Search results

Date Relevance Most replies

  1. C

    even simpler/cheaper LVC :)

    I've been toying around with current-mode chaining of LVC circuits in the simulator recently and realized that you can build a super-cheap LVC using just one TC54 chip and current mode transistor chain as a sensor/aggregator. It will not have the same threshold accuracy and temperature stability...
  2. C

    turnigy wattmeter - is Ah reading cycling ?

    I have one of the first original wattmeters from RC days. It cycles Ah reading along with other statistics which makes it a very inconvenient fuel gauge, you have to keep staring at the display until it gets to Ah reading. Does the Turnigy clone behave the same way ? Can it be programmed to show...
  3. C

    bafang/cute on a 16" rim ?

    Has anyone laced a 16" rim on a small geared hub like bafang or cute ? The 16" rims I've seen all have 16 spoke holes and hubs are usually 36. Doesn't seem to work. I need to quickly put together a very basic lightweight assist for BikeE front (16" wheel).
  4. C

    anyone tried 25-50C nanotech ?

    Has anyone tried the lower rated turnigy nanotechs (the 25-50C variety) ? Do they have any measurable benefits over the regular 20C variety ? Longevity alone can justify the price differential but I doubt anyone has done cycle tests on these. Any data will be appreciated. I need to build a...
  5. C

    help review custom torque arm design

    I've got a recumbent frameset (aluminum) and I want to make a DIY rear torque arm to make sure I never get a spinout - it would be way too costly. My metalworking abilities are limited to a drill press, dremmel and basic hand tools. After some thought I came up with the following design: Few...
  6. C

    opening 9C motor

    I am trying to open 9C hub to add thermal sensor and possibly replace the phase wires. Can't get the cover off. I am trying to hit the opposite side of the axle with a heavy piece of wood but the cover does not move at all. Should I hit it with full force or there is a better way ?
  7. C

    which temp sensor for 9C ?

    What temp. sensors/displays are you guys using for monitoring internal hub temperature ? I can certainly hack something completely DIY but I'd prefer some off-the-shelf set to save time. Need to cover up to at least 150C. Sensor would go inside the 9C hub.
  8. C

    7sp, 8sp DNP freewheel widths ?

    Has anyone accurately measured the total width of DNP 7sp (11-32) and 8sp (11-32) screw-on freewheels ?
  9. C

    9C power limits ?

    I need to size the 72V Kelly controller (KBS) for my next (recumbent) project. How many watts can you ran through 9C for 1min burst and continuously before it burns under average summer conditions (90F) ? My current bike with x5, 200amp Kelly and 850wh 66v a123 packs can do wheelies but this is...
  10. C

    spokes/rims for X5 ?

    Lost my first spoke on X5 wheel. I think of rebuilding the motor wheel this winter. What is the consensus on strongest rim / spoke combination for X5 ? I guess I need some custom length spokes for this hub on a 26" wheel ?
  11. C

    slight OT - UPS with external battery

    Is there a low/mid cost UPS unit that can be modified to use generic external AGM battery ? I do not need very high power rating (one server plus a router in my home office), just need to be able to support few hours of grid outage instead of usual 10-20 minutes. I was thinking about replacing...
  12. C

    small direct drive hub motor ?

    What is currently the lightest and most efficient direct drive (non-geared) hub motor ? 9C perhaps ? Or is there something even smaller (but reputable/reliable) ?
  13. C

    brake light options

    I'd like to discuss brake light options for ebike. I have a proportional regen brake and can use the analog signal to control the brake light. There are few few options: - on/off mode (like a car brake light); - proportional brightness control (current source control from brake proportional...
  14. C

    almost lost rear wheel at 40+mph

    Coming from a local convenience store I had to beat the coming thunderstorm so I went full throttle almost entire ride back. At home I decided to check temperatures of various parts and doing so looked at the rear wheel / motor holding nut. That thing almost fell of the axle ! Checked the other...
  15. C

    rear brake options for 20"/24" wheels ?

    What are the options for the rear brake on a frame that has only V-brake mounts for 26" wheel ? I want to be able to put a 24" or 20" wheel in there but the frame does not have disk brake caliper eyelets. Note - I do not need high performance brake, more of a backup, since I use regen in the rear.
  16. C

    linear hall sensor for brake lever - really easy

    For proportional regen. Does not require any drilling/dremmeling etc. Uses a ratiometric hall sensor (I used Allegro Micro A1321EUA-T). It has symmetric response around 2.5V so I only get 0-2.5V response in this magnet configuration but I can adjust the controller for that range. Magnet is the...
  17. C

    first ride, finally...

    After tons of unexpected delays (many beyond my control) I finally got everything together and had a maiden ride. Bad weather, so it was short (but pretty fast ;-)). There is a long "todo" list still, the last but not the least of which is some beautification but it may wait until I move the...
  18. C

    high power discrete switched capacitor balancer

    I think it should be pretty straightforward to do using discrete mosfets. It can be made to run slow enough such that generic (cheap) optoisolators will suffice for the gate drive. Then you have N-1 capacitors for N cells switched back and forth (alternating offset of 0 and 1) by 2N mosfets. The...
  19. C

    recumbent resources Q

    Could you guys post some links/pointers to recumbent forums/manufacturers. My wife wants one and I think about getting one too mostly due to lower back and lower-lower back ;-) problems (eventually converting them to ebikes). I need to get some good intro reading on recumbents - hence the question.
  20. C

    Anyone going to attend Mt. Washington event next weekend ?

    Anyone thinking of going to the Mt Washington Alternative Energy Day next weekend ? http://www.endless-sphere.com/forums/viewtopic.php?f=25&t=3063 I am thinking of giving it a try but have not yet made a decision yet. Main reason - it will be a good stimulus to finish my ebike build finally. I...
  21. C

    trunk bag dimensions for battery packs

    I am looking for an economical trunk bag for two battery packs (will used on a generic hardtail rack). LBSs I've checked have very limited selection and online places do not always specify internal dimensions. Two packs that I want to use require 13"x5.5"x5.5" internal bag space. Those of you...
  22. C

    source for handlebar mountable switches ?

    What is the best source for switches/buttons that can be mounted on the handlebar? I mean something that would look clean and OEM-like. I've checked ebay for motorcycle handlebar switch clusters but they are rather pricey (especially the new stuff).
  23. C

    looking for a *big* DPDT or SPDT relay/contactor

    Does anyone know where to get a DPDT or SPDT relay or contactor rated at least at 100A per contact for reasonable price ? I need one for series / parallel switching of battery packs. The best I found so far are NTE R51 series rated at 50A for SPDT but it kind of looks flimsy. I am thinking that...
  24. C

    A123 pack build

    Ok, I decided to share personal experience building the packs out of dewalt A123 cells. The goal is to have two 10s6p packs for my first e-bike conversion. I intend to later add a parallel / serial relay switch so I can run either as a 33V or 66V configuration. I decided not to use original...
  25. C

    bad Dewalt QC or what is normal and what isn't

    I've finally started working on battery packs (2x 6P A123) for my bike. I've bought only *factory sealed* packs from ebay - no signs of tampering was evident on the package. Today I've opened first 7 Dewalt packs. Out of these one pack had two (!) failed cells (0.45V) so I discarded it...
Back
Top