I thought this topic already existed, but maybe I haven’t looked enough.
I’m cutting a lot of hardwood: oak, purpleheart, mahogany, cherry, and maple. I seem to be going through a lot of 1/4" endmills. I run them about 30K RPM, .18 to .2" DOC. Feedrate varies, but usually is 70% of the recommended maximum on the Shapeoko chart.
My questions are:
how many flutes for hardwoods
is there a good feed and speed resource out there for multiple types of wood
HSS or carbide?
on Amazon you can get 10 BrandX 1/4" flutes for $12 or you can get one Yonico, Kodiak, SpeTool or other brand name for $20. Does anyone have any experience with the different ones?
Any information and/or links to websites would be great! Thank you!
Have you looked at the free Shapeoko E-Book V2 found here under the thread of that name? Have you downloaded the free Feeds and Speeds spreadsheet found in the same thread? If you enter the information you have in the Spreadsheet, you will get the proper F&S for the bit you want to use. The book provides a good explanation on proper settings too. I’m almost certain that you currently do not use the proper F&S for the bit and material you have.
10 for $10 endmills are crap, and not worth the money …after you have some experience… but are great to learn with. You WILL break them, may as well break the junk. Once you get the hang of things, you’ll find you stop breaking them, and will see the benefits of the $10-20 per tool endmills.
Before CNCs, I always bought good quality (but not necessary the most expensive) carbide sawblades and router bits for wood, plastic, and aluminum. Most of the router bits (for wood) are 2 flute. That seemed like logical starting points for CNCs to me. Unlike Freud, Amana, Onsrud, Whiteside? and likely many others, Yonico’s endmills are rated for operation at your 30kRPM (which is wise IMO), How long they last is dependent on how you use/abuse them. I suggest that you follow @luc.onthego’s advise on that. (I.E. increase depth of cut and feed rates when possible.)
Thanks for the great responses. The ebook was very good about explaining why you should push the envelope on feeds to avoid “rubbing.” I’m wondering if the reason my endmills are getting dull is that they are getting too hot. I’ve been using Freud and Yonico mostly. . . I’ve never tried the cheap ones.
gmack, are you recommending that I use that speed or use endmills that are rated at that speed?
IMO higher speeds are best because they require less torque and force for the same material removal rate. It sounds like you use the Makita’s highest speed, which is best in that regard. I don’t think its wise to use endmills not rated for the speed they’re used at. Carbide should last longer, is more heat tolerant, and is stiffer than HSS. But, everything gets dull eventually and different manufacturers use different grades of carbide, so who knows which brands last the longest. (Maybe you can do some life tests on different brands?) Do your endmills look discolored after being cleaned? If possible, you can minimize heating by feeding faster and more evenly distribute heat and wear by using larger cut depths with smaller widths.
2019-09-24 Update:@Joelbreaksthings
You might find this HEM Guidebook worth looking since it probably addresses some of your concerns about tool life and wear.
The problem with using the highest speed all the time is keeping up with proper feed - that can’t always we done, and that rpm is really hard on brushes - don’t expect to get 100 hours out of brushes, probably closer to 30 or so.
