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rfndzc replied to the thread 1972 Honda CB350F conversion.
" Views of the battery cage showing the original motor mounts in use with no modification to frame. Front bracket was simply flipped upside down to accomodate the 23s. Top two bolts were previously used for cable holders and will continue to serve this as well.
Attachment 8435 Attachment 8439 Attachment 8437 "

4 Hours Ago

Richard230 created the thread Cake Osa wins an EV award.
" Here is a link to a report about the Cake Osa winning a Red Dot award - whatever that is. I note that Cake has managed to make a production motorcycle look just like a homemade one.

https://electricmotorcycles.news/cak...gn-award-2020/ "

6 Hours Ago

rfndzc replied to the thread Italjet Dragster conversion.
" I said Lipo but meant just the Li-ion 18650/21700 (lithium cobalt, i think. not lithium polymer). The 21700 are a more recent tech, slightly larger and more power dense and will require fewer batteries/connections for the same power output. Less work, more play. Being slightly larger you have more volume dedicated to chemistry and less to the protective structure. These are the cells Tesla has moved to producing for themselves. Unfortunately being newer there are fewer components on the market for them, specifically the variety of cell holders for 21700 are limited to square spaced (I couldn't find honeycomb shaped for the 21700). If you have 3d printing skills then you can surely leverage them for your custom pack shapes with honecomb cell holders for higher density. I stayed away from Lithium cobalt cells because I don't have enough experience with building cell packs and did not want this particular bike that I'm working on to catch fire. Prismatic lifepo4 cells (as in those I'm using) are more stable/robust though a bit less power dense.

Rob "

8 Hours Ago

tylerwatts clicked Likes for this post: 1972 Honda CB350F conversion by rfndzc

12 Hours Ago

tylerwatts replied to the thread Italjet Dragster conversion.
"
Quote Originally Posted by rfndzc View Post
Hard to tell from the pics and the acronyms (2t, 4t, rhs..). I would advise against keeping an SVT (i got that one) for small machine where space is the real premium. You can sub out a clunky svt with solid calculation on drive specs (top speed desired, amperage, voltage, gearing...) and put that space to better use (battery or
motor?). Maybe just a profile diagram of the layout would simplify understanding the machine.

If you are looking at 18650’s you should have seen 21700’s as well. Let’s talk about the advantages there. I think if you feel comfortable with building out a custom lipo pack, that would be a big advantage as you could really fit a lot of power into some rare shapes and spaces. Thanks for sharing
Hi rfndzc

2t is 2 stroke, 4t is 4 stroke engines.
RHS is right hand side.
I apologise for using acronyms, just lazy of me.

Why do you recommend 21700 form cells? I have thought about using other sizes but not checked actual space. If you look under the front shock in the middle of the frame there is a narrow channel probably big enough for 1kwh of small cells, or a controller. That is driving me down the smaller 18650 route.

https://uploads.tapatalk-cdn.com/202...746b027552.jpg

But yes, I just measure up properly.

Thanks for the feedback. I will get better pictures or diagrams as you say. Any recommendations for sketching apps on Android appreciated.

Cheers
Tyler "

12 Hours Ago

rfndzc replied to the thread 1972 Honda CB350F conversion.
"
Quote Originally Posted by tylerwatts View Post
Ah those look like kart sprockets then. That seems like a good approach, lots of choice.
I noticed you said you were looking to use a very low gear ratio, what size sprockets will you be using?

Cheers
Tyler
The stock gearing that came with the bike is 17/38. For the chinese motor manufacturers that operate at higher rpm I would have needed a lower ratio (smaller front sprocket and/or larger rear). Because I was able to find Revolt and they offer a custom kv, I basically set kv for a factory gearing, but for a top speed of about 55mph. Again, I am into low end torque and acceleration, not top speed.

26kv at 72v gives ~1600 loaded rpm (~1800 unloaded). My rear tire is now a 4.00 on an 18" rim, thats .33m radius, and ~55mph top speed at that rpm with a 16/38 ratio, and 45mph at a 13/38 ratio with a bit stronger accel. So to answer your question, I bought a 16 and I bought a 13.


Edit: If I said I opted for a 'lower' ratio it was thinking of an inverted ratio, rear/front, so ~2 vs ~4, because I was able to use a custom kv instead of a 'higher' ratio for more torque/less speed. I think it is more intuitive to consider front/rear, but the resulting number (.4 vs .3) is maybe less intuitive. "

19 Hours Ago

rfndzc replied to the thread Italjet Dragster conversion.
" Hard to tell from the pics and the acronyms (2t, 4t, rhs..). I would advise against keeping an SVT (i got that one) for small machine where space is the real premium. You can sub out a clunky svt with solid calculation on drive specs (top speed desired, amperage, voltage, gearing...) and put that space to better use (battery or
motor?). Maybe just a profile diagram of the layout would simplify understanding the machine.

If you are looking at 18650’s you should have seen 21700’s as well. Let’s talk about the advantages there. I think if you feel comfortable with building out a custom lipo pack, that would be a big advantage as you could really fit a lot of power into some rare shapes and spaces. Thanks for sharing "

19 Hours Ago

tylerwatts replied to the thread 1972 Honda CB350F conversion.
" Ah those look like kart sprockets then. That seems like a good approach, lots of choice.
I noticed you said you were looking to use a very low gear ratio, what size sprockets will you be using?

Cheers
Tyler "

19 Hours Ago

tylerwatts replied to the thread Italjet Dragster conversion.
" I'll try take some better pictures as the angles aren't great. Bit tight in the garage at the moment, with an i-MIEV drivetrain and battery on my work bench...

