## Search found 978 matches

Mar 09 2011 5:05pm
Forum: E-Bike Technical
Topic: Brakes on Electric MTB's - A Lesson Learned
Replies: 26
Views: 1813

### Re: Brakes on Electric MTB's - A Lesson Learned

Use regen; problem solved =).
Mar 09 2011 4:55pm
Forum: Motor Technology
Topic: 12 kw rc motor
Replies: 1876
Views: 236790

### Re: 12 kw rc motor

holy...! Nice!

Alright, so hmm, would an infinion 36 fet at 140ish volts reach the e-rpm limit with the stock windings?
Mar 09 2011 2:35pm
Forum: Motor Technology
Topic: 12 kw rc motor
Replies: 1876
Views: 236790

### Re: 12 kw rc motor

lol how fast can the new version spin?
Mar 09 2011 12:51pm
Forum: Motor Technology
Topic: 12 kw rc motor
Replies: 1876
Views: 236790

### Re: 12 kw rc motor

Ahh hrmm, so I guess there is just one stock winding, and i'd have to re-wind the motor for my rpm needs?

What is stock wound for K/V wise?

So really you can't go higher than 7,500 rpm? hmm alright... is it just that one bearing stopping it?
Mar 08 2011 10:11pm
Forum: Motor Technology
Topic: 12 kw rc motor
Replies: 1876
Views: 236790

### Re: 12 kw rc motor

Hmm i will be extremely careful with that Biff! Thanks for your experience.

Does anyone know what the practical voltage limit these can be run from is? I was wanting to use 36s... Will that just kill efficiency/destroy bearings?
Mar 08 2011 12:53pm
Forum: Motor Technology
Topic: 12 kw rc motor
Replies: 1876
Views: 236790

### Re: 12 kw rc motor

Well, technically they are the different sets of windings electrically. Physically, they would lay in the exact same slots, with the same number of turns, they would just be split in two. So each controller would see a winding with 2x the resistance of normal (making it much easier to drive hopefull...
Mar 08 2011 7:30am
Forum: Motor Technology
Topic: 12 kw rc motor
Replies: 1876
Views: 236790

### Re: 12 kw rc motor

Even if I split the windings into two parallel sets of equal wire counts? That would still need three controllers to work? How were you planning on splitting the windings up for multiple controllers?
Mar 07 2011 3:47pm
Forum: Motor Technology
Topic: 12 kw rc motor
Replies: 1876
Views: 236790

### Re: 12 kw rc motor

Blah! Damn, that is really nice Splinter... I was not really following this for a while, but noticed that there was progress since the initial no-load testing and bearing issues, etc... Hrmm, I was going to use the ME0913 for my ninja 250 conversion (using 2 separate 36 fet 4115 controllers for each...
Mar 07 2011 3:33pm
Forum: E-Bike Technical
Topic: Doc EXTREME 36 FETS controller
Replies: 177
Views: 25239

### Re: Doc EXTREME 36 FETS controller

Doc, even with the water cooling setup i'm going for, I still plan on putting a blower in the case of each controller. There is no reason to have 0 airflow, even if your fets are kept perfectly happy there are other components that will have at least a bit of heat buildup (shunt, caps, traces if not...
Mar 04 2011 10:53am
Forum: E-Bike Technical
Topic: Doc EXTREME 36 FETS controller
Replies: 177
Views: 25239

### Re: Doc EXTREME 36 FETS controller

Hmm, I see where the extra complication of using the aluminium case is coming into play. I have some abs project boxes for my controllers, so I have plenty of extra room in the case, as well as I don't have to worry about having electrical isolation from the case. I may not get the added benefit of ...
Mar 03 2011 5:36pm
Forum: E-Bike Technical
Topic: Doc EXTREME 36 FETS controller
Replies: 177
Views: 25239

### Re: Doc EXTREME 36 FETS controller

Yay Doc! So you are gonna use screws instead of solder?

I guess we will see which way turns out better in the end =)! By the way, in case it wasn't clear in my thread, I am building two controllers as well, I am just building them at the same time identically. I think the copper was a good idea.
Mar 02 2011 4:22pm
Forum: E-Bike Technical
Topic: Best electrically conductive thermal paste ?
Replies: 37
Views: 3885

### Re: Best electrically conductive thermal paste ?

That is a good question... I know I got some leaded 63/37 solder paste to try it with, so it should have a melting point of only 187c... Much below the 300c for 10 sec stated. What is the temp they will start to see damage though?
Mar 02 2011 3:11pm
Forum: E-Bike Technical
Topic: Best electrically conductive thermal paste ?
Replies: 37
Views: 3885

### Re: Best electrically conductive thermal paste ?

Doc, I really wouldn't worry too much about the weight on these things... if copper even allows you an extra few hundred watts because of better cooling, it would probably be worth it over the 1/2lb you may save with just aluminium. It's not like the controllers are a major source of the total weigh...
Mar 01 2011 5:43pm
Forum: E-Bike Technical
Topic: Best electrically conductive thermal paste ?
Replies: 37
Views: 3885

### Re: Best electrically conductive thermal paste ?

Doc, if you look at how I am planning to do my controller, you can use the heat sink on the high side for current sharing too. You just then need to insulate the three high side heat sinks from each other electrically.

