Sunday 14 July 2019

Mercane Dual motor underbelly

being one to always like to look under the covers (as well as check all the screws) I decided this afternoon to to pull the cover off the battery pack on the Mercane and have a look. Compared to the single motor its quite "pregnant" under there. Basically everything below the red line is unique to the bigger battery system of the dual motor.


Its certainly made the whole thing heavier, with my scales suggesting that the weight is actually more like 23kg. Interestingly it has a front rear weight distribution which puts 14kg on the front and 9kg on the back (bathroom scales under each wheel and confirmed with my digital luggage scales and also with my holding it and getting onto the bathroom scales). Update: my single motor variant is 11kg front.

Interesting.

So what's under the cover?


In this shot we see that the battery runs the full length of the available tray, as well as the wonderful webbing cast that strengthen that entire platform and the controllers.

plural you say?

Yes, two controllers, stacked one atop the other and thus hanging down lower than the battery pack.


as well as seeing where the plastic belly pan screws into we see the location two controllers. Which is interesting and confirms my suspicion that the way the dual motor version was implemented was to just double the controllers and bung a back wheel on the front with its own controller. Simple and quick upgrade, run some more wires and voilla. Indeed that cable that powers the front wheel jutting out of the goose-neck at the front sticks out like an after thought to me when I think of it.

The basic maths on the controller is that being rated at 15 Amps it can handle 720W which is more than the peak draw of each motor, so there is built in margins there, which is nice.

Now its interesting to look at these controllers and observe that they are passively cooled (fins give that away), given how much heat controllers need to shed (from switching as much power as they do) is this a bad thing in an enclosed and sealed case? Perhaps, lets recall that the Wide Wheel has its origins in a indigogo campaign (link here) and when it was envisaged it was a single motor design.

Now owners of Mercanes may have noticed this set of 4 bolts directly above the controller ...



I understand that this is for a seat (I'd feel shame) ... none the less mounting the controllers up against the chassis looks to me a very tidy way of making use of that big cast aluminium frame as a heat sink. Cunning and well designed!

So it would appear that the original single wheel version planned for this from the outset, but the dual motor version just whacks that controller onto the bottom of (not a big heat sink) but the other side of a hot controller.

I'd hope that this was tested before being done, but somehow I have some reservations. Indeed I've seen examples of burnt out controllers on the dual wheel on YouTube already (by perplexed non technical owners).

I dunno ...

Anyway, moving up front we see more clearly that lovely webbed cast plate which is the main chassis of the scooter. It actually looks fantastically well designed and made. Looking at the lip around the bottom of the chassis you can see that the belly pan fits snugly into that. However also you can see that any water throw up from the front wheel will be likely to gradually work its way into that crack and down into the belly pan (where there is no way out). This is why I put duct tape over that join to prevent such (as I've owned old English cars in the past ;-)  (post on that here)


as well we can see the underside of the XT60 charging port (so clearly no problem if a little moisture found its way in there past the plugs and cover)as well as one of the belly pan mounts and holy moses look at the bracing around where the goose-neck mounts.


I'd have to pull it apart to see, but it looks like the goose-neck goes down into there and mounts somehow. I'm keen to pull that apart and look (especially after seeing a few Zero's bite the dust exactly due to insufficient engineering there (this is a shot from the internet):


as an engineering sort of guy that even looks inadequate before it broke. Sure, the front part looks solid, but you know what they say about the weakest link in a chain right?

Round up

Well that about rounds up what I've got to present tonight. The Mercane chassis looks great, I love the way the controller uses the chassis as a heat sink, but I have my reservations about the piggybacking of the second controller down there.

Then theres the weight ... its a lot heavier to heft around than my Single motor version ... which to me is shaping up as the sweet spot of the design (and indeed closer to the original conception of the designers. As I see it the original concept of the single engine 8.8Ah battery is not only sufficient (as I've already found) but robust.

I'm starting to feel like the move to dual wheel was more about being seen as "not competitive" in a market which is more interested in bling and "hot looks" than in good robust transport.

