Best Drill Bit for Slotting Blue Tube?

I made a jig and slotted a 6" dia. Blue Tube with 1/4" fin slots using a Roto-Zip knockoff from Harbor Freight. Everything worked, but the holes had a lot of rough "slivers" running along the outside and inside of the slots. A dremel and some hand-sanding smoothed everything out, but I was wondering what would be the best high speed cutting drill bit to use. I used a titanium nitride saw drill bit, also an inexpensive purchase from Harbor Freight, which worked the best for me. I also tried with less success (on some scrap Blue Tube stock) a 1/4" spiral cut bit and a 1/4" floor tile and countertop bit.

I plan to continue using the Roto Zip tool, and won't be buying an actual router. The project I'm working on is the Saturn V/ Skylab. Thanks!

Mike Momenee
TRA # 12430 L3

No drill bit, router bit 1/4" shank.
One with up flutes or an end mill.


JD

Or one of these from Dremel, it makes slotting easy, draw slot on tube and cut. The edge cuts and the disc sands. Its rapidly becoming my favorite Dremel accessory for building rockets.

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Edit: I use this disc/cutting wheel on wood, plastic, fiberglass, and cardboard, while they are carbide grit coated they are not meant for use on metal.

rharshberger said:

Or one of these from Dremel, it makes slotting easy, draw slot on tube and cut. The edge cuts and the disc sands. Its rapidly becoming my favorite Dremel accessory for building rockets.

View attachment 275036

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+1. cut off wheels are the way to go.

rharshberger said:

Or one of these from Dremel, it makes slotting easy, draw slot on tube and cut. The edge cuts and the disc sands. Its rapidly becoming my favorite Dremel accessory for building rockets.

View attachment 275036

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Headed out to Wally World to get some of this goodness!

I've pretty much gone exclusively to using my Festool jigsaw for slotting larger tubes. There is an angled plate attachment that helps keep the saw vertical and "on track" during the cut. Super smooth edges.

Here is a link to a great company that sells bits. https://www.hartlauerbits.com

Bosch has good router bits - I would use carbide or carbide tipped.

Don't buy bits from Harbor Freight.

Thanks for the input, guys. I forgot that I had purchased, but never used, a Dremel carbide grit coated cutting wheel as pictured above. I just tried it on some scrap Blue Tube and it is amazing!

I always use a dremel cutting wheel. Just be careful!!! Wear a mask when cutting Fiberglass/ Carbon Fiber! Quantum tube tends to melt as you cut it. You will most likely need to adjust spindle speed and feed rate. Since Bluetube is similar to cardboard, you shouldn't have any problem.

jmmome said:

I made a jig and slotted a 6" dia. Blue Tube with 1/4" fin slots using a Roto-Zip knockoff from Harbor Freight.

Mike Momenee
TRA # 12430 L3

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I buy things from Harbor Freight because of the low prices, but you really have to be picky about what you buy. The prices are low because the quality is also low. One of our member had a set of drills from Harbor Freight. After drilling a 1/8" pilot hole through a 1/4" thick piece of mild steel we tried his 3/8" drill. It barely put a scratch in the steel before it was too dull to do anything but smoke the oil we used as cutting fluid. A 3/8" Dewalt drill went through the steel in about 10 second and was just as sharp and quick for the next 3 holes.

If you need a packing blankets to wrap your rockets in, Harbor Freight is the place to get them for about $6 on sale, if you need high quality cutting bits and tools, you might want to look elsewhere. YMMV

I always had to file/sand my slots clean and bigger after having them cut by ARR

The best tool to use is SOMEONE ELSE!
I hate cutting slots. Gladly pay someone else to do it.

I also built a sled (for 4" BT, will build another for an upcoming 6" build). I use Freud brand router bits in the router table rig. I clamp the tube so it stay fixed in the sled, drill a pilot hole at one end of the slot, then carefully plunge the sled down onto the spinning bit. 30 seconds later I have a clean slot. There's always some cruft with BT but it is easily sanded away.

https://www.rocketryforum.com/showpost.php?p=724169

cbrarick said:

The best tool to use is SOMEONE ELSE!
I hate cutting slots. Gladly pay someone else to do it.

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+1 on that.

But when necessary, I use a 4 flute carbide end mill in a router table.

I use a CNC with rotary axis and a carbide bit made specially for me.

I used a $8 rotary tool and their diamond cutting wheels for a nice , easy to control cut.

Even smoother with some angle iron taped to the tube as a fence .

Kenny

KenRico said:

...
Even smoother with some angle iron taped to the tube as a fence .

Kenny

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I like the angle iron idea a lot - I don't have steady hands with the Dremel, that sounds like a good solution.