Search results

Date Relevance Most replies

  1. O

    A whole days work...

    ..destroyed in 5 seconds :( It took me a few hours to build up a 12FET controller with irfb3077 FETs and to improve all the powertracks etc. I was so excited to test the controller, I skipped the final shortcut test and went directly to fire up the motor. And it burned up in less than 5...
  2. O

    Hobbykings new 5000mAh hardcase LiPos

    There must be a hook. The price is to good to be true: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=15521 -Olaf
  3. O

    highest voltage for 6FET infineon?

    Hi, would it be save to build a (sensorless) infineon 6FET with 500V Fets ( 420V fully charged battery )? Are there capacitors for 500V with the same footprint? Max. amperage would be 2A with almost no torque ripple. For the sensorless controller: is there a problem with such a high backEMV? I...
  4. O

    Nice 5:1 gearbox

    Since I'm building the electric pocket bike, I find some useful stuff coming from there. Someone found a CVT-gearbox, but IMHO that's a bit overkill, since we don't have to worry about lack of torque. Here's a small, light and tough looking 5:1 helical gearbox: I ordered some sprockets from 11...
  5. O

    H2O cooled infineon [was:highside FET w/o Kapton?]

    Hi, I'm building my own watercooled 12 FET infineon controller. The cooling bar has no connection to the housing. Q: Can I use the aluminium bar to feed the highside FETs with positive voltage? ( Drain is also connected to the backplate of the FET as u know ) I would only put Kapton tape between...
  6. O

    6x6s parallel charge board from hobbyking

    A new item on the site of hobbyking: http://hobbycity.com/hobbyking/store/uh_viewItem.asp?idProduct=14856 You can charge and balance your packs now without disconnecting. For 12s I ordered two boards and I'll modify one port on each to adapt a cell-log8. I wonder how much charge current the...
  7. O

    Anyone tried a logarithmic potmeter?

    The title says it all. There are logarithmic potmeters usually for audio amplifiers. Their curve starts reaaaallllly smooth and gets steeper at the end. Probably worth a try to tame our oversensitive controllers? -Olaf
  8. O

    adjustable Servo speed circuit [ramp control]

    Hi guys, I know there is a circuit at the hobbyking shop to reduce the servo speed for retractable landing gear in rc-planes. It would be useful to reduce the startup current for our rc-ESC abusers ( like me :D ). Just plug it between the servotester and the ESC and find a 'servo'-speed that...
  9. O

    Universal hall sensor solution

    Hi guys, we don't have to use the original magnets to trigger our halls. It is possible to build a small decoder that fits on the shaft of any HXT's. Containing 14 small magnets and three hallsensors. Or attach a tiny 7-pole hxt motor-bell; throw out the stator and replace it with the halls...
  10. O

    Flevobike meets Colossus jr.

    Hi guys, there are lots of motors coming my way these days. The first one was a HXT 80-85. I took this opportunity to make some shots of the rear wheel. I want to figure out, where to put the motor and reduction gears. I like the hollow shaft of the rear swing arm. If I could use it as...
  11. O

    Turnigy 120-70 8.6kW and irfb3006?

    http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14427 I hope the no load current isn't 17A :shock: <edit> I just renamed this thread to start a discussion about the right FETs for an infineon mod. I think 60v is more than enough to heat up the skirt bearing. I guess that's...
  12. O

    First numbers from Colossus 7kW

    I thought, I start a new technical thread about the colossus 7kW motor, because the sale-thread is somewhat unnoticed by many motor geeks. I just saw the torque constant of the HXT 80-100/180kV. It is 5,26 Ncm/A The colossus will have roughly twice as much (with 75kV), but still its "only"...
  13. O

    building a manual wye/delta switch!

