I'm designing some furniture that will be cut on an CNC machine out of 18mm Baltic birch plywood. After I get a pre-production prototype I'm happy with I plan to kickstart it with a minimum initial batch of 50.
I've already had one prototype made on a CNC machine, and I learned a lot. But I have questions for the next prototype.
I plan to design it to be assembled by gluing pieces face to face with 5/16" diameter wood dowel pins, 1” long, giving me a 36mm thick slab with features on both sides. This worked well on the first prototype. That said, I only used the pins for location, and screwed the parts together.
Question 1: Will I need to chamfer or otherwise relieve the edges of the holes in case the glue swells the grain around the hole?
Question 2: How accurate can I expect things to be on the Z axis? I thought +/- .010” was reasonable… but this shop was way off. It worked for the prototype, but it wouldn’t work on production runs. Am I asking too much of CNC? I don’t think they had a vacuum hold down system.
Question 3: Due to the number of holes (3 different sizes), I know I will need to send this to a shop with a tool changer. Should I strive to make sure the majority of the non-hole features can be cut by a 3/8” bit instead of a 1/4” bit?
Question 4: I’m plan to do my own nesting, primarily to make sure I can keep my materials cost down. If I am cutting two parts next to each other, I assume I should keep the parts farther than one tool diameter apart so you don’t cut both edges (one climb, one conventional cut) at the same time? So that both parts can be cut climb or conventional as fits the bit / material?
Question 5: Any face to face joining techniques I should look at other than dowel pins? I am worried about glue squeeze out.
Question 6: Other than making parts self-align and making it easy to assemble by keeping part count and confusion down, what else can I do to make this cheaper and easier to manufacture? I’m planning on a clear polyurethane finish.
Thanks for any help you can give!
-Jeff