Flycutter woes...

[DAN_IN_MN]

Re: Flycutter woes... Updated with second try

Hi all,

Thank you for all of the advice.

I tried it again today. I reground the bit, this time with a small radius and a lead angle. Also, I ground off all of the mill scale with my angle grinder. I also used a faster speed.

Unfortunately, the tip of the bit got ground off again...

Then I put a little remnant of the steel that I had from a hole saw into my lathe and faced it with a HSS right hand tool I made. It cut through it like butter.

I'm thinking that my mill is just not stiff enough to handle steel. Any thoughts?

Thanks,
Darren

Well, you know a couple of things. The cutter you ground will cut, and the steel from the hole saw is soft enough to cut.

Would it be possible to chuck that piece of steel you were trying to fly cut in your lathe's chuck? Trying to rule out the mill not be solid enough.

Have you tried a file on it?

I'm thinking you found a hunk of steel that's around 45-60 rockwell. If is file will not touch it, it's more than 60r as I remember files are around 60 rockwell.

 

[THE OLD MILLER]

I agree brazed carbide bits work much better in a fly cutter. At least for me.

Yes,you should never persevere with a bit steel of unknown grade,stick a bit of steel of grade you know and try cutting that,as for your cutter,someone suggested going on youtube and looking at how to grind a flycutter,be honest your tool looks poorly ground,also your toolsteel could be supermarket grade-Good luck,you,ll get there-Brian

 

[Timehunter]

My 2 cents.....
Looks like your piece of metal was cut with a torch.
When cutting with a torch it hardens the metal for about 1/8" to 1/4" or so..or more... from the cut.
With the same metal cut with a bandsaw you will get entirely different machining results.
Try grinding the edge ....(at least enough to get rid of the torch marks)....where it was cut with the torch.....then try machining it again.
That way you will ay least get rid of the hardest part of where it was hardened......
At least that is what I have to put up with....with pieces that have been cut with a torch.
I hate to mess with them ..but sometimes you have no choice.
On the other hand... with these old eyes.. that is what your piece of metal looks like!!??

Post edit: After looking at it again...
12 Bolts, Post #5, has the right idea.
After looking at it again ..it looks to be the end piece of a piece of flat bar that was cut with a torch.
Now you have two things working against you, the end of the bar where it cooled the quickest and the torch hardening.
I think your machine will be fine if you try a different piece of metal. It might be just too small of a machine to grunt its way through that
chunk of obtanium you came up with!!??