The Shapeoko Is Back

After killing it, replacing the Atmega 16U2 IC and re-flashing it, our Shapeoko 3 Driver Board Registers on the USB Bus

After killing it, replacing the Atmega 16U2 IC and re-flashing it, our Shapeoko 3 Driver Board Registers on the USB Bus

 

A few weeks ago while cutting out some wooden letters for one of my Wife’s Christmas present projects, our Shapeoko died. The machine itself appeared to be OK, but it disappeared off the USB bus, and was never seen or heard from again. I tested the traces on the board, and verified pin to pin continuity between the USB connector and the Atmega 16U2 IC, which it’s driver board uses instead of an FTDI or similar USB to TTL Serial converter. Normally when you plug in any USB device to a Linux computer, you see [something] in the dmesg output – even if it has no drivers for the device and in many cases even when the device does not even work. (I recently ran into a case where a USB device kept complaining that it was “unable to enumerate USB device” – but the kernel was still aware of its’ presence on the bus.) In this case, plugging in our Shapoko yielded nothing. Not even the awareness of something drawing power off the port.

 

I traced out the pins, made sure the zeners weren’t bridged, and I could connect to the 16U2 via the ICSP header (in fact, I was able to save the binary program from it along with all it’s fuse bits!) However, despite all this, it simply did not work. This evening Jeremie replaced the 16U2 with a new one that arrived today from Digikey, I re-loaded the binary programs from the old chip into the new one and voila: The screen shot you see above! Now all I need to do is re-assemble the machine and test it with a real live cut, but that should be peanuts at this stage now that it is alive and well again.

 

I just love fixing things!

 


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Collets, Christmas and Catastrophes!

A few weeks ago I ordered a three-pack of different-sized collets for the router in the Shapeoko, and yesterday they arrived. One of the things I love about shopping online is that with the delay in shipping sometimes, you can easily forget that you’ve even ordered anything and such was the case this time. When I opened the mail and found this cardboard box addressed to me, I had no idea what might be inside, and was just as pleasantly surprised when I opened it and realized it was something I’d wanted for a long time!

As it turned out, I had been discussing at that *very* moment a Christmas project my wife wanted to do with some letters cut out of wood, much like I had done on the Shapeoko in previous years. With the new collets in hand, I was more excited than ever to give them a try! Yesterday morning I headed out to the garage early in the day to begin dusting off the Shapeoko. It had sat in it’s corner for several months prior to this, having cut all that I needed it to. I had been experimenting with using Inkscape to generate items with pockets – carving out sections of wood with the end mill, and was getting quite good at it. The only problem I kept running into was that the bit would sometimes slip, drop, and then gouge the wood it was trying to cut a pocket in. Hence my delightment at getting the proper collets for the router.

I spent the better part of Saturday working on this, and cutting out letters for my wife’s Christmas craft. They turned out practically perfect, and I was thrilled with the results. I repositioned the wood I’d been cutting from to make one last set, and was positioning the router into place when all of a sudden Carbide Motion reported that it couldn’t talk to the Shapeoko. That’s odd, I thought, but sometimes it would disconnect when the router was switched off, so I wondered if maybe this wasn’t a similar problem. I unplugged the USB cable and plugged it back in. No dice. Power-cycled everything. No dice. Even rebooted my computer. Nothing. It was as if the USB cable wasn’t even plugged in. I checked dmesg – and there was no indication as far as the computer was concerned that anything was plugged into the USB port. It was dead in the water.

And so it sits now. We’ve contacted Carbide to see if they sell the controller separately. I can read and write the Atmega 16U2 chip which is the USB to TTL converter for the driver board, so it seems to be OK, meaning the problem is most likely elsewhere on the board in some other tiny component. When powered from the 24VDC power supply, the 16U2 has power, so that’s not the problem, and there are only four components between the 16U2 and the USB port which all seem to check out, so I am truly at a loss for what might be causing it to not appear on the bus. Wiggling the board doesn’t help, and like I said – it was working fine all day and then suddenly just disconnected. Bizarre. Maybe it is time to consider a controller upgrade as well.

