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3DRoboGuy replied to the thread KwSAKI Mk1 (Ex 500).
" That looks AWESOME !
Once I finish my current Scoot project (on the forum, nearing completion - hopefully later today / tomorrow) I want to convert a Kawasaki VN650 Vulcan but the donor price is HUGE !
Anyways, good luck with your controller configuration and, hell, the whole project.
Simply AWESOME ! 10 / 10 !! "

1 Hour Ago

3DRoboGuy replied to the thread 50cc Scooter conversion.
" After 'playing about' with the Volt / Amp meter it was time to re-visit the motor 'stutter' and the un-modified clutch.

I grabbed my hand-held tacho (nothing special here, 15-oddEuro on Amazon), removed the chain between front / rear sprockets and applied a little reflective tape the motor shaft / gear.
Attachment 8331

Ahhhh.... All became apparent... The 'stutter' kicked in at between 5700rpm and 5850rpm. The light dawned... with ears alone, I had absolutely no idea the motor was spinning that fast !! Oops ! The stated maximum motor revs is stated as being 5000rpm and 5900rpm absolute tops ! OK the controller was either deliberately limiting the revs of I'd reached the motor / controller capability limit... either way... " I have a problem Houston ! "

So, using the tacho it became apparent that the onboard clutch only kicked in at around 3000 motor rpm.

The motor arrived with a 13tooth sprocket and the lowest rear (driven) sprocket I could find with a large enough centre through-hole (to pass over the rear vari-drive / clutch drive shaft) was 69tooth. I should have done some more math... Idiot !

Anyways, couple the 13 / 69 sprocket ratio, the clutch and the, internal-to-rear-wheel, gearbox ratio of 14:1 and... nothing surprising here... high motor revs = low wheel revs ! I should have thought of this way before now. Idiot (again!).

OK. I immediately reverted to a plan I'd been concocting that was to simply lock off the clutch by welding 4 short studs between the outer (driven) clutch bell-housing and the inner (drive) clutch pad plate. That took 10 minutes; I popped then off the end of the gearbox input shaft, slipped the bell housing off, welded on 4 short 10mm studs and reassembled (the studs simply located in 4 similar holes in the driven (inner) section of the clutch.
Attachment 8332

Stand up, wheels back on the floor and... OK... 11kmh max speed but.. although I'm disappointed at the, not-so-dazzling, top speed, I'm also grinning - I <b>have</b> converted a petrol scoot to an, albeit rather slow, electric scoot !!

After a poodle (I wanted to say 'whiz' but that really wasn't the case) around the garden and patio with my wife saying... 'Nice dear... but won't won't the milk have gone off by the time you get it home ??? " I reverted to the garage. I stripped down the clutch assembly and started to re-work the plan... but this time with some math first !

Accepting that there is very little I can do with the internal-to-rear-wheel gearbox (14:1) ratio and that the maximum motor revs are 5000 (forget about the over-rev portion (that can simply be a later date 'Brucie' bonus ! ) and the rear wheel circumference of 1.45m I calculated for a 45Kmh top speed (matches the original top speed - although still not dazzling) :
Attachment 8333

5000rpm x chain/sprocket ratio (CSR) x internal gearbox ratio (GBR) x 1.45 = speed (mtrs / min)
=> 5000 x CSR x GBR x 1.45 x 60 = Speed (mtrs / hr)

convert revs per minute into revs per hour (because I need Km per hour - kmh - at the end)
=> (5000 / 1000) = 5

=> 5 x CSR x GBR x 1.45 x 60 = Speed (Kmh)

I know GBR = 14:1, so 1 / 14 = 0.0714 (GBR = a multiplication factor of 0.0714)
=> 5 x CSR x 0.0714 x 1.45 x 60 = Kmh

to isolate the CSR (chain sprocket ratio)
5 x 0.0714 x 1.45 x 60 x CSR = Kmh
=> 31.1 x CSR = Kmh

