Razor e300 heritage scooter mod heavy.

[Ianhill]

Basically im putting together a brushed dc scooter with what i can consider the strongest parts of the cheap stuff. I want to make an old school mule so i can abuse it and failure not be an option.

Most think the brushed motors burn out but geared lightly they can run on for many years if theres care taken to not fill the brush plate with mud sand or any crud, stock they like gearing of 5.4 for t8f on small wheel with a 70kg rider

I came across my first scooter the razor e3kw still on the road same motor after many years beat out all my other rides so im going to remake it a bit less powerful overall my calcs ill be at 2.65kw max vs 3kw of old but my 12s has changed to 14s and the 36v motor to a 48v so all in all ill spin slightly slower speed and little less torque but ill have a lower no load current and geared at 6-1 rather than 5.4-1 of old.

The main problem with these cheap brushed/brushless motors for me has allways been the t8f chain snapping and wearing out fast cuz its shit and getting a sprocket that fit's the small rear wheel and gearing is low enough on the motor side is not easy.

Now theres a oset mx10 that uses a 219 54t sprocket that fits a 6 bolts disc mount flange, plus theres a freewheel to disc adapter so thats the rear wheel sorted remove the freewheel and go direct drive no more wobbling sprocket with poor degrees of engagment.

Motor mod
Secondly is the motors t8f 8mm sprocket and fitting the 9t 219 its 12mm internal so to get it to fit looks hard but is simple, the motor has a 11mm spanner slot to lock the sprocket down i filed down one side flat to the threads on the shaft and then taped the holes on the motor up spun it and just took a thou off with a hand file as it turned then the sprocket fits on.
To finish it off the face plate needs its bearing hole opened out to 18mm i used a step drill and a collar to go on the shaft from a piece tube 12mm id 16mm od and 7mm long to hold the sprocket square to the bearing face and then use the original nut and tighten it all up.



Build overview.

20-25mph top speed
10ish miles range
25kg or there abouts
Simple to charge
Volt amp wh display with built in relay to isolate controller plus a lm2596 hv step down to give me 12v to
power the shunt setup and front light.

Power.

Zy1020 48v 1000w brushed motor
Yk43c 60v 45a 1500w controller
14s 10ah turnigy graphene lipo cells 15c.
45amp bms, 10amp charge.

Frame.

Modified stock handle bars with star nut to fit mtb stem and bars to give a forward standing position.
Replace fork cup nd cone bearings with concealed cartridge and use a scs 4 bolt clamp
Few strategic holes placed on the frame and front fork for consealed wires with a headtube badge from a razor e prime to finish the puzzle as all will be revealed as i go.

Bits and bobs will change along the way but the setup will be similar to my old one motor on top of deck so theres good ground clearance but now the controller will sit in the original motors place giving plenty of clearance and opening the battery box front area up to give more room.

 

[SlowCo]

I had one of those motors in my old scooter and it served me well :thumb:
I'll be following your progress. Good luck and enjoy building!

 

[Ianhill]

Thank you slowco.
I should be picking up a local e300 white last of the bunch today all being well ill start modding this weekend.
Ive changed my mind on using a razor eprime badge when i checked it didnt fit its designed for a alloy headtube with a thicker wall giving a large OD.

So ive had a look about and got an appropriate badge.

So I'm making a bulldog not a pitbull :wink:

 

[Ianhill]

The scooter is white don't work and needs my help the drive is locked solid, chain rusted out, battery's dead and electrics need attention so all in all its perfect for what i need.

Got the controller today and run the motor on 12s to test it and theres a fair bit of noise at low rpm but theres no brush spark suppression on the motor at all so ive ordered a few 10nf ceramic capacitors and a pair of ferrite beads so ill wait for that fit it time the motor up neutral show what i mod and attempt to run at 16s as the controller looks like its set up for 60v lead acid or 66v fully charged so ill try 67.2v see what happens and ill give an update the motor should spin at 5000rpm if alls well ive done that with a 36v version in the past so it should be fine.

 

[Ianhill]

Made a start on cable managment.
20mm hole under frame ready for a blind grommet.

Then the more difficult 20mm hole inside the headtube, I started off but driving a 4mm hole through both sides then progressively opening it up to 10mm boths sides.
I then took a step drill and opened the front hole out to 20mm and used a hole saw with a 10mm guide bit and pushed it through the rear hole being guides by the front 20mm hole its quite hard to go wrong just take time to be sure the alignment keeps true as you step the hole size up and dont jump up drill bit sizes fast and use cutting compound or wd40 what ever.

With 20mm holes through the frame theres now plenty of room to pass lots of cables no problem just mod the back of the fork now to get them through and job done, below is a pic of the final front with the head badge placed on ive swaped the steering end stop cover with a grey one to give more contrast to the area.

