met my every expectation. Goto's were right in the field of view and the image when centered stayed there for a long time, the longest I stayed on a target was maybe half an hour and the image remained in the same general location.

I was using my 8"SCT at f/3.3 so mount error wouldn't be to noticeable, so I thought. Well unfortunately I started noticing that the image of M13 would slightly move a small amount and 8.5 seconds (camera integration time) later move back. This would happen on what appeared to be a random basis and the jumps would vary in length and were mostly in the vertial direction (Dec axis), but always eventually returning to the center. I tried other targets and saw the same small occasional jumps, thus ruling out scope position. I first thought it was the stepping motors, but looking at it's randomness I decided that it might be periodic error and that the quality and finish of the worm gears might be questionable. This is the first mount I've owned that exhibited this much and frequent jumps. The mount I just sold, also an alt/az used a spur gear drive and it had two small steps every 8 minutes, which was one complete gear cycle.

You might wonder why I would be using an alt/az mount in the first place and why not something more appropriate for imaging. Well that is a good question and I do have a 60 lb. GEM that works flawlessly, it has one draw back, me. I have a very bad back and also am not into piece by piece set ups. My previous mount was a NexStar and it was doing an adequate enough job but the 8"SCT with camera was pushing it and when using refractors they would hit the base of the mount. Hence the MT seemed to fit the bill, just a few pounds heavier but still manageable and I could use two scopes.

Well I don't know whether I have a defective mount or if this is typical. I'm hoping that I've over looked something. I know I've gone on, but without some explanation one wouldn't get the whole picture (and you still may not LOL). I'm into quick set ups using light equipment and small scopes and video imaging fits my make up, and that's instant imaging.

So if you have any thoughts or suggestions on what to do to remedy the jitters please pass them on.

Thanks for bearing with me,

Don
W3DAL
8"SCT from 8SE
80ED Celestron
120ST Orion
MiniTower
LXD650
Stellacam II
NexImage

#2 mtlott

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Posted 27 April 2009 - 08:26 AM

Try setting the anti-backlash to 0. That helped me tremendously. It comes set at 150.

Marie

#3 wsuriano

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Posted 27 April 2009 - 11:38 AM

I had the same problem. At IOptron's suggestion, I updated the firmware and set the backlash to 0. Problem gone.

Bill

#4 Telescopeman54

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Posted 27 April 2009 - 05:09 PM

I'm glad to hear that it was an easy fix and that things are working well for you. I suspected the anti-backlash setting, but, I forgot to ask which version of the firmware was in your controller. Duh-OH!!

Steve

#5 DonBoy

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Posted 28 April 2009 - 02:18 PM

As an update I have used the mount a total of four times. The last three times it still had the wandering motion but two warnings about the Dec motor came up. One was that the Dec motor was drawing too much current and the other warning was that the Dec motor lost communication to the controller. I called Ioptron yesterday and explained all the symptoms and they said they would call me back. They called today and I am to return the unit for repair. I learned on the Yahoo Ioptron Group that two other people are having the same issues with their new MiniTowers and they will be going back also. To Ioptron's credit they were very amiable and will be picking up the shipping.

Don

#6 jayfish

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Posted 28 April 2009 - 06:14 PM

Now, this is just my opinion but you should be getting a replacement unit not a repair. iOptron should cross-ship it to you with a prepaid return label. If it was a couple months out from your original purchase, I would understand a repair RMA. Seeing that it's only a week and a half though...

Jay

#7 DonBoy

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Posted 28 April 2009 - 07:51 PM

I think they want to see what's wrong and they just may send me a new one. I wouldn't send a new one out without the return of the old, how do they know if I really am in possession of a unit. They are picking up the shipping charges.

Don

#8 jayfish

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Posted 28 April 2009 - 08:14 PM

Well, worse case, you give them a CC number and if you don't return the defective unit they charge the card. I just bought an AT Voyager that had a finish problem on it's alt arm. I e-mailed AT some pictures of the problem and they cross-shipped a replacement. No CC card and no questions asked. It's pretty standard fair.

Jay






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