... or...
=> CSR = Kmh / 31.1

so, for a top speed of 45Kmh :
=> CSR = 45 / 31.1
CSR = 1.45

and, for a top speed of 60kmh - illegal :
=> CSR = 60 / 31.1
=> CSR = 1.93

and for 75kmh - also illegal but fun to work out :
=> CSR = 75 / 31.1
=> CSR = 2.41

That's to say;
for 45kmh, the front sprocket has to have 1.45 more teeth than the rear sprocket
for 60kmh, the front sprocket has to have 1.93 more teeth than the rear sprocket
for 75kmh, the front sprocket has to have 2.41 more teeth than the rear sprocket

So, math over, the motor arrived with a T8F sprocket / shaft fitting, that's to say a double 'D' fitting on a 10mm shaft or a 10mm shaft with two flats cut into it, 180' opposed.
Attachment 8334

The challenge here is that for the (theoretical) power involved (3000W / 3Kw) this type of fitting doesn't allow for larger than 17tooth sprockets (not unless custom built - or someone has a source I haven't found ) To be fair, above 17tooth is probably placing a HUGE amount of stress (even with the 14:1 rear gearbox ratio) on the motor shaft and as the number of teeth are increased so too does the sprocket diameter and, therefore, so too does the side or cross stress and the torsional stress.
The long and the short of all this ?
17 teeth front sprocket is (probably) the limit (but, if I could find a 19tooth sprocket I wouldn't mind a try !).

So, taking the 17tooth front sprocket and the CSR for the three 'required' top speeds above :
to calculate the drive ratio of these two sprockets :

Front Sprocket Teeth (FST) / Rear Sprocket Teeth (RST) = CSR

=> RST = FST / CSR

Front sprocket teeth (FST) = 17teeth

feeding the numbers into the final equation :
for 45Kmh and a CSR = 1.45 :
=> RST = FST / CSR
=> RST = 17 / 1.45
=> RST = 11.7
obviously, a sprocket can only have a WHOLE NUMBER of teeth. A 12tooth sprocket will provide a top speed of slightly under 45kmh, whereas an 11tooth sprocket would provide a slightly greater than 45kmh top speed.

for 60kmh, CSR = 1.93
=> RST = FST / CSR
=> RST = 17 / 1.93
=> RST = 8.8
A 9tooth sprocket will provide a top speed of slightly under 60kmh, whereas an 8tooth sprocket would provide a slightly greater than 60kmh top speed.

for 75kmh, CSR = 2.41
=> RST = FST / CSR
=> RST = 17 / 2.41
=> RST = 7.1
An 8tooth sprocket will provide a top speed of slightly under 75kmh, whereas an 7tooth sprocket would provide a slightly greater than 75kmh top speed.

It should be noted here that a 9tooth sprocket is the smallest I was able to find BUT I'd be very surprised if the chain ran smoothly over it on a standard shaft. Obviously, sprocket tooth stress increases with a lower number of teeth on that sprocket - there are simply fewer teeth for the chain to engage with and transfer power to.
It should also be noted that whilst some even number sprockets exist within the available 9-17 tooth range, there are more odd numbered ones that there are even numbered ones. I believe this is because sprockets with an odd number of teeth wear, both themselves and the chain, more uniformly that sprockets with even numbers of teeth. If a sprocket has an even number of teeth, then the same tooth will be engaged by the same pair of chain rollers upon each rotation. This, in turn, leads to uneven wear on the chain and sprocket and a shortened service life for both... as I understand things.

I thought about the above for a good few hours whilst I was away on business someplace else and couldn't see any other, relatively simple (DIY) and low cost approach to my speed dilemma...
As I was originally 'aiming' to replicate the original / standard scoot I decided to settle for slightly improved 45kmh performance and opted for an 11tooth sprocket.

