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Super commuter GT hardtail MTB cyclone build...

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  • moarpower
    commented on 's reply
    That is pretty awesome. I want a bike that can do that!

    Great job on the build. Looks like the long hours have really paid off.

  • nuggets
    replied
    Rolling burnouts anyone?

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  • nuggets
    replied
    Originally posted by commuter ebikes View Post

    I have made battery boxes out of ABS before, and I reinforced the joints with angle aluminum. Unfortunately, it did not hold up. The ABS was not strong enough; this might be my fault for running into so many things. In any case, I now make my battery boxes out of aluminum bar and angle aluminum.
    Thanks for the tip. I'm mainly planning to use the kydex for non structural covers. I've got plenty of aluminum for structure, but don't have any alloy sheet big enough for the side covers. The alloy sheet is costly in the larger sheets.

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  • commuter ebikes
    replied
    Originally posted by nuggets View Post
    I ordered a 2' x 4' kydex sheet to use to build the battery box...
    I have made battery boxes out of ABS before, and I reinforced the joints with angle aluminum. Unfortunately, it did not hold up. The ABS was not strong enough; this might be my fault for running into so many things. In any case, I now make my battery boxes out of aluminum bar and angle aluminum.

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  • nuggets
    replied
    Whoops, forgot the battery when I weighed it. 49.6 + 7 = 56.6lbs

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  • nuggets
    replied
    I ordered a 2' x 4' kydex sheet to use to build the battery box. While I am waiting for that, I put it all back together, and put the battery bag on the bike. Then I took it for a shakedown ride to the local singletrack. I figured the rooty track would quickly suss out any issues.

    The battery bag sucks since it doesn't fit the frame well, and lets the battery bounce around too much. It would be a great bag for a larger frame, or for riding on the street. Other than that, the rest of the bike was solid. It could use a bit more brake though. Even with the larger front rotor and hydraulic brakes, it felt a bit manic at times. Of course, when you twist the throttle, the thing takes right off.

    The exposure went nuts on this photo... As shown, it weighs 49.6lbs.


    You can see the outline of the battery in the bag. It was just flopping around the whole time.



    The bike handles well, even with the extra weight. I spent some time showing another biker around the trail system, so I did just pedal it for a few miles, and it does surprisingly well just pedaling along. I did nearly whiskey throttle the thing into a tree, but otherwise avoided any trouble. When I stopped to check the controller and the battery, they didn't feel hot, but the motor does get hot to the touch.


    I maxxed it out at 39MPH on the surface streets, and was hanging nicely with 35MPH speed limit traffic.


    When on the gas, the thing feels like a light weight dirt bike. It's got tons of torque, and is a bit scary on the MTB trails, so I'm happy.
    Last edited by nuggets; 06-11-2017, 12:54 PM.

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  • nuggets
    replied
    The bottom bracket spacer makes a huge difference. The bottom bracket is nice and tight now. Spins free and no more slop.

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  • nuggets
    replied
    I got busy with the lathe this morning to make a few spacers. All for the motor mount.



    First I cut a spacer for the bottom bracket. I was having an issue where the bearings could move side to side inside the bottom bracket, so I cut a spacer to make the outside bearing stay in place.


    Next I cut a couple of spacers so that I can replace the weird 4 bolt setup on the motor mount with two long and strong through bolts. Here's all the spacers.


    The long spacers will replace this threaded piece... See how I have set the spacer there.

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  • nuggets
    replied
    I took the damaged sprocket off and cleaned it up. You can see the violence of the arc in the smoke pattern on the sprocket.



    A little grinding, and the sprocket is salvaged.


    A few more shots of the motor mount.




    I ground a notch in the mount to provide clearance for the rear derailleur cable.

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  • nuggets
    replied
    Originally posted by Sebz View Post
    Wow this is a very very nice build! All done without a CNC or specialized tools... Love it!
    Thanks SEBZ! I've been wanting to make this into a real solid bike with a robust drivetrain. I hope this beast of a motor doesn't snap my chainstays. I've watched some real craftsmen make magnificent things with just simple tools. Me, I hack away with angle grinders and aluminum sheet.

    Originally posted by Truck View Post
    omg awesome brackets and excellent battery integration! I personally wouldn't be running an ebike for only 10 miles but I bet this thing is rad!
    Thanks!, though I'm not sure what you are talking about with the battery and 10 miles... I haven't started on my battery box yet. If anyone has any suggestions for inexpensive panels for the sides of the box, I am all ears.

