Doctorbass
100 GW
madin88 said:thank you master
if i calculate with 1,82mm height it would be 7,28mm² for the bar.. maybe a typo somewhere?
Thanks.. info corrected!
Doctorbass 2WD ADAPTTO / NYX / MXUS 32kW 105 pounds
- Thread starter Doctorbass
- Start date
Thanks.. info corrected!
John in CR
100 TW
Doctorbass said:
Please do explain how the "holes in a pizza pan" approach to ventilation creates a flow of fresh air through a motor. Once you can explain the flow, the next step is to quantify. Start with the specific heat of air, then include the expected temperature increase from ambient air drawn in to the air exhausted, and multiply by the flow rate required to remove say 1kw of heat, a fairly easy to create quantity of heat. Sorry I'm not going to serve it up on a silver platter, because that doesn't work. Moving heat requires at least some basic research, and once armed with the physics, then more people can increase the knowledge base instead of blindly copying what barely works.
I maintain that it is both foolish and unnecessary to make large holes in hubmotor covers, and I run my primary ride at 27kw peak input into a ventilated hubbie that only twice in 2 years has exceeded 100°C at the stator. A higher efficiency motor is only part of the equation. FWIW nothing larger than 1-2mm can possibly enter my motor, and the overall shell structure isn't weakened in any meaningful way unlike the all too common and barely effective (as proven by Justin's thorough tests) large hole approach.
While Doc gets his ebike ready for the quarter mile and top speed runs, let's at least make the discussion interesting from a physics standpoint instead of the direction the quoted posts suggest.
John
Doctorbass
100 GW
John in CR said:
John I like your point,.. But dont forget that the air in these holes will flow not only by convection or centrifugeal but also with the speed of the bikeThe holes are facing the radial side too not only axial. So the air that arrive at the same speed of the bike will enter thru these holes on the radial side.
But for a 10-15 sec run a motor that stand at 25 degree C ambiant and get like 1500W of heat during this time does not represent alot of temperature increase....
Doc
if i look at the covers i cannot see anything wrong. if the motor spins, the air will flow into through the round holes near the axle, over the windigns and through the outer holes out of the motor. works like a radial fan and with the outer holes as far as possible outside it is optimal. additionally the entire inside is painted which should lower thermal resistance of core to shell about 20% (source: justins tests)
only one word: fantastic job doc!! okey, that was two words :lol:
you have right john that you can improve things everywhere, but i personally would not want to have that large radial propeller blades you have mounted to the covers. it for sure will keep the motor cooler and also adding more surface area, but it looks not really good
and it could be dangerous if you get in contact with the blades when the motor spinns.. the thing with only small debris can enter the motor is great. i like that.
only one word: fantastic job doc!! okey, that was two words :lol:
you have right john that you can improve things everywhere, but i personally would not want to have that large radial propeller blades you have mounted to the covers. it for sure will keep the motor cooler and also adding more surface area, but it looks not really good
and it could be dangerous if you get in contact with the blades when the motor spinns.. the thing with only small debris can enter the motor is great. i like that.John in CR
100 TW
Doc, by that logic it doesn't need any ventilation at all. Of course you'll use it for more than the drag run.
Madin88, the discussion isn't about my approach, but your argument is on par with a fear of running a wheel with spokes, since you could hurt yourself sticking your fingers in the wheel while it's spinning. My point is that people should stop encouraging others to copy what Justin has already proven to be ineffective at moving air. Claiming otherwise is silly. You guys are so innovative in every other area, why remain stuck hardly moving from Steveo's pioneering 5 years ago? I realize fluid dynamics and thermo-dynamics can be daunting, but defining the problem requires only elementary school math...multiplication and division. Our single biggest performance limitation demands more than wishful thinking.
Madin88, the discussion isn't about my approach, but your argument is on par with a fear of running a wheel with spokes, since you could hurt yourself sticking your fingers in the wheel while it's spinning. My point is that people should stop encouraging others to copy what Justin has already proven to be ineffective at moving air. Claiming otherwise is silly. You guys are so innovative in every other area, why remain stuck hardly moving from Steveo's pioneering 5 years ago? I realize fluid dynamics and thermo-dynamics can be daunting, but defining the problem requires only elementary school math...multiplication and division. Our single biggest performance limitation demands more than wishful thinking.
After looking at Justins experiments with ferrofluid Ill be heading down this path, keeping the motor sealed and providing effective cooling. Id still be interested to see what that combination would be like with a heatsink too. Now to find a heatsink in a ring shape.
jansevr
1 kW
macribs, here's a picture of John's motor
John in CR
100 TW
madin88 said:this motor has the rim attached to the case thats even better for heat emission. have you put thermal paste between when mouting it?
