Skymax 90 to dovetail

[Andy Mitchell]

Hi All,

Any suggestions for how to adapt a Skymax 90 onto a dovetail bar that can be used on an Skywatcher HEQ5 or similar mount? I have the newer version of the scope that has what looks like (but isnt) an upside down dovetail. The scope attaches to the EQ1 via two M6 bolts with a centre to centre spacing of about 75mm. There are also a couple of camera tripod threads as well on the scopes base.

As the ST80 also drops directly into the same non standard mounting on the EQ1 I was suspecting something like this might work:

   http://www.firstlightoptics.com/slt-series/skywatcher-st80-dovetail.html

Thanks,

   Andy

[RichM63]

Don't know why you can't just drop it into the HEQ5 head and clamp it down however.

The dovetail you show seems to have been designed for the job.

This afternoon I bought one for the ST80 that has two long center slots so that the rings can be positioned in the most convenient position. Handy for balancing in my situation.

[alexog]

I've had the same problem with the Skymax90. Hopefully the dovetail for the ST80 will work but I doubt it.

The Celestron Skymaster Tripod has an adapter that would work but I can't find them sold separately. It is possible using the short dovetail bar and tripod attachment screws but it's far from ideal and not very secure.

The only other solutions are buying tube rings or taking the stupid "upsidedown" dovetail off and bolting a dovetail on. Still not ideal.

If I find anything I'll let you know.

[Macavity]

Unfortunately, the "upside down dovetail" (I suspect I know JUST what you mean!) can be an obstacle. The least invasive solution is probably to buy the standard sort of dovetail you link to, and then try to attach that to the inverted dovetail? Perhaps it is possible to drill clearance holes in the new one for countersunk M6 screws that go right through into the 75mm spaced threaded holes?

But WAIT a minute... (just thinking)

Alternatively, you might be able to use a *slotted* 120mm dovetail from Modern Astronomy. 

http://www.modernastronomy.com/accessories.html#accDovetails (The "Photo Dovetail" half way down the page)

Whatever my "abilities", I lack a drill-stand - Hand drilling holes in dovetails can be a chore!

Aside:Trouble is the surfaces of the dovetails may or may not sit flat on top of one another? If not, you face a more challenging solution of replacing the non-standard dovetail with the standard one. Or you might consider tube rings? Either way, you may have to gain access to the inside of the OTA, to remove any nuts attaching the original (inverted) dovetail. That will usually be possible - The complete corrector assembly unscrews from smaller Maks. I would not recommend disturbing the other (rubber sealed) end! But either way you face the issues of dust ingress, fingermarks etc. Maybe best to consider the doubled dovetails first? Sadly there are a number of possibilities and perhaps no "approved" solution? 

[alexog]

But WAIT a minute... (just thinking)

Alternatively, you might be able to use a *slotted* 120mm dovetail from Modern Astronomy. 

http://www.modernastronomy.com/accessories.html#accDovetails (The "Photo Dovetail" half way down the page)

That's exactly what I was looking for too.

Thanks.

[JamesF]

I think I'd probably go for scope rings attached to a second dovetail if possible and just completely ignore what's there already.

As Chris suggests, if you're confident and competent enough you could replace the existing dovetail with a "standard" one (which is how the larger Maks generally seem to come), but no way would I do so without completely stripping the thing down to just the tube.  Reassembly is no big deal, but collimation afterwards can be something of a faff.

James

[TractionMan]

Hi All,

Any suggestions for how to adapt a Skymax 90 onto a dovetail bar that can be used on an Skywatcher HEQ5 or similar mount? I have the newer version of the scope that has what looks like (but isnt) an upside down dovetail. The scope attaches to the EQ1 via two M6 bolts with a centre to centre spacing of about 75mm. There are also a couple of camera tripod threads as well on the scopes base.

As the ST80 also drops directly into the same non standard mounting on the EQ1 I was suspecting something like this might work:

   http://www.firstlightoptics.com/slt-series/skywatcher-st80-dovetail.html

Thanks,

   Andy

I've got a dovetail like that for my little 90mm Mak. Nice and stable. I sometimes use the scope on a photo/video tripod and sometimes on my GSO ATZ mount, so I find it very convenient to have a dovtail that I can attach and remove when needed.

[Andy Mitchell]

Thanks for all the great suggestions, much appreciated. Just orderd the slotted dovetail from modern astronomy and an HEQ5 Syntrek.

Hope the mount can handle all that weight