Using a Flycutter

We've had at least as many "flycutter threads" as "glue threads"...

-dave w

Setting it is mostly trial and error. I use a sheet of masonite scrap and verify the size until it is right. Keep the speed under 500 RPM. Cut halfway through then turn the stock over and do the rest. If you are using a big sheet of stock, you can hand hold, but use common sense (clamps) on smaller pieces. By no means do you want to wear gloves, or long sleeve shirts, or any jewelry.

I've cut over a thousand centering rings in one day with these methods.

Mike Fisher Binder Design

Most "mint sacks" are gigantic pallet sized bags that cannot be lifted by humans (they require a forklift). They switched to those to avoid injuries from people lifting the old fashioned bags.

They still have a few small mint bags in the system that you can get from some banks and they also sell some bags directly from the mint for HUGE mark-ups over face value. Generally the armored car companies that roll the coins delivered to banks and industry get the giant pallet sized bags.

I get a Mint Bag of 2000 Golden Dollars from my bank to mostly spend. I do sort out the shiniest coins and offer some of those up on eBay. I would NEVER dump them in a coinstar machine for a loss of almost 10%.

Now that was short, simple, to the point, constructive, and helpful. A fine example was made here. Thank you Mike.

Please refer to

Regarding other comments in this thread:

Do *NOT* use gloves, they can get caught and make things more dangerous. Use clamps to hold the work down. And don't forget the safety glasses.

Cut the OD first. Once you cut the ID, you don't have the pilot hole for center reference any more.

Rotate the cutter tip NINETY degrees when changing from OD to ID. The tip still needs to be on the leading edge, but needs to move from inside for the OD to outside for the ID. I often use hole saws instead of the fly cutter for the ID cuts.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Corregated cardboard box scrap makes good test cut material. And even works for centering rings on Questes size rockets.

Once I get the setting right, I have a scrap of wood that I make a shllow cut into and mark for future reference. I've got half a dozen concentric cuts on each size, for re-setting common tube sizes.

For someone like Mike, who is a kit manufacturer, I'd advise buying a seperate fly cutter for each different size cut you ever need to make, and saving them. $10 for a cutter is worth the savings in setup time, and the consistency of all rings being identical.

Another good tip. Use the pilot hole to allign the material on the flip side.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Hi Bob.

I'd like to also..

Can you recomend a hole saw brand and sizes that work ?

seperate fly cutter for each different size cut you ever need to make, and saving them. $10 for a cutter is worth the savings in setup time, and the consistency of all rings being identical.

I use calipers to set my cutter, this takes alot of the trial and error out of it.

I use a micrometer and calculate the size, then adjust it to this size. It cuts the correct size almost every time, so of course test it in some scrap. Another thing you can do is take a piece of 2x6 and cut into it just enough to make a mark. Then label each one and use it as a guide the next time you cut.

I ground down the end of my flycutter so its only 1/8in thick, cuts alot better that way.

RDH8

Missed that first time through. Probably a bad choice of materials for test cuts. Masonite is VERY hard and abrasive, and will quickly dull your cutter. I use either Luan subfloor scraps, or cardboard boxes.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

I've found that a well-ploaced finger will keep the cutting blade from kicking out too far, should the blade unexpectedly hit something hard in the workpiece.

BTW, the idiot in the picture learned his lesson and doesn't let his hands get anywhere near that danged flycutter! :-)

cp

Haven't messed around with brands. The same pointer to the Astron Workshop includes hole saw sizes that are close to body tube sizes. Sometimes you need to slightly increase or decrease the hole saw tooth offset to get a bit closer to the right size.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

I hope that means you have a set of cutters you don't mess with at all, for standard rings, and an extra one or two for custom settings.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Likewise. It gets me VERY close the first time. But I wish there were a fly cutter with a small vernier to allow for those fine adjustments, like on some of my dad's old drafting compasses.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Hadn't thought of that before. I'm staling this for "The Astron Workshop"!

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

So tried cutting my first bulkhead/rings tonight. Ran up a 29mm bulkhead with sharp new flycutter, trouble was the cutter seems to chatter and the B/H ended up more like a cog. Any idea please. John.

Feed VERY slowly and make sure the material you are cutting is held to the table securely.

My glove comment ASSUMED this was somehow practical.

Hint :)

Tech Jerry