Author Topic: Homemade carbide flymill  (Read 4292 times)

Online vtsteam

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Homemade carbide flymill
« on: August 13, 2013, 05:56:25 PM »
I've dulled a few of my HSS mills cleaning up some of the iron castings I've made lately. The iron is easily machined but the skin after casting often includes abrasives from the sand. I do grind them first with a hand grinder, but it's not possible to get everything.

I have no carbide tooling, but I do have about 100 new carbide inserts that were offered to me for $10 at the Bernardston engine show -- couldn't pass that up. When I got them home I was disappointed to learn that they were odd looking with a big radius instead of the usual flat diamond shape. But I thought they might find a place in a fly cutter of some sort.

Well today was the day to find out -- I decided to just do a quick and dirty experiment with a piece of hot rolled 7/8" rod as a mill, and just slot it to take an insert. I didn't even turn the scale off, since it was .874" already and I didn't want a loose fit in the mill collet.

I faced the ends in the lathe and just ran a little fine sandpaper to reduce the scale some. Then milled a .375" slot to take the insert. I held the insert about where it looked right and transfer punched a dimple for a screw. Then drilled and tapped the hole 8-32. I had a plain round head screw to fit, so put it all together, and gave it a spin in the mill.

It worked great on cast iron! I'm sure my geometry isn't optimum, and I will make a bigger, and better fly cutter paying more attention to the relief angles, but for now, this thing chews off the cast iron skin, which is all I ask. With 100 inserts to play with I should be set into the next century.  :dremel: :wack:





« Last Edit: January 07, 2018, 02:21:18 PM by vtsteam »
I love it when a Plan B comes together!
Steve
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Online vtsteam

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Re: Homemade carbide flymill
« Reply #1 on: August 13, 2013, 06:52:15 PM »
Does a nice job, too. This was what it did to a back yard casting.



« Last Edit: January 07, 2018, 02:21:52 PM by vtsteam »
I love it when a Plan B comes together!
Steve
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Re: Homemade carbide flymill
« Reply #2 on: August 13, 2013, 06:59:18 PM »
Oh, one more thing. The inserts are beveled the wrong way, so I have to run the mill backwards. But that's simple.

I think when I make an "official version" fly cutter I'll mark it as a reminder. I definitely need that kind of thing  :doh:
I love it when a Plan B comes together!
Steve
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Offline tom osselton

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Re: Homemade carbide flymill
« Reply #3 on: August 13, 2013, 07:05:33 PM »
Good to see my son brought  home some spare inserts that I don't have holders for I'll Give it a go.

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Re: Homemade carbide flymill
« Reply #4 on: August 13, 2013, 07:14:57 PM »
Tom the hard part for me was figuring how to mount the inserts since I had no reference tooling for them. There's plenty of info on the net for the inserts themselves -- all the specs. But not for the tooling that holds a particular insert. I spent half a day puzzling it out and about an hour making it. It turned out to be the simplest machining imaginable -- just a simple straight slot. But before I realized that I'd machined a different holder, trying to run the insert flat along the radius of the mill -- as a more typical insert would require. Stuff is always obvious after the fact, but not always before.
I love it when a Plan B comes together!
Steve
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Offline Brass_Machine

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Re: Homemade carbide flymill
« Reply #5 on: August 13, 2013, 11:21:35 PM »
Not shabby. What kind of radius for version 2?

Eric
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Offline srm_92000

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Re: Homemade carbide flymill
« Reply #6 on: August 14, 2013, 06:17:22 AM »
I think they'd be used to make up something like this.
Cant find a picture of one with inserts though.
Steve,
I put it back together using all the right parts,
just not necessarily in the right order.:scratch:
(Eric morecambe - ish)

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Re: Homemade carbide flymill
« Reply #7 on: August 14, 2013, 02:05:46 PM »
Not shabby. What kind of radius for version 2?

Eric

I think 3" Eric. Most of what I want to fly cut in iron now is about 2-1/4" wide. I noticed you have to stay somewhat clear of the edge because of the generous radius on the insert. For instance, in flycutting by multiple passes you have to overlap the cuts a fair amount or you get a little ridge. So I think 3" would probably be okay for 2-1/4" cuts, even though the slot for the insert brings it in .375" in diameter and you would want some overlap of the edges.
I love it when a Plan B comes together!
Steve
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Re: Homemade carbide flymill
« Reply #8 on: August 14, 2013, 02:08:31 PM »
I think they'd be used to make up something like this.
Cant find a picture of one with inserts though.

Thanks sm_92000, a horizontal milling cutter then?
I love it when a Plan B comes together!
Steve
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Re: Homemade carbide flymill
« Reply #9 on: January 07, 2018, 02:24:28 PM »
Photos restored after Photobucket fiasco.
I love it when a Plan B comes together!
Steve
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Offline Meldonmech

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Re: Homemade carbide flymill
« Reply #10 on: January 17, 2018, 07:41:03 AM »
 
 Hi Steve

                 Glad to see the pics. Missed these on first showing. Great surface finish on the iron, considering your inventive lttle tool holder. Just shows you don't need expensve holders.

                                                                                             Cheers David

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Re: Homemade carbide flymill
« Reply #11 on: January 17, 2018, 07:24:45 PM »
Thanks David!  :beer:
Glad to re-read it myself. I really should make a 3" version -- forgot about that intention. :scratch:
I love it when a Plan B comes together!
Steve
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