How to cut fin slots?

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bsexton

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For someone who has limited power tools (me) how would you recommend cutting slots in Dyna-Wind (Giant Leap) tubing for G10 fins that you don't want to got all the way to the end of the tube?
 
I didn't know at the time I ordered the body tubes what I wanted in the way of fin slots. Not going to send it back now...
 
Fiberglassed tube isn't the easiest to cut without power tools. You could try a razor but you'd waste your time. Get a cheap Dremel and cutoff attachments (heavy duty fiberglass ones recommended) for one of your cheapest and most flexible possibilities. A fine tooth jigsaw will do well but then you have a problem of getting the blade in position without cutting into the ends. There are many other ways with other tools but these will be the cheapest/easiest for someone who needs to buy the tools to do it.
 
I didn't know at the time I ordered the body tubes what I wanted in the way of fin slots. Not going to send it back now...

I've cut some pretty thick tube (not FG) with a dremel and a cut off wheel like the suggestion...it took a steady hand and care, and time. The cut was ragged before it was all done..but I was doing "thru the wall" so the attachment to the MMT was the real strong point and glassing over and filleting the fin slot anyway...so the rough uneven cut wasn't as big a deal to me.
 
You might be able to set up a Dremel with the plunge router accessory and a diamond-tipped bit to cut an even and straight slot in the tube. You would probably need to create a box sized to fit over the tube with a slot in the top (gap between two boards). You would position the router attachment on top of the box with the router bit extending down to the tube through the slot in the top.

I have also heard of using a either a radial arm saw or a compound miter cut-off saw for this.

MarkII
 
The EASIEST way is to ask someone in your club to do it for (with) you.

If someone is set up with a plunge type router and has a guide box for that size air frame it will take no time at all.

If they don't have a guide box...ask them if you build the box and buy them a new bit or two can you use their router.

Just a thought.

Tom
 
I shouldn't say I am completely without power tools. I do have a Dremel with a fixed router attachment (not plunger) and a jigsaw. I may look into purchasing a plunge router attachment and set up a jig. Thanks for the responses...
 
An X-Acto knife can and will work -- been there, done that. Just takes a bit of patience. It's easier to do on cardboard tube than phenolic, but it can indeed be done.

A Dremel cutoff wheel (reinforced; don't use the unreinforced ones -- they shatter too easily) on a flex shaft is my preferred method and makes this a quick and easy task.

I've slotted cardboard, phenolic, fiberglass, fiberglassed cardboard, fiberglassed phenolic, and phenolic w/ carbon fiber, all with a Dremel cutoff wheel. Never had a problem.

-Kevin
 
Bruce,
I have a 3" high speed air cut off tool that shold do it with a steady hand.
It's like a large Dremel with a cut off blade. Cuts steel with no problem.
If you want to bring it out here, we can give it a try.
I also have a plunge router you're welcome to try, but you would have to rig up some type of a guide box.
Tim
 
I've cut some pretty thick tube (not FG) with a dremel and a cut off wheel like the suggestion...it took a steady hand and care, and time. The cut was ragged before it was all done..but I was doing "thru the wall" so the attachment to the MMT was the real strong point and glassing over and filleting the fin slot anyway...so the rough uneven cut wasn't as big a deal to me.

This is the method we suggest for our MPR kits, with one difference. STack cutting wheels together to reach the width the fin slot is supposed to be. With a steady hand simply move the stack of blades cutting along the alignment line. Do it right and you only have to make one cut per fin slot.
 
This is the method we suggest for our MPR kits, with one difference. STack cutting wheels together to reach the width the fin slot is supposed to be. With a steady hand simply move the stack of blades cutting along the alignment line. Do it right and you only have to make one cut per fin slot.

I've seen that mentioned elsewhere, as well. Seems like a good method. I've not tried it, myself.

-Kevin

Oh, and it's probably best not to let a Llama handle the Dremel....
 
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