 


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CNC-Made Wooden Snowflakes

Snowflakes carved with a Shapeoko 3 CNC Router

Snowflakes carved out of 1/4″ Baltic Birch plywood with a Shapeoko 3 CNC Router

Once I got the Shapeoko 3 setup, my wife quickly started churning out projects for [us] to work on using it. The first of what I’m sure will be many was this: Making wooden snowflakes to hang in our windows. Of course, I’m just starting to break the ice in the ocean of CNC Routing, but the Shapeoko 3 is a pretty nice machine and I think I’m starting to get the hang of some of the basics.

Quarter Inch 5x5" Baltic Plywood with 3M Mounting Tape Strips

Fixing the material to the wasteboard with 3M Mounting Strips

The first challenge is fixing the material to be routed to the waste board. Because of the intricate cuts in the snowflake designs I was attempting, I needed both the inside and the outside of the object to be fairly rigid; too much movement of either component would lead to sloppy cuts. I picked up a variety of double-sided tape products from my Home Depot, notably Carpet Tape, Gorilla Tape and 3M Mounting Tape. Here too there is a fine balance between good adhesion and holding strength versus can you get the stuff off your finished product? With the carpet tape, did it hold the material in place? Yes. Could I remove the remaining pieces from the finished work? Not a chance. The clear Gorilla tape did a decent job of holding and peeling off, but I ended up using nearly the entire roll on one snowflake.

The far and away winner was the 3M Mounting Strips. Good holding strength, easy to remove from finished works, and as an added bonus – because of their thickness – a narrow gap was created between the working material and the waste board, allowing sawdust to clear out below the material being cut as well. This really helped since my end mill employed a downward cutting style. I adjusted the G-Code to cut pretty close to 1 mm below the bottom of the Baltic Plywood so that it did not excessively gouge my scrap piece of waste board.

Shapeoko 3 Carving Wooden Snowflakes Out Of Quarter Inch Baltic Plywood

Shapeoko 3 Carving Wooden Snowflakes Out Of Quarter Inch Baltic Birch Plywood

Watching the Shapeoko 3 work is like watching a fire burn: It is truly mesmerizing. The last hurdle I have to overcome centers on the type of end mill I’ve been using. When I got the Shapeoko 3, we only ordered one end mill with it. On Amazon, that bit cost about $20 for a 1/8″ 2-Flute Spiral Downward Cutter. Despite careful planning and placement of a table clamp on one of my earlier attempts, the router effortlessly carved out the piece I was making – and then on it’s way back to the home position, it pulled the spinning bit across the metal clamp – decisively ending that bit’s cutting career. I had a couple of spare Dremel cutting bits, so decided to see if any of them would work. Early results with thick (5/8″ – 3/4″) plywood were very promising, but the CEL (Cutting Edge Length – see, I’m starting to spricko the lingo!) on those bits was about 26mm if I remember correctly, and so on the 1/4″ Baltic Birch, the bit had so much flex in it that trying to cut the intricate patterns was like trying to write with a pencil whilst gripping it by the eraser: Cuts were sloppy, circles did not completely carve out, and I thought I was going to break the bit. Slowing down the cuts only caused the wood to start burning, while faster cuts produced cleaner edges but less precision.I think one of my Dremel bits got a bit gunked up with some of the adhesive residue, which – combined with the heat from the friction produced some bumps that increased the friction and filled my workshop with smoke. I replaced the bit with a new one and it cleaned up the cuts substantially, but it was evident – this was not the ideal application for these bits.

Since then I’ve ordered a variety of end mills from my favorite online wholesaler Aliexpress, and once they arrive I have many more projects and cuts to attempt.

While not specifically Venturii-related, I am hoping to use the router to build several enclosures and housings, perhaps even some control panel and user interfaces for Venturii and Venturii devices. That is my loose tie-in, and excuse for posting this project here. 🙂 Actually I’m envisioning a number of button / switch / LCD Display panels made out of wood and/or Acrylic that would be appropriately located near relevant data sources. More on that later!


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