Thread: reducing template by [X]mm

Originally Posted by newflavour

Hey folks, I've been given a template that I am wanting to reduce by 3mm so that I can get it to work with a specific template bushing and spiral bit.

I usually design and cut all my templates with an allowance for the bushing and bit. I'm stumped on how to reduce an existing template though (could be a case of fridayitis)

what would be the most accurate (not necessarily the easiest) way to reduce the overall size of the template by 3mm?

thanks in advance for your help.

Purchasing a Rebate cutter (Small) and you might be able to exchange the bearing to get the 3mm reduction you require. The other alternative to produce your item smaller is to select an alternative template guide and cutter combination
Tom

thanks Tom, I'll look into that.

I don't know how complex your pattern is, and how tight the radii are. But assuming something relatively simple, you could do this..

Use a 10mm template guide with a 3mm cutter, follow the outside of your existing pattern, and cut out a piece of mdf. You now should have a female template which is 6.5mm larger than your original.

Now fit a 16mm template guide (same 3mm cutter), and, using the female template just produced, cut out a new male mdf template. This should be 3mm smaller than your existing one. At leaset it will be if I haven't stuffed up my calcs.

hey chris, the idea of making a female template larger and working backwards had crossed my mind but i couldn't get my head around the math while cycling home from work today. Thanks for helping me figure out the numbers on that and I've got plenty of mdf laying about to make templates from.

I've gone in to illustrator and mapped out the sizes required and it looks like I'll be making my own bushings from 1/4" HDPE or Perspex (depends what I can find in the man cave).

Just to confirm what Chris has suggested I have enclosed a drawing of the situation
Tom

thanks Tom and chris, the template isn't that complex so this should be an easy process thanks to your assistance. I'll be able to make the bushings quite easily, hopefully this weekend.

thanks a bunch.