OneWheel Project Log

Thursday, April 29: Kickoff Meeting

First day of projects! Today we met with our sponsor, Mr. Chun, and our mentor, Dr. Wideman, to go over and organize our collected parts. So far we have the hub motor/tire, frame kit, battery, charger, and a lot of other smaller materials like nuts and bolts. We also spent time going over the safety guidelines of the makerspace. Next we need to work on our tasks list and watch the fungineers videos (https://www.youtube.com/channel/UCgOoc8_50iTDSDrLjcDn6eg) so we can brush up on the beginning steps of our project! Later this week we plan to start 3D printing the foot decks and bumpers.

Friday, April 30: Collecting Parts / Adapting

This morning our Fungineers contact reached out to say the controller would unfortunately not arrive in time because of the global shortage of chips which has resulted in the drv8301 being unavailable for the next six months. Therefore, we spent a lot of today figuring out alternatives and researching other possible controllers (https://www.ebay.com/itm/303624428751?hash=item46b16d1ccf:g:svQAAOSwfs9fDy1K).

We also organized all of the STL files for 3D printing so we can start the actual printing process on early next week. Also, today we collected the rest of the nuts and bolts from Curry Hardware to finalize our collecting parts process (see image).

Monday, May 3: Controller Search + 3d Printing

Today we solved our controller problem and bought a new controller from Tindie as well as two BMI160 chips (one as extra just in case we blew one up). We also tried our first test object for 3d printing that worked well- we tested the smallest printing piece which was the battery enclosure plug. Furthermore, while the plug was printing we assembled the rail and hub motor kit with the screws we got from Curry Hardware. This was just a basic assembly to ensure we had all the right parts because we have to reassemble everything later with blue loctite for security.

BMI160 Chip

(bought from DigiKey)

New Vesc Controller

(bought from Tindie)

Tuesday, May 4: 3d Printing (Cura)

Today Dr. Wideman walked us through the 3d printing process. We tried to look for reduced stl files for the OneWheel parts since the ones from the Fungineers website turned out to be hundreds of megabytes. We then printed multiple copies of the plugs for the battery enclosure and are now im the process of printing the bigger components. We both downloaded the app Ultimaker Cura which is the software that connects to the 3d printer. Looking ahead, the controller is set to come on Thursday so we should start our electronics unit sometime this week.

Ultimaker Cura

Dr. Wideman walked us through the software Ultimaker Cura which is what we are using to create the gcode files that send to the printer. We manually plugged in the settings while he gave us a walk through of how to format an stl file before the card is inserted to the printer. The image on the left is the battery enclosure print that we started this morning. The bigger prints like the battery enclosure can take up to 2 days so the whole printing process should take a week or so.

Wednesday, May 5: 3d Printing

We continued our work on the gcode files for the remaining parts and checked on the prints that began yesterday (the bumper, rubber stoppers, and the battery enclosure). The bumper and stoppers are printing in TPU and the enclosure is printing in ABS. We finalized the gcode for the other enclosure (vesc enclosure) and the other bumper so everything is ready to print as soon as the current ones are completed.

Link to video of 3d printing progress at Dr. Wideman's office printer: https://photos.google.com/share/AF1QipMgJhPG3wDb0TyYmKzF1XiTLEwG1Oxec0TTh7Ai4kTZsDF5oHs98BmH2rx26ffywQ/photo/AF1QipOkuGVbEtSSat2X70jz_4BsR6VgVFMtMGVCrvBb?key=WC1tQmVSOHNuVU9iSXdNdHJPTGpmeTh6Z001NWVn

The prints that have already begun look great but will not be completed until tomorrow. Today we also talked about adding new features to the board like a carbon fiber deck and grips for the footpads. We are also considering using Mr. Chun's CNC machine for all the footplates instead of 3d printing them. The CNC machine is faster than the 3d printer and it and allows us to learn more by exploring a process we've never tried before.

Bumper 1 3d printing progress

Battery Enclosure 3d printing progress

Thursday, May 6: 3d Printing + Wiring Videos

Completed Bumper 1

Battery Enclosure 3d printing process day 2

The front bumper finished printing today and it looks great! We talked through the supports and how we would change the variables like wall thickness and wall density to create a support that's easier to pull out. The battery enclosure that is printing in Dr. Wideman's office should be done printing today and then we can continue with the rest of the parts.

The controller is set to arrive sometime today but the BMI160 chips won't come until early next week it looks like. So we are planning to begin our electronics unit next week!

When talking about the future wiring for the controller we went over capacitors vs batteries. Capacitors hold a ton of power which could be a danger. Both Mr. Chun and Dr. Wideman are helping us find way to decharge them so it's safe for use.

Since we ordered a controller not from the Fungineers website who gave us the STL files, we decided to hold off on printing the controller case since the dimensions may end up being different.

