Hello, I hope there is a solution for something I’m trying to accomplish. I hope someone can help me to think of a way…
Picture a 2″ x 24″ tube. It is made with paper that is glued and wrapped in a spiral multiple times to obtain a .2″ wall thickness. This tube is very rigid (cannot crush by hand) and the walls are pretty solid, albeit made of layers upon layers of paper.
I need to cut four 1/4″ slits from on one end of the tube going down length by 4″. The slits will be like a cross (90 degree angle from each other).
I have attempted to do this with a jigsaw and a Rotozip bit. The Jigsaw cut okay with the first cut across two walls, but when I did a 1/4 turn of the tube to cut the remaining two, the paper starts flapping around. It seems I need a saw or something with a 1/4″ blade that will go so fast that the tube doesn’t have time to react.
Does this make sense? Any questions? I will appreciate any thoughts!
Replies
Sounds like a sharp 1/4 spiral cut router bit in a router table or shaper. You might consider making a soft wood insert to slide into the paper tube. Having a backing while cutting should make it more stable.
If you can support it from inside, treat it like a mortise and chop it out with a chisel.
Bandsaw.
You could buy this and widen the slots or glue a wooden dowel inside your tube to make it stiffer and rout or bandsaw the slots.
https://locprecision.com/products/slotted-cardboard-airframes?variant=39778658648255
You must have used some sort of cylindrical material to wrap the paper around. Re-insert that material, cradle it, and then chisel it out as _JF1_ mentions. Chisels should be newly sharpened. If the slots are perpendicular, a bandsaw cut using a cradle jig would also work.
(Reply meant for OP)
I think Gulfstar's link has the answer. Start your cuts half inch or so from the end and then open to the end by hand.
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I think I would probably attempt this in one of two ways, with a knife( utility , exacto,) or with one of those reinforced cutting wheels and a dremel tool. Its paper after all. Nothing with teeth. Being able to insert some kind of backer for support like a dowel or a plastic pipe would be a great help or possibly even necessary. If you made this tube yourself you must have had some kind of cylinder to wrap the paper around that would fit. Could you, after cutting a slot in one direction treat the edges with something like superglue before making the cross cut to prevent some kind of unraveling? I have one of those sets for cutting holes in gaskets....I would probably use that to cut the ends of the slots first before I made the straight cuts. In thinking about this I just remembered I have one of those tools for cutting mat board, makes very clean straight cuts for framing pictures. Unless I was making many of those I don't think I would look for a machine solution.
Thanks to all of you! This was the first time I've ever posted in a forum, and am so happy I did.
First, I had not thought of supporting it from the inside. That's a great idea.
Second, #Gulfstar, I didn't know tubes with slits such as the ones you shared even existed. This is precisely what I was looking for, with the ability to finish snipping the ends myself, but they cost quite a bit, and I would be making a lot of these pieces.
The tubes are being made for me, but the manufacturer will not do any cutting for me. You have all given me some ideas to try to make it work. I'm going to go give them a try now. If you think of anything else, please do not hesitate to share.....It's very much appreciated!
They also exist made of phenolic and fiberglass for high power rocketry, they will sustain mach1 speeds !
Bandsaw. Flexback blade will pretty much do the job based on what is given!
Drill out the end of the slit before cutting.