Thread: Creeping up on a good fit

I use a chain saw file on mine if tight fit.

I take a dowel or metal rod and hacksaw a slit, lengthwise, an inch or two (30 to 50 mm) long. Put a strip of sandpaper in the slit and wrap it a couple, three turns around the dowel/rod so the flap end is trailing the direction of rotation when put in a drill. Put it in the drill and slide the blank over the paper and spin your home made flap sanding tool until it is the hole is correct size. After a while when the end of the paper dulls, rip it off to expose fresh abrasive. It is also handy to smooth the drill marks from the inside of translucent acrylic blanks before painting the inside of the blank.

Pete

Thanks Cookie and Pete, both simple solutions, don't know why I didn't think of them. Pete great tip about cleaning the inside of an acrylic, that should really help the final finish.

Tiger, I sometimes use a rat tail file. Amos

Originally Posted by PenTurner

Tiger, I sometimes use a rat tail file. Amos

Thanks Amos, will give that a try.

If this is only happening for you with timber blanks, but acrylic/resin ones work fine, I would suggest that it could be a timber warping situation. On the Timberbits website (not sure if it's still there on their new site) there is a great instructional video about timber warping and brass tubes not quite fitting into the holes they are supposed to. Essentially the fix for this is to drill out, wait a day while the timber does it's thing, then drill out again. The second pass will remove any material which has warped into the path of the brass tube. It should then give you a good fit. Just a thought.

While drill bits are generally bought is sets in .5mm, 1/32, 1/64 etc increments, it is possible to buy single drill bits in .1mm increments. If you not sure where to buy locally, check out your nearest metal machining shop & ask him where he gets his.

United Fasteners is where I go.

Steve

check out ebay
thats were i get most of my odd size drill bits
cheers Tony

I have a tool makers set of drill bits 6mm to 10mm in 0.1mm increments. Invaluable!
SM30 + SM41 http://www.sutton.com.au/CatalogueVi...rial+Catalogue

An adjustable hand reamer, maybe?

http://www.ebay.com.au/itm/1-5-1-4-C...item5b0067467c

Thanks for all the suggestions. The drill bit that I needed was over 1/2 inch mark, I have all the drill bits under 1/2 inch. I found the best way to cope when your hole is too tight is to use the dowel sander method, just a couple of seconds and the hole is just right and fairly concentric too. The file was a lot of work and still not as concentric as the dowel method.

When I was a kid, my dad taught me this method for honing Break & Wheel cylinders. That was in the days when Mechanics fixed things, rather than just change them.

Steve