My new toy a Fullerscope IV mount.

[Doc]

I have been thinking about what you said Rusted and went into the shed to set up an experiment.

As you can see from the photo's below. I first tried a 45mm lump of wood and then set the PA to 53° which is the correct latitude for nottingham and the gap between the casting and the adapter is about 10mm.

 

I then included another piece of wood to make the height 60mm and this gave me a gap of 22mm.

 

 

So in essence any lump of aluminium between 40mm and 60mm will do. Where would you connect the adjuster, I see you have connected yours around the circumference of the end of the PA casing, but thats a little close for mine to the adapter plates.

Anyway time to mull this over.

 

 

 

Edited March 28, 2020 by Doc

[johnturley]

It looks like your mount has stainless steel shafts, the original Mark III (which I once had), and I'm pretty sure the original Mark IV also, had mild steel shafts making them prone to rusting.

John 

[Doc]

3 hours ago, johnturley said:

It looks like your mount has stainless steel shafts, the original Mark III (which I once had), and I'm pretty sure the original Mark IV also, had mild steel shafts making them prone to rusting.

John 

The magnet still sticks on the shaft so my guess is Chromium plated steel. I'm sure magnets don't stick to Stainless.

 

 

Edited March 28, 2020 by Doc

[Rusted]

Looks good Doc.
I could let you have a lump of 7" Ø alloy bar.
But the international postage would bankrupt one or both of us.

BTW: Your shafts may be chrome plated steel.
No magnet sticks to any of my stainless steel shafts.
I'd like to use my own clinometer like that but it just won't stick.

Edited March 30, 2020 by Rusted

[Peter Drew]

Not all stainless steel is non magnetic, it all depends on the "mix".   Slightly magnetic steels are rust resistant.        🙂 

[Doc]

Spent a few hours today raising the height of the Fullerscope mount so the polar axis casing clears the adapter plates. A lump of ash wood 65mm thick was used. There is now enough room between the casing and plates to design a turnbuckle to raise and lower the polar axis to enable polar alignment.

The last one is a video.

 

 

 

 

 

 

 

 

 

 

Edited April 7, 2020 by Doc

[Doc]

Made a latitude adjuster today. It consists of two clevis yokes which I made in the milling machine. The next part is a left handed and a right handed M10 threaded bar with a 6mm hole in the end for the clevis pin. The middle part is an hexagon bar with a M10 left hand thread in one end and a M10 right handed thread in the other. The way it works is you screw in for the mount to raise and unscrew for it to lower. I have about a 9° latitude adjustment. It was quite hard to do as there was not a lot of room between the polar shaft body and the adapter plates but it was fun project, and it works very well.

 

 

 

 

 

 

 

 

 

Edited April 20, 2020 by Doc

[Doc]

Another day in the workshop. I designed and built an adjuster to adjust the azimuth axis on my Fullerscope mount. It works really well and has about 10° of adjustment for polar alignment.

The last video shows the altitude adjuster which has about 9° of adjustment. For some reason only works on full screen.

 

 

 

 

 

 

 

 

 

 

Edited April 20, 2020 by Doc

[Doc]

Spent the day in the workshop again and this time built myself a dovetail clamp for the Fullerscope. It's 250mm long and 125mm wide and has three large thumbscrews to tighten the clamp up, the telescope ain't going anywhere.

 

 

 

 

 

 

 

 

 

 

 

 

Edited April 27, 2020 by Doc

[Rusted]

You are a clever chap!

What about concealed compression springs in blind holes to hold it open until tightened down?

[Doc]

5 minutes ago, Rusted said:

You are a clever chap!

What about concealed compression springs in blind holes to hold it open until tightened down?

Yep one step ahead of you, the springs are in the post.

Thanks for your comments Rusted.

[Doc]

After a bit of faffing around I mangaed to get the worm and wheel rotating in unison. There is still a little backlash in the gears but it's pretty good. Any ideas how to eliminate the backlash. I made a few videos for you to view, next step will be pulleys, belts and stepper motors. 

