-
Welcome back Guest! Did you know you can mentor other members here at H-M? If not, please check out our Relaunch of Hobby Machinist Mentoring Program!
3/4" Straight Shaft Fly Cutter
- Thread starter PurpLev
- Start date
- Joined
- Jun 23, 2011
- Messages
- 786
Sharon,
The stiffness won't increase with hardening (I know it's counterintuative, right?). This is because Young's modulus is fixed. Wear and tear will be reduced however.
If it were my project, I would just leave it annealled.
John
The stiffness won't increase with hardening (I know it's counterintuative, right?). This is because Young's modulus is fixed. Wear and tear will be reduced however.
If it were my project, I would just leave it annealled.
John
- Joined
- Nov 8, 2011
- Messages
- 1,678
Very nice job, I thought a guy was gonna give me one he made in trade school that was made with R8 taper but I guess he changed his mind:slapping:
- Joined
- Jun 23, 2011
- Messages
- 786
Yes. Very nice job indeed. Forgot to say that in my last post.
Is that just a long bit in there or does the bit protruding from both sides have a use? Do I need one too? :thinking:
Also, my fly cutter set (Chinese) has a much steeper bit angle. I've been told before that many machinists prefer a shallower angle like yours. What're the advantages/disadvantages of the different angles?
John
Is that just a long bit in there or does the bit protruding from both sides have a use? Do I need one too? :thinking:
Also, my fly cutter set (Chinese) has a much steeper bit angle. I've been told before that many machinists prefer a shallower angle like yours. What're the advantages/disadvantages of the different angles?
John
- Joined
- Jan 26, 2011
- Messages
- 632
John,
I used 10 deg. because it was stuck in my mind for some reason, maybe when I worked in a machine shop. I figure if I did not like it I could increase the angle. The cutter bit I was just playing around in my head with a grind and thought I would try it out and after I put it in the holder it looked like I made a mistake and decided to try it anyway the way it was and it worked better than I thought it would so I left it like that. I tried to take a pic of the cutter to see how I cut it and this pic was the best.
Paul
I used 10 deg. because it was stuck in my mind for some reason, maybe when I worked in a machine shop. I figure if I did not like it I could increase the angle. The cutter bit I was just playing around in my head with a grind and thought I would try it out and after I put it in the holder it looked like I made a mistake and decided to try it anyway the way it was and it worked better than I thought it would so I left it like that. I tried to take a pic of the cutter to see how I cut it and this pic was the best.
Paul
- Joined
- Feb 22, 2012
- Messages
- 924
Thanks for the replies everyone.
John - that IS a long bit (4" I believe) - I got a few as they were darn cheap and I planned to split them down to shorter bits for use in boring bars and other applications. As for the angle of attack, as I mentioned- mine is a shallow angle of about 12 degrees. I chose the angle from how the edges on the cutting tools are cut (12-15 degrees). I'm not sure if there really is any advantage to this other than the tool having less variation in thickness all around in terms of centrifugal forces and more stable operation. the disadvantage is that the tool is REALLY close to the work piece. I'm planning on doing a dry run over the part before finishing to make sure nothing will snag/hit the cutter more than it should. all in all, It's a finishing tool - as long as it does what it needs to do, I wouldn't over think it. the decision here for the angle was more of a choice than a necessity.
And...
as promised, here are pictures of the ground tool bit:
front view showing the rounding of the cutting edge
side view showing relief cuts (face and back):
And one more for good measure:
John - that IS a long bit (4" I believe) - I got a few as they were darn cheap and I planned to split them down to shorter bits for use in boring bars and other applications. As for the angle of attack, as I mentioned- mine is a shallow angle of about 12 degrees. I chose the angle from how the edges on the cutting tools are cut (12-15 degrees). I'm not sure if there really is any advantage to this other than the tool having less variation in thickness all around in terms of centrifugal forces and more stable operation. the disadvantage is that the tool is REALLY close to the work piece. I'm planning on doing a dry run over the part before finishing to make sure nothing will snag/hit the cutter more than it should. all in all, It's a finishing tool - as long as it does what it needs to do, I wouldn't over think it. the decision here for the angle was more of a choice than a necessity.
And...
as promised, here are pictures of the ground tool bit:
front view showing the rounding of the cutting edge
side view showing relief cuts (face and back):
And one more for good measure:
- Joined
- Aug 30, 2012
- Messages
- 105
I have been asking myself if I needed a fly cutter, after seeing the finish over the end mill I may have decided that I do need one. Next question is to build or buy. I am thinking build now afer reading this.
Job well done!!
Turbo
Job well done!!
Turbo
- Joined
- Feb 22, 2012
- Messages
- 924
Thanks.
I must say that the finish is by far superior to facing with end mills, you should definitely have one, build or bought.
- Joined
- Jun 17, 2011
- Messages
- 2,069
I got a 4" shop-made fly-cutter with my Victoria mill. One piece heavy body with an MT3 shank turned on it. Your results look so good I just made a note to pick up a piece of 5/8" HSS to go in it.
Nice tool and nice results, Sharon.
Nice tool and nice results, Sharon.
- Joined
- Feb 22, 2012
- Messages
- 924
Thanks Mike, curious to see what the 4" FC looks like. got pics?