Attaching Parallelogram to EQ mount??

[tosh]

Well I just won and collected what seems to be a used but never used EQ mount for.....99p off ebay. Came complete with both flexible control thingys?? Plus counter balance and a separate counter balance too. The tripod itself is very very cheap looking and split from where some ham fisted previous individual tightened it up to tight - but it's 100% salvageable. But the EQ unit looks to be made from cast, doesn't appear to have any weakness as such and is far better than what I could possibly expect to knock up without spending an astronomical sum of money - which defeats the whole purpose.

My query is why can't I attach a parallelogram to the cast fixing designed for the telescopes main tube. I'm totally naive when it's comes to things like this, but my logic says if the parallelogram was actually running parallel to where the scope would normally be attached whats stopping me from incorporating the EQ movements.

I'd like to design and build a tripod out of 100mm diameter steel tubing. The legs will again be steel tubing (40mm), how I intend to fix them is still undecided, but as I'm working for a engineering firm, pretty much anything is possible. My main priority is to ensure the heavy oversize main tube sits very low to the ground for obvious stability reasons and rather than the 3 legs being attached near the bottom, I intend to attach them near the top so it becomes bottom heavy. The EQ mount will then be attached to the centre column and any difference in height required would simply involve utilising the movements available from the parallelogram.

So what am I missing?? I just know its something major, otherwise it would have been done before.

Any logical problems in laymens terms would be greatly appreciated.

Thanks

Tosh

[ollypenrice]

I'm not quite sure what you envisage but an equatorial mount (asssuming you're not at one of the poles!) tracks the sky in an arc. (Orion rises tilted over to the left and sets tilted over to the right for me.) So if you have binoculars on a mount like this you'll have your neck kilted over to the left at the start of the night and to the right at the end of it, looking broadly south. This would be a dead loss! Parallelogram mounts go on horizontal top plates attached to piers or tripods.

Funnily enough a friend built a prototype pair of giant binoculars made of two 11 inch scopes, but he could only test them on an equatorial mount. It took my neck about a month to recover from the contortions involved in looking through them.

I think I'm saying 'no!!'

Olly

[tosh]

Hi Olly

Cheers for the reply.

That scenario you described had indeed crossed my mind. The whole reason for this is to allow both me and my young son (6yrs) to view the night sky. I had grand plans of making this a dual purpose, in that I could use both a scope/refractor or swP for binoculars.

But as you rightly pointed out the bin's would cause no end of problems. I'm just trying to envision another linkage based on the parallelogram principle that would correct both axis!!

[tosh]

Just to confuse matters even more.

What do you recommend I build the parallelogram out of?

I've already machined and drilled 4 pieces of 2x1 walnut. Been in the loft space in my garage for the past 2yrs. its got 10mm steel bolts passed through all the holes keeping everything true, square and flat. But on Friday I managed to scavenge 4 lengths of 2x1 aluminium box section. I can work with both, but can't decide which to go for.

Any advise??