Search found 1710 matches

by Farfle
Jun 21 2017 11:48pm
Forum: Electric Aircraft
Topic: Farfles Electric Ultralight.
Replies: 206
Views: 36090

Farfles Electric Ultralight.

Heya all!! Started this project around the beginning of the year, and have made enough progress to post it up on the forum. Heres some stats: Airframe: Belite Ultracub Motor: salvage Zero 75-5 IPM Battery: Farasis 29AH 28S4P pack Controller salvage sevcon Gen4 Size 4 Bms: None Charger: Meanwell RSP2...
by Farfle
Jul 28 2016 11:14am
Forum: EV Business World
Topic: High end motors - priced out of existence?
Replies: 45
Views: 11443

Re: High end motors - priced out of existence?

I would be down for helping with the design. We need a 200ish kw peak motor for our racecar so that we can ditch this leaky POS remy thats on it. We have a pretty baller CNC at farasis now too, so anything is fair game.
by Farfle
Mar 25 2016 11:17pm
Forum: Motor Technology
Topic: The limits of torque production for a given weight of motor
Replies: 107
Views: 10312

Re: The limits of torque production for a given weight of mo

I have seen a high specific torque motor with magnets on both sides of the iron. Essentially replacing the yolk iron with magnets, similar to the way a two rotor single stator axial flux motor works, but with radially configured flux instead. i wonder what that would look like in FEMM.
by Farfle
Mar 25 2016 10:50pm
Forum: Motor Technology
Topic: Triple solid slot Zero 75-7
Replies: 62
Views: 10187

Re: Triple solid slot Zero 75-7

macribs wrote:
Hillhater wrote:Did this project get completed ?...shelved ?....or has it gone "black" ? :?:
Shelved maybe? I see Farfle is still active on ES just not on this very thread.
sorry guys, just busy with work stuff.
by Farfle
Dec 25 2015 12:32am
Forum: General Discussion
Topic: 4130 tubing question: Why is 5/8 x .035 so relatively cheap?
Replies: 2
Views: 351

Re: 4130 tubing question: Why is 5/8 x .035 so relatively ch

Also, aircraft spruce is expensive IMHO.
Check out onlinemetals, they like to give away free shipping and 10-20% off in their email subscription pretty often
by Farfle
Nov 19 2015 12:14pm
Forum: Battery Technology
Topic: Ultra power dense charger project.
Replies: 59
Views: 6461

Re: Ultra power dense charger project.

No idea!
by Farfle
Nov 02 2015 2:36pm
Forum: Battery Technology
Topic: Ultra power dense charger project.
Replies: 59
Views: 6461

Re: Ultra power dense charger project.

Sick! Looks awesome. 2.5kw damn... What's the input/output voltage for that? (sorry if I missed it somewhere) 220 in, ~120 out? Thanks, -Troy Right now it is just a current limiting buck, as I have not implemented the voltage feedback loop. That being said, the main drive fet and diode are SiC part...
by Farfle
Nov 02 2015 11:55am
Forum: Battery Technology
Topic: Ultra power dense charger project.
Replies: 59
Views: 6461

Re: Ultra power dense charger project.

I made some good progress! I got my boards back from OSHpark, and proceeded to do a solid 25A sustained with two burly fans into a zero cellbox. Thats 2.5KW output for a critter the size of a paperback :D LFP ordered some more fets for experimentation, So we will see what all happens here soon. (Ign...
by Farfle
Sep 24 2015 11:52am
Forum: Battery Technology
Topic: Ultra power dense charger project.
Replies: 59
Views: 6461

Re: Ultra power dense charger project.

Woot! I successfully charged a battery today! a single 18650 at .8A. Then, disaster struck when changing the shunt value to make it flow 2A http://i1281.photobucket.com/albums/a507/sirfarfle1/Mobile%20Uploads/download_20150924_094029_zps066r9i2z.jpeg The fet turnoff makes a spike on the clock pin, s...
by Farfle
Sep 22 2015 9:35am
Forum: Battery Technology
Topic: Ultra power dense charger project.
Replies: 59
Views: 6461

Re: Ultra power dense charger project.

Nuts&Volts wrote:What kind of parts cost estimate would you say one of these chargers would run? Debating whether to wait and try building one or purchase an off the shelf charger.
The total parts cost should be somewhere in the 50-100 dollar range depending on what current you are after (mosfet and inductor size)
by Farfle
Sep 16 2015 12:35am
Forum: Battery Technology
Topic: Ultra power dense charger project.
Replies: 59
Views: 6461

Re: Ultra power dense charger project.

Yeah, my power supply mentor here has also stated that the arduino is great for oversight, but not control. Ideally this design will switch much faster than 8 khz, that is just a starting spot. Ideally i am hoping to switch at 20 or even 30khz, but i will take what I can get. As far as maximum energ...
by Farfle
Sep 15 2015 9:24pm
Forum: Battery Technology
Topic: Ultra power dense charger project.
Replies: 59
Views: 6461

Re: Ultra power dense charger project.

Woot! Today was a good day for progress. I got the timer circuit hooked up and running, and the chip is outputting an exploratory gate drive signal. Tomorrow Ill screw around with the feedback pin in an open-loop configuration to see how the gate drive changes. Then ill close the loop, and screw wit...
by Farfle
Sep 09 2015 10:25am
Forum: Battery Technology
Topic: Ultra power dense charger project.
Replies: 59
Views: 6461

Re: Ultra power dense charger project.

