Cutting PVC/ABS Pipe at right angles?

pandabarnes

Active Member
Hopefully someone can help with this one...

I keep trying to make things that require pipe, I cut the pipe; the end is wonky, I try and cut a small slice for a detail part; the width varies noticeably, making the part useless.

This has been driving me insane for months, I keep having to shelve projects while I have a rethink, I've tried everything I can think of, chop saw, mitre block, metal hose clamps, clamping in a vice and sanding (turns out the vice wasn't quite able to line up), pipe is too thick for a rotary pipe cutter (at least the one I have).

I can mark the pipe nice and straight, just can't cut/sand it straight.

And for thin sections like rings? Seems like a dark art!

Ok, rant over - thanks in advance for any help.
 
Razor saw, files and sanding block.

Wrap tape where you want to cut then slowly work around it with the razor saw making sure you don't get out of line.
Once done go over the end with a file then sanding block.

My Dark Forces II saber required several thin rings so it took a while.
I don't have access to any machines.
 
You need JIGS for this kind of work (believe me, I speak from experience!). Also, beware that cutting pipe can be dangerous. It's hard to secure the material and if it catches on the saw bad things can happen.

Try building a BOX that fits tightly around your pipe. Make this box as perfectly square as you possibly can. Drive a screw through the box and into the pipe to keep it from rotating. This will hold the pipe and help you secure it for cutting. Then, use the same box as an alignment aid to sand the end true and flush. Thus, cutting is a 2-step process:

1) Using a JIG to secure the pipe, cut it as accurately as you can.

2) Use a large power sanding disc (one that has a table attached to it) and a JIG to secure the pipe, sand the cut end flush and true.

Hope that helps!
 
Your chop saw, if set up properly should have been your best bet so far. I use a table saw with a metal cutting blade and cut tubing all day long at work with no problems. Might try that if you know someone with a saw.
 
Cutting round objects 'square' is a PITA. If you have a square starting edge, you can scribe a cut-guide groove using an engraver held at a fixed distance from a referential stop-plane. Then the pipe is held against the stop-plane and rotated against the engraver/scriber. Of course, this doesn't help if you don't have a 'fresh, square' edge to work with...the main point is that rotating the pipe laying on a surface will move about its centerline parallel to that surface. Best result will come from using some kind of jig.

Also consider using a hose clamp to establish a straight end cut. The kind I mean has a worm gear drive on a strap. When tightened up & the edges aligned, it should be 'square'.

Another trick is to have another pipe that fits over the one you want to cut (a 'telescoping' set). If it has a square end, then it can act as a guide.

That's all I've got...

Regards, Robert

[Update: Well, something else occurred to me: the pipe fittings! They are made for the various pipe sizes, are a tight fit, and have a square edge. Instant cutting guide - at least for PVC...]
 
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I use pvc pipe all the time for my models. Making right angle cuts on round stock is difficult to say the Least. I find the best way to cut it is on a lathe. In fact it's a breeze on a lathe. I have the mcro-mark 7x16 mini lathe. It runs around $800 bucks if you get it on sale. Closer to $1,500 with all the necessary accessories. It's an expensive toy for sure. However once you get one of these babies you will use it for everything! You could also look at a wood turning lathe, they are a lot cheaper. I have also seen on YouTube a few videos where guys use a power drill and make a jig to hold it, and use it like a lathe. That may be an option for you too. I hope this is of help to you.
 
Here is what I'm talking about. I just fished there out of my spare parts bin. I machined these out of PVC pipe. For your application, it sounds like the two in the foreground is what you are looking to do. As you see I have created all kinds of profiles using the lathe. The lathe is supper fun to use too. Your imagination is the limit with this tool. image.jpeg

I also use the lathe for "home repair"projects......... That's how I justified it with my wife ;)
 
For pvc the pipe cutter is very good,
how model maker Martin Bower taught how to do it was to wrap an a4 piece of paper around the pipe , by aligning the edge of the paper your ensuring a square cut (like rbeach84 hose clip/ jubilee clip , great idea )
you can then run your saw against the paper edge rotating the pipe as division 6 said

i would not use rotary cutters for pvc, if your not used to using them you can distort the pipe , you could use them to mark the pipe before proceeding with the saw

i have used a dedicated PVC pipe cutter, which is a ratchet driven blade which is great for plumbing , but I'm not sure how fine a finish it would give you.
i would try and find someone you know is a plumber and explain that you want to be able to cut clean pipe work. Get them to demonstrate these methods (pipe cutter and pvc cutter) and at least then you can move forward .
image.jpeg
 
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Hey thanks for all the replies.

I've managed to talk someone with lathe into cutting/squaring off for me so hopefully that will sort it this time around.

I need to find a solution for future projects though so thanks for all the suggestions - I did try pipe cutters already but maybe I got a rubbish one - it just wasn't giving me clean cuts and I couldn't do thin slices with it.

Hose clamps I also tried but I had real issues where the bolt makes the band wider, once I moved it around it never seemed to line up with the cut again.

I'm thinking of investing in a bench sander and a few other power tools soon so I'll give that a go as well. Sander sounds like a good option, lathe might be something to save up for!

I also wondered if I could drop some steel angle into a vice I have for drilling pipe, clamp the pipe in and use the angle end to sand by hand, I attached some pics (sorry for the quality!). So the angle would be a sanding guide, assuming the angle is square! (the vice wasn't).

.20160919_183952.jpg20160919_184013.jpg

Thanks again for all the help
 
The angle bracket looks like a good trick! You could even incorporate a clamp using a second bracket and a nut & bolt through the slotted hole. In any case, it should be mounted on a board to prevent flexing.

R/ Robert
 
One of the best tools any modler/artist should have when working with pvc pipe. And they make different sizes too. This one is up to 2" and easily cuts straight and angles cuts. For doing a lot of cutting, the best is a chop saw. Jus make sure you wear eye protection. If you are not handy or novice with this type of tool (chop saw) stay away. All kinds of things can go wrong if you are inexperienced. The shears are easy to use even for a beginner. Hope this helps
image.jpeg
 
Thanks guys - I'm having a look at the various cutters and found a few slightly more expensive, better quality ones that might do the trick for some sizes.

I've just bought a bench sander too! Wanted one for a while but hopefully that'll help with the squaring off.

Gonna play with the angle and the vice as well, so hopefully i'll find some combination that works.

In the meantime the parts I managed to get lathed are all done and looking very accurate so I can at least work on something!

Thanks again.
 
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