For the Enchanted Cottage project I wanted to add a structure to hide all the mechanics and electronics. Because the weather house was made from 3mm plywood, I thought it made sense to make the rest from the same. The servos also needed testing so to make this easier a simple test rig was made.
I bought a 600mm sheet of hardwood ply from Hobbycraft. For this project I did not need such a long sheet but it was better value than the half sized sheet and I did not want to run out and have to make a second trip. The cottage parts are mainly thin strips of 10mm, 15mm and 20mm with one 100x100mm sheet for the back where the electronics will be mounted. I will build a cover to fit over the back once everything is working.
To cut the thin strips I used a large piece of angleiron to clamp everything to the bench. The steel was orientated so that it followed the surface grain of the ply. I then used a knife to score through the wood. After about 5 or 6 cuts the strips were complete. This worked remarkably well and gave a nice clean finish. For cutting to length I used my bench hook and a junior hacksaw. The square was cut with a knife and steel ruler, working across the grain did not seem to cause any issues. The edges were given a light sand with some fine sandpaper.
I had a couple of holes to drill so I just used regular HSS twist drills with a piece of wood for backing. There was minimal breakout on the other side and all that was needed was another light sand.
For my slot cutting I built a simple coping saw table from a piece of hardwood laminate flooring screwed into an offcut of wood. This clamps into my bench vice.
My final challenge was to make some keyhole shaped slots for the servos. I needn’t have worried, these were filled with a small circular file. Again no problems with breakout on the back and it was easy to file straight slots.
All in all, 3mm hardwood plywood a great material to work with. My only observation is that its thinness does mean that it’s quite bendy and my servo test rig does seem like it could be easily damaged. However that’s only a test rig so will likely be disassembled once my testing is complete, alternatively I could add a couple of battens to the back to stiffen it up.