So basically I'm saying I'm thinking of seeing if I can send the dual motor one back and sticking with the single ... but then again, maybe I'll just keep it longer. Besides, its convenient to have two right now.




22 comments:

Unknown said...

Hi! Do you know how the batterycells are stacked?
Also. Isn't that controller a bit undersized? At peak voltage 54,6V x max current 15A you get at best 819w. The the dual motors @500w (Nominal!) could definitely use more.

obakesan said...

Hi

I don't, but I can infer from the dimensions.

if you look carefully there are two controllers, one for each wheel, indeed directly over the photograph is the following words:

plural you say?
Yes, two controllers, stacked one atop the other and thus hanging down lower than the battery pack.

ceabbott2 said...

In your opinion is there any way to isolate the controllers from one another without making the heat issue worse?

obakesan said...

Hi Ceabbott2 ... to this point in time I've not found any problems ... I'm interested to make a few experiments in summer and actually measure temperature to see if this actually is any problem. To this point in time (with some massive hill climbs) there has been no overheating or blown controller (more than one can say for the Dualtron range).

Anonymous said...

Ive noticed that the power seems to cut out when you hit bumps or rough road. Not sure if this is by design but it makes for a bit of an unstable ride at higher speeds. Annoying!

obakesan said...

Hi Anonymous

I've noticed this "hesitation" more with my single than with my dual. I'm interested to get to the bottom of it but its not made my ride ever unstable. I wonder if its a "connection" being bumped issue or if its actually something to do with motors.

Either way I've noted that it only happens when on "full power" not so much on partial throttle.

I'd be intersted to hear your situation

Unknown said...

Hi,

Did you ever find out if the hesitation/cut out over bumps was caused by a lose connection or something? I find it really annoying as well.

obakesan said...

Hi Unknown

I don't know for sure but I have a working theory. I think its actually nothing electrical and something related to physics. If you look at the first diagram (with red and blue arrows) in this blog post of mine: https://cjeastwd.blogspot.com/2019/12/scooters-going-fast.html you can see that for many sizable impacts the energy of impact is directly along the line of the suspension arm, so basically the wheel takes the first impact of that hit directly and while the rubber can and does absorb a lot of that it results in energy lost (meaning the energy of momentum), within fractions of a second however the motor has pulled the wheel over that obstacle and speed returns.

I've found that if I just jump a little over obstacles (pavement cracks) of that size (and magnitude) that my "jump up" also results in the wheel lifting up a bit (suspension is unloaded) and the "whack" does not happen and nor either does the speed hesitation.

I'd need a highspeed camera and some better monitoring equipment on the electrical system to be sure however.

So why doesn't this happen with pneumatic tyres? My working theory is that the tyre can elastically deform further (and thus over a longer time for any given speed) and thus "soften the push back" ... also larger diameter wheels will mean a bigger bump is needed to do the same.

Basically what this means for me is that I get better at observing and avoiding bumps and all goes well. I notice this is mainly on uneven concrete pavement, where sections join and one raises and or the other sinks.

Best Wishes

Unknown said...

Yeah, maybe it has something to do with that.
I didn't however notice that at all on my m365 which had solid tires as well, and the neither on my Joyer F5S which have a solid back tire.

No one else has been writing about it in forums and Reddit, so hoped maybe it was a kind of defect that was fixable.

obakesan said...

firstly I thought the m365 had pneumatic tyres, and secondly (and of importance) I'm talking strictly about the front tyre (did you go look at that image?)

Unknown said...

Yes, I did look at it, and can see what you mean.

I have replaced the original tires on my m365 with solid tires both front and back, but on my Joyer only the back tire is solid, so that doesn't really count.

But like you, I only really notice it in full speed, so your theory might be correct.

Unknown said...

My ww pro refused to switch on after being on charge.switches straight off.did i overcharge it?

obakesan said...

Hi Unknown

its impossible to "over charge" ... that's what the BMS inside the battery takes care of. I'd measure the voltage at the charge point of the scooter and see what that is, knowing that will help with the process of diagnosis of the problem.

