Home made Fly Cutter

[basildoug10]

Hi, on a previous, and my first ever post, on the "Beginners" forum was a few days ago. I did however get some very good advice. The outcome of that was as follows. I would purchase an index able type face cutter to replace my existing face cutter as it was not an easy tool, to sharpen 3 separate tool bits in an identical way so that all 3 bits picked up an equal share of the cutting. But at the moment spare cash for a new cutter is not available at present. So having read other posts regarding tooling that has been home made and, the pictures are amazing, the quality of the tooling is also outstanding!

Below is my present face cutter that uses 3 HSS bits.



So I thought I should give it a go and make a Fly cutter, and perhaps making some simple tooling is a start in the same direction like so many others that have been so successful in making great tooling.

So I started as follows, I mounted my huge milling vice on my trusty "Chinese 3 in 1" machine and squared off the jaws.



This is the blank that I machined earlier.



Clamped the blank in the vice and set the angle at 16 degrees, I thought this would be a reasonable angle.




Started milling with a 10mm Slot drill at 836 rpm, (is this the correct cutting tool to use?)




Stopped for a picture, almost done



Done with milling the 16 deg. face angle



Busy with the 6mm tool bit slot



Milling completed. Please comment on the surface quality of the slot. Seems a little bit "Rippled"
Perhaps I am using the wrong cutting tool?




Fly cutter clamped for drilling and tapping of holes for the Pinch screws



All done, and now for the TEST. I have a piece of scrap 25mm thick mild steel off cut which I use as a small hand hammer to rap on what ever needs a little "knock". So I used this for the test. Spindle speed is 290 rpm.




Well it seems to work much better than my "3 HSS BIT" face cutter.



Here is the tool, it is 24mm dia. and it has a 13mm shank, and with the tool bit set where it is, it cuts a 34mm wide swarth. Since taking this picture I have replaced the small pinch hex screws with "cap head" screws.



I did make a mistake in the machining of this fly cutter, and I am sure that nothing gets passed you guys, so I will just come clean and tell you. I am sure you spotted the mistake. I milled the slot for the tool bit on the wrong side of the center line, so this fly cutter has to run anti clockwise to cut.
Well these type of mistakes will go as experience increases.
I would certainly appreciate your comments, as I can only improve from them

 

[Andre]

Nice writeup, I like your facemill. Did you make it?

When you were indicating your vise, it looked like you were indicating off the moving jaw by the picture. Make sure to indicate the fixed jaw not the moving one, as it does not have the slight bit of wiggle the moving jaw

 

[basildoug10]

Hi Andre, I assume the face mill you are referring to, is the first picture of that MT3 cluster thing with 3 x HSS tool bits, No I never made that, it came with the HQ400 Chinese 3 in 1 Lathe mill/ machine that I purchased 14 years ago.
Good spotting on the issue of indicating on the moving jaw. To be honest, I never gave it a thought. You are quite correct, thanks for pointing that out.
Regards Basil

 

[Inflight]

Nice write-up!

That is a nice looking cutter but I think you can improve the surface finish and reduce tool pressure if you knock the sharp corner off the bit so it is presented to the work at 30* or 45*. You won't be able to machine up to a sharp corner, but that is somewhat rare with fly cutting tasks.

 

[Andre]

Nice write-up!

That is a nice looking cutter but I think you can improve the surface finish and reduce tool pressure if you knock the sharp corner off the bit so it is presented to the work at 30* or 45*. You won't be able to machine up to a sharp corner, but that is somewhat rare with fly cutting tasks.

Yes, either grind an angle on the leading edge of the tool or a 1/32" radius or so. Good point!

 

[T Bredehoft]

You might want to replace your cap screws with set or grub screws, will reduce some of the balance problems, also will hold the bits better.

 

[eightball]

You could also use your facemill with only one toolbit in it. You could put the other two bits, where they wouldn't cut if balance is an issue.

 

[Andre]

You might want to replace your cap screws with set or grub screws, will reduce some of the balance problems, also will hold the bits better.

Besides possibly a better grip on the head, why would a cap screw hold better?

 

[basildoug10]

Nice write-up!

That is a nice looking cutter but I think you can improve the surface finish and reduce tool pressure if you knock the sharp corner off the bit so it is presented to the work at 30* or 45*. You won't be able to machine up to a sharp corner, but that is somewhat rare with fly cutting tasks.

OK that is a good point, in the past 14 years of owning my beloved "Chinese 3 in 1 machine" , the only work that I have done is to make Bushes and washers and the occasional odd bits and bobs. Since joining this Hobby and machinist forum I have become a "machine freak" you guys are so experienced and your help and assistance is exceptionaly good.
So your point regarding the angle that I should sharpen the tool at, is a good point. I did notice that the finnish was a little rough. Incidentally, the tool bit that I used in the fly cutter was made by a friend many years back and the only reason I used it, was because it was the only 6mm tool bit that I had. I actually had no clue whatsoever how to sharpen a fly cutter bit till reading your comment now. So I am grateful for your input.

 

[basildoug10]

You might want to replace your cap screws with set or grub screws, will reduce some of the balance problems, also will hold the bits better.

I bought cap head screws yesterday to replace the hex head screws that used. My first choice was to fit Grub screws
but the local hardware store ( a round trip of 160 Kim) did not keep them so I settled for the Cap head screws.
I agree the grub screws would look a lot neater. Thanks for your input