Cheers
Tyler "

19 Hours Ago

tylerwatts replied to the thread Italjet Dragster conversion.
" Placeholder: other 5

Cheers
Tyler "

20 Hours Ago

tylerwatts replied to the thread Italjet Dragster conversion.
" Placeholder: other 4

Cheers
Tyler "

20 Hours Ago

tylerwatts replied to the thread Italjet Dragster conversion.
" Placeholder: other 3

Cheers
Tyler "

20 Hours Ago

tylerwatts replied to the thread Italjet Dragster conversion.
" Placeholder: BMS

Cheers
Tyler "

20 Hours Ago

tylerwatts replied to the thread Italjet Dragster conversion.
" Placeholder: charging

Cheers
Tyler "

20 Hours Ago

tylerwatts replied to the thread Italjet Dragster conversion.
" Placeholder: wiring & electrics

Cheers
Tyler "

20 Hours Ago

tylerwatts replied to the thread Italjet Dragster conversion.
" Placeholder: restoration

Cheers
Tyler "

20 Hours Ago

tylerwatts replied to the thread Italjet Dragster conversion.
" Placeholder: battery build

Cheers
Tyler "

20 Hours Ago

tylerwatts replied to the thread Italjet Dragster conversion.
" Placeholder: motor solutions.

1: modify current 2t motor by splitting the crankcase and fitting an inrunner motor in the bore. This would remove the engine mount though and be a small dia motor.
Could potentially reuse the water pump and liquid cool for more performance.
Could also keep the CVT for greater starting gear ratio and mechanical advantage also allowing higher constant ROMs for efficiency and cooling fluid flow.

https://uploads.tapatalk-cdn.com/202...26e9d1631d.jpg

2: placing a larger motor in the RHS case with a longer shaft through the crankcase. Makes the motor wider.
Could allow an outrunner motor.
Likely air cooled.

3: option 1 or 2 using a larger 4t engine donor, ideally big 200cc. But weary of larger wheel and heavier drive assembly etc.

4: fabricate a cradle for carrying the battery and allowing mounting a QS Motors mid drive kit.
Also allows for alternative rear shock placement.
Could increase wheelbase significantly.

https://uploads.tapatalk-cdn.com/202...08b55b16c8.jpg

https://uploads.tapatalk-cdn.com/202...746b027552.jpg

https://uploads.tapatalk-cdn.com/202...0827056d2c.jpg

5: fabricate own swingarm using new QS mid drive motor design (see Revolt Motors - India design) with motor pivoting with wheel but much shorter wheelbase.
Would work with cradle of 4 or without, or alternative design of stock engine assembly mount.

Revolt RV400 motor:

https://uploads.tapatalk-cdn.com/202...2c0c0e9923.jpg

Note: the Battery will still require a support but this can be via a suspended case if swing warm uses the original mounting design.

PS: yes, I'm an engineer, I over engineer! I have to try to KISS...

Cheers
Tyler "

20 Hours Ago

tylerwatts created the thread Italjet Dragster conversion.
" Hello forum

I drug my Italjet Dragster out the storage garage today to start thinking about conversion so figured I'd start documenting my build.

This is a smart hopped up ICE example:

https://uploads.tapatalk-cdn.com/202...7e34148a2d.jpg

I've not done a conversion before but am quite proficient mechanically. Learnt slot from forums also and basic Engineering knowledge (by degree and experience).

The Dragster will be an interesting challenge, I bought it for form over function and never aspired to converting it to electric. I intended to do a motor swap from its Italian family for more performance and longer range touring. Then it struck me it'd be a cool EV but I didn't plan on having significant range. But I've steadily convinced myself that I can get enough range for practical every day use by building my own 18650 battery from the modular kits.

You'll understand the challenge from the photos. The scoot has a brilliant tubular trellis chassis and hub centre steering up front. But not much large open square space for a battery block. No leaf modules in this build unfortunately...

https://uploads.tapatalk-cdn.com/202...fa96edc8d5.jpg

https://uploads.tapatalk-cdn.com/202...fa28901e17.jpg

https://uploads.tapatalk-cdn.com/202...590cbf62cb.jpg

https://uploads.tapatalk-cdn.com/202...13d64780dc.jpg

https://uploads.tapatalk-cdn.com/202...ee5bdde295.jpg

Next is the motor. I am very taken by the QS mid drive kits, however the Dragster has a unique rear suspension design. So I'm not sure the QS kit would work. Still tbc but my alternative and I've always liked the idea, is to replace the crank with a motor and fit a fixed belt primary from the motor to rear drive. It's a bit complicated but doable. I might look for a scrap 4t engine with a much larger crank case to fit a bigger motor too, just because...

https://uploads.tapatalk-cdn.com/202...d62a162153.jpg

https://uploads.tapatalk-cdn.com/202...fc8709e763.jpg

https://uploads.tapatalk-cdn.com/202...af3a080ed5.jpg

So right now these are my musings but hopefully I can start making some decisions and get started on building (and some restoration of the scooter bits).

I appreciate your constructive input and discussion but please minimise chit chat and opinion to keep my thread easier to read and maintain.

Thanks


Cheers
Tyler "

20 Hours Ago

rfndzc replied to the thread 1972 Honda CB350F conversion.
" Thanks Tyler. I think maybe Thunderstruck turned me onto this outfit: https://www.rollerchain4less.com/50-...Iz6ogQBA%3D%3D

Kind of in awe. They have a very specific purpose and they fulfill it extremely well at an incredible price.

Rob

Edit: The one's Thunderstruck has linked were able to resolve my rear sprocket, which I decided not to change. This particular outfit I think I just came to thru google wander "

20 Hours Ago