Motobecane Cady with an RC drive

[matt_in_mtl]

Well, I thought it might be time for an update. The bike has moved under it's own power. I got the motor up and running as discussed using an RC speed controller, and also ordered a 6-fet infineon controller. I have mad a couple topics on the forum since then about trying to program the controller (it was my fault.. that's what I get for making my own cable ) and once everything was together I ran into issues with the controller cutting out. That has all been resolved (see 'infineon cutting out problem' thread for info). anyone looking to use infineon controllers with RC motors or at high voltage may want to check out that thread since we made some interesting discoveries.

Today I was able to ride the 'ped under it's own power at 48V, with the controller set to 75A phase and 40A battery. At up to 15mph I was not pulling over 20A battery, so I can only assume I was phase limited. Unfortunately after a couple of blocks going up a medium grade... the controller stopped working, measuring the phase leads shows that one of phases is shorted to ground so looks like a low side fet blew So the bike is back up on blocks while I source some replacement fets. After the run the motor was barely warm though :lol: so that is good news. I did not get a chance to do a high speed run before the controller blew. I think my primary belt drive may be killing my efficiency though.

 

[gwhy!]

Hi Matt,
Sorry to hear that your controller went pop.
I was just wondering what was your gear ratio was to achieve the speed of upto 15mph . I have just bought myself a small auto scoot ( should be picking it up within the next couple of days (so thats the summer project sorted out ))
http://endless-sphere.com/forums/viewtopic.php?f=10&t=17389&start=30
and Im thinking about pulling away ratios, Im hoping to fit my bigger motor (6500w) straight into the crank casing onto the variator. I will be starting a build thread soon if your intrested.

 

[matt_in_mtl]

Hi Matt,
Sorry to hear that your controller went pop.
I was just wondering what was your gear ratio was to achieve the speed of upto 15mph . I have just bought myself a small auto scoot ( should be picking it up within the next couple of days (so thats the summer project sorted out ))
http://endless-sphere.com/forums/viewtopic.php?f=10&t=17389&start=30
and Im thinking about pulling away ratios, Im hoping to fit my bigger motor (6500w) straight into the crank casing onto the variator. I will be starting a build thread soon if your intrested.

gwhy, yeah I have been watching your thread.

I can`t recall exactly what my ratio was, but it worked out to about 30 - 35mph no load based on kv of the motor at 48V. The 15mph was not the top speed, I did not get a chance to test that, the controller blew too soon. I think I was in the 10:1 to 15:1 ratio. There was a project a while back with a turnigy in a piagio boxer that had a variator.. you may want to look there for variator ratios.
here it is:
http://visforvoltage.org/blog/nasukaren

-Matt

 

[gwhy!]

Thanks Matt for the link,
Nice, It looks like he never used the variator which is a shame ( would have upped the top speed ), but it is encouraging that he said that the starting torque was very good running on only 24v pulling 3kw and cruising with only 300w. Fun times

 

[pankaj_india]

is the hobbyking 90-100a esc is of any good....
was it the infinion or hobbyking that burned it's one FET

 

[matt_in_mtl]

is the hobbyking 90-100a esc is of any good....
was it the infinion or hobbyking that burned it's one FET

The infinieon blew it's FET after I abused it

The Turnigy has no built in current limiting, I am sure that it would have also blown.

-Matt

 

[northernmike]

Know what this is beginning to remind me of?

50cc bikes on the salt flats.

You can do what, 300mph or something with 50ccs?

It's GETTING GOING that's the problem.

Say you had a bike that weighed nothing. Actually nothing.

It was only your body weight that you wanted to accelerate.

Would a little R/C controller handle it? To move YOU from a standstill to 30mph?

Sure, the power figures are impressive - 50 volts, 100+ amps - but at what LOAD?

FWIW I've only had CVT gas mopeds, with automatic clutches - and they're awful off the line.

The eTek Moby hauls - because it's built to - but I DO wish it was lighter.

Keep it up guys, but keep it in perspective.

If your motor is designed to power aircraft, let it spin waaaaay up before you try to load it down. You might need one hell of a transmission before you get something like this to move well.

Just my $0.02.

 

[recumpence]

Know what this is beginning to remind me of?

50cc bikes on the salt flats.

You can do what, 300mph or something with 50ccs?

It's GETTING GOING that's the problem.

Say you had a bike that weighed nothing. Actually nothing.

It was only your body weight that you wanted to accelerate.

Would a little R/C controller handle it? To move YOU from a standstill to 30mph?

Sure, the power figures are impressive - 50 volts, 100+ amps - but at what LOAD?

FWIW I've only had CVT gas mopeds, with automatic clutches - and they're awful off the line.

The eTek Moby hauls - because it's built to - but I DO wish it was lighter.

Keep it up guys, but keep it in perspective.

If your motor is designed to power aircraft, let it spin waaaaay up before you try to load it down. You might need one hell of a transmission before you get something like this to move well.

Just my $0.02.

http://www.youtube.com/watch?v=WKAMus3oSdw

Hmm, this is with two RC controllers and motors. It pulls 800 amps at 44 volts (under load). That is 400 amps per controller.

It is possible to see HUGE power and torque from these systems. It just has to be done right.

That is my $.02

Matt

 

[northernmike]

Matt, I love that video. I've watched it over and over, and shown it to so many friends who think I'm a bit nuts for being so interested in ebikes.



But consider this.

If you were to set up that trike such that it actually "hooked" - that is - used the power it has available to produce ACCELERATION instead of wheelspin, you would likely fry those little Castle Creations instantly.

Imagine it with a tire 3x, 5x the width, weight biased for launch. You have the power, yes, but you've offset it with a complete lack of traction.

