Broken router collet. Why?

Questions about tools and jigs you want to buy/build/modify.

Broken router collet. Why?

Postby Simon Magennis » Wed Jan 24, 2018 7:25 pm

I was trying to set up my Bosch GK600 (colt) the other day and the cutter went flying through the room. When I open the nut and looked at the collet, it was in four pieces. What is the likely cause? Overtightening? Or is this something that just happens to routers once in a while?

I ordered two replacement collets which will arrive in the next week but I hope I don't actually need more than one. :-)
Simon Magennis
 
Posts: 390
Joined: Sat Jan 07, 2012 7:51 am
Location: Würzburg. Germany.

Re: Broken router collet. Why?

Postby Barry Daniels » Wed Jan 24, 2018 8:22 pm

How much force did you use when tightening the collet nut?
MIMF Staff
Barry Daniels
 
Posts: 1814
Joined: Thu Jan 05, 2012 10:58 am
Location: Houston, Texas

Re: Broken router collet. Why?

Postby Daryl Kosinski » Wed Jan 24, 2018 9:05 pm

In the 40 some years using routers, I have 3, I have never had a broken collet.

Your collet must have been defective.
Daryl Kosinski
 
Posts: 87
Joined: Sat Oct 12, 2013 11:14 am
Location: Fultonville, NY

Re: Broken router collet. Why?

Postby Simon Magennis » Thu Jan 25, 2018 4:11 pm

Thanks both. I don't really know how tight I made it. I doubt if it was different from the few other occasions I have used it. I have just a short spanner for tightening it so it is not really possible to crank it a huge amount.

The only thing I have done with the router his cut binding ramps for 3 guitars using a jig based on the one in the Gore and Gillet book. If there was a decent selection of mid-lower range routers here I would pick up another in any case but the only ones I have seen here are professional level so I am waiting till the replacement collet comes by post before I try again.

I was fortunate where I was standing so that nothing happened me when the cutter went flying. That was a lesson in itself.
Simon Magennis
 
Posts: 390
Joined: Sat Jan 07, 2012 7:51 am
Location: Würzburg. Germany.

Re: Broken router collet. Why?

Postby Bob Orr » Thu Jan 25, 2018 4:17 pm

Just a thought but do you clean out the collet regularly. I lost a cutter once because the collet was all gummed up with fine dust and although it felt tight it was not gripping the shank properly. If it was gummed up perhaps that caused the collet to split|? Bob
Bob Orr
 
Posts: 72
Joined: Fri Dec 28, 2012 1:20 pm
Location: Nailsea, Nr Bristol, UK

Re: Broken router collet. Why?

Postby Dan Smith » Thu Jan 25, 2018 7:45 pm

Make sure the bit is not bottomed-out before tightening.
Stick it in and pull it out 1/8” or so.
I learnd this when I had a bit fly out.
Ever-body was kung fu fight-in,
Them kids was fast as light-nin.
User avatar
Dan Smith
 
Posts: 306
Joined: Mon May 18, 2015 9:33 pm
Location: Texas

Re: Broken router collet. Why?

Postby Mark Fogleman » Thu Jan 25, 2018 8:50 pm

I've had bits creep out also during a rabbit/dado cut but have never had a collet chuck to break. That took a lot of force or your collet chuck had a defect or both. I saw a tip in one of the WW'ing magazines a while back where the author used a small rubber ball known as a Spaceball http://www.spaceballs.com dropped into the collet to allow space for the bit to expand yet maintain a repeatable depth. I've not had any creeping bit problems since I started using one. These balls are normally used to maintain pressure on floating panels in wooden cabinet doors during dry season when the wood shrinks and compress during the wet season when wood expands. They are sold at most cabinet supply stores in the US. I'm not sure where they're found in the EU. Rockler has a 100 each bag for ~$7. If you can't find them PM me your address and I'll send you one. You'll owe me a Neumarkter Lammsbräu Festbier the next time I visit my friends a little south of you near Künzelsau.
Mark Fogleman
 
Posts: 107
Joined: Sat Apr 27, 2013 10:02 pm

Re: Broken router collet. Why?

