Cutting Body tubes for fins

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Well-Known Member
May 22, 2015
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What are techniques you use for slotting tubes for fins. I have some 5.5in tube from loc a started cutting with an exacto knife. It is a tedious proccess. Are there faster betters ways to do this?
For loc cardboard tubes, after drawing the lines for the area to be cutout with the aid of a piece of aluminum angle, I tape a metal ruler down next to it to use as a guide. I then use multiple light passes with a sharp xacto blade to cut thru the tube. Then I re-position and re-tape the ruler down and finish the cuts.
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The Dremel 543 cutting wheel is the bomb.

I have also used a steel rule and Exacto knife. Slow and steady is the ticket.
In the off chance I'm actually working on a rocket, I like to use a piece of angle aluminum to get my straight lines then I lay out slot areas with masking tape and freehand it with a dremmel diamond wheel. I have the body tube mounted in angle iron so can cut a heck of a straight line just holding the dremmel with both hands.
I put it into the dividing head on my mill and go from there :wink:

Before that I had been known to put the Dremel in the lathe as a toolpost grinder and use a cutting wheel to make the slots.

Before I had my mill and lathe the Dremel and a cutting blade did a fantastic job. Really easy. Just mark it out accurately, take your time and use safety glasses.

I suspect there are some other stores in the US (not sure of their names) that have knock-off versions of the Dremel at a cheaper price. Or fork out the $ and get a Dremel and be happy :). You won't regret the purchase.
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In regards to using a Dremel, or other rotary tool, with a cut off wheel, what is recommended... High RPM, Mid RPM, or Low RPM?
I usually run it a little under half-throttle for fiberglass. For Cardboard I crank it up a bit more.

Have a go and see what works for you. If you can clamp the workpiece and use both hands on the Dremel you will get better results and there is less chance of breaking the cutting disks if it grabs and tries to do a runner.