 

 

 

 

 

Edited April 29, 2020 by Doc

[Peter Drew]

There appears to be adequate provision for adjusting backlash on either axis.?    🙂

[Peter Drew]

The gears would have been made "in house" at Fullerscopes, probably by Ernie Elliot or latterly by Rob Miller so can be expected to be nice and concentric.  More than can be said for some modern equivalents!     🙂 

[Doc]

The gears are excellent and I would say very concentric. I've managed to get the backlash out of the RA but there is still a very small bit in DEC but I'll concentrate on that a later date. Thanks for the info Peter, did you know Ernie or Rob or even the main man Dudley?

[Peter Drew]

4 minutes ago, Doc said:

The gears are excellent and I would say very concentric. I've managed to get the backlash out of the RA but there is still a very small bit in DEC but I'll concentrate on that a later date. Thanks for the info Peter, did you know Ernie or Rob or even the main man Dudley?

I met Ernie, I knew Dudley well and Rob was my closest colleague for many years I'm pleased to say.    🙂

[Doc]

I thought I would update my work on the Fullerscope Mount.

While trying to attach a plate to the bottom of the RA worm housing the metal on the original just gave way, it was very soft and just crumbled away so I decided to remake the worm housing with a bronze bush. I then designed a plate to house the stepper motor and attached it to the bottom of the new worm housing. The stepper motos are nema23, 0.9° step, 1.26Nm, 2.8 amp. I then added GT2 pulleys and installed the wiring inside a nema 23 back panel via a cable gland.

My next job is to do the whole lot again on the Dec axis, not sure if I should make a new worm housing to match. I'll see when I start drilling and taping the old one. The metal these one fullerscopes are made out of is not very strong and threads easily strip.

New worm housing made

Attached to new base plate

Stepper motor attached

 

 

With back panel fitted

Fitted to the Fullerscope IV Mount. The flex will be connected to a EQStar Control Box.

 

 

 

 

Counting the teeth, I need a 105 toothed belt to complete 

Video

 

Edited June 3, 2020 by Doc

[johnturley]

I assume that with the new motor you have fitted, you will be able to slew at various speeds, the original mount would have had an AC synchronous motor, the speed of which could only be increased by up to 100% using a variable frequency oscillator. 

In theory I assume that the same sort of motor could be fitted to my 1980's 14in reflector, which is driven by a 1/2 rev per minute synchronous motor via a 720 teeth brass RA wheel.

John 

[Doc]

Yes John it will slew at any speed and track the stars. It's going to be connected too one of these:

https://astro-gadget.net/gadgets/control-of-telescopes/eqpower

Edited June 3, 2020 by Doc

[johnturley]

26 minutes ago, Doc said:

Yes John it will slew at any speed and track the stars. It's going to be connected too one of these:

https://astro-gadget.net/gadgets/control-of-telescopes/eqpower

That's interesting, so in theory at least my 14in fork mounted Newtonian could be upgraded to computer control.

John 

[Doc]

Yes in theory, the item above is for EQ mounts but they do make and other firms make. one that works in EQ and ALT/AZ format.

[Doc]

Today I made the plate and bracket to hold the Nema23 Declination motor and pulleys. The motor is the same as the RA one being a 2.8 amp, 1.26Nm, 2.5v, and 0.9° step angle type. Just like the RA motor the Dec motor requires a 105 tooth GT2 belt.

The DEC housing drilled tapped perfectly this time so there was no need to make a copy out of aluminium like I did on the RA housing.

 

 

 

 

 

 

 

 

 

 

 

[Doc]

All belted up. Next step the controller.

 

 

 

 

 

[Alan White]

Now this is looking so good Doc.
I wish I had the patience, skills and kit to do similar.

[Doc]

29 minutes ago, Alan White said:

Now this is looking so good Doc.
I wish I had the patience, skills and kit to do similar.

Thanks Alan, I just love tinkering in the shed it's very therapeutic.