What material does your team prefer to build an electrical board out of? This year I want to use something able to be to cut with a laser, but we are particularly concerned with weight as of now. What are some adequate materials to consider?
Wood or thin sheet metal are cheap and easy to use. I would also recommend Delrin if you’re looking to up your production quality.
We have used polycarbonate before, but are looking to do .09" aluminum this year.
We have generally used plastic cutting boards. They’re easy to cut and drill, stiff, and isolate the electronics
This is what we use, we put it at the bottom of the kit chassis and mount everything to it.
Coroplast corugated plastic is mostly fresh air so it is very light and stiff especially if kept to under 18". It is non-conductive. You can cut it with a box cutter or razor knife. To install components with zipties, use a small screwdriver and punch holes where you need them. In 2017, we mounted the panel using zipties through 3-4 holes along each side.
Since 2015 our electrical boards have been made from 1/4" Foamed PVC sheet. It’s not as stiff as a cutting board but our electrical boards tend to be mounted vertically anyway.
We got some foam PVC this year as well, we will cut to to shape and size using our router.
OP, please note that you should not laser PVC so this isn’t a suggestion for you. PVC will create deadly chlorine gas when burned/cut on your laser.
Personally, I’m partial to 1/8" perforated PVC or polycarb sheet. They’re relatively rigid, non-conductive, not too heavy, and come with evenly spaced holes to mount things to. You can get them from AndyMark, McMaster, or any number of other sources. It makes it easy to add to or modify your electronics layout without needing to drill new holes.
No matter what you choose, I recommend not using aluminum or anything else conductive. A loose wire touching a conductive electronics board can make you fail your chassis isolation test; two loose wires can cause a fault. Also, if you need to drill or modify the board you don’t want conductive swarf falling into your robot, especially near your electronics.
^^^^ This. Works well for us.
What do you folks mean about foam PVC? If it’s extruded PVC I would caution against it. It is not hard to crack and prone to static electricity.
Foamed PC (aka Expanded PVC) is commonly used in making signs. One brand name for this material is Komatex. I haven’t noticed it to be any more of a static generator than any other plastic.
Weather you call it Sintra Celtec or Komatex I stand by my statement.
Large format printing is what I do for a living and I can tell you this stuff is by far the most problematic when it comes to printing issues due to static electricity build up.
For years we have taken 6mm Baltic birch plywood and laminated carbon fiber cloth on both sides. End up with a very stiff but durable panel. The electronics board incorporated as a structural frame element. This gives an opportunity for student experience in composite layups. The panel is cut on the router with attention to dust collection.
Is this more a product of your printing processes, or do you find it inherently prone to static? Working with it so far I have not noticed any.
Some materials are more prone to accumulating static charge than others. Wiping with fabric softener sheets or spraying with fabric softener will help dissipate the static charge. They are both less expensive than the professional stuff.
Just the Baltic Birch plywood would also be good.
I recommend non conducting. Wood is good. Polycarb is good. My team mostly uses 3/8 thick UHMW scrap that was given to us.
We mostly use 1/2" nominal thickness plywood, Birch or other higher quality wood preferred. But we haven’t been building heavy robots lately, so we can get away with it. And this is usually rather low on the robot, helping keep the center of mass down low.
4183 has been using 1/4" birch and laser cutting it, for years. I think it takes them three passes with their laser to get through the wood all the way. We just use a circular saw to cut parts, it’s much more exciting for the students.