Hello all, long time lurker and first time poster here.
This thread will detail my journey designing and constructing an electric recumbent trike. I started the design process in June, with the intent to replace my car by the end of summer.
40 mile range at 40mph
Full suspension with anti-roll bar, for maximum ride comfort
Security features will include keyed ignition and gps tracking. Rear panniers will be used for storage, and later replaced with a locking trunk integrated into the fairing. Safety features include brake lights and turn signals, horn, and a (now crash-tested) battery box design that should minimize the risk of a battery fire in the case of a collision.
78v nominal 12ish Ah Battery (21s3p Haiyin 6ah 50c cells; actual remaining capacity closer to 4-4.5ah each)
300a bluetooth BMS
48 inch wheelbase
MXUS 3k Turbo 4t motor
Sabvoton SSC72150 150a motor controller
Full fairing, android dashboard, etc.
The frame is mostly welded .065" thick 2" steel square tube. The rear wheel is attached to the back end of a cheap craigslist bike frame, and suspended by a RockShox Debonair mtb shock. The front suspension incorporates fiberglass leaf springs, separate adjustable dampers, and an anti-roll bar (not yet mounted). The battery pack is attached behind the (go-kart) seat, in a fiberglass box. A pair of fiberglass electronics trays attach under the seat (not shown in rendering), with the HV side (motor controller, power supply, circuit breaker) on the left, and LV side (dc-dc converter, fuse box, relays, etc.) on the right.
The basic frame design came together pretty quickly:
The uprights are made by KMX for their line of recumbent trikes, with the steering link mounting points adjusted with steel plates for correct steering geometry in my design. The upper a-arms are welded steel, with rod ends from mcmaster.
Front leaf springs are 22 layers of 10.35oz/sq-yd unidirectional fiberglass from US Composites, for a total thickness of just over 1/4".
Here it is straight out of the press- it will look much better after some sanding!
The leaf springs were bolted into weld nuts, which were leveled off with some JB weld. (not shown)
After cutting, sanding, and adding cross-plys (one of the bolts is a bit short currently- oops!):
And here's the completed front suspension and steering assembly.
Stay tuned for updates in the near future!
Next up: Battery pack construction.