We also went through the Fungineers wiring videos for the OneWheel to prepare for our next step!

We decided to use the CNC machine for all the footplates and Mr. Chun's friend was nice enough to offer his machine! We should start the CNC process either at the end of this week or early next.

We also explored Mouser for an LED latching switch push button for our on/off switch that lives on the side of the vesc enclosure.

Friday, May 7: 3d Printing + Controller

Completed Battery Enclosure

The battery enclosure finished printing! We did a partial assembly with the frame kit, hub motor (wheel), battery enclosure, and bumper. It looks great and the other parts have already begun printing. The controller also arrived so I brought it into the makerspace. We identified where the IMU will go and are asking Mr. Elias' help with attaching it to the board (probably on Thursday or Friday). We decided to not attach the heat sink or thermal pads until after we attach the BMI160 chip. After the chip arrives (should be sometime next week) we will begin working on the controller as well as fully assembling the OneWheel with the rest of our 3d printed parts. We hope to be done with 3d printing early next week.

We are also currently coordinating with Mr. Chun about using his friend's CNC machine for our footplates and centerplates.

The hole for the on/off switch is roughly 23mm so we are ordering a 22mm red push button switch from Mouser.

Monday, May 10: Assembling the OneWheel

Completed bumper 2

Completed Vesc enclosure

The second bumper and second enclosure both finished printing over the weekend which means we completed all of our 3d prints (excluding the FOCer case which is still tbd). The BMI160 chip is also set to arrive tonight!

Today we worked on the frame assembly of the OneWheel. We used loctite on the screws so this is really our final assembly. The wheel was hitting the edge of the enclosure so we decided to sand off approximately 1/8 of an inch so the wheel has space to move freely.

Ian used an angle grinder to take off some volume from the side of the enclosure. We also had to release some air from the tire which helped with our problem because the tire deflated. We'll use a polisher to sand out and smooth the enclosure (left). We will also be spray painting everything so you won't really be able to see the fill that is currently exposed. The enclosure will also be covered by the foot plate so most of this won't even be seen. In this process we learned how to use a palm sander, an angle grinder, and a polisher.

First assembly of the OneWheel!!

Today we also had our meeting with Mr. Chun (our project sponsor) at 12:30pm. We reflected on the schedule we made prior to project season and we seem to be on schedule! According to our schedule, we should be in our building phase early this week and start the controller work at the end of the week which is perfect because Mr. Elias is helping us install the BMI160 chip on Thursday! We did figure out that we need to run down to Curry Hardware to get smaller standoffs/inserts. The ones we got were 6mm but actually ended up measuring closer to 6.88mm so we need to get new 5mm ones.

Tuesday, May 11: Center Plates and Inserts

Today we worked on the gcode files for the 3d prints of the center plates. We are still hoping to use Mr. Chun's CNC machine for the plates, but we decided to 3d print them as well for our backup option. As we saw yesterday, the components next to the wheel have to be grinded off a little so there's a big enough gap between the plastic and the wheel. So we spent some time today in Tinkercad and Onshape editing the prints so they will fit perfectly instead of us having to manually grind them off. We also decided to do edit the enclosure prints with the same gap.

We ordered new 5mm standoffs/inserts from McMaster Carr (instead of going to Curry Hardware to buy them in person) that will arrive sometime tomorrow.

(https://www.mcmaster.com/hex-nuts/system-of-measurement~metric/nut-type~coupling/nut-type~hex/thread-direction~right-hand/width~6mm/material~stainless-steel/material~18-8-stainless-steel/)

We also ordered the pushbutton switch from Mouser that should arrive later this week.

(https://www.mouser.com/ProductDetail/612-PVA6LRE21211)

Natester from Tindie (the guy whom we bought the controller board from) gave us a helpful and instructional video on inserting the IMU chip that we watched in order to prepare for our installation later this week.

(https://www.youtube.com/watch?v=kmX_oLPy08o&t=290s)

Wednesday, May 12: Center Plates + Temperature

One of the centerplates finished printing today so Ian worked on taking out the supports. The two IMU chips also came today (they are so incredibly small) so Mr. Elias is going to help us install it tomorrow morning.

Since the heatsink and controller is going to be in an enclosure with little to no air flow, we talked about how to control/ monitor the temperature. Dr. Wideman taught us about the thermocouple which is essentially just a voltmeter that converts to temperature. We also requested a power supply to test our FOCer from Mr. Chun.

We joined the discord server for the fungineers onewheel and spent time troubleshooting with other people who are trying to build the same thing. We were specifically looking for a wiring diagram for the footpad sensors and FOCer controller.

We also made the gcode files for the footplates as a backup option if the CNC falls through or doesn't work.

