Is it really that easy?

[geneb]

I got to thinking today about building patterns that can be cut out with a hand router that has one of the pattern follower collars installed in the router base.

Here's what I'm thinking - given a part designed to be cut on the 'bot using a 1/4" cutter, could I create the tool path giving a cutter diameter the same as the pattern collar and have the hand-routed result be the same size (assuming the router was using a 1/4" bit) as the ShopBot cut part?

tnx.

g.

[zeykr]

Just offset your profile by the distance between the router bit and collar. I.e. the difference in outer diameter of the bit and the outer diameter of the collar.

[geneb]

Well isn't that what I'd be doing by "lying" to the software (VCarve in this instance) in telling it to use a (for example) 1/2" bit, but cut it with a 1/4" bit?

tnx.

g.

[zeykr]

Think offsetting the part profile by the right amount (diff between od of bushing and od of bit) and doing a profile/outside toolpath would be simplest for me.

I'm sure you can do it your way, but would take me a little thinking - if part is drawn correct size and you cut with a profile/on line toolpath, your part will be small by the radius of your bit, cut it with a 1/2 bit instead of 1/4 and part is now smaller by the radius of the 1/2 bit or 1/4". If you put a 1/4 bit in the hand router with a 1/2" od bushing, the the bit in hand router would be spaced back out 1/4" so it seems you should get what you wanted if I'm thinking it through correctly.

[mitch_prest]

changing bits instead of offsetting is a very bad habit to get into.. you can bet it will come back to bite you in hiney... you may not remember to change next time you run the file or you might have someone else run the file who does not know to use a different bit..

m

[Gary Campbell]

Gene...
I agree with Ken. Measure the bit you want to cut with, measure the bushing and offset the vectors to the outside by half the difference. This way you wont build in problems with inside vs outside profile cuts.

Are you looking to build these for those without a CNC?

[geneb]

I think I'm going to have to make a test pattern or two just to get my head around this. :)

I would like to make patterns that can be cut out with a regular router - I offer a set of plans for building a flight simulator cockpit and it would be easier on the builder if they could cut the ribs out using a template. Even including drawings for the template would be helpful.

Thanks all.

g.

[geneb]

I found a description of the process that helped -
http://www.templatesbynumbers.com/?q=howtomakeroutertemplate

I think this would work well for creating a template that is going to result in the finished part being a "positive" of the router pattern, which is what would work for the cockpit ribbing. (It's curved and has a number of stringer notches.)

tnx!
g.