Golden Motor, HPM 3kW non-hub w/air-cooling

[liveforphysics]

I will share my experiences running both the 5kW version and 10kW version, with lots of dyno tuning and real-world racing experience with both.

Pros:
Quite durable for things with short bursts of power, followed by long periods of cooling off. Mechanically the bearing/shaft setup is pretty robust. Never lost a magnet on one, even when they were hot enough to be making all sorts of foul smells. When they become plasma, neither one locked the rotor up, which is a nice safety benefit.

Cons:
They have pretty bad efficiency and make a ton of heat as a result. They saturate pretty quickly when you start pumping serious phase current into them. They have an abysmal thermal path to get the heat out, you can have the windings so hot the varnish is off-gassing, and the heat-sink fins on the case are room temperature, so all the heat sinking fins you see are just dead weight in my experience, because they don't have an adequate connection to the parts that get warm.

 

[K-ray]

Hey Thanks for that Luke!

Curious as to their KW potential vs their rated size... within reasonable temps?
And also... I've heard their liquid cooled models suffering from a poor design as well...
Do you have any insight there or suggestions on how either design could be improved?
I know you is the "Thermal Man" 8)
Appreciated

 

[teklektik]

They have an abysmal thermal path to get the heat out, ... all the heat sinking fins you see are just dead weight in my experience, because they don't have an adequate connection to the parts that get warm.

I've heard their liquid cooled models suffering from a poor design as well...

A quick look at the drawings seems to show a single basic case fabrication with different side covers to accommodate the different cooling techniques. With a poor interior thermal path to the case, the side cover cooling method isn't going to make much difference. Since motor rating is tied to the steady-state heat dissipation and the two models have the same rating, it appears that the liquid cooling doesn't really do a spectacularly better job and is primarily useful in enclosed mounting situations.

 

[speedmd]

I will share my experiences running both the 5kW version and 10kW version

Luke, do you see any improvements in the 3k motor to note from the little info they are posting. 90% is relatively high efficiency for typical ebike stuff but the axial setup has me worried on it's heat shedding ability. Do you think the thermal path can be improved/ super conducting paste added. What do you think of the mating controller? Attractive price, for a run around bike and may be worth a try.


Teklektik, thanks, thought you were using the .ca simulator some how with the data. Not sure how the 3k would compare.

 

[K-ray]

As per liquid thermal control design... Ah yes of course :lol: Thanks T.
What about covering the vent holes outside the fan requiring the flow to come from within creating vents on both case sides?
Anyone know if the design allows an air path that would be proper for cooling? One could have an air filter on the intake side
to keep things clean...?

 

[teklektik]

Here's the 10kW data.

View attachment 1

The 'rated' rpms don't really seem to make much sense and the dyno really wasn't run down to very much lower rpms to see what happens under heavy load...

'Interesting data' for each voltage is on the 'rpm vertical' defined by the intersection of the 10kW power level and the 'Motor Power' curve (e.g. about 3500rpm, 3875rpm, 4050rpm). These verticals show the Battery Power/Waste Power/Efficiency at the 10kW power level for each voltage...

Tabular data:

 

[liveforphysics]

That is a kinda fishy looking graph. Also it seems they have much worse copper fill on the 96v version if I'm seeing that correctly?

 

[speedmd]

Was thinking that also. Looks like they left off the lower rpms from the data for some reason. The 72 volt looks better to me except for the higher end dropping off sooner. Most likely wound a extra turn or so which would explain the efficiency improvement. It is powerful, some 11.5kw at 3800rpm /88% eff. The 96v version looks to be headed for a melt down a bit below 3900 rpm. The 72V rated torque is 3500 rpm and the 96V at 3700 rpm, neither of which is shown in the data.

Look forward to what they show us on the 3KW version.

 

[liveforphysics]

Number of turns doesn't effect efficiency/performance/etc if you are also changing the input current proportionally (if you get the same amount of copper in each slot).

 

[speedmd]

Was assuming they were getting more fill on the 72v motor. Wire diameter / turns may make the fill on the 96V a bit less. Do not have a feel what they are up against. What voltage / winding's were you running?

 

[Sean9002]

Want to try one in a LMX frame

I have been thinking the same for my Oset 20 mod frame.

I'm happy to get one with a controller for my Oset to see how breakable they are..... if someone can direct me to a #219 motor sprocket that I can use =)
If I've measured everything correctly it will fit, I just need to make sure the sprocket has clearance.

 

[stonezone]

yeah, i'd also like to throw one in my 24" oset... I was wondering the exact same thing about the sprocket. I actually have the 72v and controller already in a shopping cart for a few days... haha

 

[speedmd]

Has Golden given any more information to anyone on the 3KW motor or controller. Must be at the bike shows.

 

[stonezone]

Well i ordered the 72v air-cooled one with their sin controller. I'll report back after I test it. What pack configuration would you recommend (series of 5s, 6s?) and how much mAh you think would be reasonable to get a good 2 hours of riding out of it.

Bike will be similar to the LMX frame with mtn bike components.

