Last night I spent a lot of time crimping tiny connectors onto wires. The results are that I have proper-length wires running from power to control circuits, from the limit switches to the Arduino, and from there to the OLED display location (you can see the connector hanging there at the upper-right side of the control wiring picture below). I’m trying to avoid having to make a ground bus bar, I’ll try tapping in to the ground connections on the stepper controller board that aren’t being used.
My M2 bolts are out for delivery today. If they arrive in time I’ll have my wife bring them to me at work so I can get down to my local makerspace and install the OLED and glue in the idler assembly.
Last night I glued up most of the parts and also made some standoffs to support the electronics. I cut out the OLED display holes from the front of the idler, but don’t have any bolts small enough to attach it, M3 is too big. But I glued down everything else, and ran a lot of wire under the machine. I still need to trim some wires and crimp connectors onto them to get everything connected before I can start programming, but I’m close. Real close. The Arduino Uno is annoying, one of the holes is too close to the header for an M3 bolt, but the other 3 holes are all sized for M3. I ordered a bunch of M2-sized bolts, washers, and nuts—they’ll be here in a few days.
Well that didn’t take long. After assembling all the parts and checking alignment, attaching the GT2 belt, tapping the spool holder end stop for a set screw, and cutting out two small neoprene washers to hold the spool, it was time to evaluate where the electronics will go.
I played around with the parts (mainly an Arduino Uno, a custom stepper controller board, and a 12v power supply), and found a layout that made me happy. I drew up some CAD plans for the Arduino Uno mounting holes, the stepper board holes, and the MeanWell 12v power supply and added them to my base CAD drawing. I also added feet at each corner, and also drew up a custom assembly to hold the C14 power socket and switch. Then I added holes to route wires underneath the board. Then I cut everything out (except for the power assembly) and checked the fit of the feet. Looking good!
So to say the least, last night was extremely productive. I plan on making some small standoffs for the Arduino mount, and maybe a thin-gauge metal plate for the power assembly to fit into. The final bit I haven’t drawn up is the OLED that will mount on the front of the idler assembly, which will be quick but require a new idler set to be cut out.
All that said, I expect to be testing electronics and writing code very soon.
…and hopefully the final version, but only time will tell. I cut it out last night and fit all the parts. Behold!
As you can see, I’ve marked where the belt will attach to the carriage, and haven’t attached the limit switch to the adjustable right-hand stop yet. I also haven’t made the other end of the spool holder yet. I’m also considering changing the 8mm shaft on the solenoid spool holder to the full size of the central spool hole, but I’m not sure that’s necessary yet. It would also mean making another new shaft coupler.
After the spool holder and carriage belt mount, the next step is to add the electronics and I’ll be up and running!
Last night I took all the coiler parts out and estimated distances between each of them. I arranged a new CAD file with the cutouts in their proper places. Today is Pi Day, and there’s a celebration at the makerspace so I don’t know if I’ll get to cut the base out, but it will happen this week, and if everything looks good the carriage motor and idler assembly will have the belt cut for them and the carriage will have attachment points for the belt before the end of the week.
I finalized the idler plans, measured the height of the carriage motor at the belt location and used my idler parts thickness to decide the full height of the idler assembly. A quick cut out with the laser cutter and an overnight glue job yielded a final part. Lastly, I took a picture of (almost) all the coiler parts together. Not appearing in the picture are the electronics and the magnet wire spool holder assembly.
The CAD for the idler parts is not the final version, I dropped the curved top but you get the idea.
I did some more work last night, made pieces to finish the idler and the pulley bar caps. Here are some pictures of the parts and assemblies in action.