Ioptron MiniTower Pro fixed pier adaptor

[Tinderboxsky (Steve)]

After I purchased the Mini Tower Pro early last year to upgrade to a go to system for visual observing, I started thinking about how I could adapt the quick release dovetail system that I had been using for quick set up and take down on my external fixed pier. I have developed a prototype fixed pier adaptor for the Mini Tower Pro out of spare ply and other leftovers in the workshop. It has been working so well that it might be some time before I make the final one out of aluminium.

So, a series of photos to explain:

Existing observing pier with a Vixen dovetail rail that was used previously to quickly attach a Vixen Port Mount. The marks are accurate SCP markers for alignment purposes.

Top side of simple prototype base plate adaptor for the Mini Tower Pro made out of two pieces of quality waterproof 13 mm ply, glued together. Three stainless bolts have had grooves cut in their 6 side faces and then epoxied into the ply. Three simple level adjusting bolts were made from a length of spare threaded stainless steel rod and nylon rod.

Underside of the base plate adaptor with a leftover vixen dovetail clamp screwed to the ply. The bolt shown is used to attach the base plate adaptor to the mount.

First stage of assembly: The base plate adaptor is fixed firmly to the pier with the dovetail clamp and the three adjusting bolts are levelled accurately.

Second stage of assembly: Firmly bolt the base plate adaptor to the mount taking care not to turn the levelling bolts.

Third stage of assembly: Simply attach the mount to the pier using the dovetail clamp. Then complete the standard alignment routine. The mount is now fully set up and aligned.

At the end of the observing session return the mount to the Park Position and remove the scope and accessories. It is then a simple matter to release the dovetail clamp to remove the mount. If the base plate adaptor is left firmly attached to the mount then, when the mount is put back on the pier for the next observing session, it will be in exactly the same position and orientation. The go to controller will recall the setting from the previous session’s Park Position and be immediately ready for slewing to your first target.

To simplify carrying and storing the mount I have fixed another small section of dovetail to a flat piece of wood set in a plastic crate as per the photos.

So, the setup routine now is simply; attach the mount to the pier using the dovetail clamp, attach the accessories and telescope, turn on and slew to first the first observing target.

It is working very well, with no loss of accuracy. I was concerned that the ply might flex, or that the epoxied nuts might move in the wood, resulting in some loss of pointing accuracy, but this has not been the case. The fact that I have the scope and mount accurately balanced in in all planes probably helps with minimising any flexure.
The only change I will make when I eventually machine the final version out of some scrap aluminium is to either make or buy a much broader dovetail and clamp. I am thinking of something the size of a Losmandy D clamp and dovetail. Not sure when this will happen as the prototype is working well and there are other things gobbling up my time.

Anyhow hope this might be of interest and trigger some ideas of your own.

Cheers

Steve.

PS, as you can see, I have replaced the standard counter weight with a cradle to hold the battery that powers the mount. This has simplified things further, in particular, the balancing of the scope and mount accurately in all planes. I’ll explain this in another thread if people are interested.

[mikerr (Michael)]

Steve, that is a well thought out and practical setup.

Retaining the Park/Home position sure speeds up the next nights's setting up procedure.

I put a mark on the upper and lower halves of the MkII mount when it was in the Park position. Now I just return it to the pier in the same position and make sure the OTA is exactly vertical. It is then ready to go. No alignment necessary.

The Battery/Counterweight is great. More details on the Battery type (model, weight etc.) and housing would be welcome. I guess it is balanced around the shaft axis as well as balancing the OTA?

Michael

[Tinderboxsky (Steve)]

Hi Mike,

Thanks for your comments. How do you attach your mount to your pier?

I have put up a separate post explaining the battery/counterweight. Let me know if that does not answer all of your questions.

http://www.iceinspace.com.au/forum/s...d.php?t=117608

Cheers

Steve.

[mikerr (Michael)]

Hi Steve, attached are a few pictures showing the mounting plates I made for both the top of my Celestron tripod and my Pier.

You can see the white dots on the two halves of the MiniTower MkII which represent the park position. Then you can also see the mark on the MkII little mounting leg and the mark on the Mounting plate adjuster.

The little leg with the mark has to always sit on the adjuster with the mark. Then I line up the two little white dots and it is in the Park position as far as South-North is concerned. Set the OTA vertical using a little level and the mount is completely in the Park position and ready to find objects.

This system only works on the fixed pier. I guess if the tripod was returned to a fixed location on the ground it would work there as well. I only use the tripod to fiddle with things indoors.

If any of this is not clear please come back to me with questions.

Rgds

Michael

[Tinderboxsky (Steve)]

Hi Mike,

Thanks for that. I like the simplicity of what you have done. Obviously starting with a pier where you can access the central securing bolt has allowed you to do this. My solution had as it's starting point an existing cement filled pier with a large central bolt securing the wooden pad at the top.

Your hand controller holder brings a smile to my face ...

Cheers

Steve.

[mikerr (Michael)]

Steve,

"Your hand controller holder brings a smile to my face ..."

The holder was a little plastic lolly bin that my wife found for me at one of the department stores. I just cut off the lid, put a piece of black rubber sheet on the bottom and around the inside.

When I dump the controller into the bin it completely shields the red glowing screen from my eyes until it goes out. Super simple, cheap and effective.

I can even put my specs in there when I take them off.

Rgds

Michael