The problem as stated is not related to charging, but knowing the voltage will be the first "next thing" to investigate.

Given there is zero additional information here I can't really say more

Best Wishes

fred said...

Hi
Excellent technical review of the Mercane wide wheel pro thank you.
Im currently rebuilding my wide wheel pro and am in need of assistance pls.
The Back section has broken off where the back curve section starts which holds the back led. No mudguard is present either - the Back wheel assembly inc connecting rod and brake assembly inc disc pad is missing as well as the back suspension arms.
Everything else is intact and looks ok. I noticed some wires pulled out of the controller the wire colours are blue and white.
Im capable of fixing the controller and reattaching the loom (or replacing if need b)
I would like to post some photos of the damage and get assistance with helping me to rebuild if this would b possible and acceptable. I presume the battery and controllers also front display box are also ok.
because these pieces were not present and removed by me any detailed photos of the back section would b highly appreciated.
If anyone has some advice would also b appreciated
Thank you all fro your time

obakesan said...

Hi Fred

>The Back section has broken off where the back curve section starts which holds the back led.

ok, that's probably come from standing too far back on it ... sadly (assuming its what I am thinking it is that's broken) you just can't repair it easily because cast alloy isn't possible to repair. Best you can do is use some two part Metal Weld epoxy and repair it and brace it as best you can.

Are you rebuilding one you bought used?

Need some pictures and I'm not sure what you mean about the brake caliper and am worried about what you mean with the back arms are missing.

Grozdanovd said...

Hi IV got a mercane wide wheel pro 2019 error code 5 now,and nothing works.Saw it can be communications error but which communication?

obakesan said...

Hi Groz

well as you see I don't have the Pro (which I recall was 2020) but I'm willing to bet its one of the motor plugs coming loose (or worse). My advice is plug and unplug both motors, make sure they are firmly plugged in, watch how far the plug moves in when doing it.

James T. Heires, PMP said...

Anyone have a wiring diagram for a 2019(?) widewheel dual motor (8.8Ah) scooter?
I am helping a friend rebuild his scooter that has been hacked to pieces.
There are cut wires, missing connectors, and maybe a missing controller (I have only one).
The controller has just one heavy-duty connector which I think goes to the battery, which has two identical mating connectors. That's why I feel there is a missing controller.
Too many questions for a post, but suffice it to say this scooter needs major surgery.

obakesan said...

James, if it has 2 motors then it has 2 controllers.

Sorry about the wiring diagram but the Y junction from the throttle should split to each controller.

James T. Heires, PMP said...

OK - I am still working on the WideWheel dual motor, and have most of the parts, but have 2 questions remaining.
1. I don't see where the "ignition" wire is supposed to connect. it has 2 "barrel" type push on connectors (blue, yellow wires) and one 3-wire snap-on connector (red, black, green wires).
Thanks, #obakesan, but there are no mating connectors on the controllers, battery or dash panel. The provided wire is long enough to reach the back wheel, if routed through the steering column. Perhaps I have the incorrect controllers?
2. I haven't been able to source the wire coming from the front wheel/steering column connector to the front wheel controller. Mine has been cut off, and I don't even see a connector available online, which I could solder into place, in a pinch.
Thanks in advance,
James

obakesan said...

Hi James
can't help you with #1 as I've not pulled mine down at that level, but I thought it just worked to isolate the power. I've not looked specifically but I'm pretty sure it plugs into the small board at the top of the stem.
#2 the wire for the front wheel is exactly a standard. This ebay item shows what you need (that's the male) which should come from the motor. https://www.ebay.com.au/itm/265599342524

James T. Heires, PMP said...

#obakesan,
Thanks a million! The eBay item is what I have been looking for on #2. My #1 question I feel has been answered by another search for a Mercane Wide Wheel throttle. The one I have (after-market twist style) has the wrong connector and WAY too much cable. The original goes into the small board as you describe. So, I will need to order 2 more parts to get my scooter on the road.
James