Griff
(Well crap, my hypometric precursor device is blown…)
1
Haven’t noticed this mentioned in the forums so I thought I’d pass it along.
Subsequent to ruining some jobs plus a wasteboard and an almost fire due to end mill slippage in the collet I decided to do a bit of research. First time, I figured I didn’t tighten the nut properly. Second time, a week or so later, I ASSumed the same. Third time and here we are.
I’m talking ER20 spindle collets here but I’d guess this applies to any type of collet. Not surprisingly, but never considered by me, collets require inspection and care. They have a lifetime. They should be considered a consumable. You need to have spares on hand.
True that!
Which reminds me, I have not said anything about that in the ebook, so I will.
Also, here’s a semi-recent thread on where to get good ER20 spare collets
I wonder if a failing collet will show runnout issues before it gets to the point it slips. Also due to our low machining forces, it would be interesting to find a realistic lifespan for our application.
Definitely good advice! At least one spare set of collets is good to have.
Also, one question I still have no good answer for: what if a collet falls on the floor ? Who would throw it away and who would continue using it ? Not that it ever happened to me, I’m asking for a friend
2 Likes
Griff
(Well crap, my hypometric precursor device is blown…)
5
Embarrassed to say, I did know better, once. Thanks to Precise Bits. Dug this out of the bottom/back of my maintenance drawer.
Thanks for the advice, I visually inspect the collets and collet nuts when I change the collets during a job and also check for sawdust buildup in the collet nut. I bang the nut on a table to get the sawdust out if there is some in there and use the air hose to clean if anything gets stuck before reinstalling.
4 Likes
Griff
(Well crap, my hypometric precursor device is blown…)
7
My routine as well. Recently I’ve been cutting Wenge, it really gummed up my collets. I was tapping but not looking.
For the collets themselves they get gunk between the “blades” in the little saw cuts - doesn’t really show when you look. This turns into runout because they don’t close evenly. Stick one in a plastic jar ¾ full of mineral spirits and give it a good shake…always amazed at what shows up. Have seen a lot of grinding gunk come out of brand new “freshly made in various Asian lands” collets. And adjustable parallels. And…
Griff
(Well crap, my hypometric precursor device is blown…)
12
Good point. Going to get one of those.
Also, a disadvantage of having extra collet nuts is NOT removing the collet with any sort of frequency. Allowing for the buildup of crud in mine. I’ve added collet care to my daily start-up list— wheels, belts, tool-off motion checks etc.
Griff
(Well crap, my hypometric precursor device is blown…)
13
It does a bit, probably due to the fact it’s 70-80% light naphthenic distillate.
It’s small and it was quite cheap, it doesn’t have much power and you tend to have to run it a few times to get any stubborn gunk off the part. It’s got a notable strong spot in the middle of the tank. I bought it for cleaning small stuff like metal watch straps.
No complaints with it for what it is and how much it cost but I’d buy a slighly bigger one with more ultrasonic power for tool cleaning that didn’t need quite such a long time to get things done.
to say, I did know better, once. Thanks to Precise Bits. Dug this out of the bottom/back of my maintenance drawer.
