Yet Another Pier

[tmarkuk]

It feels like pier building season every time I look in here at the moment, and a good thing to, they really do make all the difference as I have found out. Here's mine :

Excuse the very messy shed, this was taken just after I finished getting everything back together.

I based my design largely upon the ideas presented in this article. The main points I took away were :

1) Don't get hung up on tube wall thickness, the requirement is that it can hold up the weight, it does not have much effect on stability at all.

2) Tube diameter is the most important thing, get as big as you can.

3) A telescope pier works like an inverted pendulum, make sure the base is heavily reinforced against movement.

The pier itself is build from the following parts :

1m length of 6" diameter steel tube, 2mm wall thickness.

10mm thick steel plate, 3x250mm square, another 250mm square to be chopped up for gussets.

1 length of m20 threaded rod and bolts.

My dad kindly welded it all together for me, the hardest part by far in the construction was drilling the 20mm holes for the uprights. I bought all the parts off ebay, and painted it with whatever car paint I happened to have in the garage, I had a big can of undercoat, another of Mitsubishi blue and some clear coat which was handy.

The adapter plate I bought from Altair Astro at astrofest, though annoyingly the CGEM altitude adjustment bolt actually sits lower than the mount base, so I had to put in a spacer to stop it hitting the top plate.

It currently holds a CGEM mount, 250mm F4.7 reflector, 70mm guidescope and all the cameras and other parts to go with it. I've had a few nights use with it so far and I'm massively pleased with it.

[Daz1969]

Excellent!

I must admit i hadnt thought of gussets. Do you think they are that important?

Just about to start my own:)

[Bizibilder]

I would definately go for gussets on the pier. They have the effect of making the whole thing MUCH more rigid - they are not there to "make the joints stronger" simply to add rigidity. They will considerably reduce the flexibility of the tube used in effect making it behave like a much larger, stiffer beam.

You can see in the picture mine go just ABOVE half way up the tube and are welded in several places along each joint.

[gary1968]

NIce one tmarkuk, it looks the biz mate. You'll have much faster start up times now.

Gary

[Daz1969]

That looks fab , I shall now be adding gussets.

I learn so much on here its great:)

Daz

[tmarkuk]

I'm slowly getting to the point where I can go from turning everything on to imaging in a short space of time. However with clear nights few and far between, coupled with a busy work schedule it's slow progress.

I've just come in for the night, which is a pity as it's actually clear out all night but a 5am start tomorrow doesn't allow for a late night. I did however get the CGEM PEC training done, down from +/- 15 arc sec to +/-4, and got my alignment a bit better dialled in.

I had set it up to grab a couple of hours imaging but then the CGEM suddenly stopped responding and gave rather nasty error codes which is a bit worrying. I got it working again but I'll have to keep an eye on that.