How to Make Matching Male and Female Templates

Here are two ways to create templates that fit seamlessly into each other. January 27, 2008

Question
I’ve been scratching my head over this one. I need to make a male and female template that fit each other exactly. How do you make a male pattern from a female or visa versa?

Forum Responses
(Furniture Making Forum)
From contributor R:
A low tech method is to make one template by router or hand, then cut a rough approximation of the matching half out of another piece of MDF. Wax your exact template and pin it to a waxed or polythene covered board, mount your rough cut board a few mm away from it. Next get some smooth automotive bodyfiller and fill in the gap. When it sets, break the two apart and you will have the perfect mate. Sometimes it helps to tooth the rough edge with some small bandsaw cuts to provide a key. There is another way using two guide bushes, but it is somewhat more complicated.



From the original questioner:
That's a great idea. I hadn't thought of the casting method. I do have the Bosh template guide and sleeve - can it be done that way?


From contributor R:
The guide bush method allows you to create matching templates straight off the router. The object here is to offset the router cutter so it cuts each side of your joint line. However, to do so you need to make a master template by hand. This only needs to be as precise as you visually need, as any inconsistencies will be taken care of through the matching templates. Virtually any shape can be made, the only limit being the diameter of the largest guide bush.

Let's assume you want to make a curved lipping to go onto the edge of a curved top, and let's also assume it is not a true arc, so you could not create it using a trammel bar or the 3 stick method of creating a large radius.

You need to draw the joint line in plan on a piece of MDF. Next, you need to draw the smaller master template. To do this, you need to know what size guide bushes you are to use. The important thing here is that the difference in outside diameter of the two guide bushes is double that of your straight cutter.

For example, assuming a 10mm cutter, a 15mm and a 35mm guide bush would work. With this setup, you would need to mark out your master template 12.5mm smaller than your actual joint line and then cut out and shape to the line. As I said earlier, you do not have to be precise here - just be aware that any lumps or bumps will be apparent in the joint line, but not as a gap.

Next, set your router up with one of the guide bushes and screw or pin your master template onto your actual template material. If you have the smaller guide bush in, you are creating the lipping template. The important element is to keep pressure against your master template.

Next put a fresh piece of template material under your master template and swap over guide bushes and cut. It sounds complicated, but once you have the right combination of cutter bushes, you can have some fun, if you can draw a shape and it can be a real squiggle, i.e. completely random shape. You can then make two templates that fit into each other perfectly.



From contributor G:
I really hate to do this, but here goes nothing... Get your artwork to someone with a CNC. What are the dimensions of your project? How complex is the shape?


From the original questioner:
Contributor R, your explanations are very good, but my problem with the template guide and sleeve setup is that if you come off of your pattern with the router, you’ve ruined your work. I like your idea with Bondo. I can tape and wax my stuff and get a perfect match.

Contributor G, if I farm this out, I'll be out money and experience, but I understand your thinking. Thanks to both of you.



From contributor R:
One thing - you only make your templates with the guide bush technique, that way there is no risk to your work. As with anything, you could get it done with a CNC, but having an alternative option is great when time is tight.