Matz making stuff: December 2013

I couldn't help it. This machine looks too awesome to pass up. Let me introduce to you... Robox.

Why did I back this Kickstarter project? After all, I already have a Mosaic M1, 2 PP3DP UP! Pluses, and a Replicator 2. The main reasons were better layer resolution (0.02mm vs 0.1 for the R2) and material support. I recently saw nylon prints and found them amazing -- I bet a lot of people would love to print their own soft, custom iPhone cases! In addition, the extruder head has two nozzles -- one large diameter one for fast infill, and another small diameter one for fine details. On top of that, they will be supporting dual extruder heads soon, which means I'll be able to print support material out of dissolvable PVA and HIPS. They have put a lot of thought into the design of this machine -- only time will tell if they can deliver. I'm a beta tester, which means I'll get my unit in January 2014. I cannot wait. This machine should be truly awesome... and if it delivers, it looks like I'll have a few printers to sell soon.

For SLAS 2014, my company is going to build a custom booth. You know, because we just roll like that. It turns out that the custom tabletops that would normally be really expensive fit on the ShopBot (just barely), so I was tasked with running the job.

Yesterday, I went to the TechShop to generate and verify the toolpath. I haven't used the software in a while, but got through it with a little bit of help. In this post, I just want to record the little tidbits of info I re-learned so that two years from now, I will be able to recall the necessary info.

First, I got the DXF in AutoCad R12 format to be on the safe side. Then I created a new project in VCarve Pro 7.0. Since the DXF was in mm, I set the project to be in mm as well.

The important thing to remember with the software is setting up the origins and XY definition properly. The origin should be in the lower-left corner.

I then used Import Vectors and specified the DXF. It might not appear on-screen, but hitting F9 will auto-center the part. Awesomely useful!

I'll jump ahead a little and talk about a problem that I had. After generating the toolpath, I noticed that the endmill was doing something weird. While the bit was supposed to cut on the outside of the part, in a few places it was actually flipping to the inside! In the end, it turned out that some points on the path were not joined. So after breaking the path up into discret curves and using the Join function in VCarve Pro, this problem went away.

Another part that gave me problems was the exporting of the ShopBot toolpath file. Most normal software packages put something like that under File -> Export, or File -> Save as, but in this case, there's a "Save Toolpath" button that appears when you close the preview window. Ok. Hopefully I won't make that mistake next time.

After loading the .sbp in the ShopBot software and previewing the cuts, I was happy and it was time to call it a day.

This morning, Eric (coworker) and I stopped by MacBeath to pick up the wood for the tabletops. Instead of mahogany plywood, Eric decided to try bamboo because it would preclude the need for veneer or any other finishing strips to cover the edge of the plywood. This is where a minivan really shines -- you can fit a stack of 4' x 8' pieces of plywood in a Honda Odyssey without any problems! Sweet!

Then we made it over to TechShop, got Eric his $25 guess pass, and unloaded the material. I love how TechShop has everything you need -- we found one of those Home Depot-like carts and used it to get the raw materials over to the machine.

Getting the material aligned properly wasn't too bad. After homing the X&Y axes to their proximity switches, I moved to the far end of Y (48") and then commanded a 96" X move. We watched the bit as it traveled over the end of the bamboo, and believe it or not, our first try was pretty much dead-on! After drilling four brass screws through the wood and sacrifial layer and into the leveling bed, we were finally ready to start! This is where the wheels came off.

I really need to post screenshots, but the short story is that ShopBot came in last night to perform a software upgrade. That's great and all, but they never bothered to tell any TechShop staff how to iuse it! Man, I'm getting really sleepy so I have to make this quick. After selecting the file and clicking start, a dialog pops up. It has a yellow square next to the part filename, with what looked like a "!" inside. So that means we have a problem, right? Well, normally I wouldn't have looked at the yellow box if the dialog had a Start button in it. Instead, it had a cancel button. So we thought it might have something to do with my .sbp being in mm instead of inches, yada yada yada. Apparently, TechShop SF had the same problem last night and couldn't run the machines. In the end, the yellow exclamation point was really an I with a _ underneath it. Seriously??? It turned out that you juse have to click the Start button again and then things magically worked.

Here are some photos of the machine in motion.