 

[speedmd]

Sounds great! Mileage may vary . My guess is that any of the good 30 amp rated bricks should keep from sagging much in a 18s2p setup. If I have room I will try six of these, mainly because I have them already. http://www.hobbyking.com/hobbyking/store/__16228__ZIPPY_Flightmax_8000mAh_6S1P_30C_.html Unless your light on the throttle it most likely will not last anywhere near two hours. You may need 9 or 12 of them. 18s3p or 18s 4p to run two hours. For more power and even less time 6 of these in 18s2p http://www.hobbyking.com/hobbyking/...avy_Duty_Series_5000mAh_6S_60C_Lipo_Pack.html You start getting into a very heavy pack in a hurry with these big bricks.

 

[stonezone]

right now i have 12 of the 6s 5000mAh packs running 12s6p for my Oset. figure I'll break it up but probably add more since i want max range (no pedals).... pricing out a new pack looks like it will run upwards of 1k but still that's a hell of a lot cheaper than what you pay for gas over a 6 month period on a regular moto...

right now my batteries are only 20C... will the 30c (or even 60C) make a huge difference? I'm not sure how much juice my controller is pulling as they discharge.

Also, how about running 20s with 5s packs to up the voltage just a little bit? regardless i'll need to split the packs to charge them on my hyperion since it only maxes out at 14s.

 

[spinningmagnets]

The parallel strings you add will add to the current capability. Since you have a 6P set-up, and since the 20C-rated packs are probably comfortable at half that (10C), then...a 6P pack "should be" fairly capable of 60A of constant current without any problems, and maybe 50% more (90A?) as a temporary peak.

I haven't done this, so it's just speculation on my part...based on reading others' results...

I think a lot can be discovered by data logging, and comparing the voltage sag you get...

 

[stonezone]

What would the advantages/disadvantages be whether running 20s or 18s for the 72volt motor (besides obviously the price).

I don't know what the LVC will be on the controller so maybe the 18s would drop below that?.... on the same note, maybe the 20s would overpower the controller after a peak charge. I said screw it and ordered the sin wave controller from GM, so hopefully it's decent and configurable enough.

Either way, it's going to be a huge chunk of cash to build a big enough pack, then I'll have to figure out a clean way to split it for charging.

Also, what's the deal with putting a drive sprocket on that motor? I don't even know what it comes with, haha.

SZ

 

[speedmd]

Best to know the exact battery to better judge what to expect. This 20c http://www.hobbyking.com/hobbyking/store/__9176__Turnigy_5000mAh_6S_20C_Lipo_Pack.html they claim can put out 20 amps continuous and 30 amps for max 10 seconds bursts. You will be running four parallel strings of three bricks in series that should be able to dump out (4x30)120 amps for 10 second bursts. At 75 volts (18s), it should be good for 9kw briefly if my math is correct. Controller is pulling max of 100 amps at 72 volts going by the sheet. Most of the good folks here using this kind of power can tell you better what to really expect to get from the exact battery if they have experience with them. My Zippy 6s 8ah can dump a bunch of current when asked to and no where as much as the ones Luke is using on his death bike.

 

[stonezone]

per recommendation above for the 6s i was going for the 8000mAh
http://www.hobbyking.com/hobbyking/store/%5F%5F20837%5F%5FZIPPY%5FFlightmax%5F8000mAh%5F5S1P%5F30C%5FUSA%5FWarehouse%5F.html

for the 5s the same 8000mAh
http://www.hobbyking.com/hobbyking/store/%5F%5F20837%5F%5FZIPPY%5FFlightmax%5F8000mAh%5F5S1P%5F30C%5FUSA%5FWarehouse%5F.html

both are 30c, just the diff is the peak and minimum voltage with the 2s difference. I'll probably want to run 4p unless I can afford more...

 

[speedmd]

Personally I would go with the 18s3p using the 6s bricks just to make it less complex and smaller with 9 bricks total and see how it goes. I have been using the 6s 8mah lately in 12s1p and 18s1p configuration and they work very well and it saves a bunch of weight off the bike that I notice much more than the extra capacity that 2p gives. My motors and controllers are much smaller however. Would be great if they supplied more data. Not sure what if anything would go sour in a 20s setup.

 

[stonezone]

well I got my box from golden motor today with everything except the 72V/3000W BLDC Motor with Fan Cooling..... I hope they sort it out because I've been jonzing for this thing hard! They did send the magic pie4 so i still get to play.


Edit: got a reply pretty quick.. they were low on stock so it's taking a few extra days to ship. No worries because i haven even started on the frame yet. the sin wave controller for it looks pretty amazing and well built. very large heat sync and surprisingly heavy...

 

[stonezone]

motor arrived ok, the thing looks mean! It's got a 20mm notched shaft. how are most everyone attaching the front sprockets?

I haven't decided but was thinking something like this will/may fit but i'm not sure where the slot is:
http://www.globalindustrial.com/p/motors/sprockets/finished-bore-sprockets/sprocket-06bs18hx20-metric-38-pitch-20mm-finished-bore-18-teeth

#35 or #420 chain... dunno...

 

[speedmd]

It's got a 20mm notched shaft.

Fun Time! Does it have a key way shaft? Internal Spline? Threaded hole in the end? I see a bunch of different ones shown.

 

[stonezone]

it's got a really fat key shaft....