Dobsonian mount for konus motormax 90

[space_education]

I have a konus motormax 90 which is a Maksutov-Cassegrain type telescope. I got it for £25 at a car boot sale but I don't think the mount is the original one. It is virtually impossible to use, I tried converting it from eq to alt-az which helps a little. The main problem is it vibrates so much, focussing is next to impossible even at low magnification.

I got a little dob from ebay - 300mm FL. This is rock steady and great for what it is but the lack of magnification is limiting.

What I want to know is: Can I convert the konus motormax 90 to a dob mount with something like the Omegon Mount Dobsonian mini base with synta dovetail?

The attachment point on the konus motormax 90 for the mount appears to be non-standard (very thin) do you agree.

Thanks in advance.

[Cosmic Geoff]

Anything is possible, but we need to know details of the dovetail or whatever on the Konus tube to advise you further.  My (larger) Maksutov has a standard dovetail bolted directly to the tube and it is not obvious whether it can be removed without dropping nuts inside. 

[space_education]

27mm in the center and 34mm at the edges.

Edited November 25, 2020 by space_education

[Cosmic Geoff]

Yes, it does look non-standard. 

How good are you at metalwork? With a bit of drilling and/or filing or thread tapping, it should be possible to either fit a standard dovetail in place of the I-shaped piece or bolted to it.  It would be better to have a dovetail at the balance point of the tube which with the 127mm Mak is about halfway along the tube.

Or you might be able to find a pair of small tube rings to fit and bolt a standard dovetail to them.

Edited November 25, 2020 by Cosmic Geoff

[space_education]

I wonder if that bar has been added so it attaches to the (non-original) mount. If I removed it would it then attach to this?

[space_education]

2 minutes ago, Cosmic Geoff said:

Yes, it does look non-standard. 

How good are you at metalwork? With a bit of drilling and/or filing or thread tapping, it should be possible to either fit a standard dovetail in place of the I-shaped piece or bolted to it.  It would be better to have a dovetail at the balance point of the tube which with the 127mm Mak is about halfway along the tube.

There is no dovetail on the bit behind the bar in the picture, which might imply it's not meant to be fitted directly.

Does that mean I need to get get a piece of dovetailed metal to attach to the OTA which then is clamped by the (pictured above) dob mount?

[Ricochet]

It looks to me like the original telescope uses a 1/4" photo thread adaptor and the non standard dovetail had been screwed to that. All you need to do is to undo the two screws shown in your photo and then fit one of the following to your telescope to fit it to any standard vixen mount. 

https://www.firstlightoptics.com/dovetails-saddles-clamps/astro-essentials-vixen-type-photo-dovetail-bar.html

 

[space_education]

Thanks Ricochet that's the answer.

I'm trying to do this without spending anymore money except on the dob mount🙁

Quick follow up question is there much difference between Omegon Mount Dobsonian mini base and the Omegon Mini II Dobsonian mount apart from the extra £10?