Thread: Fine tuning inside holes

how about using a circular cutter for your router?
You can set them up pretty accurately and then use a straight bit.
Wolffie

Thanks Wolffie, I was hoping not to have to go to the trouble of creating an accurate enough jig to do this but may end up doing this if I can't find a quicker way.

I reckon you could get away with using a rasp or even a block of wood with a curve on it and sandpaper. Sounds like you will only need to remove a smidgen, I can normally get very consistent holes when filing out steel and that is normally a lot harder to do then wood

ditto,a rasp is fast and easy

a circle cutter would be adjustable.
Wolffie

Cut a 100mm hole in a scrap of 6mm MDF and sand or file it to the exact size you want. MDF is quick and easy to shape, especially with a drum sander in your drill press. When you have tested that it is the size you want you can use your template to enlarge the holes in your wood to the correct size.

To do this, cut your 100 mm hole where you want it, clamp or double sided tape your template over your work piece and trim your hole to size with a pattern bit (a straight bit with a bearing on it) For sizes or shapes you can't do with a hole saw, rough it out with a jig saw etc.

You can then make as many as you want with your template. I often use a template for even one off jobs as it is a lot easier to shape up the 6mm MDF than a piece of thick wood. Then again, I dont often require just circles in what I do.

Regards

Chipman

Thanks for the replies. I have been able to complete the job with a rasp, although there was a bit of chatter as the work was only 12 mm thick, maybe my rasp has seen better days too.

DJ, must remember that you can fine tune metal holes as well with sandpaper.

An adjustable hole cutter is on my list of things to do and the template idea is also worthwhile. Thanks again.

Originally Posted by Tiger

DJ, must remember that you can fine tune metal holes as well with sandpaper.

I didn't say that I you can use sandpaper for metal holes, I said that I can normally get very consistent holes when filing out steel