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plunger
01-26-2012, 02:52 AM
I need to make 400 brackets to hold the absestos gutters in a complex. I was hoping someone could put me in the right direction as to how to make this. I made a 87mm die to bend the bracket. The pipe is 90mm . Is there a formula to know how to make the die .I seem to get alot of springback and land up with a http://i941.photobucket.com/albums/ad254/eugeneeman/007-1.jpgbracket of 110mm.Is this maybe a bad way to try to make this bracket

millwrong
01-26-2012, 03:45 AM
A block of wood cut out in a band-saw . Use in a hydraulic press. You will have a male and female form, which will easily do 400 pieces. First bend your 90 degree tabs, insert in die and press. Adjust as necessary. This kinda assumes a press and band-saw! Love the shop flip-flops!

winchman
01-26-2012, 05:35 AM
I didn't think anybody made anything out of absestos anymore.

Have you looked at McMaster-Carr? Their 9439T16 Two-Hole Mount for Pipe and Rigid Conduit looks pretty close to what you want, and it's only $2.55 each in galvanized steel.

You don't say what you're making them out of, but I'd certainly consider stainless steel pipe strap.

plunger
01-26-2012, 07:16 AM
These are old absestos downpipes.I wanted to make them out of aluminium 25x3mm flat bar. I was unsure of making them out of stainless because its so dam hard to drill.Also isnt it hard to paint .I am worried that the aluminium will corrode especially at the drilled holes.I was told aqnodising would not make much difference.I live in s africa so unfortunately there is no master mcCarr in my country.Millwrong I dont own a band saw or a press Just a 4x6 bandsaw and a 3ton arbor press. Could I use that?

plunger
01-29-2012, 11:10 PM
wood would not be too soft to use

oldtiffie
01-29-2012, 11:42 PM
Making the brackets is one thing.

The possible consequences of/with working with or on asbestos products can be horrific - and has a possible multi-decade latency period.

Read these carefully:

http://en.wikipedia.org/wiki/Asbestosis

http://en.wikipedia.org/wiki/Asbestosis#Treatment

http://en.wikipedia.org/wiki/Mesothelioma

http://en.wikipedia.org/w/index.php?title=Special%3ASearch&search=Asbestosis+Australia&button=

Check your local OH&S/asbestos advisory/regulatory body - before you start working on or with asbestos or asbsetos-based products - the more so if the product (roofing and down-pipes) are "weather-worn", old and showing signs of protruding or loose fibres.

This is real top-grade OH&S stuff.

This is not and is not meant to scare anyone.

plunger
01-30-2012, 11:29 PM
Old tiffie I wont be cutting the pipes ,just replacing the brackets.I have however cut many facsia and barge boards in my life without using a mask .When you are young you are bullet proof. I hope I dont pay the price later on in life.
These downpipes are well painted and don't think they are a risk. There is a new product called new spec which looks just like asbestos that has replaced these gutters and barge boards etc.Do you think these brackets could be pressed or could they be formed with a bender?

J Tiers
01-31-2012, 12:22 AM
I think the 90 bends are the hard part..... that and cutting strips if you have to do that.

The round part can either be formed as and where used, OR pre-formed over a wood form.

I suspect that minimal tooling is the key.... I'd be tempted to form over a piece of pipe.....maybe by hand... Thin aluminum would form OK, and if you establish the proper overbend, you can put a block to stop the bend.

An afternoon of boring work and they are all bent.

Non-alloy aluminum is resistant to weather. use the screws for corrugated roofing, the seal acts as an insulator.

Some types of stainless steel WILL react with aluminum in presence of moisture..

BobL
01-31-2012, 07:23 AM
I just made a dozen or so 150 mm PVC ducting bracket that needed a similar calculation

Having an exact die dimension is not that important, I would just work to a fixed length of strap as it's not so much the formed size but the installed size that matters.

The length of strap you will need is (2 x r) + (∏ x r) plus whatever size you want on either side of the right angle bends.

ie (2 x 45) + (3.14 x 45) = 231.4 mm + say 50 mm for each of the right angle bends.

I would accurately mark and bend the right angles first and then form the curve using your die. If you bend around using your existing die it won't matter if the curve is not exact as they can be bent or opened up the extra bit on installation.

I would make a couple first and see how snugly they fit a real pipe and then adjust the length of strap accordingly.