.040 slitting saw cut need input please

[RicktheStick]

Hi All

I have 25 cuts to make 14.754 x .040 x .600 deep slots to put into 2 pieces 6061 al (2.165 wide) heat sink I believe but with tight tolerance.

I have a 2in x.040 carbide slitting saw 40 teeth

Manufacture suggest 1500 SFM AND .001 CHIP = 2925 RPM X 117 IPM they say 5x width depth of cut = .200 so 3 passes per slot.

does this sound right ?

I was thinking maybe 750rpm x 10ipm at full depth maybe 1/2 depth conventional cut (chip spends less time in slot)

WHAT DO ALL YOU SLOTTING GURUS THINK ?

Rick

 

[Omega]

I would go full depth 2500 rpm 20 Ipm to start..climb cut..see how it sounds, then bump up the feed, If the fins are close together you may need to slide a shim in the previous slot to dampen harmonics.

Robjack makes some good saws

 

[doug925]

I would think a pitch of 0.157 per tooth is too tight (and carbide too unforgiving) to get crazy in nonferrous.
One chip doesn't get washed away, and BAM!

Something hollow ground, with 6-12 teeth will cut much more freely in aluminum.
Something like this, if you can find the 0.040" face width.
https://www.rockrivertool.com/assets/images/products/2550.jpg

 

[Mtndew]

I would think a pitch of 0.157 per tooth is too tight (and carbide too unforgiving) to get crazy in nonferrous.
One chip doesn't get washed away, and BAM!

Something hollow ground, with 6-12 teeth will cut much more freely in aluminum.
Something like this, if you can find the 0.040" face width.
https://www.rockrivertool.com/assets/images/products/2550.jpg

Agreed, 40 teeth is too much for that size saw.
Been there, busted em in half.

 

[G00 Proto]

I just use plain old HSS jewelers saws for that type of slot. I’d probably start at 2500 RPM and 10 inches a minute. You’ll be able to hear how it sounds. If you turn them too fast they melt the aluminum and things go bad fast. I use a fairly coarse pitch blade.


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[RicktheStick]

Well both slotters went bang in the cut. They both started sounding really good in fact could hardly hear them. 1st try was full depth climbing got about 1/2 in maybe just fully engaged then boom , looks like chips packed. 2nd try conventional 1/3 depth got about 7in then boom, once again looks like chips pack.
So then the boss tells me to use end mills, I says yes sir 7 !!! Set up 5 carbide 3 flute .04 end mills of increasing length of clearance but only .060 LOC (only cut .02 a pass) wrote the program pushed the green button then went home for the weekend got in Monday then left Monday night still running I think the total was around 95 hours. NO end mills broke but they did walk off enough to see at the ends of each slot maybe .01 on exit ends