Postby Brian Evans » Fri Jan 26, 2018 1:45 pm

I do know you can damage collets if you tighten them with an undersized shank, or no shank at all. But I too have never damaged a collet or had one break. I've killed my share of bits, mind you.

Brian
Brian Evans
 
Posts: 570
Joined: Sat Aug 30, 2014 8:26 am
Location: Tatamagouche, Nova Scotia

Re: Broken router collet. Why?

Postby Simon Magennis » Fri Jan 26, 2018 7:04 pm

I doubt if the photos really tell any story except how small the collet is (1/4"). I would need a fancier camera to get a more useful image. Anyway, just for completeness sake, this is what it looks like now. My new collet should arrive sometime next week and then I can continue with my current builds which are waiting for the binding.

Insides
collet1.jpg


External
collet2.jpg



Edit:

Since I posted the images I searched online and found the user manual. This might be the root cause:

Do not tighten the tightening nut of the collet without a router bit inserted. Otherwise the collet can be damaged.


While I don't recall tightening the nut very much when there was no bit inserted, obviously I had it at least tight enough enough to prevent the not and collet falling off - perhaps I over tightened it then.
Simon Magennis
 
Posts: 390
Joined: Sat Jan 07, 2012 7:51 am
Location: Würzburg. Germany.

Re: Broken router collet. Why?

Postby Clay Schaeffer » Fri Jan 26, 2018 11:56 pm

That is a really delicate collet design for a trim router. The PC and Rockwell routers have a single cut through . As others have said leave a little space at the bottom of the chuck because the bit gets pulled down some as the collet is tightened and if it bottoms out it will not tighten properly and even if it holds the bit you will get more vibration with it in contact with the spindle. I have used broken (in halves) collets in larger routers which still worked o.k.
Clay Schaeffer
 
Posts: 1078
Joined: Fri Jan 06, 2012 12:04 pm

Re: Broken router collet. Why?

Postby Simon Magennis » Sat Jan 27, 2018 6:40 am

Clay Schaeffer wrote:That is a really delicate collet design for a trim router….


Tacky is the word you are looking for. :-)

When I bought the thing, the Bosch Colt routers were getting great reviews. This is the Euro version or to be more specifically the UK version. The Euro version takes 6mm and 8mm bits. The UK version only takes 1/4". That is not at all obvious from the product name and the box set I bought with accessories included the 8mm collet which won't work due to the way the shank is routed out. I got it from the UK as I though I was getting a bargain - about 30%-40% cheaper than in Germany at the time.

Hidden away on the small print in the specs for the GFK600 is another number: 3601 FOA 171. This is the key. 3601 FOA 1xx takes 6mm and 8mm (and I assume 1/4" as well). Whereas 3601 FOA 16x and 3601 FOA 17x take only 1/4" due to a conical routing of the shaft. All of them come from mexico like the colt.

I am not very lucky with my router choices. I also bought a trend T4 based on some forum recommendations. Again there is an issue that might be nothing for an experience person but makes it next to useless for me. The height adjustment on the base is shoddy beyond belief. There locking mechanism consists of a nut covered by a plastic lever. The nut wears the plastic out in no time flat with the result that the only way to lock off the height is to use a spanner of some kind, as opposed to just using your thumb to press a lever, and even then it gets loose. I suppose with a third party base or locked into a jig it would be alright.
Simon Magennis
 
Posts: 390
Joined: Sat Jan 07, 2012 7:51 am
Location: Würzburg. Germany.

Re: Broken router collet. Why?

