graphite milling

[Rick46]

I know that most cutters come with formulas to use when cutting various steels but are there any specs when cutting graphite.. d.o.c.'s speeds and feeds and what nots.. just curious.. trying to speed up my graphite machining processes and cutter life as well and didnt know if theres a rule of thumb to go by or specs listed somewheres when being used in graphite machinging applications.. also daimond coated end mills are there different specs when using these on graphite as well... currently I use millstar HSN coated inserts and diamond coated 2 qnd 4 flute ball and flat bottom endmills but dont know if Im pushing them as much as I can or using the right speeds and feeds to prolong my inserts and cutters life expectancy.. I wouldnt think machining graphite would wear a cutter out as quickly as it does but I go through about 6 electrodes of sizes being 1.0 x 1.0 in lengths and widths and depths of detail being 1 inch to 2 inches tall..then I have to change cutters.. is this normal or should I be getting more life out of my cutters.. thanks..

[Jason B.]

EDM grapgite is very abrasive. (that's why you don't use the graphite dust as a lubrican't for anything. ) We used TiALN coated tooling and ran at .004 chip load per tooth for roughing and .002 for finishing. This seemed to give us the most out of our tooling and still be able to cut fast enough to meet deadlines. (you have to find the happy medium) but this is just one example. Hopefully more will respond with their examples.

[Midwest]

I use diamond coated em from SP3 the web site has a lot of info.........plus give them a call........they R very helpful.

 

 

HTH

 

 

[The Chipmaker]

Use shallow doc and use ball endmills to leave radii in corners to keep vertical walls strong. They will also have a better finish because they won't be vibrating.

[Thee Rickster ™]

I just cut my non electrode grade graphite as fast

as possible. I have no formula since my entire mold

bases are Graphite for our graphite permanent mold

process. I need to cut with tapered custom ground

diesink type cutters as long as (1/16 ball,1 deg) 6" reach. I have the speeds and feed for each size and

length recorded but for the most part, it all in

part of the empty space in my head.

 

I don't buy diamond because of regrinding issues plus

I can not get the variety of customs cutters I

need to do the job.

[MAKINOPAT]

There is a chart with speeds and feeds on the osg website for diamond coated endmills. I buy alot of diamond coated endmills from cetdirect.com- i believe they can custom grind endmills and have them diamond coated. They are not the highest quality available but very consistant with size, and do hold up relatively well.