Options for electric Drift Trike

[dmcke]

Hi guys, I guess I should start by introducing myself.
My names Daniel, I've been looking through these forums for a month or two now for ideas on how to achieve what I'm looking for. I figured I should sign up and ask a few questions, as I feel like I'm just not getting anywhere with my research.

Basically I'm looking for the cheapest(Very limited budget!) option possible to power my E-Drift trike which I'm building from scratch. I've used brushed motors before on things like this, but I've never been overwhelmed by their performance so I would like to go brushless this time. In my spare time I fly model planes(mostly electric) so I've got bits and pieces of gear from those lying around and I feel like this may be a good option. From what I have read so far if I wish to achieve acceleration from a stand still(this trike won't have pedals) with a brushless motor I will need a motor with Hall sensors and a current limiting controller.
I have access to CNC machinery so gearboxes and just about anything else I could possibly need shouldn't be a problem.
Has anyone successfully run a cheap hobby grade brushless outrunner(with added hall sensors) on a cheap ebay ebike controller?(do these have a fancy name I'm not aware off?)
If you could point me to a thread that specifically mentions which controller, motor and sensors were used that would be great!
If I had 500 watts, what speed would I be likely to achieve assuming that the trike weighs approximately what a regular bike does and that I'm about 80kgs on top of that?

I should also mention, battery wise I would like to eventually run a lifepo4 pack from ebay when my budget allows but for now I have two options:
Keep the system at 12v and run my massive (25kg) deep cycle 105ah battery on it. Or use some 9ah 12v sla's that I already have (I've got two, but would happily buy 2 more if needed). Weight isn't an issue as the frame will be designed to be able to carry a heavy battery safely, and it will only be 100-150mm or so off the ground.

I can post pictures as I build if anyone is interested, I know all the RC guys go by a motto of "Pictures or it didn't happen".

Any help you can provide is greatly appreciated!
Cheers!
Daniel

 

[racer_x124]

I'm no very experienced, but I am running an eBay 1000w 20" wheel on my trike going 27mph. I believe that the local motors trike is going about 18mph with their 500w motor, which I doubt would be fast enough.

Be sure to get some weight over the front tire by having a good amount of distance between the rider seat and rear axle. Our trike spins the tire too much, makes it very difficult to hold a drift.

I'd love to see your trike.

 

[dmcke]

Thanks for quick response,
I've really only got a photo of the donor bike and seat at the moment, not too much has happened yet but I'll put them up anyway. I really like the idea of the hub motors, but sadly they are a bit out of my budget(for the moment anyway) If I could get my hands on a motor and controller that would work for less than $150, it would be awesome. I've also considered a standard electric plane motor/speed control and using a centrifugal clutch to limit the amount of starting current and too allow the motor to spin up to speed first. I saw a youtube of someone with that on a go cart somewhere, but I can't for the life of me find the video right now!

-Daniel

 

[dmcke]

Got some more work done on the trike today. Frame is starting to come together! I've been emailing someone (He's bound to be a member on here but I don't know his user name) who's helped me a lot with the decision of which motor and controller to use. Think I'm going for a Kelly controller and this motor http://www.hobbyking.com/hobbyking/...nner_Motor_AU_Warehouse_.html?strSearch=sk3 1.
Here are a few more photos:

Pushbike front all ready for welding.


The plasma-cut rear stiffener plate, made out of 3mm steel.


The frame all welded up, tubing is 33.7mm OD with a 2mm wall.


Etch primer applied and front wheel assembly attached.

Handle bars and forks still need to cleaned up and primed, and maybe a little badge on the front where the old Malvern star one was, haven't decided on what I want that to look like yet though.
Hoping to attach the rear wheels and seat tomorrow so I can at least sit on it and get a feel for where the foot pegs need to be.
Also not sure if I want to friction drive or Belt drive the front wheel. Decisions Decisions.

- Daniel

 

[nechaus]

20inch wheel would be better to use I reckon...

