Power in Flux

What's on your mind?


Live Feed

flo replied to the thread Motor Selection for a 200cc comparable performance.
" Hi
to me there is something wrong in your calculations.
I think the motor could be choosen smaller.
Why is there 60Nm of torque required? a 200cc 4 stroke might have what 20Nm? and usually gear ratio in first gear is still slightly lower than our elecrics anyway..
5300 rpm sounds odd to me too, as i calculated around 4300rpm on my bike to get to roughly 70...geard 3,9:1
so either of us both seems off.
The ME1115 is a good choice still, as it is capable to sustain 12 Kw continous so if you live in a hilly area it will not overheat as easy as a smaller one.

good luck keep us posted

flo "

1 Day Ago

3DRoboGuy replied to the thread Honda C50 conversion.
" Hi Supercub50,
Good luck with the project.
Like Flo says, it'll be interesting to see how you shoehorn everything into the available space (doesn't look like you have a lot of it)
Have you selected your batteries yet, 60V but, home-made 18650 cells or... ?
Super interesting to see how it all pans out. Keep the posts coming.
Robo "

2 Days Ago

Spoonman clicked Likes for this post: Soyachips’ Electric FZR250 by soyachips

3 Days Ago

Akash Pardasani created the thread Motor Selection for a 200cc comparable performance.
" Hi Everyone,

I have been thinking about giving a shot at converting my Yamaha FZ S and while I am at it, maybe even amp up its performance. So I did some quick calculations to choose the most ideal motor for my use case (considering cost and motor specs) to achieve the desired performance:

1. Top speed of 110 kmph (~ 70 mph)
2. 0-80 kmph (0-50 mph) in about 5 seconds

My calculations for a 4:1 gear ratio and 17" rear wheel suggest a motor with instant torque of 60 Nm (~ 45 ft-lb) and a peak loaded RPM of about 5300. After digging up a little, I found ME1115 to have a similar performance (although I would have to further lower the gear ratio and maybe compromise a bit on the acceleration side).

Hoping that I have not messed up with my calculations, I wanted to get some opinions on the motor selection and whether I'll be able to get this performance out of the motor? Any other suggestions or advises are welcome as well.

Thanks in advance,
Akash "

4 Days Ago

Richard230 clicked Likes for this post: Soyachips’ Electric FZR250 by soyachips

5 Days Ago

soyachips replied to the thread Soyachips’ Electric FZR250.
" Put the new blocks into the existing swingarm, swapped the tyre over and got it all into the bike. Next step is to work out how to mount the batteries and controller inside the frame. Decided to push the bike home from the workshop and got some interesting shots on the way






https://forums.aeva.asn.au/download/file.php?id=1303 "

5 Days Ago

soyachips replied to the thread Soyachips’ Electric FZR250.
" Had some awesome help from Danny Ripperton (AEVA member) machining the swingarm blocks that hold the hub motor axle.



https://forums.aeva.asn.au/download/file.php?id=1298 "

5 Days Ago

3DRoboGuy replied to the thread 50cc Scooter conversion.
" This was some fun ! I took some measurements and started designing (SketchUp, again) a replacement fuel filler neck & cap some weeks ago.

First I thought I'd use the same Anderson connector as was on the batteries I intended to build (and have since completed). I can't, right now, remember why but I changed my mind and used the XLR 4-pin socket to match the plug that arrived with the charger... the same sockets in fact as I fitted to the two batteries for charging - keeps the parts list simple
Attachment 8313
Attachment 8314

During first fit though, I decided to change the design (again) to a 3pin IEC mains 110/220V AC socket - as per the mains cable between the wall outlet and the charger input. This was mostly because, having a drink at the bar, discussing charging one night, we all agreed that the charger would always be required to charge the scoot (obviously). My idea was that the charger should be carried in a back-pack / ruck-sack or, if space wasn't too important, under the seat ! It was pointed out to me that the charger would then need to be connected to both an available wall outlet and the charge socket, behind the seat. Seemed pretty obvious to me... what wasn't so obvious was that everyone agreed it would be simpler just to connect the bike to the wall socket - no charger to play about with or fall off the seat (or wherever else it had been balanced) and break. Seems reasonable ! In addition the space under the seat (on this scoot) is pretty poor anyways (I think I've already mentioned that somewhere along the line...) so... why not use it for the charger ? ? ? As a bonus, the charger is always dry under the seat - it wouldn't necessarily be so, balanced on the seat / next to the scoot during charing...So... why not indeed ? !
And, as it transpires, there's still some space left over for documents, tools and gloves etc...

The 'downside' to this approach is that the scoot will have a fixed / permanent mains AC item wired in at all times and although it won't (obviously) be live at all times, I'm unsure as to any safety regulations with this approach. Having said that, the IEC connector could always be swapped out for the XLR connector in around 10 minutes... so... What's not to like with this approach ?