Working out the math on this one from the original formula :
5 x CSR x 0.0714 x 1.45 x 60 = Kmh
CSR = 17/11 = 1.55

=> 5 x 1.55 x 0.0714 x 1.45 x 60 = Kmh
= 48Kmh
...and... the max motor rpm was stated (and seen on the tacho as the 'limiter' cut in) as being 5900
=> 5.9 x 1.55 x 0.0714 x 1.45 x 60 = Kmh
= 57Kmh

So, with a 17tooth sprocket up front (on the motor) and an 11tooth sprocket on the rear (gearbox input shaft) I should expect a top speed somewhere in the region of 48 to 57Kmh.

That was OK. I was 'happy' again... the question though was how to get an 11tooth T8F sprocket onto an overly long, 38mm diameter shaft !!

In the end, the solution was pretty simple, if a little drastic. But, hey, what the heck, I'd already gone way past the point of no return...

Adapt the shaft !
So, I'm off to do just that !! "

18 Hours Ago

3DRoboGuy replied to the thread 50cc Scooter conversion.
" At the outset I decided it would be really handy to be able to see battery voltage and motor / controller current primarily for test purposes but also whilst riding. However, because I hadn't found a relatively in-expensive meter and because it was simpler at the time and because I really had no idea where I would fit such a meter on the bike and because I didn't want to 'invest' in 'just' a V/A meter without knowing if I would later wish for more (power, temperature and maybe speed...) and because... because... because...
all I did was fit a 100A shunt and a 5 pin test port (both of which I had) ;
pin 1 = Gnd
pin 2 = 12V (DCDC converter
pin 3 = 72V (Battery pack)
pin 4 = Shunt 'A'
pin 5 = Shunt 'B'
All in all a really simple 'test port'...

Later down the line, I found a volt / amp meter on eBay (about 10 euro) using the same 200mA shunt. Needless to say, I ordered one and here it is cabled up and plugged in to the test port :
Attachment 8325

Now though, some 6 weeks into the build, I've arrived at this point and I really think I'm going to need to see this stuff whilst riding. So, whilst I had the covers / fairings off (to add an earth cable to the charge IEC socket - good point Bill), I'm revisited my 'test port' idea and ran a multi-core, screened, cable from the port up to the instrument panel and terminated it with a standard cable socket. In fact, at the same time, I ran a second multi-core, screened, cable from the port up to the instrument panel although not having any immediate real use for it - I'm bound to want it later and, if not, nothing lost !!

Keeping to my original, circa 800Euro costs, I still couldn't find a waterproof V/A meter, that could be retro-fitted on the scoot and be seen whilst riding, for any reasonable price. There was, however, a clock built into the instrument panel... maybe I could remove it and re-task the vacated space for the new V/A meter...
Attachment 8326

Anyways, like I said, I already had all the covers off again, so I removed the instrument panel and stripped it; 3 screws and it was off, 4 more screws and it was opened up, 2 more screws and disconnect 3 cables and the clock was out. No damage done...
Unfortunately, no matter how I tried I couldn't fit the V/A meter in it's place - it was simply too tall. What I came up with though was to split the two 3-digit displays into two, and site them separately.
Attachment 8327

I left the voltmeter on the PCB - it fitted just fine in the available space - then added 100mm of cable between the, now removed, 3-digit display panel (Amps) and the original solder pads on the PCB. I then re-sited (with a little help from Sketchup and the 3D printer) the Amps 3-digit display within the housing...
Attachment 8328
Attachment 8329

I then fitted a matching cable plug to the previous one I'd fitted on the end on the new cable from the controller / battery area to the instrument panel, connected it up and tested it all out...
Attachment 8330

Result !

All's good... ready for testing !

