One MOW Flycutter

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I started this little project before cold weather settled into the south, north central Florida. Cut a piece of 1 inch thick cold roll to get a disc a little larger than 5 inches.

Drilled and bored the center to .750 -.05 for shrinkage. Heated the disc up to a nice red-ish tone and shut down the flame. Dropping the shaft that was in a cut frozen in the freezer over night. After sticking it in the hole hit it once with a hammer to set the shaft. Went to my South Bend 10K putting my ER32 collet chuck on and a .750 collet. Spinning went very well, the first time I turned anything over 3 inches.

Today I pulled it off the shelf and well the humidity had done its job. Several rust spots. Milled a slot on the outside diameter to mount a tool.

Then went to my private stock I picked up many years ago. A nice piece of metal with a HSS insert brazed on the tip ( or what I made the tip ). Cut a profile with relief where needed. A little bit of milling and a little bit of filing and fit like a bug in a rug.

After getting it all together I had to test it out but did not have anything large enough to give it a good work out. Then I thought about the old aluminum I had melted years ago and poured into triangle molds. Stuck one in the vise and took a cut from one of the angle side until I cut a nice shelf to be able to flip it and take a rather good cut. A 2 hp motor running it just mowed the aluminum off. I tried and pushed it by dropping down .250 and mowed it off. Had popcorn flying and did not miss a beat. That 1 inch stock really made a big difference.

There is nothing better than a tool that preforms as needed.



Looks good , do you have more bits with two there super hogs. I've always used high speed too. I've made many fly cutters and like to build different ones , I even made one with four bits on a 4" chunk of cold roll about 4" long turned down 2" to 3/4" diameter and slotted and cut flats for set screws two to each bit . Like you said with yours it throws the chips ,,popcorn,, really well. I've always been a fan of fly cutters . Thumbs up nice job.
That was the first bit made for it and yes I was entertaining the idea of three cutters on it. The only problem with multi cutters is getting at the same height. I am going to make a cutter that will take inserts. It just a matter of getting around to it. This time of year is garden planting which takes a lot of my time and all the other responsibility of a property owner.
Thanks for the kind words.
I assume that you meant that you deducted .005", and not .05" (as stated) from the .750" for the shrink fit. The general rule of thumb is to deduct .001 per inch of diameter for shrink fits, the same allowance is used for press fits, but the shrink fit is 3-5 times as effective in holding power as a press fit, according to what I have read, because the roughness of the fitting elements is more or less smeared smooth with a press fit, and not so with a shrink fit. In my experience, there is not much advantage to excessive allowances for either press or shrink fits, and given the likely temperature differential of freezing in an ordinary freezer, there is little to be gained in it's use; liquid nitrogen or even dry ice is another matter.
That was just a typo, I meant it to be 5 thousandths. Thanks for the info about the freezing, next time I'll just drop it in the hole. As much as I've used it so far it seems to be rock solid.
Thanks for all.
I played about 2 hours today making a new cutter that took inserts and would you believe it, I snapped the tap when almost complete. Throw another to the scrap bin. I believe I am going to drill my holes, one for relief of other cutter edge and the other to mount. Tap the thread and have it ready for all the machine work, at least I will not trash it at the end of everything. I hate it when things go south too quick.
Hi Nelson, looks great! For freezing, I have used a can of circuit cooler/freeze with very good results. Maybe put the part in the freezer for a head start then hit it with the can of circuit freeze. Heat the outside part…freeze the inside part and they just sloppy fit together. And DON’T screw around or you will have a problem real fast!…Dave
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Hi Nelson - Looks like it works well! I am glad you are getting into the shop despite your admin load!
Sometimes you just got to cave in and go to the shop (man cave). I have been in the shop a lot but it has been trying to fix one problem after another. It started with my old lawn/garden tractor and one thing after the other. Kind of like something was telling me not to plant this year but it is something in my blood that requires all the wonderful veggies that come from it. This year I am going to try to sell some of what I produce, we will see. I like to just give it away too.
Hi Nelson. I made something a while back that was supposed to be more of a face mill,but ended up like almost the same tipe of flycutter you made. Nice job by the way.
I have been doing some cutting with it and it works great. I had several large carbide cutter that was too big for my lathes so I milled two of them down to a slide fit and drilled. That worked very nice.
Watch the chips they can get very hot.
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