Introduction: Technique: Multiple Copies With Router and Templates
This instructable will show you how to make multiple copies of a complex hardwood object using templates and a router. This example is a wall-hung hardwood tablet frame for a Nexus 7.
To make multiples of an object by hand, you need to be able to make controlled, exact cuts quickly. Using a hand-held router with template guides and plywood templates, you can do just that.
Step 1: Tools & Materials
Step 2: Design
At Pier 9, there are a lot of favors being traded. This project is a favor for Paolo Salvagione, who graciously did a ton of stainless steel welding for one of my projects.
The frames are for four Nexus tablets that will have interactive art displayed on them at a museum in San Jose.
Paolo and I worked together to design a frame that would allow the tablet to fit snugly, leave space for audio and USB connections, and hang on a wall with key holes.
We ended up with a 2-part design: a hardwood routed frame with an inset aluminum back with integrated key holes.
The attached DXF and PDF files have everything you need to make your own mounts.
Step 3: Make the Templates
I laser-cut these templates with 1/4" plywood, but if you don't have access to one you can easily cut your own using a drill and a jigsaw. Check out my Digital Fabrication by Hand Instructable for more info about how to make complex geometry with paper templates and hand tools.
It's important to make sure that the main template is exactly the same depth as the piece of wood and fits snugly. It should be so snug that you almost have to beat in the piece of wood with a rubber mallet.
The circular bump outs at the corners of the outer template make it easy to apply and remove the template inserts, and also gives you a place to apply countersunk screws to keep everything in place while you're routing.
Step 4: Template 1
The sequence of the templates is important- if you do this right, you won't end up with chipped and broken wood pieces.
For this piece the first piece you want to cut is the Nexus perimeter piece. Adding the rectangular piece in the center keep the router base level throughout all the routing.
The offset for the distance from the outside edge of the template to the outside of the router bit is accounted for in the template files. It's about 1/16".
First, cut the edges with the 1/4" bit. Use no more than 1/4" deep passes at a time. If you rout too deeply, you can bind the bit and break it, and you'll also probably end up with messy edges. The full depth for this pass is 1/2".
Once the edges are cut, switch to the 1/2" router bit and do the surfacing. You should also be doing about 1/4" steps with this bit.
Step 5: Template 2
Template 2 is for the screen cutout. When you place your scrap piece for the first template, make sure it leaves enough room for the 1/4" router bit. There's no need to do any surfacing with this pass, since you're cutting out the piece by routing at full .688" depth.
Step 6: Template 3
The last template is the back surface template, making a recess that fits the back piece with the key holes. This depth is 1/8".
Again, start with the 1/4" bit to cut the edges, then switch to the 1/2" bit to do the surfacing.
Step 7: Test Out the Fit
If you use the templates properly, you should end up with a snug fit. The Nexus tablet shouldn't move at all when the screen is touched.
I used water-jet cut aluminum for the back plates, but 1/8" wood or plastic would work fine.
Step 8: Repeat, Repeat, Repeat...
Templates allow you to control your cuts without a lot of focus, so you can crank out multiple copies of a piece in a short time. The bulk of the work is in the setup.