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  • Truck
    replied
    omg awesome brackets and excellent battery integration! I personally wouldn't be running an ebike for only 10 miles but I bet this thing is rad!

    Leave a comment:


  • Sebz
    replied
    Wow this is a very very nice build! All done without a CNC or specialized tools... Love it!

    Leave a comment:


  • nuggets
    replied
    An update on my install.

    I've pretty much finished the motor mount.

    I made this plastic block to prevent the motor rotating upward under power.


    And I made this strap to prevent the motor rotating down when hitting bumps.


    I've also built my controller mount.



    I replaced the rack bracket with the mount. I think it is pretty well integrated in that spot. It has good airflow, and the wiring passes through between the seat stays, so it will help prevent the wiring from being too eye catching.



    Yes, I am missing fasteners. I didn't have enough M5 hardware, so I will have to order some. Once I am finished with all the prototyping, then I will order hardware.

    Also, I learned a lesson about battery safety. I was mocking up the battery location in the triangle when the charge connector brushed against the sprocket. There was a tremendous flash, and the charge connector got burnt, and one of the sprocket teeth got ruined. I should be able to save the sprocket with some careful file work. Now the battery connectors are bagged, and I have to order new XT60 connectors.

    Notice the tooth with the gold material from the connector welded to it.

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  • nuggets
    replied
    Back to the saga of the massively over-powered homebuilt e-bike project.
    Mount progress....

    I used this bent piece of 0.90 aluminum to tie the motor mount to the bottom bracket mount.


    And I added these braces.


    Another angle...


    This whole thing is put together with a collection of random fasteners, so I will have to buy the correct fasteners.
    Here it is mounted on the bike. I had to change all the fasteners on the sprocket side to low head socket screws since the hex heads intererfered with the sprocket and the chain.


    Once everything spun well without power, I turned it on and throttled up. Previously, the mount would twist just spinning the wheel under no load. It doesn't do that anymore. I used the brake to hold the wheel, and applied power. The motor twists... WTF?!

    I look at it some more. It's not the mount. As it goes when you strengthen one thing, you find the next weak thing. It turns out the mount does not twist anymore, it's actually twisting the bike frame. The cycle analyst says that I put 100 amps into the motor to do this....

    The good news is that the mount is strong enough. I'll see how long the frame holds up...

    POWAH!!!!!!!

    I've got to add a bracket to tie the motor into the down tube so that the motor won't rotate down when I hit bumps, and so the motor won't rotate up when it pulls on the chain. Once that is built, I'll finish all the motor mount parts, and be done with the motor install.

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  • nuggets
    replied
    So the motor mount that comes with this motor is a pathetic joke, it has multiple issues.

    1. the mount will flex side to side.
    2. the mount twists.
    3. under power, the mount is pulled up to the frame, and crushes the rear brake line.
    4. the mount falls down when you hit bumps.

    I'm not going to use the cheesy giant hoseclamp and zip ties that come with the kit, just too hokey, and the zip ties are guaranteed to fail over time.

    I held the brake and applied power, in order to test the mount.

    So, I set out to beef up the mount.

    I initially planned to do something like this, but I don't think that will help much with the fact that the mount twists under load.


    After a lot of head scratching and false starts I laid out some lines and curves on some metal and started cutting.


    I'm using 3/8th 7075 plate.

    I used some tricks to match the curve to the motor...



    Once I got the curves right, I laid out the mount holes.


    And drilled them, and test fit them...


    Then I added the holes for the mount brackets...


    Then I made up a third plate from 1/4 plate. Then I test fit the mount again. Here you can see the weak and cheesy mount blocks that my plates are replacing. The two 3/8 plates, and one 1/4 plate were not quite thick enough, so I had to add a shim plate from 0.030" sheet. It already feels much stiffer.


    The new motor mounts are close to complete, and they look like this.


    I asked a guy I work with to bend me a small bracket from 0.090" plate. It will bolt onto my mounts, and then bolt to the black brackets. Then the motor will be highly resistant to twisting with respect to the bottom bracket. Here it is mocked up.


    I'll drill and tap the mount plates from this direction.


    More to come... But no work for a week...



    I do have one question.

    Does anyone know the resistance of the shunt in the cyclone controller? My multimeters are not sensitive enough to measure it. I could use the info to set up the cycle analyst.

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