Collimation Cap Research

[TopHouse]

Crrying on with my obsession with collimation, and looking at the collimation caps available and the fact that most seem to use a home made film cannister cap, I have a good friend who owns an engineering company, I handed him a drawing today for a collimation cap, spun in aluminium, 30mm up the tube it has a shoulder, so the bottom half is 31.75mm (1 1/4") then a shoulder as the top half is 40mm (allowing dead square allignment) The end will have a 2mm hole in dead centre.

When he's got round to doing it I'll add a couple of pics, but after looking at what's available, how many would be interested in one of these, a quality engineered item to replace their 35mm film cannister and would last a lifetime if the price was right?

[LukeSkywatcher]

There's no reason why a homemade one wont last a lifetime. Once the dog doesnt eat it. I didnt have any 35mm canisters laying around so i used an old dust cap from a star diagonal i have. Seems to have worked very well.

[johninderby]

I had one of Astro Engineering's aluminium ones. Unfortunately I found that it was much harder to use than the Celestron version in translucent plastic. The extra light passing through the Celestron one made it much easier to see the reflection.

Now if the aluminium one had a large diameter (20mm or so) hole in the centre with a translucent disk set into it and with small hole with a black circle around the hole on the inside surface of the disk that would a real winner. Similar in function to the Celestron one, but just a much higher quality item.

John

[Astro_Baby]

I'd not bother and get a Cheshire collimator OR if I was REALLY obsessed I'd get a Catseye Collimator.

[cdd2455]

Oops, I must be really obsessed, I got the three piece Catseye system in a nice wooden box, best thing I ever did for my Obsession.

Seriously though, they do allow you to collimate to the limit that your focuser, spider, secondary holder and primary support will allow. Takes a while at first, as especially the autocollimator is a bit fiddly, but the end result is worth the time and fiddling.

Bye for now - I've got clear skies steady air and a cooled down, collimated scope. Yippee.

Carl

[TopHouse]

Lucky you, it's pi**ing down here!!!

[TopHouse]

As an aside, my mate works mostly in stainless steel, makes equipment for the food industry and also for the steel industry. If anyone wants stainless steel leg upgrades for mounts etc I can prob get them cheaper than the commercial ones.