[CNCnoob]

Hey all,
I've got 17 orders that must be ready by this Friday and I am losing my mind over this. Really hoping you can help!

My collet isn't grabbing the bit.
I'm using a dewalt 618, tried various bits, bought a new collet, what am I doing wrong??
When I tighten the collet to the router there's no problem, it gets tight. But it doesn't tighten the bit. I must be forgetting to do something....

Any help is appreciated. Thank you!!!

 

[DaninVan]

When you say you've got 17 orders that suggests that in fact this isn't your first dance. You've obviously installed and removed bits in the past, which sort of eliminates the most obvious reasons(?).
Could the nut have a damaged thread, or the arbor? Crossthreaded? It wouldn't take much to stop the nut from tightening properly. Have you tried different bits? Checked their shank size with a caliper?

 

[Stick486]

bit shank is undersized...
get a different brand of quality bit...

 

[CNCnoob]

This is not my first dance, but I certainly have my senior moments.
I tried a new collet and tried different bits.
I'm wondering if the threading where the collet threads onto the router is bad.

 

[Stick486]

you got any kind of lube on the bit shanks and in the collet..
bit set too deep???

.

 

[DesertRatTom]

The collet is supposed to have a portion that as you "screw" the collet down, the interior closes in on the shank. Look at the grooves cut through the collet in this picture. You can see that it is designed to close in on the shaft. If that part is missing or broken, it won't hold the bit.

If you've tried other collets and other bits and it doesn't hold, then you probably have some defect in the threads, either cross threaded or possibly the threads are damaged so the collet nut still rotatess, but only turns in a circle without going further down the threads. You can look at the threads with a magnifier to see if there is something about the thread that doesn't look right. Or take it to a tool service station and have them look it over.

Stick's suggestion about lubrication or too small a shaft. 12mm vs 1/2 inch can be enough to prevent holding tight. The collet itself really doesn't change size much, it is, after all, a pretty high quality of steel, and very carefully machined. But they do break or stop working right, for example, the Bosch Colt is known to "eat" collets. We're talking a few thousandths size changebetween loose and tight.

You didn't say whether the problem persisted with other collets and bits you know to have worked in the past. If no collets or bits tighten, I'd bet on damaged threads on the shaft.

 

[Cherryville Chuck]

The threads aren't what holds the bit in. It's the force applied by squeezing the male cone of the collet into the female cone of the router shaft. If you are able to tighten it down it should squeeze the slots together in the male cone. The only situation I can think of where it wouldn't happen is if the female cone wore badly and the nut bottomed out on the end of the router shaft without tightening the cone together. That's fairly unlikely and maybe even impossible. I'm 99% sure without checking a reference that the 618 collet is the same as a 1617 Bosch collet which is the same as my Hitachi M12V2 and VC. I don't think it will bottom out without forcing the cone together.

If all else fails you could consider switching your collet out with a Musclechuck instead. The manufacturer's test say that it holds I think 4x what a regular collet will.

 

[DesertRatTom]

What was the result when you tested other collets and bits? Did any combination work? Did NO combination work?

 

[hawkeye10]

On the 618 collets, you unscrew the nut but the bit won't come out. The nut comes to another hard spot and you loosen that, then the bit will come out.

I have a 618 and that is how mine works.

 

[Stick486]

On the 618 collets, you unscrew the nut but the bit won't come out. The nut comes to another hard spot and you loosen that, then the bit will come out.

I have a 618 and that is how mine works.

does it work the same when you are tightening the collet...
could it be that you only think it's tight but it needs more tightening to do it's thing...

 

[lowracer]

6mm vs 1/4 inch? (so 6mm dia shank router bits in a 1/4 in collet)

 

[lowracer]

or 12mm vs 1/2 inch as per Tom's post

<snipped>

Stick's suggestion about lubrication or too small a shaft. 12mm vs 1/2 inch can be enough to prevent holding tight. The collet itself really doesn't change size much, it is, after all, a pretty high quality of steel, and very carefully machined. But they do break or stop working right, for example, the Bosch Colt is known to "eat" collets. We're talking a few thousandths size changebetween loose and tight.

<snipped>

 

[Cherryville Chuck]

I have a 6mm bit that I thought was a 1/4" when I bought it. It literally fell into the collet. If it's the right size you'll feel at least a slight amount of resistance when you slide the bit in. If it's nearest metric equivalent you won't.

