cedar cutting

[lutchman]

can anyone give me the average cutting parameters to cut cedar? we have a shopbot alpha, if that is any help! the material is .5"thk. also.

[adrianm]

I cut red cedar with a 1/4" down spiral running at 15k rpm feedrate of 4ips. Pass depth of 3/8".

[dlcw]

can anyone give me the average cutting parameters to cut cedar? we have a shopbot alpha, if that is any help! the material is .5"thk. also.

I cut about a hundred cedar signs, plus many other cedar projects a year at 12k rpm at 5ips (figuring 3/4" thick material). 2 passes. First pass is climb cut and leaves a 1/16" skin. Second pass is conventional and I cut 1/32" thru. Down spiral is my bit of choice. 2009 PRSAlpha.

Beware that even a brand new, super sharp carbide bit will leave it a bit ragged on end grain. I use a oscillating edge sander to smooth it out.

[knight_toolworks]

Beware that even a brand new, super sharp carbide bit will leave it a bit ragged on end grain. I use a oscillating edge sander to smooth it out.

Ya I had t cout some rounds from cedar a couple days ago. used one of the great finisher down-cut bits from onsrud and it still did not cut cleanly. but it was a bit damp too and that did not help.
Give me hardwoods any day. bring on the purpleheart.

[lutchman]

thanks guys!!
don- would that be a .25" down spiral bit? we use the same method too, it helps with the vacuum...only difference is on our first pass there is .02" or .015" offset and the final pass there is none...that helps with any end grain lines created by each cut depth (if any)

also, i see that the suggested feed rates are a bit fast, i'd like to do something a little slower, our bot tends to get some jagged edges when we move too fast, can anyone suggest a chipload factor so i can use the calculator or even better some parameters which uses something like 2ips or thereabout. Our client only gave us one piece of material for this job, so i have only one shot, i did some test pieces on mdf but its just not the same...lol...i need to be absolutely sure on this...thanks again for the help...