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I found some 1/4 inch shank end mills that are 3/32 and 1/16 which I could use for bridge saddle but the problem is that in Taiwan shaft diameters are metric which means my laminate trimmer accepts 6mm router bits and end mills but 1/4 inch is a hair too large therefore would not fit (no matter how hard I tried) so I tried drilling out the collet (they're cheap... a buck each so not too bad if I mess it up) bit had no luck because the steel is way too hard. I am not sure what to do here because I need the end mills to fit and I can't find any router bit smaller than 1/8 inch that fits properly... Is there any way to soften the material so that it could be drilled easily? I had trouble holding the collet too since it's such a small part no amount of vise pressure will get it to stay put.

I could use the drill press for bridge saddle but not rosettes so if I can't figure this out inexpensively then I will probably use the 1/8 inch router bit and just route rosette with purfling on either side (ie not three separate routes)

These Chinese made end mills are too well made I tell you!

Oh and that also means any of the router bit from Stewmac or LMI or Woodcraft or Rockler won't fit in my Taiwanese (metric) routers... I'd get American routers (you know Bosch Colt or Porter Cable 6xx) but the problem is that they're expensive to ship here and not to mention getting spare parts will be difficult/expensive and seriously routers here are good enough.

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

That sure seems odd to me. I live in Canada, we are apparently on the metric system yet hardly any tools I have are metric and I didn't know you could even get a metric laminate trimmer (over there that is).

The collet has a slit in it to allow for expansion/contraction right? I know mine does. So why not just try and wedge a screw driver in there and open it up. You only need 0.35 mm which is only a hair under 1/64". Use a smaller piece of steel rod (3/16" or so) through the collet, then force the screw driver into the slit in the collet and turn the screw driver to open up the collet. If it doesn't work or the collet deforms, you're only out a buck (as you say they are cheap there).

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Maybe you can find a machinist in your area to help you Out. They might be able to modify the collet. What if they could turn the router bit down to fit the collet? I'm not to knowledgeable about metal so I would make freinds with a local expert.

Maybe I'll try that if I could find a machinist... I think they're not as expensive in the US either (maybe 15 bucks an hour MAX compared to over 100 an hour in the USA)

Anyways don't do this to your favorite end mill but here's what I did...

I took the collet and inserted the end mill business end first into the back of the collet and pressed it in with a drill press. It's a VERY tight fit by the way I pretty much needed to put my muscle into it to get it to go in (not to mention the amount of support too) so now the collet is pretty much permanent to the bit (although I can probably release it by pressing it further in using a rod) and I just chuck the whole work into the laminate trimmer and with a circle jig I am ready to make rosettes. All I need to do is remove the whole nut then insert a regular collet for normal bits... it's a pain until I can find a machinist who can make me something that works.... It's a 5 dollar end mill and a 1 dollar collet so who cares if I trash it. The 5 dollar end mill is pretty well made considering its country of origin (China), cuts ebony without any fuzz. I'll try my best not to break it too...

And yes normal Taiwanese router bits are .015 smaller than a 1/4 inch shank bit! The .015 is enough to make it not fit.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

You're not going to be able to drill out a collet. If there isn't a 1/4" collet available for your router you'll have to take the collet to a machinist and have it honed or reamed. Pretty easy operation if you've got a lathe and the correct tooling. You'll pay more in set up fees than actual machine time.
-C

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Freeborn Guitars
and home of BeauGuard©

Is that a Maktec trimmer?
Maybe you can try to ask the supplier if they have a collet for the 1/4" shank
My Maktec (Makita) trimmer comes with the 1/4" collet (6.35mm).
I had a 6mm bit which is too loose for the 1/4" collet .
I called my agent and they do sell the 6mm collet, but in the end I managed to get some 1/4" bit instead.

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Sen CL Goh
http://senguitar.blogspot.com

Trying to modify the collet or the bit is NOT the way to go. Both are hardened and tempered and would need precision grinding to modify them. Someone may be able to reduce a 1/4" bit for you, but it would certainly be cheaper to buy a bit with a metric shank. The bore of the collet must be parallel to grip the cutter properly. If you forced it open to get a bigger bit in, it would almost certainly not run true and would be downright dangerous.

You should be able to buy a 1/4" collet for your trimmer. My router came with 8mm and 12mm collets and I had to buy a 1/4" collet to use with some 1/4" shank cutters I bought in the UK.

I had this problem when living in Brazil. I took the existing collet to a machinest and had him make me a couple of extra collets to fit different size shanks.

In this case, it's much easier to just buy a 6mm end mill. There are lots of places that sell them at good prices. Last time I looked, the prices from lutherie suppliers were between two and eight times what I pay for quantities of one from actual end mill places, and it's similar with woodworking stores. Go on eBay if you can't find anyone locally.

Any end mill should work; the ones made especially for aluminum have sharper edges and cut better. Buy carbide as the price difference between that and HSS is quite small now and the amount of use you'll put one through by hand should take decades to dull it.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

I just need to find a machine shop here.... no I can't buy inch collets for my laminate trimmer and it's not a Maktec (they are orange) they are made by a Taiwanese company called Rexon or something (I suspect they are the same company who makes tools for Grizzly though). The end mill forced through the collet works great it is a tad inconvenient though but both pieces were inexpensive anyways and it runs true enough for woodworking...

One of the problem with end mills that are really small is that there are not too many choices and usually they are expensive. The HSS bit I got cuts ebony just fine with no fuzz but who knows down the line.

Can someone give me a link to a place that sells end mills with metric shank? I tried Enco and MSC and they all use inch shanks. If someone got a 1/16" or 3/32" endmill with a 6mm shank that would be great since I can't find a 3.5mm collet for my router.

Or if a machinist OLF'er could help me out that would be great. I can send you the pieces (in fact I'll send several because they're cheap) and you can machine it for me...

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

I think you would end up saving yourself a lot of head ache if you just purchase a different router instead of trying to get bits machined to match the one you have. Lots of companies make 3mm shank micro end mills but you've said you can't get a 3-6mm adapter for you router.

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"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

first hit from using Google with the parameter of Metric End Mill:

http://www.positiveflow.com/cuttersm.htm

Yes, but they don't have the size he's looking for either.

_________________
My Facebook Guitar Page

"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

Loads of 6mm end mills on eBay, both in 6mm cut and some with smaller cuts.

If you do find a 1/4" collet, PreciseBits sells their cutters with optional 1/4" adapters. They're pricier than some other places, but they are the best.

_________________
Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

**cough**...OK, so I was lame and didn't fully read the thread and too boot had my eyes crossed on that previous url and thought I did see a 6mm shank with about a 3/32 (in metric) cutting end...

try this: http://www.tapdie.com/html/endmills__me ... _hss_.html

I modified my google search to be metric end mills 6mm shank which gave more defined results....