Need Ideas to Rip Cut a Tube

[Bob Winkler]

I have a lexan tube that I need to "rip" down the center to make two semi-circle halves. The tube is about 10" diameter and about 2 foot long. I'm worried about guiding this accurately to make a straight cut and also chip-out of the Lexan. To be safe, I thought I would use a metal cutting blade on my MM16 bandsaw.

Does anyone have any good ideas to keep the cut true and not ruin the tube.

Thanks in advance.

Bob

[Tom Walz]

sacrificial wooden trough?

Put the tube in a v shaped trough and cut through both.

[Rick Moyer]

sacrificial wooden trough?

Put the tube in a v shaped trough and cut through both.
Yep. Can't speak about chip out for your material, but I was asked to rip some small pvc pipe in half lengthwise. I made an open-bottomed box and ripped the pcs on the table saw against the fence. worked very well. Something similar should work for your application, probably on bandsaw though for that size unless you can rip-and-flip.

[Matt Meiser]

When I cut Makrolon, Bayer's version of Lexan, on the TS I didn't have chipout problems but I did get some melted slag on the back side of the cut. Not enough to be a problem for my use but something to be aware of. Fine teeth may actually not work as well as courser teeth, but I'd contact the blade manufacturer for advise.

[Dan Hintz]

If internal tearout is a concern, one wasteful way to mitigate that would be to put a wooden dowel inside that matches the ID of the acrylic tube.

[Rick Moyer]

yeah but his tube is 10" diameter!!

[ray hampton]

can the blade be reverse on the saw so that it are cutting backward,

[Joe Bradshaw]

I would make a C shaped holder the same height as the tubes od and just long enough for the tube to fit snugly. Use a length of all-thread to hold the tube firmly. Cut one side, flip over and cut the other side. Use masking tape on the inside of the tube on the cut line. Would take a few minutes to make, but you would be able to do the cut safely.

[Jim Neeley]

We call that a carefully turned stump! :-0

[Charlie Velasquez]

An open on top 10" box, 3' long, a router with a quicky auxillary 1/4" hardboard base 12" long with a fence screwed to it 5" from center and a small veining bit.

[Peter Quinn]

I'd use the BS, make a sled with some v blocks and a piece of plywood you cut through, a little hot melt glue to keep the tube in place through the cut, not sure the best blade for lexan. I could also see making a 10" box around the tube, putting plywood on the ends and cutting it on the TS, cut/flip end for end, cut again...the plywood on the ends keeps the things together as your lexan is probably not much more that 1/4" thick?

[Bruce Wrenn]

I would make a right angle carriage for table saw. Bottom leg needs to be 5" wide from where it meets the vertical leg, and vertical leg needs to be over 5" high from top of bottom leg. Using 3/4 ply, bottom piece would be 5" and vertical piece would be at least 7" high to allow clamping the pipe to carriage. Clamp pipe to carriage, and cut bottom, them rotate pipe 180 degrees, clamp to carriage and make second cut.

[Keith Westfall]

cut 2 10" squares with a hole in the EXACT middle, put a through bolt (ie ready rod) through it and tighten up. Raise the blade just enough to cut the tube and then turn it over and do the other side.

[Andrew Kertesz]

If you cut it on the TS use an 80 tooth blade. We use a Freud 80 tooth TCG blade without any chip out or slag problems. If you use the bandsaw many options would keep the tube level. Quickest and easiest would be to glue a sacrificial sqaure of wood to each end and cut through that.

[Larry Edgerton]

I cut plastic pipe on the tablesaw, and I have cut flat Lexan on the tablesaw with no issues.

What I do for pipe is make an L out of plywood, the side that is vertical a bit more than 1/2 the pipe diameter on the inside, in you case 5"+. The lower part of the L that is horizontal I make wide enough that it is it is a bit more than 1/2 the pipe diameter on the inside. I screw the pipe to the vertical at each end cradled in the L and run a bead of hot melt down the length to stabilize, then run it through the saw with the blade just coming through the lower side, flip and repeat for the other side.

In my opinion it is too hard to control roll cutting pipe on a bandsaw freehand in a trough. Tried it and got better results from the tablesaw. I have a tablesaw blade made for plastics, but can't really tell you what is different about it, never really looked.

Larry

[HANK METZ]

Use a 24” or longer “V” block secured to the fence, center the blade at the v’s bottom. Run it into the blade about 12” and set in a wood wedge to match the kerf. This will prevent twist or roll, and also keep the stock from clamping the blade. I use a flat top blade with a negative rake for my plastics.

- Beachside Hank
Improvise, adapt, overcome; the essence of true craftsmanship.

[Bob Winkler]

Wow- thanks to you all. There are some great ideas here. I especially like the square ends connected with a threaded rod for the TS, and the use of hot glue on a BS sled. I can't wait to test some of the ideas this weekend.

Thanks again,
Bob

[Bob Winkler]

Just by way of update, I cut the tube this weekend using a threaded rod with square ends. I connected the plywood ends with a lengths of plywood top and bottom and ran it through my table saw. The plywood top and bottom acted like a zero clearance insert and the cut was very clean. The only issue was a little "remelting" of the tube which was easily cleaned up with a spokeshave.

Thanks for all the great ideas.
Bob

[ray hampton]

Just by way of update, I cut the tube this weekend using a threaded rod with square ends. I connected the plywood ends with a lengths of plywood top and bottom and ran it through my table saw. The plywood top and bottom acted like a zero clearance insert and the cut was very clean. The only issue was a little "remelting" of the tube which was easily cleaned up with a spokeshave.

Thanks for all the great ideas.
Bob

high fives to the cut