So... back onto the motor 'stutter' and clutch... "

1 Day Ago

Richard230 created the thread Honda Grom EV conversion.
" Here is a video of a really amazing electric-drive conversion of a Honda Grom. It looks like it could have come out of the Honda factory. A very impressive build, although I found the presenter a bit irritating: https://www.youtube.com/watch?time_c...&v=03Wekp2mf0g "

1 Day Ago

Richard230 clicked Likes for this post: Sachs xtc 125 conversion by flo

2 Days Ago

Stevo replied to the thread Sachs xtc 125 conversion.
" That s a fun observation too about the noises! I never knew how loud the chain was with a gas engine!LOL "

2 Days Ago

flo replied to the thread Sachs xtc 125 conversion.
" Officially joined the r-E-volution

all sorted, insured and licenced..
Attachment 8324

Took her for a ride to show my parents and generally staying close to home just to be save.

Not to fast from a complete standstill but above say 20 kph it starts pulling quite nicely i would guess comparable to a modern 300cc, definetly quicker than my old SR500.

Could not get her to take more than 17 kw- but then my controller is still on 55% to run in the battery packs.
Accellerates effortlessly to 115 kp/h (aprox 72mi) and there is more still. Just found out that the front wheel bearing makes some noise so will swap that out before going bonkers with the xtc.
Very easy to corner for the CoG being low ( just right for my liking) and the bike being smallish anyway.
Weard to hear all sorts of noise while riding (fairing craking...), actually i constantly wondered if something come loose. Guess it takes some time to get used to the normal- as in no worries - sounds that may usually be just unhearable when the ic engine is running.
Back wheel dampener is to "hard" for my liking so that has to be tuned in as well.

On a looong flat stretch it took 4,8 kw at 80kph and 7,9 at 100 (60mi). Without tucking under..Rode it 45km and used up 28 KWh acording to the CA. Had regen upped for this ride and that got me 3kw back when decellerating from 100 so i just tuned it down again some 2%...guess it will take some time to find the sweet spot for my liking.

Have the feeling that this bike will see quite some riding unless - like now - it`s gonna pour down for the rest of the summer.


Flo "

2 Days Ago

Stevo replied to the thread Sachs xtc 125 conversion.
" CONGRATULATIONS! Good news and good work! "

4 Days Ago

flo replied to the thread Sachs xtc 125 conversion.
" Hi
passd MOT today without a glitch
The guy was quite impressed with my conversion and took all but 15 mins to look through , aked 3-4 questions, then we copied some pics on a stick for him and his documentation so he wouldn`t need to take them himself and after another 15 min of paperwork me and my brother took off- sheepishly smiling like two young boys. All papers signd and stampd.

Tomorrow being a pulblic holiday i will register it by friday morning and i will be done.
Wheather is supposed to be quite bad tomorrow anyway...


flo "

4 Days Ago

3DRoboGuy replied to the thread 50cc Scooter conversion.
" On the home straight now !

Just a bunch of wires (all with plugs / sockets on) to connect to the scoot and we're pretty much ready for a dry test !

[1] Throttle / Twistgrip
It was day 2 or 3, I think, when I got round to disconnecting the twist grip cable from both the carburettor and throttle ends. After that the original handlebar grips were pretty simple to remove; friction fit, so... a little brute force... and off they both popped. The throttle / 5K twist grip and clutch side had already arrived...(again, a friction fit) and were pushed on taking care to align the right hand / throttle cable exit so as not to interfere with the front brake or cylinder...
Attachment 8316
Attachment 8317
Attachment 8318

Unfortunately the connector wasn't the same type as that on the controller harness. Fortunately, I had some spares, so removed the un-required, black, cable end connector, trimmed the three cores, matched up the colours (red/+ve, black/-ve and green/throttle), crimped on new terminals to match the new connector and connected the cables / plug'n'socket !
Attachment 8319
Attachment 8320
Attachment 8321

Throttle... done... until the dry run / test !!

[2] High Level Brake
According to the manual, this is to remove power from the motor when the brake is applied - makes sense. But, upon reflection... that would mean that pulling away on a hill would require a little more... finesse / timing... As this was simply a question of adding a suitable connector to the brake tell-tale I'd already 'T'ed off the brake light cable (during week 2 electrics tidy-up) and putting cable plug into controller loom (beige wire) socket I thought I'd add an in-line switch to enable / disable this feature. I mounted the switch adjacent to the fuse panel.

