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  1. fitek

    Clearance problems with freewheel attached to 3spd hub

    Not using the freewheel adapter isn't really an option. I've given up on this approach. I guess I'll have to try this idea out on another bike.
  2. fitek

    Clearance problems with freewheel attached to 3spd hub

    Well the critical piece with that adapter is that it will save me a few mm if the sprocket adapter is on the inner side of the 22t sprocket. Currently both the freewheel adapter and sprocket are on the outside. But, that's only about 1/3 of the depth of the nut though so in the end it wouldn't...
  3. fitek

    Clearance problems with freewheel attached to 3spd hub

    I bought one of the 3 speed Sturmey Archer wheels from UtahTrikes and made an adapter to fit a freewheel and a #219 sprocket onto the wheel. Basically, there are just 3 holes drilled in the stock sprocket and the adapter has 3 holes too. They get bolted together. Trouble is, the height of...
  4. fitek

    Direct-drive 3220 setup with a 3-Speed Hub...

    I am trying out a similar setup to the original posted in this thread, but having issues with the Sturmey. It looks like there is about 5mm between the circlip securing the 22t sprocket and, um, the next piece of metal. The Sturmey 22t that comes with the wheel is 3mm thick. Normally the dust...
  5. fitek

    IR2101 hi/lo side driver discontinued?

    I just got a notice from Newark that the IR2101 hi/lo side driver is on closeout. Seems to be hard to find elsewhere. Digikey has 297 of the DIP package in stock and the rest are non-stock. I used these extensively in my motor controller and some other circuits, so just a heads up :)...
  6. fitek

    Help me understand the theory of charging

    I'm trying to make sense of how to run numbers for battery charging and what effect charging voltage has. My observations are that as I increase the voltage of a power supply attached to the pack above the pack voltage, the current that goes into the batteries increases. Of course according to...
  7. fitek

    Compact Tandem v2.6

    I was trying to get the bike ready by the Palo Alto EV Rally this past Saturday, but due to work commitments I didn't even get a chance to get started until Friday night, and I was really tired. I didn't have time to do things terribly well, so I just ran over to Home Depot about 8:30 and...
  8. fitek

    Compact Tandem v2.6

    I've shown off the previous version of this bike at a couple of shows (Maker Faire and Google I/O Conference) and. It has three problems that bug me: 1) with a passenger on the back, there is a wobble in the steering at low speed, probably because the passenger's CG is at or behind the rear...
  9. fitek

    24 v sla charging

    Just charge them in parallel most of the time. If you feel the need to "balance" them periodically, charge separately every couple weeks.
  10. fitek

    Lacing Bafang hub motor

    The PDF says M12x1.25. Maybe I just didn't find the right pitch at HD and Orchard.
  11. fitek

    Lacing Bafang hub motor

    I tried 10mm and 12mm. 10mm is too small, 12mm too big. So I tried the American sizes... 7/16"-20 was too small, 1/2"-20 fit but very loosely. Additionally, I now realize that the axle is too big to fit into any of the forks I have. It also is too wide for me to put any sort of washer on...
  12. fitek

    Hub motor makes squealing noise after reassembly

    I took apart a direct drive hub motor and put it back together again. Now when I spin it, it squeals like a tire on painted concrete. I had to use some elbow grease to get it back together so I wonder if its mis aligned or whether I screwed up a bearing? I took the cover plates off both...
  13. fitek

    Lacing Bafang hub motor

    Lacing is all done, but what size axle is this and what is this thread??? I tried a bunch of nuts laying around in the shop and none fit. Guess I'll have to go to Orchard and then perhaps order from McMaster...
  14. fitek

    Lacing Bafang hub motor

    I got 13/14 guage spokes. They will be cut to 139mm for 1 cross. We double checked the numbers using QBP's app. The ERD for the Alex DM24 20" is 395mm. Not sure where I got the wacko 405. Spokes will be done Monday... will report back when done. Guess I'll unlace the bad ones and also swap...
  15. fitek

    Lacing Bafang hub motor

    Thanks JohnRobHolmes, I found a local shop that will cut my existing spokes down. Will swing by tomorrow and try to find something that fits your numbers. I measured the ID of the rims at 395-398mm (inaccurate measurement device, heh). The published ERD is 405 though. That's 10mm off, which...
  16. fitek

    Lacing Bafang hub motor

    Tried 2 cross with the 165mm, but they are at least 10mm too long. Too short for 3 cross. 150mm or so would be ideal, but where to get those... the search continues
  17. fitek

    Blew controller by hooking battery up backwards

    I hooked the controller up and I'm getting some action out of it, but the IRF1405 blew out. Grr. I'll have to find another sacrificial FET. So perhaps it is possible to easily recover (LM7805 and some caps).
  18. fitek

    Lacing Bafang hub motor

    I bought DT Swiss 165mm. We'll see how it turns out. Also stocked up on some other goodies...
  19. fitek

    Lacing Bafang hub motor

    I called Danscomp and they said they could not cut the spokes shorter than 185mm. I am going for 14ga, I have a rim with 14ga spoke holes.
  20. fitek

    Lacing Bafang hub motor

    So I used spocalc.xls, which you can find on Google, and the Bafang PDF. 130mm for dL and dR which is the spoke hole diameter and 23mm for WL and WR, which is the distance from the center of the hub to the flange on either side (along the axis of the axle). Wheel ERD is 405mm. For 1 cross...
  21. fitek

    Oddest / strangest thing you transported on a bike?

    I once rode my motorcycle past a guy in the desert who was hauling some guitars, an amp, and some other stuff in one of those kiddie trailers. Not sure where he was headed but he didn't seem to mind... I took the attached photo a week or so ago. People looked at my bike funny, like it's a...
  22. fitek

    Blew controller by hooking battery up backwards

    The controller that just stopped working-- it was the low side on phase B that blew out. I took one of the FETs from the controller I hooked up backwards to make it live again. Will measure the voltages and report back. Now that I have a working and a non working controller, it should be a...
  23. fitek

    Blew controller by hooking battery up backwards

    Success, the controller now works again. Man, how crappy that it blew out with totally normal usage. My old Ecrazyman has been totally solid. Replaced IRF1405 into the "dead" controller and tried it too, but it just heats the big resistor on the corner of the board up. Something is drawing...
  24. fitek

    Blew controller by hooking battery up backwards

    Fechter, checked voltages, all good, checked FET resistance - the low side FET on phase B blew out, all pins shorted. I replaced it with one from the dead controller, but I did a really shitty soldering job. Does sort of spin the motor now... Will have someone with better skills and tools...
  25. fitek

    Blew controller by hooking battery up backwards

    Thanks Fechter. Let me see if this controller is dead too. If so, I can mail you both (I generally only make it up to SF on the weekends, I don't assume you work then?)
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