Fly Cutter Question

[Janderso]

How deep of a cut should I take?
Bridgeport, 1 3/8 diameter cutter, 3/8 bit.1/2 shank.
Just ordered from McMaster Carr, seems a much better way to remove material than an end mill.
Thanks

 

[Eddyde]

What material are you cutting?

 

[Janderso]

Ah, darn good question you have.
Mild steel?
Aluminum?
I can figure out the speeds but I have never used a fly cutter. I watched a few YouTube’s but the depth was never really addressed.
Also, I am assuming this is the best way to remove material if you don’t have a band saw vs. an end mill.

 

[MrWhoopee]

As I was once told, "keep turning it up until something breaks, then back off one step and run it." Try .050, if it works, try .075.......

For us poor folks, a fly cutter is the way to go because the cutter is cheap and you can sharpen it yourself.

 

[Silverbullet]

Most materials will let you know , by sound , chip, tool wear , finish. Even feeds and speeds will dictate depth of cut . With large machines fly cutters will cut 1/4" or more with coolant and power feed. It's still is all up to the material and finish. Carbide or high speed , sharp or honed also.

 

[Janderso]

I watched a YouTube, “ Toms techniques”, he ground a fly cutter bit and made it seem pretty simple. His grinding wheel was pretty course and not dressed. I do have a good McMaster Carr aluminum oxide wheel for hss. Honing I can handle.
I purchased a 1 3/8 fly cutter, after watching a few videos I may pick up a larger one as well.
Thank you for the information.

 

[Janderso]

Used my new fly cutter last night. Purchased a quality fly cutter and ground my own bit. Used it to cut through a built up piece I welded beads on, because I screwed up. Couldn’t have asked for a better finish.
I’m learning

 

[brino]

Purchased a quality fly cutter and ground my own bit. Used it to cut through a built up piece I welded beads on, because I screwed up. Couldn’t have asked for a better finish.

Good enough to share photos?
-brino

 

[Downunder Bob]

Used my new fly cutter last night. Purchased a quality fly cutter and ground my own bit. Used it to cut through a built up piece I welded beads on, because I screwed up. Couldn’t have asked for a better finish.
I’m learning

Way to go. The best way to learn is to do. Of course asking questions is always a smart thing to get a hold on parameters, but then as we say, suck it and see. As others have said start gently and ramp it up the noise and vibration will tell you, If you break something, ( hopefully only the cutter) then you went too far, go back to where you were before it broke, then go back a little bit more, that should be a good place to start again.

Something to remember when fly cutting. You will almost always have an intermittant cut, this will put a lot of extra strain on the cutter especially carbides, they don't like it. Some grades are better than others, and avoid fine points. sometimes you will get better results with a large chunky HSS cutter. Fly cutting is a bit like using a shaper only in a circle.

 

[Janderso]

This was done with a 1/4 tool bit. I only took .015 at a time. I have about 3/16 to go. I can see a 3/8 or 1/2 tool would be better but this is working. I only had one short 1/4 blank to work with. I have more cutters arriving Saturday. I may finish up tonight or wait. My wife doesn’t see me much so I may act like a husband tonight and stay out of the shop.
I have opened my eyes to fly cutting and may purchase a face mill set up. It sure is quicker and cleaner than taking endless passes with an end mill.