True, but it would require that the shell get reasonably hot to make enough difference for those kinds of efforts to be worthwhile, but I get such good air flow to reject the heat directly from the stator to the environment that I haven't considered further mods other than a few tweaks for the next. I'm not going to discuss it in Doc's 2wd NYX thread though.
steveo
100 kW
Hey Doc,
Have you opened the 14kw Adaptto you got?
I'm wondering what the differences are compared to the 10kw version? I believe the 10kw is a 18 fet, is the 14kw a 24 fet? Does it use the same IRFP4468 to-247 package mosfets?
thanks
-steveo
Have you opened the 14kw Adaptto you got?
I'm wondering what the differences are compared to the 10kw version? I believe the 10kw is a 18 fet, is the 14kw a 24 fet? Does it use the same IRFP4468 to-247 package mosfets?
thanks
-steveo
Allex
100 MW
New vs old.
Old is the one with screws on the alu heatsink
http://stokgolm.myftp.org/Share/
Old is the one with screws on the alu heatsink
http://stokgolm.myftp.org/Share/
steveo
100 kW
Allex said:
its looks identical to the old other then the caps changed... basically a relabled 10kw to 14kw.. im guessing the big changes could be in the power programming limits of the software
-steveo
Allex
100 MW
Caps are the same. You have to look closer to see the diff.
You can program the power limits yourself til you go blue the software does not limit this.
You can program the power limits yourself til you go blue
the software does not limit this.
steveo
100 kW
Allex said:Caps are the same. You have to look closer to see the diff.
You can program the power limits yourself til you go blue
you could almost make a game of comparing the two.. i noticed...
all changes are on the mosfet/capacitor board...
different 100v caps (maybe simple different band)
tiny little surface mount resistors near the mosfets (i assume they where added to prevent damage to the pcb/driver board in the event of a mosfet blow out)
I also noticed in one of the pics that there is a random tiny white wire running between the mosfet board / driver board
And i notice also a little i think .. jumper added on the mosfet pcb
small changes overall.. I'm sure its for good reason to ensure is survives at 14kw power limit...
will the 14kw firmware work on the 10kw controller ? I'm guessing it would because the driver boards look identical
-steveo
Ohbse
10 kW
Apparently the biggest changes took place in the gate drivers which I believe are the 3 smaller daughter boards. Brain PCB appears to be the same, so probably just a more robust power stage.
These controllers definitely are capable of 14kw and potentially much more with some modifications. My Mini-e is running 7kw and that's a 6 fet! With an additional heatsink the mini-e is more than enough to smoke my Cromotor. This morning got the motor to 110c and controller was 32c after a fast 20km commute.
These controllers definitely are capable of 14kw and potentially much more with some modifications. My Mini-e is running 7kw and that's a 6 fet! With an additional heatsink the mini-e is more than enough to smoke my Cromotor. This morning got the motor to 110c and controller was 32c after a fast 20km commute.
steveo
100 kW
Hey Alex
do you have any photos of the "daughter" boards old vs new ?
thanks
-steveo
do you have any photos of the "daughter" boards old vs new ?
thanks
-steveo
Allex
100 MW
Hm, which one is that? I still have them cracked up so I can post pictures.
steveo
100 kW
Allex said:
those 3 tiny "daugher" boards that are near the mosfets. they are standing up vertically off the mosfet pcb.
they are on the same side as all the capacitors, maybe you could sneak a couple good shots even though the caps are a bit in the way...
hope this helps
thanks
Allex
100 MW
Old on top:
http://stokgolm.myftp.org/Share/DSC06169.JPG
Old:
http://stokgolm.myftp.org/Share/DSC06175.JPG
New:
http://stokgolm.myftp.org/Share/DSC06171.JPG
http://stokgolm.myftp.org/Share/DSC06169.JPG
Old:
http://stokgolm.myftp.org/Share/DSC06175.JPG
New:
http://stokgolm.myftp.org/Share/DSC06171.JPG
Mr.Gen.44 said:
I think you have "bicycle" confused with "motorcycle".
Instead of soliciting personal help, which many people rarely have time/inclination for, I highly recommend you create yourself a single project thread here:
https://endless-sphere.com/forums/viewforum.php?f=10
and post your budget, needs, terrain, conditions, constraints, etc there, so you can get help from the forum.
Also, I don't recommend publishing your personal contact info on a public forum, unless you don't care what kind of stuff gets sent to you (spammers and others commonly harvest such public information).
jakequicksilver9
10 W
hi Doc, don't know if you named your bike yet or not but if not may I suggest Double Treble 
r3volved
100 kW
lol
Doctorbass and his double treble
Doctorbass and his double treble
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