Endless Sphere

https://www.electric-skateboard.builders/uploads/db1493/original/3X/a/e/aec4b188fee925221e1de56ffc58efc1e1660b39.jpeg Looks promising, and good to see someone doing some bench testing here! If I may, I'd recommend designing those bolted connections in such a way that the 3D printed plastic isn't be...

Personally I think torque sensing and even a throttle is unnecessary on a low powered assist setups like this. When riding single track, reactions need to be instinctive. Pedal and brake are plenty to think about when tracks get fast and technical. If I was using your setup, I would have a single b...

but what stands out with this bike, is the special geared crank, allows you to pedal at 43 MPH... and the bike is built to be able to pedal - get this - - EFFECTIVELY. My power calculator says you incur something like 250W of extra drag by pedaling at 43mph versus not pedaling. So sure, you can mak...

I haven’t found a metal option for a PF30 to threaded BSA adapter. I was also concerned about running 3000W through it. Anyone here have experience with this? https://www.google.fi/search?q=FSA%20PF30%20Threaded%20Adapter%20B3167 This adapter is somewhat permanent. Very tight press fit, and supplie...

Current and resistance measurement of the springs were done uncompressed, as compressing them could lead to something akin to a spring bypass. So, they were tested with a cell in place with very little contact force on the cell? The reason I ask is to help understand how much the contact resistance...

BlueSwordM wrote: ↑

Mar 19 2019 11:39am

That's why I've made my own BeCu spring design

Nickel plated BeCu C17530 springs.

Cool springs. How much spring force is on the cell when you ran your tests? 20A is impressive.

https://www.ebikes.ca/shop/electric-bicycle-parts/torque-sensors/sempu-140.html This is the only one I have found that comes close at 84mm, think it could work? I think that would work with Press-fit to Threaded adapters like this: https://www.amazon.com/Token-Products-Press-Threaded-Adapter/dp/B01...

Nobody makes one as far as I'm aware. I've been tempted to modify a Sempu T4 for this purpose. I think it's possible with some machining skills and time.

That's new. Bummer. I raced my own drive system a few years ago, that was fully within the rules: class 1, 20mph, 500W (350W actually). I assume that Bosch and the bike industry doesn't like the idea of conversions. Makes sense. They are making bank on the false notion that you need to buy a whole n...

On the BAC 500, pin 1 is bottom right. I think it's the same.
If you have the mating connector, pin one usually has a tiny little arrow or triangle molded into it that points at pin 1.

Here is the picture of the failed negative fuse wire bond; Yikes, that looks tight. I agree that spot welding a nickel strap from PCB to cell might be the easiest repair, unless you have a friend with a wire bonder. :D You will probably need some tiny spot welding electrodes to fit in that space, t...

Static tension for a 9mm wide, 5mm pitch GT2 belt in this config should be about 250lbs according to Gates documentation. Just to clarify, 250lbs is the total load on the motor shaft (125 lbs per span) per the equation: belt tension equation.png I think this is unnecessarily high... we'll see. Also...

Nice looking setup! I'm curious to see if it's possible to run a belt at much lower tension. I wouldn't be surprised if there is some margin in that 250 lb figure. Maybe I can trade tension for belt life, as long as the belt is not skipping (much...) At 250 lb, probably with a cyclic component, I w...

Doing a crank drive belt drive is a tougher problem to solve than a rear wheel mount for a given power level. If we want 60-70Nm of crank torque, using a pulley that is about the same diameter of 32T chainring, we end up with 225 lbs of peak drive tension. Static tension for a 9mm wide, 5mm pitch GT...

No experience with that material, but keep in mind it softens up at phase change temperature. The datasheet says shore 45A at 70c, which is like pencil eraser stiffness. You'll need to have cell support structure other than this.

micah78 wrote: ↑

Nov 22 2018 3:31am

I will follow this post and buy it when it's ready.

Thanks Micah, it's looking like January-February is our new target. Beta testing is process, and we have had some delays on our battery potting equipment and other bits that have pushed things later. It's the nature of product development!

Sorry to dig this up.. but I've been thinking about this.. There are many new power meters on the market, I saw one the other day discounted to around $200AUD. which would make an awesome Torque based throttle. Before i get into it, has anyone got any ideas like this, or reasons why it wouldn't wor...

Thanks guys! We are good on funding for a while, our main constraint is time. In fact, I am hoping to hire or contract the help of an electrical engineer soon. I am pretty slammed, and have a young one at home, so it's tough to keep things going at the pace that I'd like. Perhaps I'll post a job lis...

Subscribed! I am a builder/developer in the oh-so-tiny off-road handcycling scene. E-assist has proven to be a game-changer. However, most of the DIY kits don't integrate too well into the available equipment. This kit looks like it has fantastic potential. Thanks ions. We are making good progress,...

Nice idea. I had a co-worker a while back that was obsessed with using a breathalizer for detecting electrolyte. I don't think he ever actually tried it. Interested to see if this works.

Amazon has them for a slightly more reasonable cost. About $0.25 each. Splicing some 8-pin cables into 5-pin (display) and 2-pin (headlight) today. I'm borrowing a rad Hakko hot air station for doing these. I think a heat gun with a nozzle would work well too.

Another quick update. The 100mm Sempu T4 torque sensor allows us to install this kit (with a few extra spacers) onto a fatbike with 4.7" tires. Looking forward to winter, or a trip to the coast! fatbike1.png fatbike2.png fatbike3.png Also, I am looking for Beta testers for the kit. We have a few Bet...

Although not commonly advertised, Sempu can make a T3 model torque sensing bottom bracket which works with ISIS crank arms instead of Square Taper. Electrically and dimensionally it is said to be identical to the T4. If you would prefer the ISIS version and cannot find it for sale, PM me and I will...

Thanks@pictures. Regarding current, I meant what current level do you get with kWeld? Ha, oops, yeah that makes more sense. I get about 880-900A. BTW, I bumped up my energy to 40J, and I'm getting stronger welds. Ron, I attached a pic of the tabs and the fixtures I use to bend them to mate up to th...

tatus1969 wrote: ↑

Aug 28 2018 1:53am

That looks awesome! Can I use it for my web site?

Your battery looks quite small, how many amps does it do?

Thanks, and no problem, you can use the picture.
The pack is 10.5ah, 15A peak. It's for a lightweight, lower power drive.