Nothing for sale

[TexasSP]

Originally Posted by _paralyzed_

I've got a manual wheelchair with rear suspension (rock-shox!) that I've been contemplating doing this to.

How to steer? Skid steer? Add spindles and an ackerman? Someday...

Control each wheel independently. Trigger control in each hand. Just an idea, could be useless, just throwing it out there. If you could come up with some sort of mixing type controller you could do it with one joystick. When you turn the it automatically slows or locks on wheel depending on speed and turn sharpness.

[BrianG]

Probably easier to do it mechanically. The rear wheels could be attached via a differential with disc brakes on each wheel. Then, just apply brakes to a single wheel to turn in that direction. Apply both to stop.

[Finnster]

USB 3.0 implants directly in the brain. Meld the man and the machine.

The other upside would be if you ever got to be a PITA, we could just root you, re-format and flash a new ROM.

Otherwise I like TX's idea

[RC-Monster Mike]

Got the modules installed last night and went for a night run! WOW what a difference the lipo conversion made. First ran at 66% current limit(200 amps) then in full power mode(300 amps at 74 volts in theory, though in unlimited mode it bursts higher amps). Full power mode is downright scary - I seriously am in need of a better throttle(only 90 degrees of twist makes for a twitchy ride) - I would like to get a 120 degree throttle to add some resolution for sure. The gearing tops it out at around 43mph and it gets there in a hurry! At 25, if you grab full throttle, it will throw you off the back unless you let up quickly - feels like a kx250 when it hits the powerband! I dialed in a progressive curve and went back to 80% current limit(240 amps) - theoretically limiting the power to around 20HP, which is plenty for a 150lb machine. I am totally psyched!
Oh...before i dialed back the power, i managed to rip the primary drive belt in two(hanging off the foot peg). I hope to get some body panels done this week to cover the batts/wiring a bit. Here is a picture:

[RC-Monster Mike]

the bike and the broken belt

[crazyjr]

Originally Posted by RC-Monster Mike

the bike and the broken belt

Hey mike, nice bike. What is the range on the stock bike? What is the expected range on your battery conversion? I love that you used basically off the shelf batteries, makes fixing and replacing components easier. If i ever lose enough weight, i'd like to get a E-bike for commuting to work. I would look into this setup, as i know the guy doing it is one of the best in the area of engineering and ergonomic and wouldn't sell anything that either doesn't work , or he wouldn't use or ride himself.

One thing please, If you do get into the E-bike area, please don't let it overtake the rc part. Would suck if RC-Monster didn't do RC parts anymore

[BrianG]

Originally Posted by RC-Monster Mike

It has a 0-5k pot throttle(Magura twist - very common). I would love a better throttle, but aside from building one there doesn't seem to be many other options. IMO, 90 degrees is a bit stingy - I have at least this much on every gas bike I own, but with 5 or 6 speeds, the actual "speed resolution" is 5 or 6 times better. Certainly 120 degrees of twist would help, as would an exponential throttle - they just don't exist or I don't know where to get one.

Unfortunately, I don't know enough about how all these throttles are built to offer good suggestions. A pot is simply a wiper arm that scrapes across a resistor giving variable values at the wiper arm contact, so it should have virtually infinite resolution. I wonder if the controller is your limiting factor? It might apply steps of output based on different resistance input thresholds (basically a really low-resolution A-D converter ). Simple testing with a meter at the throttle output should tell you what it's doing, but testing the output of a BL controller to see what its resolution is is a bit more difficult to measure. If it IS a matter of 60* twist not having enough resolution, maybe retrofit a different 5k pot in there? I would be careful about reliability though as the mechanical action of that wiper arm "scraping" does cause wear and "noisy" actuation. I'm kinda surprised digital encoders aren't used to avoid that.

Originally Posted by crazyjr

...One thing please, If you do get into the E-bike area, please don't let it overtake the rc part. Would suck if RC-Monster didn't do RC parts anymore

While I agree with you, it is obvious more and more manufacturers are coming out with off-the-shelf electric products, so the custom side of things has to be taking a hit. It's not like the old days where if you wanted an electric toy, you basically had to build it. I think maintaining current custom items is nice for those who still like to tinker, but I can see Mike having to diversify to make enough green to keep the lights on.

[rchippie]

Originally Posted by RC-Monster Mike

the bike and the broken belt

Mike that looks AWSOME.

[mistercrash]

Those modules look awesome, very clean look. ''Looks factory'' like Chip Foose says. The whole bike is pretty darn sweet.

