Figured I’d give an update on how the tessel arm has been coming.
I have since purchased a 3d printer kit…which was a little pain-staking to get going but now that I’ve got it working, I definitely know it pretty well…which was the point. I mentally prepared myself for the trials of getting it working and am continuing to learn still.
Using the 3d printer, I’ve been using a guy’s design and tweaking it as needed.
Here are some pics.
I’ve got it using pretty simple gcode right now. The software is going to be the kicker for this. I will end up having it work pretty similar to 3d printer to pic things up and move them. I’d like the software to be pretty intuitive to the user, drag and drop “locations” and loops to handle tedious tasks. =)
A buddy an I went in on a 10 pack of some 84oz/in torque steppers….and those things hold pretty well. With the motors engaged, I can pick up the whole thing by the end of the arm and it doesn’t budge. =)
Will post more as I progress. Time for this is short but still fun to play with when I can.
So I sold a few other things and ordered the cheapest delta 3d printer kit I could find. It came in and took a bit of learning curve… but that is the point when you get into 3d printing, isn’t it? =)
First off, my stepper motors were wired incorrectly. Thanks to the help of those into he 3d printing community, I found I could just play with the wiring till I found out what worked. It did help that I had my little tessel board already programmed to play with a stepper.
Once I got the wiring corrected the motors were still extremely loud when moving. Finally a user on reddit mentioned I should check my jumper settings. Jumper settings?! I just assumed the firmware could do all that. Guess not. Of course, the kit I got was missing all the jumpers needed. Between some help from my awesome neighbor and some old computer drives I had laying around and was able to get all that I needed (12 in total). Once those were in, no more shaking and buzzing! Still not done though.
After scouring through the G-Code wiki and reading up on the firmware that I had (micromake) I found the key setting that I really needed to tweak was the z-endstop-offset. Using the “paper test” that many refer to, I was able to home that setting in. Then came the fun of learning how to load filament in this thing.
So I was able to snag one of the little Rolling Spider quads off a guy on Craigslist for $25! Figured something would be wrong and sure enough, the battery was junk. So I tried to save the battery…recharging lipos that are below 3.3v is risky sometimes but this seemed to charge fine once I got it up to 3.3.
Once I got it charged it powered on fine and I was able to take it for a quick flight! Buuutt…the battery lasted like 15 seconds. I was able to grab a quick picture during flight though!
So…I decided to see if I would figure out what the battery leads do to potentially wire up a better battery to it. You can take off the “face” of the spider and then unscrew the bottom piece. Getting the board out, you have to bend the LED “eyes” up a little so be careful when doing that. I was able to get the board out and solder some wires on to the “inside” leads. Looks like the lead closest to the side (if you’re looking from the top and the “eyes” facing up, it would be the right) is the positive and the other 2 seems to be ground (-). I wired all 3 just in case. It was a pain as I’m not very good at soldering and ended up accidentally putting a glob of solder connecting both negative leads. I had to use my dremel and cut it out. I’m amazed I didn’t cut something else by accident.
Once I got the wires done, I found that I just use the positive and the opposing ground (not the middle) is all it needs to power on! All I had were 2 cell lipos so I rigged it to the top. Needless to say, it was too heavy but it worked!!! Pretty excited! Looks like I’ll be purchasing some 1s lipos in the near future. =)
So I was able to get my hands on a tessel board and it has been a lot of fun! I’ve been toying with simple servo controls all the way to the Bluetooth Low Energy module (learning that from scratch was interesting!).
Using the servos I made a little arm to pick things up…but since it is made out of balsa wood, it is pretty flimsy.
I was able to get my hands on a stepper motor and get that working with the tessel so ideally I’ll keep going the same route to have the “arm” move up and down a track knowing it’s position as it goes. Maybe even have the arm be able to do a full 360 twist as well to be able to work on both sides of the track. Check out a video of what I have so far here.
Will be exciting to see what others pull off with this thing!