This is what's saving your drivetrain.

It should take off like a shot.

But instead it's making smoke.

Impressive, sure, but not exactly efficient.

Overall performance, I realize, especially top-end - is excellent - but for those who want to put WEIGHT on their tires and take off from a traffic light ....

 

[recumpence]

Actually in that video, it was only pulling 300 amps total. The 800 amp pulls were on fresh pavement with very minimal wheelspin. It is hard to say what my 0-60 accelleration was and it was hard to hang onto because it was pulling so freaking HARD! I had precious little wheelspin on that run. In fact, I was worried it would wheelie if I had any more hook. It was actually physically painful on the hardest runs.

What is important is the watts you pull and at what point you pull those whats. The problem is, these systems pull more and more current the more you load them up. So, you need to mechanically fuse it at some point or risk over-amping it and blowing something. That is why I have been developing a slipper clutch. In fact, two of my 3 bikes have them, now. So, there is some truth to what you are saying. However, there it is also true that, correctly set up, these RC systems (even single motor systems) are capable or puting out more power than most people will ever need.

Matt

 

[northernmike]

I'd really like to see a video of a Castle-controlled bike taking off from a DEAD stop and accelerating hard. I mean from a traffic light kind of stop.

I know they can scoot from a rolling start, that much has been established - but I mean like a drag-race launch, STOPPED DEAD.

'cause that's real-world performance.

The 80-100-B on the Moby was great fun at speed, and power-to-weight was awesome - but on take-off it's like driving a stock automatic Civic - you wish you could get the RPMs up before you had to depend on it.

I think the slipper clutch is probably a necessary evil - I'm just on the fence as to whether it should be accomplished via an electrical function or a mechanical one.

I'm leaning towards the electrical side, for some reason. Sentimental, perhaps? :wink:

So - the question becomes - does that "clutch" accomplish it's task via capacitors, resistors, slipping mechanical plates, an oil-based torque-converter........?

 

[northernmike]

...or just a way, way lower resistance controller.

 

[AussieJester]

I'd really like to see a video of a Castle-controlled bike taking off from a DEAD stop and accelerating hard. I mean from a traffic light kind of stop.

Can tell you it can't be done on my Turnigy/Castle Controller HV160 equipped bike with a mofo rear tires (20x4.25in rear) and no slipper clutch, requires a slight push off from start before hitting the throttle, whether Matts slipper clutch will rectify this i don't know, i doubt it will from dead stop withg a big Turnigy as the motor still needs to rotate some before it syncs....that said though, nothing Mr Recumpence SiR comes up with surprises me anymore, I'll definitely will be grabbinbg a slipper clutch for my Shumacker reduction drive when Matt makes them available.

KiM

 

[recumpence]

I'd really like to see a video of a Castle-controlled bike taking off from a DEAD stop and accelerating hard. I mean from a traffic light kind of stop.

I never once in that video pedalled the bike. It was from a dead stop every time.

I know what you are trying to get at. Yes, dead stop starting is a bit of an issue. However, sensored controllers have their issues as well. For one thing, you cannot have good timing in low throttle and high throttle at the same time. You must compromise. Sensorless monitor and change timing according to conditions.

Everything has its benefits and drawbacks.

RC controllers are far from perfect for bike use. That I can say for sure. However, they do solve a number of issues that in many setups are very useful.

As for the slipper clutch, yes, it "Solves" many of the RC controller problems. However, that solution is not a perfect one. But, at least in my personal bikes, they shrink any remaining RC controller woes to a very nominal level.

Anyway, we are getting off topic. I will get off the pulpit (soap-box?) and let the thread go back on topic.

Matt

 

[northernmike]

:wink:

Suppose you have great batteries, and lots of traction available.

...


Brushes don't hesitate.

Big, strong magnets don't hesitate.

Big FETs don't hesitate.

The only problem is ....weight!

 

[gwhy!]

FWIW I've only had CVT gas mopeds, with automatic clutches - and they're awful off the line.

If you think that a cvt with a auto clutch is awful off the line then it wasn't setup correct!!. I would put up a well setup cvt/auto clutch against any manual geared bike of at least twice the cc anytime and be confident that the auto will out accelerate the geared bike everytime off the line .

 

[northernmike]

If you think that a cvt with a auto clutch is awful off the line then it wasn't setup correct!!. I would put up a well setup cvt/auto clutch against any manual geared bike of at least twice the cc anytime and be confident that the auto will out accelerate the geared bike everytime off the line .

These were 1970s vintage, bone stock 50cc bikes... not much to set up!

The Peugeot 103 was nice for charging up hills, though, I will say.

 

[gwhy!]

If you think that a cvt with a auto clutch is awful off the line then it wasn't setup correct!!. I would put up a well setup cvt/auto clutch against any manual geared bike of at least twice the cc anytime and be confident that the auto will out accelerate the geared bike everytime off the line .

These were 1970s vintage, bone stock 50cc bikes... not much to set up!

The Peugeot 103 was nice for charging up hills, though, I will say.

Old 70's stuff was a bit naff , the whole cvt/auto scooters really came to life in about mid to late 90's and have just been getting better ever since.

 

[1KW]

Bump, I've got a peugeot 103 I want to convert.

Going to try and use stock variator. I need 40mph and 10 mile range... Would a 6374 do this if I use variator?(endless gearing, rocket uphills)

 

[gwhy!1]

Bump, I've got a peugeot 103 I want to convert.

Going to try and use stock variator. I need 40mph and 10 mile range... Would a 6374 do this if I use variator?(endless gearing, rocket uphills)

quick answer is yes it would, but it will be more reliable if you use a 8085 or 80100

http://endless-sphere.com/forums/viewtopic.php?f=12&t=17576