 

[dmcke]

Probably would have fit in my car a little better with the 20 inch, yes. However I like the look of the larger front wheel and at the time I was having trouble finding a 20" bike that was good enough but cheap enough to scrap.
I'm at the stage now that I'm ready to order my electronics. I'll be fitting a temporary brushed motor that I have lying around tomorrow just to get things moving until my brushless gear has turned up. It claims 180 Watts output on 24v However I have seen it take almost 800 watts in on a previous project, so It must be making at least a little more than that(otherwise we're getting a pretty poor efficiency at around 22%).

Here's a pic of it currently. I've run it down a few little hills, and It's actually a remarkably comfortable ride. Just a little difficult to get into and out of as its quite low and I can't really pull myself up on the handle bars as I end up just lifting the front wheel.

I'll get a photo of the motor and trial friction drive tomorrow when I fit it.

- Daniel

 

[Tench]

Now I have never ridden? one of these trikes but watched a few videos, it strikes me that your footrest position could be better, the amount of sideways movement on those pegs will be quite considerable. I would have thought the closer they are to the steering pivot centre line would minimise the amount of "swing" at the pegs and also place your lower leg inline with the forks so the steering action wont bring the tyre into contact with your legs. This would allow more freedom of body movement to balance the trike while ridding.

 

[dmcke]

I tried them on the steering center and I didn't like it. They may not move as much there, but the back of the wheel still comes around to bite you on the leg, but further up where your legs aren't protected by shoes. I'm considering running foot pegs that actually come out from the frame, so I don't have to move my legs with the wheel.
I think the title of my thread is probably a little miss-leading, as I don't intend to spend much time actually drifting this trike, more just driving it around so the wheel will rarely ever be at that much of an angle anyway.

- Daniel

 

[dmcke]

Here's the friction drive ready to be attached.


- Daniel

 

[dmcke]

Okay so I drove this around for a week on my little friction drive. Managed roughly 10kmh on flat ground.
I decided against a friction drive as I had great difficulty getting it to grip my wheel well enough to take off, and that was only with the little 180 watt motor. I can only imagine the difficulty I would have had putting 1kw through it.
I decided to pull the trigger and ordered myself a 1000watt 48V hub motor kit from ebay($410 by the time it got to my door, which is worth the avoided hassle in my opinion).
My hub motor turned up mid last week, and I've gotta say it really does go pretty well! I haven't set up the Speedo yet, but I'm guessing we're managing over 40kmh.
Within the first 10 minutes of running with the bigger motor, I had successfully ruined both of the cheap plastic trolley wheels on the rear. I have now swapped these for some steel hub trolley wheels which I've modified to take real bearings(6202 2RS, for anyone interested) which was actually very simple and has resulted in a couple of very strong rear wheels.
I hooked a amp meter to it yesterday for a short run to judge what size batteries I should be buying (I'm running 4 High C rated 2200mah 3s Lipo's in series which I have lying around from my model planes at the moment).
I was shocked to find that under hard acceleration I'm actually pulling 50amps at 48 Volts! That seems a bit much to me, so I'm just wondering if anyone else has checked theirs with a amp meter to see how it compares? I swear I had read somewhere that these controllers had built in current limiting of 30 amps? 50 Amps can't be real good for the cheap lifepo4 packs found on ebay, which from what I've seen are only rated at 1-2c. Once I'm moving things settle down to a nice manageable 20 amps.
After a ride the only things that are hot are my batteries (which lets face it, its a bit hard on such small Lipo's) motor and controller are both stone cold.
Otherwise, I'm very happy with the handling and ride comfort and it even copes pretty well with a bit of off-road so long as I don't ask it to climb a slippery hill and don't mind a bit of dirt in my face.
Can't wait until my bigger batteries turn up so I can go for more than 5 minutes at a time!
Ill grab a photo this afternoon with the hub motor attached.

- Daniel

 

[racer_x124]

Cool stuff, glad I came back to check it out. I've been driving mine around all summer and just got back from the convenience store reminded me to check your thread again. If you look into running friction again check out what these guys did, might be able to come up with some ideas.

http://vimeo.com/72614087