Bigger fly cutter

[Batmanacw]

Setting the cutting radius to just over the part width has lots of advantages, I suspect most have been detailed on this forum somewhere.

In your setup it looks like the part is about 2" wide, using the cutter with a 4" radius has the tool cutting for about 8% per revolution. It may be an idea to drill more holes for different cutting radii.

You are looking at a test part.

 

[FOMOGO]

Yes, true of all rotating objects, but I think round would do a lot less damage. Probably why you don't see that shape in commercial use. Mike

That's pretty much the case for any fly cutter, isn't it?

 

[Batmanacw]

Yes, true of all rotating objects, but I think round would do a lot less damage. Probably why you don't see that shape in commercial use. Mike

I'm the only one who will ever use it. Making it heavier was not my goal.

 

[Parlo]

I'm intrigued why it is preferable to cut the whole face in one pass. As this is not a decorative face, would several overlapping passes with a smaller cutter still work as well?

 

[Batmanacw]

I'm intrigued why it is preferable to cut the whole face in one pass. As this is not a decorative face, would several overlapping passes with a smaller cutter still work as well?

Every transition from pass to pass is an opportunity for leaks. It is preferred to have a consistent finish around each passage for the best possible seal.

 

[Batmanacw]

I worked on the balance this morning. The weight of the boring bar and set screw was enough to put it out of balance a little. Drilling and reaming a hole for a 7" swing helped a bunch. It still needed a few holes from the opposite side to get on balance. I did the final balance by using longer set screws to get it as close as I can with a crude setup.



There is now no discernable wiggle in the machine. Smooth as glass.

 

[Batmanacw]

4 ipm at 660 rpm. I could not be happier. Old fixture plate my friend gave me. The interrupted cut similates the engine head ports a bit.

 

[Batmanacw]

2 ipm at 660 rpm.