Thread: advice on cutting perspex tube

DON'T USE A CIRCULAR SAW!!!!

The teeth are way to coarse -you are likely to shatter the whole thing. Very fine teeth are the order of the day - hacksaw is good, bandsaw (carefully) is good. Even a jigsaw is ok.

Circular saw = shrapnel!

Your V sled idea would work well on the bandsaw - slowly slide the tube into the blade and through. Hold firmly - you don't want it being grabbed by the blade and spun! If you do want to rotate the work during the cut, remember the bandsaw blade cuts down, so rotate the work slowly in the opposite direction.

... and use the slow speed on your bandsaw, if it has 2 speeds ...

I don't have a band saw

I was planing on using a fine tooth blade in the TS.

How would i set up to use a jig saw?

Use your same V jig, and include somewhere that will hold the jigsaw in place (overhead)- doesn't have to be elaborate. If the blade is long enough to reach the pipe and cut an opening that is good, but you may then want to change to a shorter blade.

Position the opening directly below the jigsaw, with the blade through the new slot you just cut, and then slowly feed the pipe into the blade, rotating it in the V jig

Or jigsaw as Stu said, ensure it's a new sharp blade & don't rush the cut, let the blade cut at it's own speed as pushing it can cause small stress cracks off the side of the cut.

Heat is the enemy, bit of wax or some sort of lube on the blade will help reduce friction.


Cheers................Sean

If you use a fine tooth saw in the TS it will be fine, the plastic's industry does this all day every day with no probs

How many cuts are you going to make , all the plumbers I have seen cut by hand with a hand saw or if pressed a hacksaw , that thickness pvc at 150mm diam can be cut by hand quicker than it will take you to set up a jig, if it has to be perfect mark it with a felt pen and cut it with a hacksaw, or if your any good with a hand saw , slowly and cut to the line , either way it will take less time than you have spent posting
Sometimes the old easier darkside ways are better that trying to work out a way to do it burning electrons

Rgds

Hot wire cuts it best, bit impractical for a one off job tho.

Originally Posted by Ashore

How many cuts are you going to make , all the plumbers I have seen cut by hand with a hand saw or if pressed a hacksaw , that thickness pvc at 150mm diam can be cut by hand quicker than it will take you to set up a jig, if it has to be perfect mark it with a felt pen and cut it with a hacksaw, or if your any good with a hand saw , slowly and cut to the line , either way it will take less time than you have spent posting
Sometimes the old easier darkside ways are better that trying to work out a way to do it burning electrons

Rgds

'Tis perspex (acrylic) rather than PVC, Russell.


Cheers.................Sean

Yep the plastics industry cutts with a circular saw as a matter of course.

A very fine blade is the way to go. a negative rake blade as used for aluminium works best.

With any plastic there is always a threat of a grab or catch. It is very much like cutting aluminium, but the consequences are different.

You MUST have very good control of your work AND all your sawing technique need to be perfect.

Cutting tube has it chalenges the thinner the tube the bigger the chalenge.
The biggest chalenge is getting the cut to be clean and match without a step.

Some form of sled or carrier will be imperitave.
You will want to advance the tube into the blade, then rotate it, so a stop on the sled will help keep the job properly engaged.

Push the sled in then hold it in with your hip.

Blade engagement is important. Too much blade and you have recutting problems and bigger chance of a catch. Too little blade and the cutting angle isnt right, finish will be poor, controll will be hard and bigger risk of a catch.
You want the teeth well thru the material but not too far, cutting angle will depend on material thickness.

Thick material teeth should engage the material quite directly thin material a much shallower angle. The shallower the more the tube will want to self turn.

For a clean square cut without a step an endstop board the full height and width of the tube is helpfull.

once engaged you will need to rotate the tube. Conventional wisdom will say against blade rotation, I have found this can be harder done than said. That is pulling the back of the tube up. I have found that pushing ( well not pushing) the tube forward and holding the tube down and to the fence works best for me. You must understand here the important thing is CONTROL of the material slow steady advance and absolute controll of the work.

remember I have used a nagative rake blade and optomised by blade height to minimise self feed.

Remember acrilic is tretcerous and unforgiving, ( poly carbonate is worse).

This is not a task for the unskilled beginner.
Care, controll and good technique are imperative.
Practice with some heavy pvc drain pipe first.

A good steady cutting rate and a sharp blade and proper presentation and you should not have any heat problems. wax and lube wont help much

Plactics will grab, crack & shatter.
The consequences of bad technique are much greater than with wood.

A great deal of care & controll is needed here


A band saw would be safer.

cheers

I'm with Soundman on this. Use the circular saw and the X cut sled is ideal. I've cut Lexan sheet on my Triton and it worked a treat.

MOST important thing is to use the fine tooth blade AND make sure that the blade teeth only just go through the perspex - DON'T go any further than the depth of the tungsten carbide teeth - otherwise they'll catch on the perspex. Which would be BAD

Which means you'll have to make many little cuts...

Originally Posted by scooter

'Tis perspex (acrylic) rather than PVC, Russell.


Cheers.................Sean

Read to fast Perspex is another kettle of fish

thanks for all the tips guys. i'll definitly need to carefully think this through.

I need to make around 6 cuts, but i need them to be square, hence i am keen to use a jig/sled.

I think i might some how built a jig for the jigsaw. seems like the safer option.

If you havn't already got the stuff, order it cut to size.

Apart from fiddle & diddle bits and pieces, the best thing to do with acrilic is to buy it cut to size.

then any disasters arent your problem.

cheers