dr_frost_dk
Good info on smaller controller to reduce power, and on the switch for instantaneous full power. Are you considering power reduction solely for increased endurance or to reduce tire engagement wear?
My use will include 50% pedaling, but require frequent 2-12 mph (3- 20 kmh) acceleration perhaps 3-4 times per minute, much 8-15 mph constant speed, and for now rarely any speed above that. I am considering 4S or 5S, a 5065 series, and the Turnigy programmable AE 80A with "very soft" start, but it is $80- not that it's horrendous, but my goal is to have a small fleet of these bikes and cost per kit is important. If I can use a $20 controller by keeping current down that would be great, or by using a temporary "passing" switch.
That said, I am still in the foundation stage- sp. the mounting bracket. Here's my logic:
I’m a simple guy and I think the people who are going to want to do what I’ve done are simple, therefore not having to spend $200-300 on a mount or using a CNC device is important.
I always ask- especially for prototyping- what do I have laying around that will do the job; later I can find the right, common pieces inexpensively, TODAY, locally. And most importantly then I can show someone how they can buy their parts at the local hardware store and assemble it same as mine.
So, looking at your motor attachment bracket, I’d swear you only used a U-bolt, and then you hung the motor swing plate on one of the bolt sections of the u-bolt. I’d thought of this but couldn’t find a u-bolt to test. Well, while I was looking for different bracket methods (initially came up with plumbing 3/4" T and 9" pipe to mount to the seat tube, kind of like kepler's) I first found a u-bolt and then a gate latch, both of witch would mount on the main vertical.
Please take a look at my photos (I’m not asking for a critique of the bolt diameters, the plate thickness, or my “motor”, nor of the 15 years of rust, or mixed spacers- this is just to conceptualize easily obtainable parts that require little if any cutting, milling, drilling etc... ; instead just screw it into place.
I post these to give others ideas that might breathe life into FD’s via inexpensive, easily obtainable, sturdy, relatively light weight mounting hardware, removable from one bike and slapped on another quickly, easily adjustable up and down the vertical bike tube.
The first photo is an ancient U-bolt around the bike’s main upright, on one leg of which I mount the motor arm plate. I like this one best. Simple, easy, inexpensive.
- U-bolt mounting bracket
- Mounting bracket- P8190304.JPG (136.74 KiB) Viewed 3754 times
The next 2 photos show a "motor" disengaged and engaged from the tire. You'll see my U-bolt assy, swing arm, and “Motor”.
- U-bolt bracket- disengaged
- U-bolt bracket-disengaged P8190302.JPG (144.3 KiB) Viewed 3754 times
- U-bolt bracket- engaged
- U-bolt bracket- engaged P8190303.JPG (142.21 KiB) Viewed 3754 times
With 1/4" U-bolt and perhaps 2-3 ft-lbs of torque on the bolts and a thin PVC pipe between u-bolt clamp and vertical tube, I can barely rotate the bracket with maybe 10 ft-lbs of force- about what I expect the 1-1.5 HP Turnigy 5065 might exert to one side or the other at a moment arm of perhaps 2-3"- point is 1/2" U-bracket should be more than sturdy enough to resist the motor-tire engagement force and lateral/rotational force.
My question is, did you use a heavy duty u-bolt as your mounting bracket and hinge pin? Mine is only 1/4"x20, but I see 1/2" diam. (12mm) thread is readily available.
I'd post the "gate bracket" mount and the 3/4" T plumbing seat post mount if somebody really has a burning desire to see them
. Then again, if hjoore (2011) and others can prototype brackets in wood, then I can do it with a rusty u-joint and motor mock-up.
Thanks,
Ron
Jacksonville, FL
), and 24 Grit Belt Sander paper, this really seems to minimize wear as there is pretty much no slippage between motor and tire.