    I'm getting some naked 7kW colossus motors these days and plan to wind them with all six phase wires connectable outside the bell. This way it's possible to use a manually shifted wye/delta 'gear-box' without the expensive relais'. 1st gear ratio would be 1.73:1 and 2nd gear is 1:1 Has anyone...
  14. O

    Linear drive for hulled recumbents

    I started mentioning the idea of a linear drive here in this thread: http://endless-sphere.com/forums/viewtopic.php?f=28&t=17847 I don't want to hijack this build log and therefor start a new thread to explain it a bit more. Warning: This is not related to electric bikes in specific! It's a way...
  15. O

    Low friction worm drive with ball bearing

    Worm drives are the most compact high reduction gears ever. The bad thing is the huge amount of friction. A few years back I made a concept drawing of a ball bearing worm drive. Thought it would be interesting enough to share it with the genius' members of ES. Any comments welcome. I don't...
  16. O

    50cc pocket bikes as part donator?

    Hi, many of these crappy bikes can be bought for peanuts. Are there any useful parts for a non_frock e-bike like the 2-step gear-reduction? I wanted to build an electric pocketbike for a long time, but then decided, range would be too low. Next idea is to make it electric and radio controlled...
  17. O

    switched reluctance motor and VFD-drives

    I've heard that a 3~ SR motor would run with a VFD-drive, when you set the rotor resistance parameter to 'infinity'. Can anybody experienced with programming VFD's tell me if this is possible ( maybe set the rotor resistance to some Mohm?) I would have some candidates to test the theory, but no...
  18. O

    Need help with Elcon1500 charger CAN messages

    Hi Expert, we bought a batterypack that came with the Elcon PFC1500 charger. It has a CAN adapter and no further documentation about it. We didn't buy a BMS yet but we would like to know, if the charger could work without BMS. We did some CAN logging and it seems to be a weird 21 bit code. Has...
  19. O

    automated battery testing with AVR NetIO

    Hi! I thought it would be interesting for some of the battery geeks here to share my findings about the AVR NetIO board: http://www.pollin.de/shop/dt/MTQ5OTgxOTk-/Bausaetze/Diverse/Bausatz_AVR_NET_IO.html It is pretty useful with 8 digital outputs, 4 digital and 4 analog inputs. I was looking...
  20. O

    Hub is marked 8x8. What does it tell?

    I opened my 36V 700W hub today, to see what options I have to let it spin faster. On the inside it's marked 8x8, which seems to be the winding config. What does it tell me? OK, I guess it says 8 wires parallel and 8 windings per tooth. How does it compare to other windings? As I mentioned in...
  21. O

    How to adjust max RPM on a SYK 36-70 controller?

    Hi all, I bought a complete front wheel drive kit from cammy_cc in the bay. He offers the same kit with different wheel sizes and I chose 20" for my recumbent. Now I'm a bit disapointed because it is creeping slow. Maybe it's adjusted for a 28" wheel? I opened the controller and couldn't find...
  22. O

    NEW LiFePO4 with 3.7V or just BS?

    Found this pack and asked the seller, how this could be LiFePo4... http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=230426872468&ssPageName=STRK:MEWAX:IT Made of 10s2p á 3.7V 5Ah :shock: He answered, this is a new LiFePO4 chemistry patented in China. :lol: BS or what? Would it still...
  23. O

    Incredible Headway perfomance !

    Today i abused my 12v/10Ah 38120S Headway pack with starting a 2 liter Diesel engine. There was no other battery connected. At my first attempt the engined rev'ed slowly but it didn't start. 10qmm cable was not sufficient, so I took a real starter cable with 50qmm. It was like starting with a...
  24. O

    Super strong duct tape Lithium cells...

    If you are interested in super_power duct_tape-style Lithium cells ( LiFePO, LiMN or LiNiCoMn available ) that are able to deliver 5-10C constant and more, see http://www.eigbattery.com . From 6.4 to 20Ah ; several types have Ri of 3mOhm! Unfortunately they are only sold in 100+ quantities. And...
  25. O

    Anyone tested the new headway 42120 cells?

    There seems to be a new cell from headways. 8Ah and 10Ah in a slightly bigger casing called 42120. They seem to have a much better inner resistance and therefor a higher discharge ratio. http://headway-cn.en.alibaba.com/product/0/201224229/Others/8Ah_lithium_ion_battery_cell.html...
Back
Top