binlagin
100 W
I'd say we are somewhere between the fighter and the bomber!
Keyne's DH Comp Build - now with liquid cooled HX35! :)
- Thread starter keyne
- Start date
crusoe
100 W
Hey Keyne, how goes the
I need something similar!
I need something similar!
keyne
100 W
The scissor lift works ok, but I might redesign it some day, it's just not wide enough to be completely stable.
I've been gearing up to do some efficiency tests to see how much more range I get because of the cooled motor - it could be quite a bit!
I've been gearing up to do some efficiency tests to see how much more range I get because of the cooled motor - it could be quite a bit!
Stielz
100 W
Really nice build Keyne, keep up the good work!
How does your controller hold up to a bit of thrashing?
Just an idea, have you thought about liquid cooling your controller also? You've got all the hardware there, all you would need to do is make a channel through the FET heat sink and run the cooling liquid through in series with the motor. Then you could up the current limit and possibly push a few more kW through your system
How does your controller hold up to a bit of thrashing?
Just an idea, have you thought about liquid cooling your controller also? You've got all the hardware there, all you would need to do is make a channel through the FET heat sink and run the cooling liquid through in series with the motor. Then you could up the current limit and possibly push a few more kW through your system
keyne
100 W
The controller temperature has never gone over about 55C, but yes, liquid cooling my controller is on my list, mainly so it doesn't have to be an external component on the bike.
megacycle
100 kW
I was thinking to put a copper jacket over the fins on the side of the controller were the fets are bolted, the fins then making the coolant channels ( no pulling the controller apart 
)or burst fire freeze spray with a hydrocarbon propellant and piezo igniter for afterburn and faster heat draw, for 
buyouts :lol: .
)or burst fire freeze spray with a hydrocarbon propellant and piezo igniter for afterburn and faster heat draw, for buyouts :lol: .
liveforphysics
100 TW
Nice job! I've seen a couple water cooling hubmotor attempts before this one that looked like they would be less effective than simply drilling the covers or adding oil, but this one is exceptional in how you bonded the outer layer of water jacketing in a location that can absorb some stator heat effectively.
My favorite way to know if a cooling system is working is to simply watch the delta between water into the radiator and water out of the radiator. If you know the flow rate, and you know the delta, you know it's ~4.2J/gram of water raised 1 deg C. A Joule is a watt-second of energy.
So, just as an example calculation if you measure your flow rate at say 100L/hr through the cooling loop, and you observe a peak delta-T you can hold across the radiator continuously of say 10degC difference between inlet and outlet temps, then you know the rate your system can shed heat.
Crude calculation example would be something like 4.2KJ/Kg*100L*10degC = 4200KJ/hr of heat transfer, which is ~1.1Kwh of thermal energy transfer per hour capability. If you were operating the motor at a point where it was say 80% efficient, this would enable it to handle 5-6kw of input power continuously. That would make it better than any air or oil cooling alone setups to the best of my knowledge, but of course these are just make-up guess numbers just to show how to do the math. For the numbers to mean something you will need to take real data from your setup of course.
Great job!
My favorite way to know if a cooling system is working is to simply watch the delta between water into the radiator and water out of the radiator. If you know the flow rate, and you know the delta, you know it's ~4.2J/gram of water raised 1 deg C. A Joule is a watt-second of energy.
So, just as an example calculation if you measure your flow rate at say 100L/hr through the cooling loop, and you observe a peak delta-T you can hold across the radiator continuously of say 10degC difference between inlet and outlet temps, then you know the rate your system can shed heat.
Crude calculation example would be something like 4.2KJ/Kg*100L*10degC = 4200KJ/hr of heat transfer, which is ~1.1Kwh of thermal energy transfer per hour capability. If you were operating the motor at a point where it was say 80% efficient, this would enable it to handle 5-6kw of input power continuously. That would make it better than any air or oil cooling alone setups to the best of my knowledge, but of course these are just make-up guess numbers just to show how to do the math. For the numbers to mean something you will need to take real data from your setup of course.
Great job!
keyne
100 W
Thanks Luke,
It's been a while since I've posted here, also a while since I've ridden the bike. (Damn PhD getting in the way :? )
The best cooling numbers I saw were about 700W (8deg drop, 1.2L flow). Done by measuring temp difference between entry and exit of the motor (to include heat loss from the tubing). This was however before adding the themal epoxy to the windings and the motor definitely cools even better now (I was seeing up to 25degC delta T between coolant and windings, this has dropped to 15degC max), I just haven't formally measured it since the change - I should probably do that. I wouldn't be surprised if I'm getting 1kW of cooling now.