Now I'm having a hard time figuring this out. I presently run on 48V 34 amp SLAs. To get to close to the 48V mark with lipos, do I need to go with 12 or 13 cells? 3.7V nominal times 12 = 44.4V or 3.7V nominal times 13 = 48.1V. Which one is it? If 12 cells is the number I need it seems a lot easier to configure, I would need 12 6S 5000 mah packs total. I would probably try Turnigy packs at first (not the Nanotechs) as I don't think I can convince my wife of letting me spend almost $1700 for Hyperions. Turnigys 40C would be under $900 including shipping.

Man I am also having trouble wrapping my brain around the fact that I could get better power and range from just two battery modules with less than half of the volume and weight of my SLAs.

[RC-Monster Mike]

BrianG - I don't want to add 60 degrees of twist...I want to add 30 degrees of twist(90 to 120). The spring is reasonably stiff now and while it may address the issue, it may also lead to fatigue until my right forearm starts to look like Popeye's! Thumb throttles are for quads IMO - I also ride a gasser dirtbike and street bike, so I would rather stick to the twist-type...I just want a better one than what I have!

Arct1k - Chris, if the other half controlled my ride I would probably only get one ride! I like the twitchy throttle I have better than this idea, thank you. :)

Hippie - thanks for the compliment, Mike. I did some more last night and this morning - I managed to get the stock side panels on with some shimming and broke out the trusty propane torch and bent up a rear fender(not perfect, but not bad for a ghetto prototype). Pics attached

mistercrash - thanks for the compliment. "factory" is the look I was going for. The modules are held onto the bike using the two lower screws on each module(into the aluminum post on either end of the modules). I made a custom lower plate that bolts to the bike in place of the original battery plates. I still want to make a top plate for added security, but they are reasonably solid and I wanted to ride this beast. i may have John Holmes string me up a dirt bike rim onto the rear hub and get a meatier back tire on this thing - along with a gear change to get it up into the 50s(maybe - 40 is pretty fast in the trails already).

Having ridden this bike when it was a 200+ pound, top heavy lead sled I can say that the lipo conversion was worth it and then some. The 50 pound weight reduction and much lower Cg results in a dirtbike that handles like a dirt bike now(top heavy and sketchy in the rough b4). The power is unreal, too - it feels easily twice as punchy as my 300 thumper I usually ride and feels stronger than my 400 KTM supermoto, too. A rookie rider on this thing without limiting the power is almost certain to end up badly!

[snellemin]

Sounds great, but no pics.

nevermind. I see the pics now.
.

[RC-Monster Mike]

Yeah, I clicked "post" a bit soon! That belt had a small blemsih on it when I got the bike, but it held up to the 200 pound machine on lead power without issue. It lasted about 10 minutes in its first daylight run today - thankfully I wasn't far away(had to push the bike home of course).

[BrianG]

Sounds like you need an exponential throttle control so the throttle is a bit more manageable at the start. If it's just a pot, you could try a "linear taper" type (these are logarithmic - not exponential, but similar curve).

[RC-Monster Mike]

It has a 0-5k pot throttle(Magura twist - very common). I would love a better throttle, but aside from building one there doesn't seem to be many other options. IMO, 90 degrees is a bit stingy - I have at least this much on every gas bike I own, but with 5 or 6 speeds, the actual "speed resolution" is 5 or 6 times better. Certainly 120 degrees of twist would help, as would an exponential throttle - they just don't exist or I don't know where to get one.

[RC-Monster Mike]

I am not getting out of RC anytime soon, Larry - no worries, there. Before RC was my job, it was my hobby. Now that RC is my job, I have simply expanded my other hobbies to keep myself from going off the deep end. As Brian said, what used to be custom stuff is becoming mainstream - at one time I was the only guy making electric conversion stuff but the big dogs are in the mix now(major manufacturers). I am not dumb enough to think I can compete on price with the industry giants (on quality or innovation I try to hold my own, but volume dictates price and I have got nowhere near the volume of the big dogs). I also make my parts here in the USA and therefore pay my help fair wages - it simply costs me more to produce parts. I could go to Asia for parts like everyone else, but I would rather not.
As long as I can stay afloat doing what I like to do, then I am rich(may never be wealthy, but I am OK with that). I may dabble in other areas to stay in business as well as simply expand my knowledge - I have always been into motorcycles(street and dirt) and have always owned at least one motorcycle my entire adult life - this is an obvious avenue to explore, just like RC was 8 years ago when I went into business. :)

BrianG - I agree that a pot is theoretically infinatly variable within its travel, but controlling 35HP in rocky terrain with only 90 degrees of twist can be quite the challenge - remember I am using the same hand to hold on! The controller itself may be part of the problem, too - I just know there has to be a better system than what i currently have. This is not to say what i have isn't good - in fact it is quite awesome in most regards - just that overall control could be improved upon.