 

[Ianhill]

Heres a mad one
My 1st brushed razor e3kw
12s 60amp 3024w peak at full charge
4.2×12×60=3024w
This heritage version if 16s will work
4.2×16×45=3024w

Its like the stars have realigned for a new birth from the scooter gods, a brushed bulldog e3kw small wheel big torque will be born from the broken shell of a razor e300 as it rises from its rusted hell for all its sins will be washed clean in an holy ceromony that i will perform over the coming weeks.

Its got a calling this one.

 

[Ianhill]

Cable run from bars to battery box is done, it may look like ive weakened the fork alot and the gap will fold shut when the fork is compressed hard but when the support of the bearing seats and headtube is in place the area may yield earlier than a complete headtube but its still strong enough to yield after the metre long handle bars or the fork itself from kurb strike etc so i feel fine riding the design knowing that razor have very simular on the newer eprime.
Ive kept the top nut so theres tension in the fork against closing up and the bearing seats and headtube take the load, ill be using a scs clamp and oversized bars.




The eprime has a larger hole to the rear of the headtube before it was welded on so the hole in the fork is a little less invasive by a few mm width wise but much larger in height.
Because i could only get a 20mm hole inside the frame on the e300 due to the oval downtube to the frame vs a square one on the eprime and a milled out headtube ive had to go a little wider but on a custom frame its a design que spotted to follow.

All in all im more than happy with the 20mm hole through the frame its what enters the battery box so ive got a clear run front to back now.

 

[Ianhill]

I got the sprocket in post yesterday so i set about making it look decent and taking some weight out of it, its already light being aluminium but now its only 103g with the freewheel adapter and 6 m5 bolts it will be alot lighter and stronger than the freewheel system it replaces.

Ive not got any special tools this was done with a ruler pencil and patience using a hand punch, block of wood, drill with a step drill bit and normal drill bits, i find key is to take time and keep a steady arm drill level dont rush measure alot.

 

[SlowCo]

Nice work, it's turning out great :thumb:

 

[Ianhill]

Done a motor test
[youtube]DfXWyotxNW4[/youtube]

Got lots going on at moment but the scooters coming along well the rear end has a new 12mm axle all custom spacers to get the alignment spot on wheel centred and chain line straight next few days will see more progress and updates.

 

[Ianhill]

Started fettling the motor before i bolt it down on the scooter in its final home.
Conformal coated the motor all bar the commutators and side covers etc.

The vent holes are no where near upto the job of letting enough air pass through so ive opened them out to the limit of the reinforcement spider that sits behind them and smoothed them out into the front cover for the most air flow the covers can reliably give.

I've removed the mesh that goes over the hole on the side covers and will leave open for time being and keep in mind to avoid dust and water but ill put a better quality mesh back in when i get some ceramic bearings.



Next job is adding capacitors to the brush plate and rewireing it as the metal brush holders pass current and its resistance is part of the circuit terrible design so ill fettle that pop pics up and show a complete motor next few days spinning the backwheel with a fully charged battery and find out what RPM im getting.

 

[The Mighty Volt]

Hi. I have seen a proliferation of these motors and they seem a good cheap way to get around from the "better" but a bit more complicated hub motors.

Do you have any cheap/reliable source for 3 phase HIGH RPM motor-controllers?

I can find the motors pretty hand- brushed and brushless-3-phase but not the controllers so easily.

Good lucj with your build can't wait to see it finished.

 

[Ianhill]

Caps on the underside of the pcb in sleeving for the brush sparks. 10uf 100v ×5

Added terminal posts to the brushholder corners and added lugs to the brushes so the power goes direct to the brush instead of across its holder giving less resistance in the circuit and the metal is not getting hot from passing current.

The screws never come out ive allways had to drill them so im gonna add some bolts to it and reassmble it all then.

Ive not made the motor any more powerful ive just improved its continuous rating with better airflow and less heat in the brushplate.

Its pointless adding thicker phase wires to wick the heat out the motor becuase they have no contact with the core so ive stuck with 12awg but its fine stranded silicone so its nice and flexable compared to stock stuff.

Ill pop a few pictures up once its bolted together show how i fix the brushplate down.

 

[Ianhill]

Hi. I have seen a proliferation of these motors and they seem a good cheap way to get around from the "better" but a bit more complicated hub motors.

Do you have any cheap/reliable source for 3 phase HIGH RPM motor-controllers?

I can find the motors pretty hand- brushed and brushless-3-phase but not the controllers so easily.

Good lucj with your build can't wait to see it finished.

