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!
madin88 said:thank you master
if i calculate with 1,82mm height it would be 7,28mm² for the bar.. maybe a typo somewhere?
Doctorbass said:Ebikebert said:Hey doc. Really excited to be seeing you push the limits of what is possible with e-bike hubs once again. I love my mxus 4t, and wanted to know how you made those sweet venting holes.
The holes on the outer diameter are CNC machined with the help of NYX guys and the round holes on the center are diy with large multidiameter drill bit
Doc
John in CR said:Doctorbass said:Ebikebert said:Hey doc. Really excited to be seeing you push the limits of what is possible with e-bike hubs once again. I love my mxus 4t, and wanted to know how you made those sweet venting holes.
The holes on the outer diameter are CNC machined with the help of NYX guys and the round holes on the center are diy with large multidiameter drill bit
Doc
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
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?
Allex said:New vs old.
Old is the one with screws on the alu heatsink
http://stokgolm.myftp.org/Share/
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 the software does not limit this.
Allex said:Hm, which one is that? I still have them cracked up so I can post pictures.
Mr.Gen.44 said:Excuse me, mr Doctorbass, I'm really willing to build my own electric bicycle, can you give me any piece of advice? I would be extremely grateful for that! My mail is (redacted)
Actually, I'm looking for high speeds, such as 130-150 kph