Jackal's Duplex Drive Electric Motorcycle

[jackal]

Hello everyone, new user here bitten by the electric bug!

I've started thinking about building an electric motorcycle since early March I believe. It started small and it grew into a 2wd motorcycle idea. It probably is overkill, wasteful and suicidal but hell, if I'm going to do something from scratch (frame included!) it has to be exciting and challenging to keep me going, right? otherwise I might drop it and lose interest.

Anyway, it has gotten to that part where I've got my design sketches pretty much where I want them and I'm starting to look at the details so I can order parts to start fitting and testing. Oh boy, so much to read, so many calculations to do, so many inquiries...

I'm super new to this but hopefully I've done enough research by now that I don't sound like a complete idiot here. Word of warning though, I'm still an idiot, so components and calculations might not be properly matched, and I might have not grasped certain concepts yet! which is why I'm reaching out to the forum!

So here's the plan so far:

2 x QS273 40H or QS205 50H 5T (one on each wheel)

Each motor would have a 20s2p 74V 20Ah battery pack out of "Turnigy Graphene Professional 10000mAh 4S 15C" and a suitable controller for it (still TBD).

Now, I don't want to cook the motors beyond the spec sheet, I want durability. I want to always stay in parameters, so if the QS205 has a 3kW continuous rating and 6kW peak, I just want to do that. If anything, since the batteries could deliver 300A, try that for a short amount of time (which by the way, I'm still not sure if it's that straightforward)

I've read someone here recommending controllers for an application like this that have: "24fet with IRFP4468 or IRFP4568 at minimum, ideally 36fet". Haven't found a controller that fits this description (either manufs. hide this very well or my google-fu sucks), Kelly seems to use a different version of fets in their KBL72301X (would this one work?). It's important that the software suite is good and easy to work with.

I also have a slight problem if I go with the 273... it seems really hard to fit it inside an 18in rim without using some radial lacing (big no-no for me). So I might have to fall back to a QS205. It also needs to be something like 2.5 in wide to fit the tires (eg. 110/80-18 Kenda K761 Dual Sport Tire), something QS doesn't offer but I've asked them about it. Still waiting for a reply.

Anyway, thanks for having read this wall of text, sorry for the potential cringes you might have experienced! Probably not the first and not the last haha. Might post a render of what I'm envisioning later if there's interest. Any advice would be immensely appreciated.

Cheers!

 

[jackal]

Here’s a rough representation of the idea. This one in particular is using the 273. It’s a pretty bare sketch but the dimensions are accurate for the most part. Some things, like the foot pegs are just place holders.

 

[sn0wchyld]

Here’s a rough representation of the idea. This one in particular is using the 273. It’s a pretty bare sketch but the dimensions are accurate for the most part. Some things, like the foot pegs are just place holders.

nice looking bike.
with regards to the controller... i'd consider the adaptto's. they'll do 6kw easy (a midi for example) and are setup to be able to do 2wd.
re batteries, sounds more than enough but (unless im misunderstanding) sounds like you are thinking of 2 separate packs? there's no need for that, just make a single 20s 40ah pack, and then you only need 1 bms (if you use the adaptto's), though good cells tend to stay well balanced without bms's anyway, youll just need to keep an eye on them, particularly when charging.

you might also look at john in CA's motors, he's got some that allow you to use bolt on rims, and offer significantly more power should you want it.

 

[liveforphysics]

Go with the 273mm x 80mm rear only. Don't waste time with Kelly's.

 

[jackal]

I considered the adaptto but I ended up picking a Kelly KLS 7240D. I've seen the Motorino thread and he seems to be using a KLS no problem now. Kelly has a pretty big range of products the controllers seem to have decent software. Do you guys know something I don't? I haven't fired up mine yet but the hardware seems to be well built.

I ended up going with the 205 50H as it will be easier to fit inside a 18in rim. I've contacted Buchanan's and hopefully I'll be able to get a proper set of rims/spokes/nipples. I been following Gensem's story with his 273 and there's been a lot of hassle to get a non-radial lacing on that beast. He is going to have to drill extra holes on the flanges and get 72 spoke rims... I don't know.

I've also changed to an 18650 battery pack. Reason being my preference for longer lasting batteries and less hassle on the charging setup instead of just raw performance.

@liveforphysics
Holy S#!t man, that thing is a beast, maybe for a V2 bike. I don't even want to think about how you would feed it!

 

[liveforphysics]

Kelly has a pretty big range of products the controllers seem to have decent software. Do you guys know something I don't? I haven't fired up mine yet but the hardware seems to be well built.

Watching half a dozen or so Kelly's explode between my legs or on the dyno, while never yet resulting in a vehicle I would consider good to ride is perhaps influencing my feelings towards Kelly.

 

[jackal]

oh wow, going to send you a PM over that.

 

[kenwood96]

I would pick an adaptto for sure, it even allows 2wd with an adaptto master - slave setup

Verstuurd vanaf mijn A0001 met Tapatalk

 

[jackal]

Thanks for the tip. If I run into too many troubles with the dual Kelly's I will definitely consider it.

Slowly making progress. I've got the motor running on a stand with the 72V 23.2 Ah pack. Brake disc and caliper now fits properly. Tomorrow I'll place an order for the 18 inch rim 2.75 wide (rim, spokes and nipples).

Immediate next steps:
- Start prototyping the axle plate designs with my 3D printer. Once I'm satisfied I'll get a local shop to cut them for me.
- Gotta configure the controller for variable regen (it currently has the ON/OFF mode)

If I can successfully install the rim on the motor, I'll order the rim band, tube and tire for it. It's always exciting to see things come together slowly in front of you. It makes up for all the troubles one has to go through and gives you energy for the next steps.
After that, it's going to get really tricky really fast as I have to start working on the frame. First time ever doing something like that so I expect lots of errors, lots of ruined parts, lots of cursing and probably will be the part when I will want to throw everything away. I'll come out a bit wiser either way. Big test!

 

[jackal]

Alright, updates:

- Axle plates now close to "final" design but will have to be modified slightly. Despite what the drawings say, the dropouts are not equidistant to the center of the wheel on the QS 205 50H that I have. It's off by 5mm. So instead of using two 3/8" plates on each side I'm going to have to use a 3/8" for the outboard and a 1/4" for the brake mount inboard plate to shave 2.5mm on that side. On the other side I'll have to add a 2.5mm washer or something... And this will cause me to lose one pinch screw on the left side. Kind of pissed about this since I had the rim custom made for this... I could have included a bit of dishing.

NON UPDATED PLATES (both 3/8")

- Here's the front tire and the front rim from Buchanan (18 x 2.75) (before being trued and torqued)

What a weekend it's been. I almost gave up on the truing and torquing of the rim. KEY LEARNINGS: once you have it trued with barely any tension, DO NOT start torquing the spokes in a 1,2,3 sequence (this will mess everything up, waste a lot of your time and energy and you might damage your components). Do every third spoke (leave two in between), so you do three "laps" around the rim. DO NOT turn the nipples more than a 1/4 turn and do not turn an already tight one (compared to the others). Be very strict about this and use the square sides of the nipples as references. Check for "trueness" after those 3 "laps" and adjust accordingly before you do another round of torquing. I got this thing to a 1mm runout which I consider pretty satisfactory for being the first time I do this. I've read that 2mm is the max allowed on some motorcycles, so this should be good.

- I'm planning on converting these to tubeless so we'll see how that goes next week when I get the valves (get the 8.3mm by the way so you don't have to drill the rim). Gonna use some automotive Goop to seal the nipples.