Looks like the charger bits should show up on friday, excited to throw this all on protoboard!
by Farfle
Sep 04 2015 10:38pm
Forum: Battery Technology
Topic: Ultra power dense charger project.
Replies: 59
Views: 6461

Re: Ultra power dense charger project.

This charger will do CC/CV just fine, so its not tooooo bad. Just dont sit on a wet charging ebike while touching anything grounded :mrgreen:
by Farfle
Sep 04 2015 2:44am
Forum: Battery Technology
Topic: Ultra power dense charger project.
Replies: 59
Views: 6461

Re: Ultra power dense charger project.

Perhaps look at use of motor windings as inductor? That might need lower frequency, but since it's inductor mass you were already carrying, it's still like its light. :-) Not sure what the controller would think was going on if weird voltages started showing up. In fact, I think it would attempt to...
by Farfle
Sep 04 2015 2:38am
Forum: E-Bike Technical
Topic: Turning 4130 - Now 4340
Replies: 11
Views: 1850

Re: Turning 4130

Its up to you. All the chromoly alloys are really stout. If you had shaft breakage problems in the past, then bringing it to temper wouldnt be a bad thing.
by Farfle
Sep 03 2015 8:56pm
Forum: E-Bike Technical
Topic: Turning 4130 - Now 4340
Replies: 11
Views: 1850

Re: Turning 4130

4140 likes the chips to come off screaming hot and smoking. Try going to ludicrous speed and medium feed with a slightly raduised tip carbide bit and it should behave better. The trick is that its very "sticky" and develops a "tooth" on the cutting face that builds up and breaks off every couple rev...
by Farfle
Sep 03 2015 8:06pm
Forum: Battery Technology
Topic: Ultra power dense charger project.
Replies: 59
Views: 6461

Re: Ultra power dense charger project.

On to the charger in depth: The Bucking stage of this charger is an "Upside down" buck, meaning that the switching is done on the low side. This means that an N-channel mosfet can be used (better) and retain simple gate drive circuitry. Here is a schematic of the power stage: http://i1019.photobucke...
by Farfle
Sep 03 2015 8:05pm
Forum: Battery Technology
Topic: Ultra power dense charger project.
Replies: 59
Views: 6461

Re: Ultra power dense charger project.

How does the efficiency come out with your simpler charger? I understand that poor power factor inherently gives you some extra losses. Looking forward to see where you take this project. It should be very good. A low resistance fet and minimal components in the current path should achieve very goo...
by Farfle
Sep 03 2015 7:23pm
Forum: Battery Technology
Topic: Ultra power dense charger project.
Replies: 59
Views: 6461

Ultra power dense charger project.

Heya all, Under the advice and guidance from some very bright folks, I am starting a charger project. This will mostly be for E-motorcycle and car sized things, but the topology should work for anything. First off, this is a "big boy rules" charger that is for those who know what they are getting in...
by Farfle
Aug 12 2015 4:59pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: 2015 Zero Mod thread
Replies: 6
Views: 1293

Re: 2015 Zero Mod thread

i read somewhere in your blog, what is ATF cooled motor ? can you explain more about that cooling thing The ATF cooling for the motor involves either pumping ATF (automatic transmission fluid) through the motor, or just adding a small amount to the motor and letting the forced fluid convection help...
by Farfle
Jul 06 2015 7:24pm
Forum: Motor Technology
Topic: Triple solid slot Zero 75-7
Replies: 62
Views: 10187

Re: Sextuple Zero 75-7

coleasterling wrote:Farfle,

What's your time frame on this? I'm interested in sponsoring you with some machine work if you can wait 2-3 weeks.

-Cole
That would be awesome, The timeframe is (roughly) to have it in a running car by next year, so the motor build will probably be ~5 months.
by Farfle
Jul 06 2015 7:11pm
Forum: Motor Technology
Topic: Triple solid slot Zero 75-7
Replies: 62
Views: 10187

Re: Sextuple Zero 75-7

A solidslot motor! Watch out for eddy current losses in the conductors. In most motor designs the cross section of the winding wire is small enough to neglect eddy currents. Not sure if the tooth profile needs to be different for a solidslot motor, as to "shield" the conductors. Looking at a REMY m...
by Farfle
Jul 06 2015 6:33pm
Forum: Motor Technology
Topic: Triple solid slot Zero 75-7
Replies: 62
Views: 10187

Re: Sextuple Zero 75-7

Nice work. So all you will keep is the original rotor and heatsink stack? Doc All that is being kept is the stator lams, and the three assembled rotors will be mostly untouched. I am unsure about the case on the motor, as I destroyed the existing aluminum cases getting the stators out. The ID is 20...
by Farfle
Jul 06 2015 5:14pm
Forum: Motor Technology
Topic: Triple solid slot Zero 75-7
Replies: 62
Views: 10187

Re: Sextuple Zero 75-7

Heya all! quick update. The CAD model for the new motor is done, and it looks awesome. The winding config is 1T with both halves in series, whereas stock is 6t with both halves in paralell. The phase leads will be a machined copper buss that is roughly 125mm^2 cross section. These shaped busses will...