Moving / adding finder to a Mak

[eifionglyn]

Hi,

With the opposition of Mars only a few weeks away, I want to make sure I'm equipped to observe it, so out came the trusty old Skywatcher 102mm Mak. Of the scopes I own, it will give me the best views I think on a small bright target.

Here it is, which shows my problem:

 

This particular OTA was sold as a package with an EQ mount, hence the placing of the finder bracket opposite the dovetail rail. I don't have the equatorial mount anymore, and the scope is used with the AZ5, however the placement of the finder bracket is now really awkward. I'd like to move it to the top of the tube, and possibly nearer the front, somewhere around where the skywatcher logo is.

If this were a Newtonian, I'd simply unmount the mirrors, drill some new holes in the tube and that would be done, but it's not. It's closed front and back, so drilling new holes will end up with the tube full of debris that's tricky to get out and will damage the optical surfaces. Are there self-adhesive pads that will actually self adhere properly over time? Or another way to attach a new finder?

Also regarding moving the original bracket. I take it the bolts go into a captive nut on the inside - can anyone confirm? Or will unscrewing them result in having a nut or two rattling around inside there forever?

Any advice gladly received.

Thanks,
Eifion

 

 

 

Edited September 25, 2020 by eifionglyn

[Pixies]

Literally stick a Telrad on it?

[banjaxed]

Alternatively you could buy a tube ring and fit a finder shoe bracket to it.

[Steve Clay]

Double sided tape and tie wrap

[martinl]

3M VHB tape is extremely sticky and doesn’t seem to deteriorate over time. I think that would work to attach the finder base where you want it. It also comes off cleanly when no longer required. 

[John]

I would probably add a Rigel Quickfinder in the position I want it. It can be popped off leaving the base in place easily enough when the scope is not being used.

 

[Alan64]

I doubt that the nuts on the inside are affixed.  With a few of my telescopes, I have to roughen up the surfaces of the nuts and epoxy them into position...

...and for that nicety.   

You can remove just the housing at the back, since that's where you'll be working, then place a barrier between that part of the tube and the cowling at the front.  Sweep it all out when you're done, and in using a tack-cloth in addition.  That's how I would go about it.

But then, if remove both ends, you can flock the tube, if it's not ribbed, but flat instead.  My own is ribbed inside; micro-baffles...

I'd prefer flocking however...

...and for that last iota of contrast.

A Maksutov is, after all, a reflector, too.

[ScouseSpaceCadet]

Buy an L-Bracket...

[Cosmic Geoff]

I am not familiar with that mount, but can you not swing the OTA past the vertical to the other side, and rotate the star diagonal through 180 degrees, so that the finder is now on the upper side?

[eifionglyn]

On 26/09/2020 at 00:35, Cosmic Geoff said:

I am not familiar with that mount, but can you not swing the OTA past the vertical to the other side, and rotate the star diagonal through 180 degrees, so that the finder is now on the upper side?

Not on the AZ5 unfortunately, the mount comprises of an offset arm, which can be adjusted in a few positions, but is intended for OTA's with the dovetail on the right hand side of the tube. Of course, anything in tube rings doesn't matter as it can be rotated as needed.

I carefully removed the finder bracket to find there are no nuts, captive or otherwise inside the tube, but simply threaded holes in the tube to bolt the shoe on so that is OK.

Some 3M pads won't work, as the finder bracket doesn't have a substantial flat surface area to stick to, it's a wide upside-down U section. I think a Rigel quick finder is the way to go, was hoping to have something sorted out before payday but will have to wait!

[Alan64]

11 hours ago, eifionglyn said:

Not on the AZ5 unfortunately, the mount comprises of an offset arm, which can be adjusted in a few positions, but is intended for OTA's with the dovetail on the right hand side of the tube. Of course, anything in tube rings doesn't matter as it can be rotated as needed.

I carefully removed the finder bracket to find there are no nuts, captive or otherwise inside the tube, but simply threaded holes in the tube to bolt the shoe on so that is OK.

Some 3M pads won't work, as the finder bracket doesn't have a substantial flat surface area to stick to, it's a wide upside-down U section. I think a Rigel quick finder is the way to go, was hoping to have something sorted out before payday but will have to wait!

If you reinstall the screws only, to seal the tube, they will need to be shortened so as not to intrude into the light-path.  

[Louis D]

I had this issue with my 127 Maks, so I swapped sides on my DSV-1 and DSV-2B alt-az mounts, rotating everything including the handle 180 degrees.  I don't know if the AZ-5 mount is as flexible to allow this.