Which tube material for pillar mount?

[Chris]

Hi,

I picked up a very industrial looking Meade Pillar mount which sits low down for carrying large Newtonians. However I would like the option to use it with a large achromat or SCT so looking for 4" OD tubing with around 2mm wall thickness for a taller pier.

I found Metals4U online and they have lots of choice in terms of material for 101.6mm Tube - Ali, mild steel, Stainless, Galvanized etc

I'm not sure which to choose? Leaning towards Ali, but I would like to keep it as solid as possible. It's going to be obsy based and I'm likely to stick a large refractor on it at some point. 

Any thoughts?

https://www.metals4u.co.uk/aluminium/c1/tube/c22/101.6mm-x-1.6mm-(-4-od-x-16swg-)/p2814

https://www.metals4u.co.uk/mild-steel/c6/tube/c2239/tube/c56/101.6mm-x-1.6mm-(4-x-16-swg)/p2353

 

Edited August 23, 2019 by Lockie

[wimvb]

For a pier you want something sturdy. Since you're probably not going to carry it around, choose the stiffer and heavier material. 

Can you afford this? 

https://www.metals4u.co.uk/mild-steel/c6/tube/c2239/tube/c56/152.4mm-x-3.2mm-(6-x-10-swg)/p2356

Or maybe not relevant in your situation

Edited August 23, 2019 by wimvb

[Chris]

1 hour ago, wimvb said:

For a pier you want something sturdy. Since you're probably not going to carry it around, choose the stiffer and heavier material. 

Can you afford this? 

https://www.metals4u.co.uk/mild-steel/c6/tube/c2239/tube/c56/152.4mm-x-3.2mm-(6-x-10-swg)/p2356

Or maybe not relevant in your situation

Thanks, it needs to be 102mm 4" to fit the EQ mount puck, but I was looking at the 4" mild steel tube. A vote for mild steel over Ali then, cheers

[jock1958]

I wanted a light weight extension tube for my Tak FC100 and AZ4 tripod setup mainly so I can carry it around easily.

I already had the 16” skywatcher extension tube but it weighs a ton so I bought some aluminium tube off metals4u and it works very nicely.

If you cut it to long it will transmit vibration as aluminium obviously doesn’t have the weight of steel so I ended up at 5” as the optimum length for my setup.

[Chris]

12 minutes ago, jock1958 said:

wanted a light weight extension tube for my Tak FC100 and AZ4 tripod setup mainly so I can carry it around easily.

I already had the 16” skywatcher extension tube but it weighs a ton so I bought some aluminium tube off metals4u and it works very nicely.

If you cut it to long it will transmit vibration as aluminium obviously doesn’t have the weight of steel so I ended up at 5” as the optimum length for my setup.

Looks really good Jock Good point regarding vibrations also, I'm going to need a 1.3 metre pier tube if I pick up a long refractor! I think I'd better go for the mild steel and just give it a couple of good coats of Hammerite to protect it.  

[jock1958]

A 1.3 metre steel tube will be heavy but if you are using it in an observatory setting then I would go for steel, much more solid and a lower C of G. 

Aluminium is a much lighter and a softer material which will transmit vibration - not good at high magnification which is why I cut my tube down  from 12” to 5”.

[Rocket Stars]

Mild steel should be the best option for a permanent pier thingy. 

Absolutly best would be casted iron tube. But its a hassle to work with. And too expensive. 

If you are not going to move it around. Consider filling it with sand. It is easy to remove. If you need to move things around. 

[Rocket Stars]

Hmm.. Im about to redo the old plumming in my house shortly.

If anyone is up for used casted pipes. Its free to collect If you take em out. 

Would be a ”cracking” good pier! Hmm.. Now Ive got plans! 

[Chris]

12 hours ago, Rocket Stars said:

Mild steel should be the best option for a permanent pier thingy. 

Absolutly best would be casted iron tube. But its a hassle to work with. And too expensive. 

If you are not going to move it around. Consider filling it with sand. It is easy to remove. If you need to move things around. 

Read my mind! I have two 5 five year olds, so plenty of play sand laying about in the garden  

[Rocket Stars]

5 hours ago, Lockie said:

Read my mind! I have two 5 five year olds, so plenty of play sand laying about in the garden  

I know what ur talking about!  Though, my kids are about the age of moving out. (more may left to astro gear the, lol)