Found this Saturday night.
Either…
You didn’t zero the table. OR.
Your didn’t tighten the collet enough.
But one thing for sure, you walked away from your job and started a fire on the multicam CNC.
BAD.
Looks like it burned right into the rubber mat vacuum table.
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How the… skip that… how do you just walk away like nothing happened after something like that???
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You could see the thing was in flames cause they POURED water or sprite on it. Then they were kind enough to put the collet holder back into the drawer. At least they cleaned up.
Sent email to CNC supervisor with link back to thread to ensure it got tracked quickly.
Found the picture, sent to Board of Directors.
Already addressed on the woodshop forum. We have to bring in an epoxy kit for the platter. No one walked away from it without working toward the solution.
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The person did not just walk away he was with the job the whole time and if he did not act the way he did the table would have be gone.
You SHOULD thank Him
@fedakkee Hold your horses people.
I’ve already put the issue on the woodshop talk as soon as it happened. This happened while i did my job and had nothing to do with setup.
If anything its due to dull bits, the same bit that caused the fire snapped within a min of my job.
The nut your showing also had nothing to do with the fire. The gantry was already cutting another piece, the bit snapped and then all of a sudden i see a flame almost like a torch coming out of a hole a foot away from where the bit snapped.
So the friction generated enough heat to start an ember underneath the cut piece it was burning and i doused it with water which caused some nasty fumes that stunk up the place, I actually felt weird due to the fumes, not sure what the vacuum rubber is made out of but on fire, its not something to breathe in.
I posted the photo and let everyone know what happened. Yes I cleaned up cause that’s what i always do after a job, we dont have anymore spoilboards or i would have switched it out.
So no one walked away from this and this was not negligence, just an accident I had no control over.
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Put your pitchforks away.
My guess is a downcut/compression endmill and plunging. The chips pack in as opposed to being ejected then frictions starts taking place. The reason the fire is not seen is due to the Vacuum table sucking air in this also makes the fire bad fast as the air passes through the fire.
To avoid scenarios like this it is highly recommended to ramp as opposed to plunge the endmill and make many gentle passes in order to eject the chips. I would also recommend only using upcut endmills for smaller holes.
For example if you need to make a 0.25" hole in 0.75" material; Change the hole dimension to 0.3" and ramp through it 0.17" depth at a time.
If you absolutely have to have a 0.25" hole either use a drill bit or use a 0.125" endmill. If you use a drill bit you must peck it and pull the chips out to avoid the same scenario.
I would also like to add that I do not see the purpose of us having downcut endmills which are prone many problems including fires; the scenarios where people would need them are rare enough that they should just buy one for that specific job.
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It was compression bit, per Multi-cam rep, is capable of plunging. Guess he was wronnngggg…QC already dispatched.
Down-cuts are used on softer woods as the up-cuts cause nasty tear out unless it plunges at least a 1/4 or more in the material. We spoke about this the other day, in order for the up-cuts to work they need to be super sharp and set at the correct feeds and speeds to not cause tear out, we have neither.
Every time i have used an up-cut it has nasty tear out when cutting shallow, which is why down-cuts are used for softwoods to preserve the project.
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Last time I saw that compression bit, it was pretty dull. That’s my theory as to what happened.
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My apologies. I didn’t see anything posted about this. I looked and obviously missed it. I thought because I had not seen any posts, I was first to discover this. I’ve had things happen unpredictably to me as well on the CNC. That was one nasty burn hole. It looked like it had been burning a good long time. I’m glad no one got hurt.
Is the CNC safe to use or has the vacuum been compromised?
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No need top apologize, Kee…you did the (generally) right thing by posting here. You didn’t ‘miss’ the other post; it was posted somewhere else rather than here on Woodshop Forum or in the Issues Forum, where stuff like this belongs. A lot of people would have had no idea there was even a problem with the CNC router at all if it wasn’t for your post, so thanks.
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This is correct, i posted it to the woodshop talk as I am one of the supervisors, i posted it where the right people would see it asap, i didnt post it here to avoid an uprising. The maint players were notified so that it could be remedied asap instead of floating inside of a talk thread of speculation.
It was late and i was overwhelmed with fumes so my apologies for not informing the rest of the population about this issue.
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No worries my friend.
Glad you weren’t hurt, Rodney, or anyone/anything else. If this accident was something that was somehow inevitable, or at least very likely to happen, the 'Space is really lucky it was under your watch, IMO.
The incident also really underscores the absolute safety point: never leave the area when your job is running.
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Is there a way to be proactive in the future?
More than one person has opined that the likely culprit was an exceedingly dull bit. At least one other person already knew it was “pretty dull”.
(Rodney, this isn’t directed at you … you were just the person using it when the calamity happened).
Is there a better way of identifying dull bits to be proactive to avoid fires/head crashes in the future, or do we just need to wait until a dull bit buries itself?
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The bit was placed in the “dull bits” section at one point. Someone took it out. Personally, I buy my own bits to make sure they are sharp and always available.
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Duh. My bad. I didn’t realize there is a “dull bits” section. IMO, that’s being proactive.
Just wondering the status of the router. Is it safe to use at this point, or are we waiting on parts/repairs?