Inside cutting basics

[Will1987]

Probably a pretty basic question, but whats the best method for getting perfect inside cuts? that is, I want to cut various predominantly regular shapes out. hitherto I've just been drawing lines, drilling a holes to put the blade through initially and to make the turns, and using a scroll saw, no jigs or anything. Can you use a jig with a scroll or band saw? I kinda need the "rundown" on this. There must be something I'm not aware of with this because cutting with a scroll or band saw freehand is obviously not accurate enough. I guess I could use a jig (template?) and a hand held jig saw (which is all I have in the way of jigsaws). It seems to me though that the blade in any of these tools will cut into a jig unless its made out of something pretty hard. So whats the best thing to make a jig out of or is there some other trick I don't know about?

Will :o :o:o:o:o
thats the purple friendly sympathetic face I guess.

[Will1987]

or maybe its the demented derelict sleeping in an alley sniffing glue face.

[Terry Mac]

Hey Will,

The only jig I've made for the bandsaw is a ripping jig for resaw.

The scroll saw is a little different, cause the blade wants to run to the right when cutting a straight line. Not sure about using a "hard" jig with it. I've typically used cardboard to make a pattern then freehand my inside cuts.

Interesting question, hopefully some of the other guys will chime in.


sniffing glue face. :o LOL

[Don]

Hey, Will. A good answer will really depend on what you are trying to do. The most accurate repeatable inside cuts are typically made with a router and jigs of some sort. I've made many "frame" type inside cuts by plunge cutting on the table saw. (an advanced move)

Of course holes saws and cutters of various types are available.

dawjr

[Will1987]

Thanks for replies guys. Yeh i guess I'll be more specific - I'm trying to simply cut a square out of the inside (of a square), so that what I'm left with is what I'd describe as I guess a picture frame type shape. However its not a picture frame I'm working on, and I don't want to use 45 degree angles fastened together somehow. Also I want to re-use the wood I cut out of the middle. the tools I have available are: plunge router, scrollsaw, hand held jigsaw, table saw, and a band saw (though that's used and needs a thrust bearing). I have a feeling you're gonna say use the plunge router, but with what bit? i have a dado bit. also the wood I'm cutting is thin - like 3/16. would i use that dado bit or some other bit for cutting through wood? I want a generalizeable technique I can use for other types and thicknesses of wood too.

thanks a lot,
Will MacBride

[Don]

Hey, Will. Sounds like you are cutting a thin plywood. Depending on how big your frames are I have done this on the table saw. It is an advanced maneuver though so I won't go into detail.

From the tools you have, you are right, your plunge router will do the trick. You have a couple of ways to go. The first is your router in a table, a simple two flute rabbeting bit standing up. You lower your material onto the bit and run it along the fence to marked stopping points. Repeat on all sides.

Then you have a similar bit, a bushing on your router base and a pre-made template allowing for the offset. You run the router bushing against the template and the bit protruding through cuts your material.

Then, for the material you are cutting, I would say the easiest would be a self piloting bit like these linked below. You have to make a template again, but it eliminates the need for a bushing.

http://www.woodcraft.com/family.aspx?familyid=1863

http://www.woodcraft.com/family.aspx?familyid=8080

Any of these methods would allow you to make production.

dawjr

[Will1987]

thanks, some good info there.