This is my new Alt-Az.
It is made from an old EQ5 mount that belongs to David (Omegacrux) that wasn't being used.
When I saw his SW Alt-Az I thought that the EQ shuld be able to be converted and so I had a few bits removed, drilled and tapped and today David came over and we put it together.
It holds the 6" Mak beautifully and with the 3Kg of weights at the extreme end of the bar the load is balanced on the centre pivit. It is very stable, although a better tripod would improve this.
Total cost; $80 for the mount and the tripod was from an old scope/mount combo and I suppose a value of $50 is reasonable. Parts were supplied gratis by Nubco engineering.
I agree, it looks good. Can you still attach slow motion flexible handles? That would make it an excellent mount - I could not do without my slow motion flexible handles on my alt-az mount.
Not only my fault Graeme. A Launcestonian member has just bought a 10" dob today so I am pointing the finger at him.
Steve the flex adjusters will still work but I want to shorten them so that they only stick out about 10cm.
What I wonder is whether a dual axis motor will work so I can just use a hand controllor for the two adjustments.
Ha Ha Ha. I was cursing the weather too since I picked it up. In saying that, on my way home last night the sky was covered in cloud but at around 7:30 it was as clear as a bell so out I went.
If you want to stabilise the tripod a bit hang a substantial bit of weight down below it, Something over 5 kgs will keep it quite solid. I made a bridle to keep it centred on my old setup EQ2 with a small workshop anvil down below on a wire line.
Thanks Lewis. Have to say that I spent some few weeks mulling it over before the first cut and I am very happy with the result.
Brian, I have taken a few more pictures that I hope shows the process now that the final touch is done (save for one angle bracket).
Pictures 1/2
Made control knobs using three flexible contols from the EQ and an old AZ3. It's interesting to note that the AZ3 one was a hollow tube, while the EQ5 ones had a solid nylon core inside the black tube.
All were cut considerably shorter and the solid core pair were drilled and these were then pushed on to the axles: 2 on the Az axle and one on the Alt (since the tube fits only one way if I want the finder on top then the Alt conrol axle nearest the user is the only one that needs one).
These fit quite tightly. Much better than using the metal sleeve and the useless tightening screw, since these always loosen off and have to be re-tighten a number of times per session, unless you set to with a plier on the screw.
Picture 3
Shows the controls again and the area where the altitude pivot section of the EQ was removed from the base up to the housing for the axle and gears for the Dec controls.
Picture 4
This area on the new base of the mount is thin aluminium for 2/3 of the circumference of the bottom of this section of the mount. It houses the polar scope housing and the turning axle for the Dec section and polar scope. The external parts to the polar scope housing are removed and the thick block that remains after removing the altitude pivot is drilled and tapped for 2 bolts. The mounting plate on the top of the tripod and is drilled in line with these and the mount can now be screwed on.
This means only 2 bolts can be used to hold it to the mount and both are to one side. Not only that but the mount has a central circular depression spanning about 1/2 it's width where the old AZ mount base used to sit. Not ideal even though it feels firm. So,
Picture 5 Firstly: if you note the flash of silver where the mount sits on the tripod. Its a honking big galvenised washer that sits perfectly in the depression in the mounting plate. It needed about a Millimetre filed of the circumference to make a tight fit and has a correct depth to sit level with the outer rim. Providing an all over flat surfacet gives it some stability and, as you can see in the photo above, the extension for the polar scope sits in the hole in the washer. I should have actually cut that part of the PS housing off level with the new bottom of the mount, but it's not critical. Secondly: the screw I have in the base of the side of the mount marks the position of a small threaded hole which is lined up with the hole the spirit level used to sit in. That was just serendipity, but I like it when things like that happen.
The next task is to buy, cut to size, and drill a right-angle bracked and then attach it to the mount here and tripod there :-) to provide a final, but neccessary support.
I have used this with the 6" Mak and it is nice to use. We levelled the tripod on the verandah today and lined the scope up on a comm tower a couple of kilometres away and used the Alt control to see if the mount was reasonably perpendicular to the tripod i.e. mounted at 90deg to the tripods base plate. Yup. It moved straight up and down the tower: which I presume is reaonably level in the vertical plain, and therefore the mount is mounted fairly true to 90deg to the tripod.
So. I'm happy with the end result, and maybe a few dead, or unloved, EQ 3~5's will find a new life if there owners see this thread.
All up cost was negligible, and the pleasure of seeing it all come together was immense. As will the pleasure of using it.
Thanks Trevor, truly inspirational you may have started something here.
