[jm82792]

This is a rather dumb question but I'm not experienced and I'd like to know.
If I say had a 1/4" endmill with .450" of flute length and I want to cut out this profile at .8" deep can I do it with a (relatively speaking) short flute length?
http://upload.wikimedia.org/wikipedi...sat_mosaic.jpg

[ger21]

Most likely, if the shank is rubbing when you get deeper than the flutes, you'll get burning from the friction of the shank. You'd be better off with a tool with 1" flutes.

[jm82792]

Alright I'll purchase some longer fluted tooling and keep on trying.
Thanks for your help ger21

[CarveOne]

Lowe's has Bosch router bits in 1/4" with 1" flute depth. They also have solid carbide up-spiral and down-spiral cutters. These will get you going until you find something more suitable to your needs. Home Depot probably has these in other brands.

CarveOne

[jm82792]

Ah the curse of living out here is Homedepot and Lowes are about an hour and a half away, going to Kona or Hilo is an ordeal...
I'll order a couple longer fluted USA made carbide bits off of ebay.
How do I out of curiosity roughly estimate life carbide bit life? I want to use smaller ballnose endmills for my projects, such a 1/32" for finishing(after a 1/8" fishtail rougher) of a 5"X6" topographical map but I'd have a rough idea of when I should toss my bit other then seeing poor finish quality. I like the finish quality I'm seeing but at the same time I don't want to be unnecessarily thrashing bits when an extra tool-change would be wise. The amount of material removal for the rougher verses it's bit diameter is also a question. I've played with leaving .1" down to .04" for a 1/8" tougher but I'm not sure what the rule of thumb is. I'm guessing it depends on my feedrate and RPMs...

[CarveOne]

Mine usually break before they wear out, unless they are 1/4" or larger. I'm sure that someone has a formula for calculating wear, but it varies with material and a host of other factors. Not sure a formula will give you anything of use in the real world. Gerry may have a better idea what the industry uses. Probably just keeping records of the part numbers you buy is as good as it gets.

CarveOne

[louieatienza]

Some websites list it. I don't know if Mach3 has cutter comp but many commercial machines have cutter compensation based on formula, others actually laser-measure the tool. Some CAM software does this.

Carbide actually lasts pretty long in wood provided you don't heat it up too much when cutting. I would do as much roughing with straight end mills; ball endmills are way less efficient at bulk material removal, since the edge cross-section is about 28% less area, and the tip is virtually zero width; thus the stepovers have to be much smaller.

What CAM software are you using? Sight unseen, I would re-rough with a 1/16" endmill (and then maybe even a 1/16" ball endmill) before trying the 1/32" ball endmill, since you may leave steps too large for the 1/32" endmill to handle.

Also, these tiny endmills are a lot tougher than you think - I cut fret slots on my CNC with an .024" endmill, taking three .020" passes at 60IPM in ebony!

Also look into tapered ball endmills; they're a lot stronger and should last a bit (no pun intended) longer than a straight ball endmill.

[jm82792]

I am using Meshcam, it's a bit limited because I can't use any more then 3 tools at once without going against the grain and doing a hack.
I have a single tapered endmill, I'll invest in a few more of them shortly when I finish a single project that looks really nice...
Recently I gave a fishtail endmill a shot for roughing and I am suprised on how effectively they chew trhough wood