The best system to use depends on the personal circumstance of the user. Though we both agree that the metric system is far more elegant, here in the US most machinery and manufactured objects are based on imperial, making it the more convenient system to use. It is an unfortunate fact that these imperial machines and manufacturing methods will remain for long periods of time. Therefore becoming familiar with imperial is a must!

@@thecontinuingadventureso-qs5zm haha yes it’s on the budget👍

Hey, I apologize for the delay, I've been super busy lately with a bunch of other projects which I will be posting on this channel soon, but I am planning to resume the ebike come June!

​​@@engineeringdiy6311 I am doing mechanical engineering right now. I am from India. I also wanted to make my bike to ebike for my college it's 45km away from my place could you suggest me which battery do I need for reliability and durability. Lithium ion here is cheap but quality ain't very good. I am thinking of nmc but it can be quite dangerous if it catches fire.

This is absolutely a suggestion I am willing to try, since I am also doubting the integrity of the weld. Though I think the principle of using the pipe is sound, I would carry out the execution of this method differently. If I were to do it again, I would grind in deeper bevels to allow more weld to be deposited deeper in the joint, so that there is still a decent amount of weld left even after it is ground down so that the cup can fit over. I would also preheat the pieces and use high amps (85-90 for e6011) to ensure the liquified electrode can seep through and fill any gaps, and reduce the chance of internal stress. Another possible way to keep a thick layer of weld is to create small tack welds in the pipe to lock the alignment, take it out of the pipe, slide the cup over the tack welds, and then create a second thick layer of weld, and since the cup is already in position, you don't need to grind away the weld. Although of course that would mean the cup is permanently stuck onto the spindle. I'm glad this video gave you a clear idea of how to go about doing this (in a better way) for your project. I will be making another spindle with the aforementioned improvements and do rigorous testing to ensure it doesn't break or warp, and then replace this video with an improved guide on extending spindles in a reliable and precise way.

@@engineeringdiy6311 Honestly, I'd rather go for the option of putting the cups over tacks before fully welding it as strong as possible, But this definitely seems like the more elegant solution

Haha thanks! In fact, during my first try with the extended spindle, I clamped both parts in the vice but the alignment was not great, due to the fact that my vice clamping faces are scratched and worn (as you can probably see). I also didn't have precision parallels, forcing me to come up with the tube idea. It was pure coincidence that the bike seat post happened to be perfect. I'm glad I was able to keep it "DIY" with a decent level of precision without needing to go to a machine shop.

Absolutely! By sequencing the power from small/big--small/big sprockets, the torque to the wheels is maximized, and the gearing allows me to stay in the motor's "powerband". I did the calculations you mentioned in part 1 of this series. And yes, higher voltage is definitely my friend here because that also reduces the amperage requirement, which translates into less heat and strain on the battery.

Which motor are you going to use?@@engineeringdiy6311

Thanks for the comment! Absolutely, that was a oversight. Will do next time👍

Well, I think it'll work fine since the power from the motor wont need the ratchet freewheel to be engaged, but rather disengaged. Cheap freewheels are usually only problematic in the case of engagement.

@@TheAfricanGarage Yes, this bike will majority of the time be used under full motor power, however I will definitely be on the look out for any mechanical problems with the freewheel during testing.

Thanks for watching!

Thank you for the response! I actually didn't know such a method existed when I made the video. I think I'll reupload with that part.

@@engineeringdiy6311 It's so cool when you find out about it 😁

XD