Feed speed

Discussion/questions about software used with your CNC Shark and programming issues

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vanstone
Posts: 3
Joined: Thu Aug 05, 2010 3:21 pm

Feed speed

Post by vanstone »

Does anyone have a good plan for determining feed speed? I have searched the internet and am more confused than when I started. They talk about chop size, router speed, heat loss etc. One place says keep increasing speed until you break the bit. I can' aford that.

I am using a 0.125 end mill for roughing and a 0.031 ball for finish and am running both at 40 inchs per minute. I use mostly cherry and walnut. What are others doing?

Teir
Posts: 17
Joined: Fri Aug 20, 2010 12:13 pm

Re: Feed speed

Post by Teir »

Van,

You did not mention your depth of cut. This will factor in too.

I cut hardwoods at 100 ipm with a .125 bit...and 50-75 ipm with a .25 bit on the rough side.
I do this with .1 doc on .25 mill...and .050 doc on the .125 mill.

The .031 ball is a bit trickier...you can run it 100+ ipm....ONLY IF...it does not start in a hole.
If it starts on the side of a 3d image where the side load is small...as in 10% of diameter..
pour the coal to to it....If it has a tricky start...program the high feed rate, but use the
feed rate override to start slow until it cuts a small starting area then bump the feed rate back to 100.

Teir

vanstone
Posts: 3
Joined: Thu Aug 05, 2010 3:21 pm

Re: Feed speed

Post by vanstone »

What is the "feed over ride"?

Tim Owens
Posts: 361
Joined: Wed Jul 28, 2010 3:51 pm

Re: Feed speed

Post by Tim Owens »

the FRO is used to slow down the machine while it is running.
That is the main purpose but you can also slow the jog down by lowering the FRO.

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