How to make a template for an inlay

[Robert Hayward]

How do I make a template to router a recess to fit the oval coin slot in the attached picture? I am making several coin banks with post office box doors and the oval coin slot pictured. I would like to router a template and then using the template router a pocket so the cast brass coin slot sits almost flush with the top of the wood. The picture is of the back side of the brass coin slot by the way.

[Cliff Polubinsky]

Robert,

The first thing that pops into my head is going to take a few steps and some calculations.

Use the oval as a template and route a shallow trench around it with a pattern bit. It might be easier if you make a piece the same size as the oval and use that as the template. Clear out the material inside the routed oval. Then use a bit with a properly sized bearing to use the larger oval's outside edge to cut a through hole the size of the oval. Turn the pattern upside down and use a pattern bit to route your recess in your banks.

Sounds reasonable if you have the right bits and bearings.

I'm sure someone will suggest a better option. This is just what first popped into my head.

Cliff

[Mel Fulks]

I think you need a set of router collets ,router, straight bit. Enlarge the size to accommodate collets by by making a disk with a center pin
hole, and rolling it around the brass plate to make right size. I think I’ve got the COVID plague ,so detail is tough.

[Bradley Gray]

Trace around the oval carefully on a piece of plywood or other. cut into the oval with a small band saw blade and cut to the line. Back the saw out (power off) Try hardware in opening and adjust with rasp or preferred method. Use with a flush bearing pattern bit.

The thickness of the pattern material depends on the length of the pattern bit.

[Edward Weber]

Router inlay set is what you probably want.
Here is one example
https://www.mlcswoodworking.com/shop...ter_inlay.html
I have the Whiteside kit but they are all basically the same. The price can vary quite a bit, usually due to bit quality.

[Robert Hayward]

I have a router inlay kit and a complete set of router bushings. The inlay kit still needs a pattern to start with. The pattern is what I want to make from the brass coin slot.

I was trying to avoid hand making a template but I think I will end up having to do just that. If I use a 3/4 round with a pencil lead hole centered I should get a line 3/8" larger than the brass coin slot. Then use a 3/8" bushing on the router base to end up with a recess the size of the coin slot. Will still have to hand make the template.

Would rather use the coin slot as a guide to machine make the template. Anyone else think of anything?

Mel, take care of that covid. I have a bunch of neighbors that have had that. One it lasted for six weeks. Two others with other medical condition died.

[Lee Schierer]

How thick is the brass coin slot piece? If you stack several together and make a thicker piece, I think you can make a template with the inlay router bit set. I drew the bit and bushings in cad. It appears that if you stack your coin slots perfectly, You can use them as a pattern to make your template. Follow these steps to make your template for your coin slot recesses.

Use double sided tape to attach your stack of coin slots to a piece of scrap about 5/16 or more thick. Make sure the enter area you are about to remove is attached to a second piece of scrap underneath so it won't move as your finish the oval cut. With the 1/8" bit installed and the large bushing removed from the template guide, cut around your stack of coin slots al the way through your piece of scrap. This should give you a hole in the piece that is larger than your coin slot piece.

Use that pattern you just made to cut a recess in a piece of scrap using the large bushing on the template guide.

Check the fit of a coin slot in this sample recess. If the recess is too small you can add a layer of tape to the stack of coin slots to cut a new template with a slightly larger hole. If the recess is too large, add a layer or two of tape to the inside of your template to make the recess smaller.

On cad this works, actual practice may give slightly different results. I have never tried this!

Having used the inlay cutting set several times, I would suggest cutting the out line of your recess with the 1/8" bit. They are very fragile and break easily (DAMHIKT). Once you have the outline cut, use a larger sized bit to remove the majority of the waste.

Let us know how it works.

[Robert Hayward]

Did a test template and cavity. Will be difficult to hide that gap with sawdust and glue. I know what i did wrong. Based my calculations on the wrong edge of the bushing/router bit. It is a rainy Monday so I will have tine this afternoon to try it again.

[Mark Bolton]

Did a test template and cavity. Will be difficult to hide that gap with sawdust and glue. I know what i did wrong. Based my calculations on the wrong edge of the bushing/router bit. It is a rainy Monday so I will have tine this afternoon to try it again.

Edward in post #5 has your answer. Simple and fast.

[Dave VanDewerker]

Don't bother with bushings and calculations, just use a flush trim pattern bit. I would cut the template with my scroll saw and fine tune with the spindle sander if needed.

[Mark Bolton]

There is no way you can be more accurate and faster than a <$20 system that uses the actual part to specifically trace the object being templated. With a pattern set you will come out with an exact template of the part, in one shot, in close to single digit minutes. No possible with any form of tracing, sawing, filing, manual tuning. Take that to multiples (the OP states "several") and your even further into the weeds.

[Robert Hayward]

The router inlay kit needs a template to work from. The template is what I want to machine make.

The recess I will cut to hold the coin slot will be only 1/8" or so deep. To use a flush cut pattern bit it will have to be held an exact distance from the work piece to get the proper depth. This is not a through cut. Doable for sure, but a hassle I was hoping to avoid. Hand making the template seems to be the only solution lacking a CNC machine. The template in my picture above was hand made using a forstner bit to remove most of the waste then a spindle sander to finish the edges.

[Edward Weber]

The router inlay kit needs a template to work from. The template is what I want to machine make.

The recess I will cut to hold the coin slot will be only 1/8" or so deep. To use a flush cut pattern bit it will have to be held an exact distance from the work piece to get the proper depth. This is not a through cut. Doable for sure, but a hassle I was hoping to avoid. Hand making the template seems to be the only solution lacking a CNC machine. The template in my picture above was hand made using a forstner bit to remove most of the waste then a spindle sander to finish the edges.

You can use the kit both ways, with an existing template OR you can make your own from your desired piece for an exact fit.This may help
https://bobpenoyer.com/inlay_basics.htm

[Mark Bolton]

The router inlay kit needs a template to work from. The template is what I want to machine make.

The recess I will cut to hold the coin slot will be only 1/8" or so deep. To use a flush cut pattern bit it will have to be held an exact distance from the work piece to get the proper depth. This is not a through cut. Doable for sure, but a hassle I was hoping to avoid. Hand making the template seems to be the only solution lacking a CNC machine. The template in my picture above was hand made using a forstner bit to remove most of the waste then a spindle sander to finish the edges.

See Edwards reply. You can make your template from the actual item with the inlay kit. You can even file down the projection of the guide bushing if needed.

[Dave Sabo]

Just curious why the hangup with “machine made” ?

Doesn’t a router with an inlay guide count as a machine ?