Sunwin 48v-72v 1500w controllers i used to use and they were cheap and powerful do over 3kw on high speed setting but ive not bought one for years so dont really know whats best for you there maybe a better option.

 

[The Mighty Volt]

Hi. I have seen a proliferation of these motors and they seem a good cheap way to get around from the "better" but a bit more complicated hub motors.

Do you have any cheap/reliable source for 3 phase HIGH RPM motor-controllers?

I can find the motors pretty hand- brushed and brushless-3-phase but not the controllers so easily.

Good lucj with your build can't wait to see it finished.

Sunwin 48v-72v 1500w controllers i used to use and they were cheap and powerful do over 3kw on high speed setting but ive not bought one for years so dont really know whats best for you there maybe a better option.

Cheers pal I will keep an eye out for one.

 

[Ianhill]

This has got to be the most love one these brushed motor has ever got.
The brush plate is complete and theres some room left to put mesh in if i feel the need.
The studs are mounted in place of the old screws with nuts too keep the pcb level and then bolt down from the top, i left the original locating dowels so i know the brush plate is sat exactly in the same spot as it was and has all the support it used to have but now the whole assembly is serviceable.

 

[Ianhill]

For anyone struggling to put a brushed motor back together here's a little tip if theres no on the brush holder, use elastic bands and then cut them once in place.

 

[Ianhill]

Got the motor back together ferrite beads on to stop any spark noise the capacitors missed from getting back at the controller, Its never meant to be a power monster its not going to be shy with 3kw but its about using old tech to embrace the heritage and push it for one last hoorah.
The inspiration for this scooter is a 1890 battery powered blackpool tram, i wanted it to sound as simular to the brushed trams they run so i can take it along and show a simular setup all be it with a pwm controller rather than a 1890 resistive controller like the early scalextric remotes etc after all it is 2021.

The battery box holds the cells like its made for them i got to get a bms, watthour shunt gauge, antispark on off switch plus a dcdc for 12v lighting maybe a long led cob down the stem for a super clean look.

 

[Ianhill]

Building this scooter reminds me of being a kid playing with lego technics making my own designs, 1 step forward 2 steps back and so on to the finish. Only difference here is ill spend an hour making up my block/plate then chuck it in the scrap pile with a design change.

Ive got the motor mounted now, chain line is spot on all bolts cut to length ready to finish up the motor wiring in the space between the controller then focus on the battery area get it rolling with no brakes then braze on some caliper mounts, still not worked out how ill mount the front disc to hub yet but ive got ideas.

 

[Ianhill]

Got the chain fitted, and spotted id forgetten all about the tensioner so i had a look at the stock tensioner set up and it looked like it would work if i relocated it close to the sprocket as i could get it.

All in all the tensioner is spot on its alignment and width is ideal it was just a case of moving it with 2 small holes.

Depending what turns up in post next ill either be moving on with the electrics or getting the brakes sorted.

 

[Ianhill]

Got the motor wired up to the controller with a xt90 and noticed the wheel freewheels easily enough in the forward direction but if i try push the scooter backwards it doesnt want to as easily its no problem i dont intend on traveling backwards but turning round was easier on the freewheel system but i intend on wheelieing this thing so direct drive is best for me.

Ive spun the motor on my icharger to 15v so i know the chain tensioner and alignment is decent so soon as ive got my antispark ill power the controller up and link a YouTube vid but more detail than the last show it spin up the wheel on a fully charged pack and get a slow motion rpm count.

 

[SlowCo]

Great work again!
But why is the chain tensioner on the pull side? That will put a lot of stress on it and result in heavy wear. If possible I would advise to put the tensioner on the under side and make it spring loaded to keep the chain tensioned when "stretched and slacking" by the torque. Just a thought.

 

[Ianhill]

Great work again!
But why is the chain tensioner on the pull side? That will put a lot of stress on it and result in heavy wear. If possible I would advise to put the tensioner on the under side and make it spring loaded to keep the chain tensioned when "stretched and slacking" by the torque. Just a thought.

Thank you slowco.
The scooters upside down in that pic your looking at the underside of the motor, tensioner sits on the underside of the chain, and its spring loaded panic not lol good spot mind ive seen it done the otherway on a few rides and said same as you have.

Was lucky the original tensioner just about fits by skin og my teeth if i moved its holes as the chainline heads to the motor above deck now rather than below.

Allways thought how would a chain drive do regen tensioner have to be more complex than what ive got.

 

[SlowCo]

:lol: I completely oversaw that it was the underside...

 

[Ianhill]

:lol: I completely oversaw that it was the underside...

That picture has got bit of a self righting robot look to it ride it either was round thats how i guessed what u seen.

Its a shame im limited to 500mb pics with out linking it looks ruff hard to get a clean image with any detail.