The final connector, fitted on the scoot with the fairings back in place, looks like this :
Attachment 8311

The design incorporates an 'O' ring on the lid / cap and a large overhang to reduce the chances of water ingress. It has two large drain slots built in (semi-circular, forward and aft of the raised, central, IEC socket, to prevent water build-up if any gets in.
Attachment 8312

The mains cables (L, N & Earth) are soldered and heatshrunk before being liquid silicone sealed. The cable terminates in the under-seat area with the original IEC plug for the charger. The charger output (XLR connector) connects to the, now redundant, original XLR socket thereby keeping it all fully removable for service etc...

A little smear of silicon grease on the 'O' ring and the lid / cap is a simple friction twist fit !
Attachment 8315 "

5 Days Ago

jhaggerty created the thread Wanted: 120V PMDC controller.
" Hey folks,

I’m in need of a controller that can handle 115V and probably around 400 amps. Something like the Kelly KDH series or a Curtis controller. If you have something you no longer need that fits please let me know. "

1 Week Ago

3DRoboGuy replied to the thread 50cc Scooter conversion.
" This week I've been busy with the last major part of the conversion: siting the controller and associated components.
The original ICE kit has been removed.
The original wiring has been serviced / repaired / updated to remove no-longer required cabling and modified to re-task cabling to suit the new electrics and add any new / additional cabling for the imminent electric conversion.
The 3Kw BLDC electric motor has been fitted on a custom, adjustable, aluminium bracket and the cabling routed aft and up to the intended controller position.
The belt driven vari-drive has been modified for a chain drive with rear sprocket and the clutch has been left insitu (to start off with but I have my doubts here...).
All lighting has been switched to LED.
The battery pack tray has been built and installed.
The 2 x 72V, 1KW battery backs have been built, charged and tested.
The fuel filler cap has been replaced with a 3D printed charge point complete with waterproof cap (still need to update here with pics etc).
Attachment 8304

The next step was to design and build the controller 'tray' and then mount the controller before adding a 2nd tier shelf arrangement on which to mount the other electrical / electronic components (fuses, relays, DCDC convertor, 12V battery etc) and connecting the systems up prior to testing. Now it's becoming exciting...

Controller tray
Now that the batteries were sited directly above the motor, there was enough space (with a little modification) to site the controller (and ancillary parts) in lieu of the petrol tank / aft of the rider's seat. This are is a quite 'unforgiving' space in that the rear wheel is directly below (don't go too deep) and the fairings are immediately above (don't come too high). To boot, access to the rear / brake light is from this area too (don't go too far aft) and the front end is limited by the seat-lock bracket (don't come too fare forward)... BUT... all-in-all this is controller space !! Dry and well cooled...
Having decided all would be well, I set to designing and fabricating the tray. This was no job for SketchUp or the 3D printer - just cardboard, scissors and tape before moving on to foam and then fabrication with fibreglass...
Attachment 8305
Attachment 8306

It quickly became apparent that no matter how much I dislike cutting holes where not absolutely necessary and no matter how much I 'squeezed' or moved the controller or how I oriented it (within the constraints that I had) I HAD to cut two holes in the seat support bracket to enable the cables to pass through and, thereby, allow the controller to move far enough forward to facilitate access to the tail lights. In this case though I couldn't see how the holes would weaken the overall structure so... I cut the holes, rust proofed them, glossed over and trial fitted the controller...
Attachment 8307
Attachment 8308

All looked good so the next step was to mount the controller and the two SSRs with their heatsinks. I guess the 'norm' here is to use HV contactors / relays but Solid State Relays use so little power when 'On' and have the advantage of being so very flexible with their energising voltage that I thought I'd give them a go. They have worked great in other projects (like my Spot Welder) so they deserved a chance here too... especially as, having no moving parts, there can be no contact bounce / accidental disconnect due to the higher vibration of the scooter... Anyways, I gave them a go !
Two of them, one for the low voltage (12V) / controller energising and one for the high voltage, (72V) motor.

The recently removed fuel tank had been through-bolted at four points - top and bottom left and right of the recently-fitted controller tray. These were to be re-tasked to locate the "ancillary components shelf" which (because it allows me to see the controller & SSRs below and because (I think) it looks super cool - not that, when all the fairings are back in place, it will be visible !) was to be made form 8mm clear Acrylic sheet...

After test fitting the controller tray and acrylic 'shelf' it was time to drill 2 additional (corner) holes in the tray for drainage (there's just bound to be some water ingress) and finally fix it to the scoot frame.
Attachment 8309

I ended up with the painted black, GRP tray housing the controller, the 2 x SSRs and their heat sinks. The tray is angled down toward the front of the scoot (towards the bottom of the image); this is where the 2 x 10mm drain holes are situated.