I doubt my bike ever gets ridden for long at the 80% efficiency point, but then on my trails there's no way to keep 6kW on for long either!
Oh yeah, just to make it go faster I've added blue flames to the side panels
It's been a while since I've posted here, also a while since I've ridden the bike. (Damn PhD getting in the way :? )
The best cooling numbers I saw were about 700W (8deg drop, 1.2L flow). Done by measuring temp difference between entry and exit of the motor (to include heat loss from the tubing). This was however before adding the themal epoxy to the windings and the motor definitely cools even better now (I was seeing up to 25degC delta T between coolant and windings, this has dropped to 15degC max), I just haven't formally measured it since the change - I should probably do that. I wouldn't be surprised if I'm getting 1kW of cooling now.
I doubt my bike ever gets ridden for long at the 80% efficiency point, but then on my trails there's no way to keep 6kW on for long either!
Oh yeah, just to make it go faster I've added blue flames to the side panels
Obiwan007
1 kW
Lets see a picture of those flames. I am keenly interested in your build here as I am starting my second and am doing it on a DH Team frame. Did you ultimately use those 3" tires? How have you liked them? Any problems width wise for getting them in the frame? I used 3" tires on my first build http://www.endless-sphere.com/forums/viewtopic.php?t=46942 but that was on a symmetrical swing arm arrangement. My DH team has the non-centered drop-outs but I still want to go with a fat tire style like yours and my previous one. I am planning on going with bicycle tires and wheels this time and am concerned about the height of that tire. How tall does it stand above the edge of the rim?
Tim
Tim
macribs
10 MW
- Joined
- Jul 22, 2014
- Messages
- 3,702
Wow. This is some amazing work. Sorry for firing up this thread again but I just have to say your bike is radical Keyne.
Did you do anything else to your hub motor? You mentioned some liquid inside the hub to better the cooling.
Only thing I miss on your build is wheelie sensor/balancing point sensor that can take control over the throttle control, maybe for DH v 2.0?
I've been lusting for an electric bike with a wheelie mode ever since I saw the video of the Audi e-bike. :lol: :lol:
Is there any one that now sells pre modified hub motors? With reduced weight and carbon fiber covers along with cooling pipes? Or maybe someone that sells modified geared hub motors that is fitted with internal piping for cooling liquid and is ready to bolt on?
Did you do anything else to your hub motor? You mentioned some liquid inside the hub to better the cooling.
Only thing I miss on your build is wheelie sensor/balancing point sensor that can take control over the throttle control, maybe for DH v 2.0?
I've been lusting for an electric bike with a wheelie mode ever since I saw the video of the Audi e-bike. :lol:
:lol: Is there any one that now sells pre modified hub motors? With reduced weight and carbon fiber covers along with cooling pipes? Or maybe someone that sells modified geared hub motors that is fitted with internal piping for cooling liquid and is ready to bolt on?
keyne
100 W
Clearly I've been away from this hobby for a long time, hoping to get back into it.
Does anyone know if there is now a good high current SMART BMS available at a sensible price? That was my main problem with the original build, I want to know I can't kill my pack or even a cell group even if I let a friend use/abuse it, cycle analyst pack voltage isn't sufficient, I want to know each individual series cell is ok. Any suggestions?
Does anyone know if there is now a good high current SMART BMS available at a sensible price? That was my main problem with the original build, I want to know I can't kill my pack or even a cell group even if I let a friend use/abuse it, cycle analyst pack voltage isn't sufficient, I want to know each individual series cell is ok. Any suggestions?
multifrag
100 W
keyne said:
Adaptto have bms http://adaptto.com/Products/BMS/ system which might suit you. It connects directly to the controller http://adaptto.com/Products/Controllers/ and you can see individual series.
DasDouble
100 kW
yeah I know.. a little old thread but...: subscribed 
torker
100 kW
Looks like you got away for a while too.. I just got back into this after 3 yrs or so.. Now we have liquid cooling, sine wave controllers my my lol
I just got back into this after 3 yrs or so.. Now we have liquid cooling, sine wave controllers my my lol