FLY CUTTING SPEED

[matchy]

I have machined up a rectangle bar,

bored with a 32 mm hole in the middle.,

The total length of this is 210MM


A hole is bored in the middle and is

bolted to a 40 taper tool with a 32 MM spigot,

A tool holder is mounted on one end and i Balanced

the Tool on Knife Edge jig, From a Grinding Machine,(static Balance)

With a PCD Tip what is the Maximum RPM i should run this tool?


I am fly cutting Alloy Motor cycle heads with it,


I am wanting a mirror finish on my Motor bike Alloy Heads,

js

[Geof]

Your tool sweeps out about 0.67 metres per revolution. I found a reference which mentions PCD as being able to cut aluminum at 5000 m/min, so I think your cutting speed limit is probably how fast your machine can run.

However I suggest great caution. You have statically balanced your tool but dynamic balance is likely to be a whole different thing. If you have a 32mm hole your bar must be fairly big and heavy. It could create a lot of mayhem if it comes loose at a high speed. Personally I would not spin a tool like that faster than about 1000 rpm and even then I would be very nervous about the polycarbonate windows keeping it inside the machine if things went wrong.

[packrat]

Not to disagree with you but a mirror finish is not a good thing for a surface that will be sealed with a gasket. You need a smooth finish but a mirror finish will allow the mated surfaces to slide on the gasket as the engine heats up and start leaking.

If you look at brand new parts they aren't a mirror finish. Just from my own experience from working part time for a while in an automotive machine shop.

cary

[matchy]

I ran the Rectangle fly cutter on the HAAS,

I will not go faster than 1000.

I do not want to harm the spindle bearings,


there is a surface finish measured in a value Called Ra

most of my bikes are AIR Cooled,

so there is not a issue with water,

I tried a sweep on a block of alloy , 100mm wide X80MM long,

spindle In the beginning ran at 500 rpm,

The Finish is like Glass,

I have been surface grinding the alloy heads in the past,

i used a special wheel that does not clog,


The fly cutter took a long time to make,

All up Cost me $600.00

Well worth the Expence,

js,

[Brepins]

packrat is right as far as sealing... your not sealing water but air/fuel mixture on the compression cycle...if it leaks you produce less power. unless your running a lot of parts slower is better for this job.

[mactec54]

Hi matchy

A photo of your flycutter, & the job that it did, would be great for everyone to see what can be done with a hand made flycutter