Geoff I don't know any Sydney suppliers. I had a quick look at the Action Aluminium (Vic & Qld only) and 150mm ( 3mm wall thickness) seemed to be the largest diameter I could find.
for the dimensions you are asking about, I would suggest looking up a sheet metal business. They would have no trouble knocking up something that size. It will most likely have a seam, which you will need to take into acount.
I don't know if they can help but they do have a manufacturing process for aluminium tubing possibly your size but could be for commercial application.
I use Capral Aluminium www.capral.com.au for all my needs, al-be-it for square tubing for racking systems in my vans.
At least it is a staring point and would be good to know as i am considering a large appeture refractor project, although i was considering my first project with heavy duty PVC Conduit.
for the dimensions you are asking about, I would suggest looking up a sheet metal business. They would have no trouble knocking up something that size. It will most likely have a seam, which you will need to take into acount.
Mental.
Yeah, I guess that's the way to go. It's just that aluminium weighs less, which is why I'd prefer it.
Geoff
Geoff, are you looking at reworking a 6" reflector.
If so, have you looked into if there may be an old 6" scope that has been decommisioned or even if there may be 6" seconds lieing about with a retailer? The 114mm reflector I made for a cousin was made with a surplus mirror & I fluked onto a disused empty tude from a retailer.
Geoff, are you looking at reworking a 6" reflector.
If so, have you looked into if there may be an old 6" scope that has been decommisioned or even if there may be 6" seconds lieing about with a retailer? The 114mm reflector I made for a cousin was made with a surplus mirror & I fluked onto a disused empty tude from a retailer.
Mental.
Yes,
After more years than I care to own up to, I've got the urge to push glass again. I'm going for a 6" f/5 to get my hand back in again before I go for something bigger. I'll be putting it on my G8 for astrophotography, hence the need to keep the weight down because the G8 is not really a heavy duty mount.
Looking around for an old tube is certainly worth a try.
Geoff
Rather than using a solid tube and if your metal working skills are upto it, make a truss tube with a dovetail mounting plate in the middle.
Doomsayer's beautiful scope which is described in his ATM thread shows what I mean, but where his truss ends at the position of the cassegrain primary, duplicate the anterior truss assembly to the back so the end product resembles a romboid shade with both pointy ends cut of.
Have a look at this price list http://www.fab.net.au They are advertising 203X3mm tube at $55 a meter
Just click on the aluminium price list they are a Qld based company but they might freight.
Rather than using a solid tube and if your metal working skills are upto it, make a truss tube with a dovetail mounting plate in the middle.
Doomsayer's beautiful scope which is described in his ATM thread shows what I mean, but where his truss ends at the position of the cassegrain primary, duplicate the anterior truss assembly to the back so the end product resembles a romboid shade with both pointy ends cut of.
The mounting plate would then sit below the central brace.
Very old school arrangement but visually striking.
Just a flight of fancy, .
Mental.
Looks good, but probably beyond my skills. However, the other F o F I was considering was a round wooden tube. There is a good thread on Cloudy Nights discussing this. I've thumbnailed a pic--looks magnificent.
This looks good, is lightweight and seems easy to make. I'll bear it it mind, but the final choice doesn't have to be made yet. I'm only picking up the glass in 2 days time.
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