Problem- 8'' slit saw speeds and feeds?

[stovepipesteve]

using a regular high speed steel,8'' slit saw.(48 teeth)
material is A36 steel,slotting bout 1.3 deep.
the speeds and feeds im running now-50rpm with a 1.75 ipm,cutting full depth,coolant flood.
Does this sound safe?
i could use some tips and trick info.
thanks in advance

[Geof]

What is the machine? It must have a gearbox if you are running a saw that big.

Why are you using 8" for a 1.3" slit, 6" would do it?

Your conditions are what I would start with, maybe a bit conservative but with a saw that big you need to be careful.

The largest saw I have used is 6" in 6061 going in about 1-1/2 inches. A trick
I found useful was to moving the saw in a series of advancing circles. If you just go straight in you finish up with the saw cutting over a long arc around the saw circumference and your spindle load skyrockets. If you program a series of G02 moves the saw cuts over a smaller part of its diameter and things go much smoother.

If what I mean is not clear I could put up a bit of code and you can look at it in Graphics.

[stovepipesteve]

im running a VF3. 30 horse,geared.
im using a 8'' on a 6'' long arbor, the reason being , i need the reach and the side clearance. if i were to use smaller saw, the head would be into the fixture.
i dont understand what your saying bout circluar moves.
thanks for attention.

[Geof]

An arbor 6 inches long? That could give you chatter problems.

I will try to explain my interpolation suggestion without having to resort to doing a drawing (my drawing skills are even worse than my explaining skills).
I also screwed up in my first post and should have typed G03 not G02.


This description is for taking a cut along the X axis with the depth of the slot being set on the Y axis:

Imagine bring the saw up the the point where you will start the cut, with the rim of the saw at the correct depth for the first cut, but not quite touching the material.

Now program in incremental G03 I0. J-0.105 X0. Y-0.210

The cutter follows a semicircular path and takes a little notch out of the part.

Now do G01 X-.10 Y0.210 and the cutter moves to a position 0.10 into the cut but it has 0.005 clearance so it does not quite touch.

Repeat the G03 move and you take another notch; repeat the G01 and now you are ready for the third cut.

All this is programmed as nested subroutines with L counts.

The effect is more or less the same as using G75 when doing a deep part cutting on a lathe; you take short nibbles at the material so the tool is not in contact long enough for chatter to build up.