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iOptron Mini Tower with Trapezium Wedge

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#26 StarStruckCarter


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Posted 30 June 2009 - 09:22 PM

If you talk to Steve he will inform you that he designed the wedge to be fully adjustable from 0 - 90 degrees.

He will also tell you that the wedge should be pointed north and that one tripod leg should be placed under it on the north.

Steve sent me an email where John Bozeman says that the MT is apparently able to autoguide with Meade Maxim DL. He's waiting for clear weather to confirm this.

According to Steve, he originally noticed that the MT was being supplied with the same controller that was included with the gotonova. He realized the potential of the combination and when he was told it wouldn't work, took it as a challenge. I'd say that he has proven his theory that it can work in both modes.

I have noticed that Steve uses his with a CG5 or Orion Atlas tripod instead of the factory one. They are taller and stronger.

As for polar alignment, after a 3 star alignment the controller provides an error report which allows one to dial in the alignment in only a few tries.


#27 GaryML


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Posted 30 June 2009 - 10:32 PM

I don't mean to be rude, but I simply don't understand why anyone would want this Mini-Tower wedge system.

The Mini-Tower costs $800. The bearing upgrade costs $300. The wedge costs $380. So now we're at $1480 (and even more if you need to add a bigger counter-weight shaft and/or other parts). And what you have something without a polar alignment scope or any other polar alignment method, looks rather unbalanced on the tripod, has just a skinny tripod, supports 25 lbs at best, and has no manufacturer's warranty (just the store warranty).

You can buy an Orion Sirius for $1200, a Celestron CGEM for $1400, or a Losmandy GM-8 (no Gemini but with motors) for $1500. These mounts will clearly work better for imaging (e.g., auto-guider port, polar scope and/or polar alignment software), are much more stable, supports 30-40 lbs, and have a manufacturer's warranty. Why would anyone want the Mini-Tower with the wedge when you can get a real GEM mount with much better performance for the same money or less?

This Mini-Tower wedge may be interesting as a DIY hobby project, but I can't understand why anyone would buy one. :shrug:

#28 Dr Benway

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Posted 01 July 2009 - 10:42 AM

I spent this last dark cycle field testing the Mini Tower on the wedge in EQ with a C8, Hyperstar3 and QHY8 OSC. It is pretty easy to get a good alignment, as mentioned above.

The autoguiding software Steve mentioned is Orion's Maxim DL Essentials for the StarShoot DSCI II. The only reason I recommended this is because PHD Guiding doesn't support the camera. I found that the GotoNova ASCOM driver will communicate with the mount via the USB cable, so I feel pretty certain it will autoguide. I will test this feature next time out.

I got good pictures at 90 seconds exposure unguided. Each night I had a breeze to contend with, resulting in a few tossed frames.

Here is a widefield shot of M8 & M20. This was 7X90 seconds stacked in DSS, processed in PixInsight and Photoshop 7.

John Bozeman

Attached Files

#29 Luigi


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Posted 01 July 2009 - 12:05 PM

>>>but I simply don't understand why anyone would want this Mini-Tower wedge system<<<

Stand out in a crowd, go against the grain, follow a different drummer, turn a silk purse into a sow's ear, to prompt individuals to ask why would you do this?

#30 Wes James

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Posted 01 July 2009 - 12:24 PM

Looking at this setup- it just looks like it's going to put a lot of strain on the Mini Tower mount. With the mount's normal position- vertical- all weight is supported in a vertical direction- down- perpendicular to the shaft. The weight is being supported in the bearings, equal on each side (assuming a reasonably well balanced load). There is no side thrust/load on the bearings.
When you tilt it up 20-30- or 40 degrees on its side, now you're placing a lot of side thrust on the bearings and drive train that its not normally encountering or designed for.
Comments? I've never seen inside one, so I may be way off base. Have been following the MT with great interest, though.

#31 Dr Benway

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Posted 01 July 2009 - 12:50 PM

It has aftermarket Timken precision bearings installed by Steve Forbes at Trapezium Telescopes. Trust me, it is built like a tank. I imagine the load limit is probably much higher, as well. I know Steve ran a C11 on the upgraded mount at the Winter Star Party without any problems.


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