Super Totally Awesome Flycutter Bit Grind

jgedde

Active User
Registered
Joined
Jun 23, 2011
Messages
786
I was at work when I noticed one of the machinists flycutting a piece of aluminum on one of the Bridgeports. The surface finish he was getting was amazing. I stopped and asked him how he ground the cutter. Not only did he show me, he was kind enough to grind one for me.

I brought it home, put it in my fly cutter and got terrific results.

So, I thought I'd share his grind with you guys. Rather than try to explain it, I took closeup pictures. This bit started life as a brazed carbide AL (left hand) bit. I don't see any reason this couldn't be duplicated in HSS.

Here are the pictures... Note the slight radius appiled to the cuitting edge...

John

fly cutter front.jpgfly cutter side.jpgfly cutter top.jpg

fly cutter front.jpg fly cutter side.jpg fly cutter top.jpg
 
That is a mighty fine grind. What kind of wheel did he have? Diamond? I don't think you could get that with a green wheel. It would end up too mushie I would think.
 
That is a mighty fine grind. What kind of wheel did he have? Diamond? I don't think you could get that with a green wheel. It would end up too mushie I would think.

Yep, It was one of those $300 diamond wheels. I take my carbides to work to sharpen.

John
 
I have never had any luck grinding a fly cutter bit. I guess I'll have to stick to a face mill. LOL

Pat
 
I tried grinding one of those in HSS. It cut extremely well, like a hot knife through butter - notice the long spaghetti strands...
But the surface finish was horrible. Tried all kinds of speeds and feeds and it didn't get much better. :(

Then I switched to a plain old brazed carbide bit and got an almost mirror finish right off the bat. :nuts:

P7280085-1.jpg

P7280085-1.jpg

P7280085-1.jpg
 
I had one of those octagonal milling cutters at work. It cut aluminum like crazy.
 
That is the same way I grind my fly cutter tool bits. Only difference is I just leave the face flat. Nice work man!
 
Paddy, I am working on a friend to improve his surface finish on aluminum pieces like that.
Can you tell me exactly what tooling and inserts you are using?

EDIT: I did find your other thread where you listed the numbers (as shown on the pic)

Gotta find me one of those
 
I was at work when I noticed one of the machinists flycutting a piece of aluminum on one of the Bridgeports. The surface finish he was getting was amazing. I stopped and asked him how he ground the cutter. Not only did he show me, he was kind enough to grind one for me.
I brought it home, put it in my fly cutter and got terrific results.
So, I thought I'd share his grind with you guys. Rather than try to explain it, I took closeup pictures. This bit started life as a brazed carbide AL (left hand) bit. I don't see any reason this couldn't be duplicated in HSS.
Here are the pictures... Note the slight radius appiled to the cuitting edge...
John

View attachment 29336View attachment 29337View attachment 29338

jgedde thank you for the great pix. This is what I was looking for. Gives me a lesson in tool grinding as well as flycutting. Nothing beats a good picture in my book. Except maybe a video. Thanks again... :)
BB
 
Back
Top