Using a template and a router

[sailor55330]

Hi-

I'm trying to make an infinity loom for my wife. For those not familiar with what they are, look here.

https://www.google.com/search?q=afga...2F%3B274%3B170

If it turns out, I may end up making them for Christmas presents, so I'm thinking about how to reproduce them. I cut a template out of 1/4 ply using my bandsaw and my scrollsaw and then will transfer the pattern to 3/4 stock. My thought was to cut with a bandsaw and jigsaw as close to the line as possible and then use a router bit with a pilot bearing to "finish" the cut. So far, that hasn't worked so well. I'm using a Delta router/shaper table. The first time I tried this on scrap pine, the bit kept eating into the template and I had to remake the template (inside french curves with matching radius is a little time consuming!). I've never used a bearing bit in a stationery table, so maybe that's part of it.

What am I doing wrong here?

My next challenge is that I will need to drill holes 3/8" from the inner edge every 1/4" from hole to hole. I need to figure out how to lay out the drill holes and keep the distance from the edge equal. I"m thinking of making some sort of a marking jig that runs on the inside of the curves with a 3/8" spacer and a sharp pencil.

Of course, I'm not working with any dimensions, just a "trace" of an existing plastic loom. For the pegs, I'm using guitar bridge pegs that will be glued into place.

I'm open to thoughts.

Thanks

[LCHIEN]

Quick reply:

use a drill press with fence to drill holes equidistant from an edge, even a curved edge.

How are you fastening the template to the workpiece? It should be impossible for the router to cut into the template if you use a bearing riding on the template.

[sailor55330]

Thanks Loring. I didn't realize you could use a fence on a curved edge, but now that I think about it, it does make sense.

For attaching the template, I used several points of hot glue and let it cure before trying. I am thinking that maybe the bit slide down and missed the bearing? It really confused me as well. I was edging into the work piece and noticed that I had an indention that wasn't part of the radius.

[LCHIEN]

Thanks Loring. I didn't realize you could use a fence on a curved edge, but now that I think about it, it does make sense.

For attaching the template, I used several points of hot glue and let it cure before trying. I am thinking that maybe the bit slide down and missed the bearing? It really confused me as well. I was edging into the work piece and noticed that I had an indention that wasn't part of the radius.

even if the template slides around w.r.t. the workpiece, only the workpiece will be gouged. The template can't be gouged by the bit unless the bearing slips over or under the template meaning the router is not clamped for height or the workpiece was allowed to rise up off the board.

[phrog]

I made a French fit case for a antique military knife for a Christmas present for my brother. Since the "hole" couldn't go all the way through the wood, I had to figure a way to use a template to outline the cut and "hog out" the remainder of the indention.

Therefore, I used a plunge router with a top-fit bearing router bit and cut from above instead of below. I clamped the template to the workpiece. With this setup, you can actually see what you're doing, whereas, on the router table, I would have been blinded since the "hole" didn't go all the way through. The only thing that I had to be careful about was that the bearing had to "ride" on the template. If you adjust your plunge so that the bearing is above or below the template, you will damage both the template and the workpiece. So don't do that! The template can be used over and over.

[stoli]

Are you sure the indentation wasn't already there, from the bandsaw?

Anyway, in keeping with using the router and the "mass production" aspect of the build, you should consider placing some 1/2" holes centered exactly on the template where you want the holes. Then you can use the router with a 1/2" collar and a 1/4" bit (or whatever size you are looking for) to drill the holes. You will still need to lay out the holes on the template, but you'll only have to do this once.

[leehljp]

Thanks Loring. I didn't realize you could use a fence on a curved edge, but now that I think about it, it does make sense.

For attaching the template, I used several points of hot glue and let it cure before trying. I am thinking that maybe the bit slide down and missed the bearing? It really confused me as well. I was edging into the work piece and noticed that I had an indention that wasn't part of the radius.

Some router plates have a hole for a vertical pin to stick up (can't remember the technical term) from which the wood piece to be routed is worked against at different angles. As an example: There are fences only a few inches long and with a curved face for bandsaws. These act the same way as that pin does. It is more or less as an anchor from which the hand feeds the board into the cut and changes direction if needed. On the bandsaw, that short curved fence allows the feed to be manipulated when the grain suddenly wants to take the blade cut off of a straight line. On the router, it acts as a one dimension anchoring point from which to manipulate a curved surface feed. Like as "steady rest".

[phrog]

Some router plates have a hole for a vertical pin to stick up (can't remember the technical term)

Starting Pin?

[vaking]

If you are talking volume production you might want to look at pin routing attachement.
http://www.mlcswoodworking.com/shops.../daisypin.html

[capncarl]

I'd be more in favor of using the router by hand rather in the table. Fitted with a collet it should follow your template perfectly. For that large of a cutting you make a template that the whole router fits down in. This allows a deeper cut w/o having so much bit out.

[BizCoach]

Make sure the bearing is tight to the router bit (you tighten it with a small allen wrench). I recently had this problem where the bit would jump around and it took a while to find out that the bearing was loose and was rising up above the template allowing the bit to cut in where it shouldn't.

[phrog]

I'd be more in favor of using the router by hand rather in the table. Fitted with a collet it should follow your template perfectly. For that large of a cutting you make a template that the whole router fits down in. This allows a deeper cut w/o having so much bit out.

Kinda' what I was talking about except I used a bit that had a top bearing the same diameter as the bit and it follows a template that is exactly the size you want.

[capncarl]

I just threw in the using the router base as an alternate way of doing it. I've found that using the larger base does not telegraph the boo-boos in the template as bad as a smaller template and a collet. On a complicated piece it sometimes requires several templates though.