Adaptor for 1/8" bit in 1/4" inch router bore

[RomanLini]

Hi, does anyone know where to buy an adaptor to fit 1/8" tools (like Dremel bits etc) in my 1/4" router??

Thanks.

[grinder_gary]

I just purchased a set from K2cnc on e-bay, Very satisfied with product.

http://cgi.ebay.ca/K2-CNC-Router-1-8...item5885ec99f9

GG

[EBC]

http://www.precisebits.com/gateways/ColletsNutsHome.htm


Gene Crain
www.plantasymaderas.com

[RomanLini]

Thanks grinder_gary but I don't think that simple grub screw collet from ebay will do, I was measuring my Dremel bit shanks with the micrometer and the shank diameter ranged from 3.05mm on some bits to over 3.3mm on others.

EBC- I looked at the collets in your link, that looks more like what I am after but I'm not sure which one will suit my router shaft. My router collet is straight for about 2/3 of the length and then has a tapered area on the front third. Unfortunately the precise bits web site doesn't show dimensions, angles or any drawings for me to compare.

If anyone has more info or more suggestions I would appreciate it. I've been considering buying a $30 hardware store Dremel copy and cutting the shaft out and turning it down to 1/4", then I would be able to use the small collet range that comes with it.

Alternatively if I can get more info on the nice ER style collets on preceisebit.com website then maybe one of their range will fit straight in my router.

[EBC]

www.use-enco.com

Lots of stuff here...might take a while to find what you need


Gene Crain
www.plantasymaderas.com

[RomanLini]

I can't find any adaptors in that enco site, apart from the usual (high priced) proper collets for milling and stuff.

I thought this would have been a commonly sought after item, some way of putting 1/8" shank bits in a 1/4" bore router??

[SanDiegoCNC]

Do you have any idea what the specs should be for the collet you're seeking? If they match what I have, I'll just turn a few extra for you guys. No big deal.

[mcphill]

Is this in the ballpark?

http://www.mcpii.com/Nicknacks.html#anchor_96

[TDA]

EBC- I looked at the collets in your link, that looks more like what I am after but I'm not sure which one will suit my router shaft. My router collet is straight for about 2/3 of the length and then has a tapered area on the front third. Unfortunately the precise bits web site doesn't show dimensions, angles or any drawings for me to compare.

Alternatively if I can get more info on the nice ER style collets on preceisebit.com website then maybe one of their range will fit straight in my router.

What kind of router are you using? If this is a custom piece, what is your taper angle?

[SanDiegoCNC]

Here's what I did... Grabbed some 316 sst, wrote a quick turning program, and machined an adapter to convert my .250 router chuck to hold .1875 tooling. All I need to do now is to machine a slot with a slitting saw on one side and then it should work like a charm. Picture follows...

I don't see why this simple, yet economical solution wouldn't work on any brand of .250 collet chuck. Now my question is... 'Does anybody want these if I made a batch of them'? and 'What should I charge for these collets, less shipping'? And lastly, is there any real demand for these 0.1875 collets or the smaller 0.125 collets?

[RomanLini]

mcphil- that little Dremel chuck adaptor looks great and I can see me getting one in the near future, mainly for PCB drilling and some special tasks. But for engraving and machining (especially in soft plastics) I am not sure if the rigidity or runout would be up to my requirements.

SanDiegoCNC- Wow that's really nice to offer to make something, I'm new to the community here so that was kindof a surprise and of course if you do end up making something custom for me I would be happy to pay. I've already made something similar here out of a 1/4" stainless rod stock, I drilled it on the lathe and then cut a split down one side. But that has problems, one is that I am not a machinist I'm an electronics guy, my lathe has about 0.0004 runout and all I could do to bore it 1/8" was a drill bit.

Of course there are other issues that the single split causes more runout and my Dremel bit shanks measure 3.05mm to 3.30mm which poses more problems.

TDA- thanks its nice to hear from precisebits! My router is an australian brand Ozito, it has superb runout and a 42mm metal clamp outer surface so it is great for my little machine. But i don't know much about the collet specs or standards. Here are some rough measurements;

length 20.3mm
taper on the front 5.5mm length
3 splits, from the front
front and rear surfaces are flat
bore 1/4"
rear diameter 10.0mm
front (where it is the widest) diameter 12.3mm
taper angle measured with crude protractor seems about 12' each side, might be 15' it definitely seems larger than 10'.

I can post pictures if you want.

[TDA]

I don't see why this simple, yet economical solution wouldn't work on any brand of .250 collet chuck.

The general problem with this type of setup is runout. Even if your adapter is perfect (something even ER collets can't manage). You still have to deal with the runout in both the collet and the router. I have seen new stock collets runout vary from .0004-.006. Obviously some manufacturers are better then others but with most you are rolling the dice when it comes to collets.

Why does runout matter so much? When you are dealing with larger tooling runout isn't as much of a problem (although it does effect tool life and kerf width). However, when you are talking about 1/8" shank tooling it can be a big problem. A good rule of thumb is 10% of the diameter of a cutter in runout will break the tool. Currently our most popular sizes are probably .0156", .0200", .0230", and .0313". So when you are talking about even a .0313" cutter that only gives you .003" of runout. If your stock collet is over that then you will break that sucker right off.

One last note. I somewhat known for being a downer so let me try and make this clear. I'm not trying to discourage you. I'm just trying to pass along what we have found over the years.

TDA- thanks its nice to hear from precisebits! My router is an australian brand Ozito, it has superb runout and a 42mm metal clamp outer surface so it is great for my little machine. But i don't know much about the collet specs or standards. Here are some rough measurements;

length 20.3mm
taper on the front 5.5mm length
3 splits, from the front
front and rear surfaces are flat
bore 1/4"
rear diameter 10.0mm
front (where it is the widest) diameter 12.3mm
taper angle measured with crude protractor seems about 12' each side, might be 15' it definitely seems larger than 10'.

I can post pictures if you want.

If you could post some pictures it might help. I have had a hard time finding any online.