Update 2020-05-26
Figured out the wire routing (which was the biggest remaining unknown). Also complete are tires, tubes, Loctite, foam, buttons, more.
New
RJ12 Ends
In looking at how to route the sensor wires and phase wires, it was important that the design allow the enclosure to be fully mounted to the board and then connected to the motors. With the limited cabling length, the wires need to be extended from the VESCs to get these connectors to the outside of the enclosure.
The JST 6 pin 2.0mm connectors (used for the sensor wires) do not easily lend themselves to extending, are not really compact, and have no real strain relief. I looked at many different options for 6 conductor connectors including the Haggy sensor connectors, but eventually landed on using an RJ12 connector. The RJ12 connector offers a small form factor and integrated strain relief in addition to allowing for easy connection to other RJ12 connectors.
RJ45 Coupler
In order to mate the RJ12 connectors between the motors and the VESCs, a simple compact RJ45 coupler will be used. It should be noted that this coupler maintains proper pin order allowing connectors with the same wire order to be connected together. This connector was also chosen both for the metal casing and compact form factor.
4mm Bullet Connector Extenders
Just as the sensor wires required extending to reach the outside of the enclosure, the 4mm bullet connectors on the phase wires also needed extensions
Bluetooth Module
Once the enclosure is bolted to the board, it should only be removed in the case of hardware maintenance. That said, VESC programming was initially completed through a direct USB connection to each VESC. To get around this issue, a compatible Bluetooth module will allow for programming of the VESCs (including firmware upgrades) when used with the VESC mobile app. This module will connect with COMM connector on the secondary VESC.
Cogging with MakerX VESCs
Reading through the site, I came across this reply in the Go-FOC SV6 and Go-FOC SV4 …Maker-X thread. This sounded very similar to the issue I was having with my SV6 VESCs. The next step here is to upgrade firmware to v5 and test again.
Changed
Smaller latching waterproof button
The 0.7" button I was planning on using was just too huge. I found a 12mm option which matches nicely with the button from the AntiSpark.
Complete
Get tubes and tires mounted / Get spacers installed and adapters mounted / Mount wheel to the adapters
This was mostly covered and completed over on the Janux-esk8 Aluminum Hubs to fit Direct Drive thread on post 161.
Additionally, here is a side by side of an uninflated Evolve 6" tire vs an inflated tire at 50PSI:
Also a full shot of the first wheel mounting:
Loctite Janux hubs and adapters
Applied Loctite 242 to the Janux hubs and to the bolts which hold the Kegel adapters to the motor CAN.
Finalize foam placement in the enclosure
The corners of the N.E.S.E. modules required the thicker foam but the sides of the enclosure needed the thinner material in order to squeeze everything in. Additional foam is located on the top of the N.E.S.E. modules and on top of the VESCs in order to firm up objects in the enclosure once the enclosure is mounted to the board.
Wire routing for the motor leads
The motor leads (phase wires) will go through the cable glands as originally planned. Additionally the extensions will allow these phase wires to connect between the VESCs and the motors after the enclosure is mounted to the board. Quick shot of the extensions:
Wire routing for the sensor wires
The choice to use the RJ12 connector was detailed above, but some additional detail is required here.
First, with the extensions made available through use of the RJ12 connectors, the original design of using a single cable gland for all three phase wires plus the sensor wires (per motor) can be achieved.
Second, it should be noted that the wires used for the JST connectors are ~1.2mm, too large for the ~1.05mm channels in the RJ12 connector ends. As a result, each of the sensor wire leads required soldering to CAT5 conductors. Since only 6 conductors are required, the brown pair was removed from the cable length and the blue, orange, and green pairs were used. The sleeve of the CAT5 was kept for the RJ12 strain relief clamp. CAT5 was chosen over flat 6P6C wire due to a) a better fit with the (3) phase wires within the same cable gland and b) the larger gauge of the conductors.
Third, the wire colors of the sensor wires differed from the motors to the cables supplied by the VESC manufacturer (these motors are also missing the temp sensor lead). As a result, special attention needed to be paid to how the connectors were wired.
Lastly, was the consideration of total connector length. When (2) RJ12 connectors are mated using the RJ45 coupler, the entire length of the assembly is 35.6mm including strain relief for each RJ12 connector. This length gives some flexibility in cable placement for the connectors.
Wire routing for the buttons
As mentioned in my update from 2020-04-10, I relocated the buttons to the front of the enclosure. The antispark uses a momentary switch, requiring (3) conductors whereas the BMS uses a latching switch requiring only (2) conductors.
For the antispark, I used a standard 3 pin fan extension cable. For the BMS I used a small two pin connector I had available:
The connectors are both located near the front of the enclosure and the wires are run such that they have the minimum chance of being crimped when the enclosure is mounted to the board.
Regrettably the placement of the buttons in the enclosure did not go quite as expected:
Now all I can think of when I look at the front of the enclosure is Sloth from Goonies.
Mount charge port to enclosure
The charge port (on the other hand) mounted exactly to plan. The XT30 connector kept the installation simple.
Help Needed
Nothing right yet
What’s Next
- Verify functionality of Bluetooth module
- Update firmware to v5
- Bench testing completed without failures (with fall back to BLDC)
- Mount cable glands to enclosure
- Mount enclosure to board
- Route motor cables to avoid motor contact
- Test ride
Research
The helmet thread has lots of food for thought.