The SSRs screw to their (black) heat sinks and the heatsinks are through-screwed into the base of the controller tray. The two holes previously drilled in the seat-lock bracket enable the controller HV input (thick red and black) and motor phase cables (thick blue, yellow and green) - both right hand lower corner, together with the control cables (thinner, multi-coloured) - left hand lower corner, to exit the controller tray without chafing etc...

Now, things began to move really quickly !
This was the part I'd been really looking forward to !!
The first job was to finish siting the SSRs and connect the 2 x battery hook-up cables (terminated with Anderson connectors) The DCDC convertor was fitted next, followed by the Li-Ion 12V battery, the shunt (I think I'm going to want to know charge / discharge current and voltage etc) and then fuse holders. I added a pair of (red / black) banana connector sockets to measure the battery / DCDC convertor voltage and to connect an external 12V source / charger in case of 'flat battery'.

Two SSRs :
... both energised by the Li-Ion battery via its fuse, the ignition switch and the kill switch.
One 10A SSR (left hand side) for the low voltage (12V). This unit feeds 72V to the DCDC convertor.
One 60A SSR (right hand side) for the high voltage (72V, motor / controller). This unit feeds battery pack 72V to the LV / 10A SSR (which feeds the DCDC convertor) and the controller.
One DCDC Convertor :
Connections to the HV SSR output, shunt ground and the 12V fused rail.
One diode :
In-line between the fused 12V rail and the Li-Ion battery The purpose of the diode is to enable Li-Ion battery pack charging whilst preventing back-flow from the battery to any on-board items - except the DCDC convertor (for charging)
Three fuses :
DCDC convertor (all onboard 12V)
Ignition / controller enable (basically, kill switch OFF and Ignition switch ON puts 12V onto the 'power lock' / controller enable.
Onboard lighting / horn electrics
One shunt :
One side of the shunt was connected to both battery -ves, whilst the other side was connected to motor controller -ve, DCDC convertor -ve and chassis ground.
Final steps : the motor cables (green, blue & yellow) were connected via a 50A terminal block to the controller. The controller / motor hall sensor connections were made (plug'n'play)...
Attachment 8310

... and then onto the throttle, brake, reverse and power lock cables... but those are for tomorrow... (mostly because it's late and I note that the throttle cable is terminated with a different plug-type to the controller socket !

To be frank, I also have :
the High / Low speed connector to make (naturally I only need the HIGH !) but (if only for testing) i'd better make a PAIR of connectors - one for Hi and another for Lo speed - or I could add a Hi/Lo switch...

the 'fuel filler' / charge port to connect. I have designed it (SketchUp) printed it (3D Printer), fitted the matching 72V charge connector into it and test fitted it on the scoot but I need to add the diode protection, connect up and fit it...

dry test the lot...

reassemble the scoot and let my son test it for me... receive his 'review' / critique and...

and... probably, a load of other small jobs I haven't remembered to write down here... "

1 Week Ago

Warren replied to the thread Ron Horn FF coming along.
" I am embarrassed that I called him Ron, when his name is Robert, and we actually corresponded back in the day, on the old recumbent bicycle list.

Anyway, Bob has been busy with his design.


His ultimate plan is for a two-wheel steer, two-wheel-drive, electric motorcycle.


Looks like Facebook has a similar, if less ambitious, idea.

https://electrek.co/2019/06/07/faceb...ic-motorcycle/ "

1 Week Ago

Stevo replied to the thread Mugen Shinden 8 racer.
" Sounds like he had at least one "OH $HIT" moment! "

1 Week Ago

Richard230 clicked Likes for this post: Mugen Shinden 8 racer by Warren

1 Week Ago

Richard230 replied to the thread Mugen Shinden 8 racer.
" 122 mph average? I am impressed. "

1 Week Ago

flo replied to the thread Honda C50 conversion.
" Hi
will be very intresting how you get all into there.

Good luck

Flo "

1 Week Ago

flo replied to the thread Sachs xtc 125 conversion.
" Hi
well like any industrial country they want you to buy new.

Talk about customising a vehicle.. pia


flo "

1 Week Ago

Spoonman replied to the thread WORX.VOR.EMC.v3.3.
Quote Originally Posted by Stevo View Post
I think it's a functional work of art!
I see what you did there.

https://media1.tenor.com/images/b8db...itemid=4969698 "

1 Week Ago

Spoonman clicked Likes for this post: WORX.VOR.EMC.v3.3 by Stevo

1 Week Ago

Spoonman replied to the thread Sachs xtc 125 conversion.
Quote Originally Posted by Stevo View Post
...One would think that they would make it easier to convert than more difficult!...
https://wwwcache.wralsportsfan.com/a...6c-480x256.gif "

1 Week Ago