We’ve decided to jump right into the electrification.
And along with that, I’ve come up with a name.
Project Regicide
Here’s what I’ve cobbled together so far for my parts list.
Motors (X2):
Flipsky 6374 140KV
Drive Train & Stuff:
-Boardnamics MBS Matrix III Motor Mount Set (with idler)
-80T Wheel Pulley (3D Printed)
-12T Motor Pulley
-Rockstar Hubs
-MBS 8" T3 or 9" T2 ( undecided )
Trucks:
Other Planet M1
Deck:
This deck dummy. The one this thread is about.
ESC:
MakerX DV6 100A Cont, 180A Max Per Motor
Telemetry:
Voyage Minnie
BMS:
DALY Smart BMS LiFePo4 15S 100A
Parts I still don’t know what I’m doing:
Battery.
LiFePo4
Targeting 400+ Wh Probably no more than 600 Wh
Will depend on enclosure and cramming and cell size.
Remote.
I just know I want to have a dead mans switch.
Considerations
First of all, I’ve got a Lipo board for the first time after having a boosted forever.
And I very quickly came to a realization. Voltage Sag makes me very sad.
It also really cuts into the effective range when doing aggressive uphill. I’ve got like pretty significant battery left when my current board, The Empress starts struggling to get to the top of the runs.
So, LiFePo4 or bust.
Which brings me to the first problem.
I have a voltage mismatch going on. a 15S LiFePo4 BMS, and a 12S Lipo rated ESC.
It doesn’t seem like DALY has a 14S LiFePo4 BMS.
12s Lipo peak voltage is 50.4V (what esc is designed for)
15s LiFePo4 Peak Voltage is 55V
And ESC absolute maximum it can handle with voltage spikes, I’m surmising is a Hard limit of 60v. And I’m guessing that 10V buffer is important.
Is a 5V buffer still safe enough for spikes? Can I resolve this by limiting the peak charge voltage on my BMS? Or can I resolve this by configuring my BMS as a 14S?
Second Problem.
I still haven’t figured out what I’m going to do for my cells. I’m looking at options for used cells.
Most discussions I’m finding on sources have dead hyperlinks.
I’ve decided to go with a Matrix 3 motor mount. And I’ll just adapt the trucks to be Matrix 3 mount compatible. If there’s hardware that’s likely to be supported for a long time and not just disappear in a few years, I think Matrix 3 hardware is on that list.
Why such a high gear ratio?
Because telemetry on my current board suggests my average speed when hitting the trails is only 10mph. And it seems like I get much better traction and power consumption hill climbing slower than 15mph. My top speeds down the trails aren’t using power at all.