Sometimes referred to as ‘numbered bits’ , their very small diameter makes them difficult if not impossible to use in standard 3 jaw drill chucks.
The good news is that you don’t need to invest in a new precision chuck designed for the purpose. http://www.micro-machine-shop.com/drill ... cro_Chucks
Grobet USA1 makes a small pin chuck, complete with three different collets, that mounts in your drill press or portable drill (you’d need a steady hand). The bits are somewhat fragile, so the drill press is certainly a better choice.
This ‘chuck’ is available from Bear Woods: https://www.woodparts.ca/product5910.html
Anything in the Grobet catalogue can be ordered through Bear Woods (Canada)
Note that the numbered bits end at #1 (.2280”) and are followed by lettered bits A~Z (.4130”)
These bits are of particular use in scroll sawing for starting holes. A short video clip of drilling with the Grobet pin chuck in a portable drill here:
That Grobet collet device is basically a pin vise. mounting it in he DP chuck gives you a lot ofstability and control...however it is easy to over power the drilling and break or bend the bits. Fair warning : buy bits in multiples. You WILL break or bend them occasionally.
MikeSibley wrote: ↑Thu Oct 08, 2020 9:12 am
Does anyone have an opinion as to which is the better of the bunch? More importantly, which is the best value for the money?
Hey Mike; sorry, not clear on what you were referring to(?). Small bit suppliers?
MikeSibley wrote: ↑Thu Oct 08, 2020 9:12 am
Does anyone have an opinion as to which is the better of the bunch? More importantly, which is the best value for the money?
Hey Mike; sorry, not clear on what you were referring to(?). Small bit suppliers?
No, I was talking about the collets. I have some small bits that I use for pilot holes in my clock projects and they are too small for my drill press collets.
When I did my 2020 2x4 Challenge, a Kappla block set with box out of Western maple, the box sides were very thin. I couldn't spline the mitered corners so I decided to pin them. That's how I got into this whole numbered bit thing.
I found brass rod .081" dia. then paired that up with a #46 bit. As a backup I also bought some 3/32" dowel from Bear Wood* along with that Grobet bit holder. Worked like a hot damn!
The brass rod only needed a gentle tap to seat firmly in the drilled holes. I left them maybe a .001' proud and finish sanded the whole exterior down flat.
the poly locked everything in.
*Re that dowel from Bear Wood. It's made in the US and it's superb quality!!! Highly recommended.
You do not have the required permissions to view the files attached to this post.
DaninVan wrote: ↑Thu Oct 08, 2020 1:33 pm
I couldn't spline the mitered corners so I decided to pin them
I'm liking that pin idea especially on thin walled stock.
Do you think it adds any strength to the joint ? Or more for cosmetics ?
I can explain it to you but I can't UNDERSTAND it for you!
Wait a moment, let me overthink it.!
Of course I talk to myself, -- sometimes I need expert advice.
Stick486 wrote: ↑Sat Oct 10, 2020 10:47 am
I still say get a 0''~ whatever chuck and put it on your cordless....
or replace your cordless w/ the better level of a Bosch 12V that will already have that chuck on it...
The only way to get a dead on perpendicular hole is to use a drill press, hand held drills just don't give that level of accuracy. Having said that, I drilled the holes with the DP in the faces of the boards then used my hand drill with the Grobet chuck to extend the holes into the mating boards after they were dry. The outer hole stabilized the bit going in.
A thought just occurred to me (OK, you in the back, stop sniggering!)...
If you're using one of those block style guides, how do you accurately center it when you can't see the hole location?