Footpad Sensors Wiring Diagram

Thursday, May 13: Inserts + Surface Mounting

The inserts arrived so we spent some time cutting them in half since we ordered extra long ones that are double the size we need.

We tested the FOCer using alligator clips. We connected it to the 12s2p battery after it was fully charged. The green light turned on YAY which means it works! There was a bit of a spark when we initially connected the wires. That also means we charged the capacitors which could be dangerous so we will work with Mr. Elias to decharge them.

We spent most of the day working with Mr. Elias on surface mounting. First we tinned the BMI160 IMU chip, tinned the pins on the board where the chip would eventually be attached, put a small glue dot in the middle of the pins, placed the chip on with tweezers, and then used a heat gun to solidify the pins to the chip. We got to use our soldering skills again as well as learn other skills involving the heat gun and surface mounting. The chip was incredibly small (see image below for scale) so we had to be extremely precise.

Friday, May 14: Assembly + Wiring + Vesc Tool

We spent the beginning of today putting the screws into the frame and enclosures to do a real assembly of the OneWheel. The device is incredibly sturdy which is greatly assuring! We will have to take the screws out again once the footplates are printed but for now we just wanted to see a full assembly of our progress.

We also started wiring everything today. We added the fuse in the battery compartment for safety. We learned how to use connectors and how to heat shrink. We had some trouble threading the bigger wires from the hub motor into the enclosure through this tiny hole, but we did it eventually! We also worked on soldering the footpad sensors so most of our wiring outside of the FOCer is done!

Power Switch Wiring Diagram:

FOCer Wiring Diagram:

More wiring diagrams: https://github.com/shamansystems/Cheap-FOCer-2/blob/master/Schematic.pdf

According to the schedule we made before project season, our wiring/programming phase goes until next Tuesday the 18th, after which we should begin the testing/modification process. So we are currently on schedule! The power switch is set to arrive this weekend and we got all of the wiring diagrams ready so we could get a jump on actually wiring everything early.

Mr. Chun also came in today to help us with the Vesc. We downloaded the Vesc Tool app on a windows computer to test the IMU. Unfortunately the IMU was not responding so we are going to troubleshoot that next week and maybe install our second chip as a replacement.

Monday, May 17: Footpads and Footplates + Wiring

The power switched arrived over the weekend and that is our last part (aside from the working IMU chip) that we were waiting for. Thankfully, Dr. Wideman convinced Natester (the guy from Tindie whom we bought the controller from) to mount two IMU chips onto new boards. We dropped the chips off at the post office today to send to Natester and we hope to get two functional boards with IMU chips by the end of the week. Since our initial attempt at surface mounting was unsuccessful, Mr. Elias also offered to give another demonstration on reworking the mount later this week which we can look forward to!

The footplates also finished printing this morning so all of the big 3d print components are completed! We attached the footplates and connected the two centerplates with glue.

We also spent a lot of today on wiring. We started with the footpads and soldered wires to the sensors. We had to tin the wires and then the sensor and then melt them together. We then wired the latch switch where we learned we need to pass a voltage in order for it to light up.

We also had our weekly meeting with our project sponsor Mr. Chun! We talked through our progress and we seem to be on track!

Tuesday, May 18: Surface Mounting pt. 2

Mr. Elias walked us through surface mounting with a different technique in hopes of getting the IMU chip to finally work! We roughly followed the technique from this video that uses hot air to melt the pads: https://www.youtube.com/watch?v=kmX_oLPy08o&t=290s

We had a bit of a hiccup when a resistor accidentally melted off of the board but Mr. Elias provided an extra one from his collection.

We filed down the footplates a little so they would perfectly snap into place with the centerplate. We also kept working on wiring the switch which we now know needs a voltage going across it.

We researched the different kinds of rustoleum we could use for the paint job: https://www.rustoleum.com/product-catalog/consumer-brands/auto/general-purpose-paints/acrylic-enamel-2x

Wednesday, May 19: FOCer Case

While waiting for the IMU chip to work, today we focused on building the FOCer case. We needed/gathered heat pads, 5mm spacers, M3x8mm bolts and M3x6mm bolts for mounting and assembly. We had to drill holes in the aluminum slat to connect it to the holes in the 3d printed case.

Dr. Wideman taught us how to use the drill press during our sandbox project last summer. We used the drill press today to make the holes in the aluminum that goes on top and below the FOCer case. We also learned about drill tapping. We needed to use this method to secure the board to the aluminum plate.

Thursday, May 20: Spray Painting

Today we went to the Milton Academy campus to use the AMC spray painting booth. We brought red, orange, and yellow spray paint, white primer, and of course our footplates and centerplates. We did two coats of the primer then moved on to our sunset themed colors.