Not very hard to do.
Mar 01 2011 4:30pm
Forum: E-Bike Technical
Topic: Best electrically conductive thermal paste ?
Replies: 37
Views: 3885

### Re: Best electrically conductive thermal paste ?

I just bought some of this: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230590572344#ht_1995wt_905 So I think that I need to get some higher temp solder for the tubing, so that when I heat up the bars with the tubing already soldered to it for the fets, it doesn't detach the tubing. Any r...
Mar 01 2011 10:04am
Forum: E-Bike Technical
Topic: Best electrically conductive thermal paste ?
Replies: 37
Views: 3885

### Re: Best electrically conductive thermal paste ?

Well I got one of my messed up pieces of copper stock, and an old crappy fet that I tore out of a controller, my butane soldering iron (turned into a torch) and got to work. I just wanted to see how easy it was. I just used my normal radioshack solder that was sitting in a pool of flux on the copper...
Feb 28 2011 6:53pm
Forum: E-Bike Technical
Topic: Doc EXTREME 36 FETS controller
Replies: 177
Views: 25239

### Re: Doc EXTREME 36 FETS controller

Hey Doc, I love to see your efforts! I have been working on my own water cooling design for my 36 fet controllers as well. I like the way you are going about it a little better, but I might as well give my way a shot at this point since I'm already partially done :p. If you want, take a look at the...
Feb 28 2011 5:16pm
Forum: E-Bike Technical
Topic: Best electrically conductive thermal paste ?
Replies: 37
Views: 3885

### Re: Best electrically conductive thermal paste ?

I know you can only do that where the drains are electrically connected, otherwise it will short.

See my progress here if ya want: http://www.endless-sphere.com/forums/vi ... 3&start=15
Feb 28 2011 4:56pm
Forum: E-Bike Technical
Topic: Best electrically conductive thermal paste ?
Replies: 37
Views: 3885

### Re: Best electrically conductive thermal paste ?

Hmm very cool! That looks to be a MUCH better way to do it than using the screws as I was planning... Do you see any issues with doing that if using TO-220's? That won't overheat them?
Feb 28 2011 11:19am
Forum: E-Bike Technical
Topic: Doc EXTREME 36 FETS controller
Replies: 177
Views: 25239

### Re: Doc EXTREME 36 FETS controller

Hey Doc, I love to see your efforts! I have been working on my own water cooling design for my 36 fet controllers as well. I like the way you are going about it a little better, but I might as well give my way a shot at this point since I'm already partially done :p. If you want, take a look at the ...
Feb 20 2011 12:37am
Forum: E-Bike Technical
Topic: New Open Source E-Bike/E-vehicle calculator & simulator
Replies: 172
Views: 60508

### Re: New Open Source E-Bike/E-vehicle calculator & simulator

Grrr! Well I fixed a few more things such as the graph generating correctly with the Power Needed lining up and all, and I am trying to work on having it tell you predicted quarter mile times... I am just having a hard time with the math for it =/. Anyone have any ideas? I honestly have no idea how ...
Feb 18 2011 11:02am
Forum: E-Bike Technical
Topic: New Open Source E-Bike/E-vehicle calculator & simulator
Replies: 172
Views: 60508

### Re: New Open Source E-Bike/E-vehicle calculator & simulator

Just wanted to bump this and say that i've spent the past couple days coding (without all that much to show for it honestly). I committed my changes to the svn, and I still have more work to do. I reverted the inductance code from v4, because it is not working correctly. We need to get a stable vers...
Nov 16 2010 10:38am
Forum: Motor Technology
Topic: lowering the motor rpm with Voltage ?
Replies: 17
Views: 2237

### Re: lowering the motor rpm with Voltage ?

You lose power (and a lot of it) by doing that, but yes you can.
Oct 24 2010 10:37am
Forum: Battery Technology
Topic: \$0.01 shipping from HobbyCity USA! Cheap USA LiPo!
Replies: 33
Views: 2780

### Re: \$0.01 shipping from HobbyCity USA! Cheap USA LiPo!

Yeah.. paralleling the balance leads.. But.. how do you tell when you have a bad cell once you've done that? it seems like you wouldn't be able to tell as you balance charge.. and i see how some cells could get overcharged or overdischarged that way. That means... lipo fire! I'm gonna have 20aH @ 3...
Oct 22 2010 8:18am
Forum: E-Bike Technical
Topic: Want to water cool 36 fet controller
Replies: 30
Views: 2856

### Re: Want to water cool 36 fet controller

Gah, i've been a bit busy this week... I got hit by a car while riding my bike home from work on Tuesday, and i've been dealing with insurance shit the past few days now. Current bike is a bit messed up (actually, i'm amazed at how little damage there is). Knee is all nice and cut up and bruised. Wh...