Postby Clay Schaeffer » Sat Jan 27, 2018 8:05 pm

"When I bought the thing, the Bosch Colt routers were getting great reviews"

Unfortunately ideas and recommendations on forums are kind of like viruses. You have to let them run their course for awhile before seeing if they are worth adopting. I have at least a dozen trimmers. Most of them are the old green Rockwell's and Porter Cable brand, but also an older Bosch, and a Virutex. I've used Ryobi, Makita, deWalt, Freud,and Ridgid trimmers. They all seem to have good and bad points.
The current favorite on forums seems to be the Ridgid trimmer. I haven't used the new model, but the old model didn't hold up to daily use. It had a plastic base that fell apart and the motors burned out fairly quickly.
If the trend has a decent motor and is otherwise O.K. you might want to try to fix it's short comings or figure out a work around. The older 1608 and 1609 Bosch trimmers (and others) used a 43 mm mounting ring for it's fixed base - the same diameter as the trend t4 uses. So if you wanted to go to a fixed base or the various other Bosch bases (tilt, off set, etc) you can find them on ebay:
http://www.ebay.com/itm/BOSCH-ROUTER-TR ... SwmudZ9hjJ
http://www.ebay.com/itm/Bosch-360570261 ... SwAaJZ9hfY
Clay Schaeffer
 
Posts: 1078
Joined: Fri Jan 06, 2012 12:04 pm

Re: Broken router collet. Why?

Postby Daryl Kosinski » Sat Jan 27, 2018 9:07 pm

Are you sure it is a 1/4 inch collet? If it was a 8mm then that would do it.

I needed to buy a 8mm collet for my Porter Cable so I could use Leigh Jig bits.
Daryl Kosinski
 
Posts: 87
Joined: Sat Oct 12, 2013 11:14 am
Location: Fultonville, NY

Re: Broken router collet. Why?

Postby Clay Schaeffer » Sun Jan 28, 2018 12:49 pm

Porter Cable makes 8 mm collets for the 690 and larger routers, but probably not for the trimmers. An 8 mm bit is too large for the spindle shaft hole of the P.C. trimmers
Clay Schaeffer
 
Posts: 1078
Joined: Fri Jan 06, 2012 12:04 pm

Re: Broken router collet. Why?

Postby Bob Hammond » Thu Feb 01, 2018 11:00 am

It's fortunate that you weren't injured. This is the first time that I've heard of a collet breaking, but come to think of it, I've never tightened a collet without a bit in it.

On router bits that I use frequently, I put a rubber O-ring on the shank at the proper insertion depth. It also acts as a 'third hand' for tightening the collet if the arbor lock has a springloaded lever.
Bob Hammond
 
Posts: 564
Joined: Sun Jul 22, 2012 4:13 pm

Re: Broken router collet. Why?

Postby Mark Fogleman » Thu Feb 01, 2018 12:45 pm

Bob Hammond wrote:
On router bits that I use frequently, I put a rubber O-ring on the shank at the proper insertion depth. It also acts as a 'third hand' for tightening the collet if the arbor lock has a springloaded lever.


Great idea Bob!
Mark Fogleman
 
Posts: 107
Joined: Sat Apr 27, 2013 10:02 pm

Re: Broken router collet. Why?

Postby Simon Magennis » Thu Feb 01, 2018 7:32 pm

Just to complete the story.

My replacement collets came along with a 1/4" flush trim cutter which I haven't used yet. Once I opened up the fresh packet, I realized that the collet was much tighter in its not that what I remember the broken one to be. So it could very well be that I damaged the original one. They are pretty delicate. I had a go at doing the binding ledges on the three in progress instruments and the router and the collet are working fine. I will bring the ledges to their final depth in the next day or so.

I haven't quite figured out the dust collection on the jig I am using but have the vacuum attached even in provisional way sure kept the place much cleaner than using nothing at all. However, I will put two ideas into action before I sue the set-up again.
Simon Magennis
 
Posts: 390
Joined: Sat Jan 07, 2012 7:51 am
Location: Würzburg. Germany.


Return to Tools and Jigs

Who is online

Users browsing this forum: No registered users and 5 guests

Your purchase from these sites helps support the MIMForum, but only if you start at the links below!!!
Amazon music     Amazon books     Amazon tools     Rockler tools     Office Depot    

The MIMF is a member-supported forum, please consider supporting us with a donation, thanks!
 • Book store • Tool store • Links •