Just doing a 3/4" birch plywood carving with Dewalt spindle @ 50 in/min and .0625 depth per pass with a 1/8" downcut bit. The 30min carve took double that as I had to swap bits 3 times.
I’ve run (and read of peopling running) 50in/min and depth of half the bit’s width a number of times before now. Every time it broke, it broke right where the bit goes into the collet.
Guess it could be over tightening or maybe settings, but see photo. Does this look to be a problem or is this wear pattern normal?
That is not normal at all — I’ve broken numerous endmills in my machine, and never had anything like that sort of damage to the collet — contact Elaire Corp. and see what they have to say.
Also, use the stock collet and a dial indicator to check the runout in your router as a point of reference and inspect the inside of the router where the collet is inserted for any sort of damage or machining imperfection which would result in things not aligning properly.
Additionally this only happens when you insert the bit wrong. My guess is too deep so you clamped on the flutes aka the weakest spot. Ask me how I know lol.
Or you have something loose/flex somewhere and it’s bouncing the bit to the point it snaps.
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That collet is definitely damaged. You will have issues with that almost every time.
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I suspect the cause to be bit insertion operator error.
The last few times I seen a collet look like this one tool was not inserted to a proper depth in the collet and the other was when the mill was inserted past the flutes breaking off and chewing up the inside edge
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Thanks, all. Helpful to know this is an issue that I need to replace (didn’t know if this was just normal wear and tear).
And you’re right, it was probably self-inflicted. The flutes are over ~1 1/4" in length and I’m cutting 3/4" or thinner stock, so to reduce chatter I put the bit further into the collet.
Guess the solution to that is just to get different bits for different thicknesses of material, or maybe the chatter won’t be that bad it just sounds worse than it is when I hear it
As far as your birch plywood speeds/feeds; I run 3/4" birch with a straight bit at 50 in/min and .05 doc.
so the only resolution to reduce chatter is buy shorter bits?
thanks!
cutting through the wood, not carving, so can’t go shallower. And due to detail of the cut, can’t go larger bit. so time to take to the interwebs and find some shorty bits (and snag another collet…)
ahhh. thanks for the clarification.
and it’s a cut, not a carve. cutting letters out of 3/4" birch plywood. Due to the font and size, the edges of the letters can’t be accomplished with a larger bit
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Sounds like a candidate application for ‘rest machining’…
Use a 1/4" bit to do the bulk of the work aggressively, and then let a 1/8" bit take care of just the corners the bigger bit couldn’t.
Don’t know what CAM software you use, but this is a pretty easy thing to do in Fusion 360.
I was carving up some 3/4" birch ply last night with 50 in/min at .06 doc with a 1/8" straight bit, in a Elaire collet. After finishing carving the gear it snapped the bit right where it mounts in the collet. Go figure…
For best detailing it’s best to just use V-carving, even if one then uses a pocket to clear out what one can of the letterform — the V-carve cut will provide the needed details at the acute corners.
I used the bit fairly often, not a whole lot. I switch bits all the time and do various carves. My machine is finely tuned and runs like a champ. Not sure what happened, I think it might be what you mentioned, it got hot and de-hardened. I’ll slow it down a bit and see what happens; thankfully I have a spare bit. 
I didn’t think the speeds were that fast compared to things I’ve seen on here. I do have the one-piece X-axis and z-probe upgrades. When the bit would break (happened 3 times) only the first time did it move ever so slightly. But in all 3 cases, I could swap the bit, keep my X/Y zero and just re-probe for Z and it worked great. Only sucky part was if I was halfway through a cutout, then having to start the job over made the machine run for a long time before it even touched wood to finish the cut.
In the bits that broke, they all broke at the collet and the tip of the bit was darker colored and hot. I tried running the vacuum and blowing air on the bit while it worked to combat that but guess it didn’t help. These were brand new bits from Lowe’s LINK TO BIT. So I’m sure the next post is to tell me they are crap bits and to buy some online. I’ve been using these bits for a long time and they have worked pretty well until this job, so thinking the collet is the bigger issue.
And I get the online market, but sometimes you just need to run to the store and buy it when you need it, like I was able to do when this bit broke and could quickly get a replacement in 15min without turning the machine off. 
What speed are you running your Dewalt on? You shouldn’t really need to go higher than 1 or else you run the risk of seeing exactly what you’re seeing, burnt bits and bit breaking.
My Elaire works just fine and I have no issues. I also run it at a speed of 1. I bumped it up to 1.5 once and then took it back down.
see original post photo for collet damage. Maybe didn’t word my response well, but I think that is the main issue since I’ve used these bits many times before. so thinking a replacement collet needs to be purchased.
And I keep the Dewalt a little over 2 on the speed dial. I know the Dewalt goes a lot faster than others so needs to be ran at a lower setting. Is 2 even too high, need to drop to 1?
and 90,000 posts??! dang! thanks for your interaction with this forum. It’s helpful to me and others as well I’m sure!
answered the question as I clicked the POST REPLY button. haha. thanks!
When tempering steel you get different colors depending the temperatures reached.
Faint-yellow – 176 °C (349 °F) – engravers, razors, scrapers
Light-straw – 205 °C (401 °F) – rock drills, reamers, metal-cutting saws
Dark-straw – 226 °C (439 °F) – scribers, planer blades
Brown – 260 °C (500 °F) – taps, dies, drill bits, hammers, cold chisels
Purple – 282 °C (540 °F) – surgical tools, punches, stone carving tools
Dark blue – 310 °C (590 °F) – screwdrivers, wrenches
Light blue – 337 °C (639 °F) – springs, wood-cutting saws
Grey-blue – 371 °C (700 °F) and higher – structural steel
If the chips are too small they do not carry the heat out of the product and the back of the tool rubs against the material to build up more heat. You can try to reduce rpm and increase feeds.
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