In theory, 'making' the switch would disable motor power whilst one or other (or both) of the brakes were on and 'breaking' the switch would disable this feature, thereby enabling power to the motor even though the brakes were on ! It took me no more that 15 minutes to complete so I thought it was worth it ! We'll see...

[3] Hi-Speed / Lo-Speed
The controller loom has a 3-wire (blue/black/white) connector. Apparently blue/black = Hi-Speed and white/black = Lo-Speed. Making a change here (switching between Hi and Lo speeds using the cable loom), when all the bodywork was back in place, would be difficult, I thought. So, again, I added a wee switch, adjacent to the High level brake switch at the fuse panel to select Hi...or... Lo.

A little more time to complete than the brake switch but... bound to be useful... although I'm sure the only 'real' / 'likely' position will be High !! Again, we'll see...

[4] Cruise control
The controller comes with a black-white cable pair for cruise control... I thought there would probably be more disadvantages to this that advantages... and I'd already allocated the kill switch as Controller 'Enable' so... there were no more handlebar switches and... adding one wouldn't be too easy / pretty and... like I say, why would 'Cruise' functionality be required on a wee scoot ? !
I left this connector in the loom - disconnected.

[5] Reverse
The controller also has a black/blue cable pair for reverse... I'd already modified the Starter button for just this purpose so... I crimped the terminals onto the two wires I'd led aft to the controller area from the Starter switch and connected the two up. In theory... we've now gotten a Reverse !!

[6] Display
This is a single purple cable exiting the controller. I have absolutely no idea as to what capabilities it has or what specific display to connect it to. Currently I have left the original Chinese instrument panel display as-was EXCEPT where I'd taken the fuel gauge cable back to the controller / shunt area along with the Low Oil Warning lamp cable. These two are going to be re-tasked as battery level / SoC gauge and a Lo Voltage (<68V ?) lamp...

[7] Hall sensor
The 6 pin hall sensor cable existing the controller simply plugged into the matching cable exiting the motor. Simple.

[8] Power
The thick red and black cables exiting the controller were connected :
red --> HV SSR out (HV 'relay' output terminal)
black -> output side of the shunt (opposite side of the shunt to the battery -ve terminal)

[9] Motor phase
The thick blue, green and yellow cables existing the controller were connected to the same cables exiting the motor via a 50A terminal block.

[10] Power Lock
The controller has a power lock cable. The controller will not become active / energise the motor if this cable is not connected to 12V. This cable was, therefore connected with the 2x SSR energising cables to the ignition switch via the kill switch and side-stand switch.

If the ignition switch is 'Off' or the kill switch is in the 'Off' position or the side stand is down then this cable is disconnected from 12V and the controller remains inoperative.

[11] Anti-theft
As of yet, I don't have an alarm for the scoot. I did spend a little time looking into bluetooth , and other keyless-type alarms but although pretty cheap I felt that, for where we live (extremely quiet) didn't really require anything... yet...

[12] Control panel electrics
During the electrics tidy-up phase I 'found' the cable (original ignition output) that supplies the instrument panel and, therefore, the onboard scoot electrics (head light, side lights, indicators and horn etc...) This cable was connected, via a 10A fuse, at the fusepanel to the DCDC convertor output. Remember the DCDC convertor is fed with 72V from the LV SSR only when the ignition switch is on and regardless of the kill switch / side stand positions.

Attachment 8322
All electrics finished (NOT tested). Just refit the battery tray and connect up the Batteries !
Now, I'm almost finished, I can smell it... I'm off to dry-test... YIPEE !!

Couldn't stop myself, ignition On and the lights all work... the horn doesn't.... hmmmmm "

1 Week Ago

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 Week 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 "

1 Week Ago

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

1 Week 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 "

1 Week Ago

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

1 Week 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 "

1 Week 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 "

1 Week 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 "

1 Week 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. "

2 Weeks Ago