Primer

First Coat

Second Coat/Final Product

Friday, May 21: Materials +New Space

We had left the 3d prints that we spray painted to dry in the AMC overnight so we brought them into the makerspace today to look at the final product!

Natester also gave us great news: the IMU chips were successfully mounted! He is shipping them back to us today so we should have them this weekend or early next week. That means we can upload the code and put everything finally together on Monday and hopefully have a functional board by the beginning of next week! Then we should begin our testing/modifications phase!!

Dr. Wideman will be out of town Monday-Wednesday of next week so we prepared all of our materials in boxes to move to our temporary working space: the engineering lounge at Milton Academy.

Monday, May 24: New Controller + Wiring

We received a new board from Natester with a fully mounted IMU! We tested it on the Vesc Tool and it works YAYYY!! You can see in the image on the left that the graph moves as the device moves. We then moved on to testing the system using alligator clips. We followed the Fungineers video for this portion. https://www.youtube.com/watch?v=BBJTK9U4umk&list=PLiYCRuOFm1MMOLEVzXt_07ODDgjAudZHW&index=7

Today we also had our weekly check-in with our project sponsor, Mr. Chun. We realized that we needed new connectors to attach the footpad sensors and switch to the controller so I am going out to get them at You-Do-It Electronics tomorrow!

Tuesday, May 25: Connectors + Wiring

Today I went to You-Do-It Electronics in Dedham to purchase JST connectors for the foootpad sensors and power latching switch. We had to replace the fuse because it was evidently blown. Tomorrow we plan to wire the rest of the system and modify/test accordingly.

Wednesday, May 26: Wiring

Today we worked on wiring the power switch and footpad sensors. We hit some road blocks with the wiring of the footpads but Mr. Chun came to help us! We also successfully wired the power switch YAY! We cleaned a lot of our workspace up in the lounge because we will be moving back into the makerspace tomorrow morning.

Friday, May 28: Wiring

All of today was spent on wiring. The footpads are still giving us trouble and the ADC inputs aren't reading any voltage. We worked through some possible solutions but nothing has seemed to work. We also started wiring the motor to the board. We stripped the motor phase wires and used female and male connectors. We used our heat shrink and crimping skills on the connectors. We restored to Discord to ask other engineers if they ran into the same problems.

12:46pm UPDATE: we fixed the footpads and everything works!! YAYYYYYY!

Now we are moving on to soldering the final wiring connections. Ian and Dr. Wideman finished wiring the footpad sensors, power switch, motor, and battery.

Tuesday, June 1: Putting It All Together!

So.... we accidentally destroyed our controller board by shorting the negative terminal. Fortunately we have another board that we are able to use that we also got from Natester. We tested the motor using alligator clips and saw the wheel spinning for the first time! We followed the Fungineers video for the Vesc Tool app setup Motor Config. After we ensured the whole system was working, we started soldering the final connections.

See Wheel Spin Test on** Testing Video page for clips!!

We finished programming the controller and motor and bolted everything temporarily in place. We then tried riding it for the first time! It was not very sensitive and it went very slow but that is on account of our manual programming. We had reduced everything to half speed and half sensitivity in hopes it would make it a little safer. However, we found that it actually needs to be very sensitive in order for the angle to even affect the speed and acceleration.

Wednesday, June 2: Testing/Modifications

Today we tried to fix the sensitivity problems that we had yesterday so the motor would go faster. We watched the Fungineers videos religiously and tried testing again. It was still going pretty slow so we took it back to the table to rework the program. The wheel spun perfectly on the table! However, suddenly the motor started stuttering and the software ceased to work. We attempted many solutions but nothing seemed to get it back to its original function. One major problem is that our board constantly flashes a red light which signals a fault either in the software or on the board. We are hoping with some rest the board will be healed tomorrow!

See First Test** on Testing Video page for clips!!

Thursday, June 3: Testing/Modifications

We actually reverted back to our original board which worked after many alterations! We reconfigured the motor with the new board and got everything to successfully work! We first tested it at half speed but we found that it was too slow. So we increased the speed and sensitivity of the angle and got a successful ride!!

See First Successful Ride** on Testing Video page for clips!!

We fiddled with the program on the Vesc Tool software for a long time and it was definitely a trial and error process. It was also very hard to balance at first but once we got the hang of it it became much easier- like riding a bike! Tomorrow we need to fix some of the inserts that are in the enclosure because they have been pushed down which means the threads aren't catching onto the screws.

We are all so excited with the way it turned out!!

Friday, June 4: Testing/Modifications

LAST DAY OF PROJECTS! Today we spent our time modifying and testing different speeds on the OneWheel. We also worked to finish up this website to make it presentable for our submission which is due at 3pm. We took more videos, with Mr. Chun's help, of our functioning OneWheel to add to our Testing Videos page.

Page updated

Report abuse