 

[radios]

The threads aren't what holds the bit in. It's the force applied by squeezing the male cone of the collet into the female cone of the router shaft. If you are able to tighten it down it should squeeze the slots together in the male cone. The only situation I can think of where it wouldn't happen is if the female cone wore badly and the nut bottomed out on the end of the router shaft without tightening the cone together. That's fairly unlikely and maybe even impossible. I'm 99% sure without checking a reference that the 618 collet is the same as a 1617 Bosch collet which is the same as my Hitachi M12V2 and VC. I don't think it will bottom out without forcing the cone together.

If all else fails you could consider switching your collet out with a Musclechuck instead. The manufacturer's test say that it holds I think 4x what a regular collet will.

I seriously would advise against the Musclechuck, as it defies good engineering practice, namely, it distorts a band of metal on one side of the chuck, making it non concentric. if that chuck is used, careful attention must be paid to how tight it is made, any tightness will make it distort, but making it really tight will give you a serious wobble!.. contrast that with a standard chuck, which supplies even pressure to all sides of the bit..

 

[Cherryville Chuck]

Martin I bought a Musclechuck not long ago and installed it on my table router. I did have issues with run out until I loosened the retaining nut a bit and tightening it is covered in the MC website videos. I just gave it a bit too much as a matter of habit. If you don't own one then I suggest you search it with our Community Search function before you comment further. Quite a few members have one (or more) and the majority recommend it highly. I had no issues witth my original chuck as far as holding power and concentricity but what I was having problems with was freeing my bits after which the MC has solved.

 

[CNCnoob]

Thank you all for your thoughts/suggestions! I took the router in for repair at the dewalt repair center and they said the threading on the router collet (can't remember exact phrasing) was damaged. They also said it wasn't worth repairing. I borrowed a friends' router to finish the project.
I'm in the market for a new router! Strongly meaning towards another 618, anyone want to convince me otherwise??
I have a PC in my cnc, a ryobi in a fixed base, but need one for my bosch router table.
On another note, anything I can do with a router motor? It still works great! Just the threading is messed up.

 

[JOAT]

I have a 6mm bit that I thought was a 1/4" when I bought it. It literally fell into the collet. If it's the right size you'll feel at least a slight amount of resistance when you slide the bit in. If it's nearest metric equivalent you won't.

Now that is interesting. I don't know if I even knew there were metric bits sold here. However I do read the bit size on the box before I buy, so I am sure I get a 1/4", and not say a 3/8", but don't recall any metric sizes Good to know.

 

[DaninVan]

He shoots! He scores!!
https://www.routerforums.com/1967567-post2.html

 

[Cherryville Chuck]

Thank you all for your thoughts/suggestions! I took the router in for repair at the dewalt repair center and they said the threading on the router collet (can't remember exact phrasing) was damaged. They also said it wasn't worth repairing. I borrowed a friends' router to finish the project.
I'm in the market for a new router! Strongly meaning towards another 618, anyone want to convince me otherwise??
I have a PC in my cnc, a ryobi in a fixed base, but need one for my bosch router table.
On another note, anything I can do with a router motor? It still works great! Just the threading is messed up.

The Bosch 1617 is an equivalent as is the Hitachi M12VC. Most will recommend the Bosch but I've been very happy with my Hitachi which is only fixed base and I rarely use in a table (only my backup bench top table when I do). Triton also makes one that size and everyone who uses a Triton in their table swears by them. They also swear at them if they have to use them hand held as they are top heavy.

A machinist might be able to repair the threads on the old router depending on how bad the damage is. A very fine triangular file might do it if you want to try it yourself. You have to keep the file in the valley of the thread and restore the ridges. The biggest issue is where the thread starts at the end of the shaft and this is likely where you went wrong. My guess is you had trouble threading it on once and forced it with a wrench. If that is the case then never do it again. If it doesn't thread on easily with just your fingers it's because you started it wrong. Back it off and try again and if it still dowesn't check the threads out to see why. There is a chance if you repair the threads enough that you could get a Musclechuck on it and you would be okay after that as it never needs to be unthreaded again. But that could be a costly experiment as they are around $70-75.

 

[Cherryville Chuck]

Now that is interesting. I don't know if I even knew there were metric bits sold here. However I do read the bit size on the box before I buy, so I am sure I get a 1/4", and not say a 3/8", but don't recall any metric sizes Good to know.

I bought it from Cripe Distributing in Boise. It's a Bosch roundover, gold in colour and cuts really nice. I think Ron Cripe bought them in bulk and he was selling them cheap and may not have even known that they were 6mm shank. It wound up not making a difference as I had bought a 6mm sleeve for some Onsrud bits that I also got cheap.