# Planning DERBI bike conversion



## o_teunico (Oct 25, 2012)

Oooooooooooops! Maybe I should have posted it in "Bike" section of forum.


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## o_teunico (Oct 25, 2012)

Hi!

This weekend I´ve been searching in the old barn (in the farm belonging to my parents-in law) and this is the stuff I´ve found.

Left to right:

-Spanish built "ZALDI" industial single phase AC motor (attached to waterpup)
*110/220v
*3/4 H.P.
*8/4 Amp.
*1400r.p.m.

-DC(12v) to AC(220v) sine wave 0.3kw device 

-Homemade waterpump (seems like ex-washing machine parts)

-Italian ex-water pump "VEMA" AC #6 collector type motor
*160/220v
*3 2 Amp
*4500r.p.m.

-German "AEG" AC motor
*220v
*5.1 Amp
*0.75W (don´t understand how little with more than 5 Amp)
*2700r.p.m.

-Several 12V alternator and batteries

I also found a 2.1kw (220V) BOSCH angle grinder


For this project I think that the angle grinder will be good choice.
Power is the same as 50cc ICE used in small workhorses, like Piaggio Ape









-
A motor this size (small) will have low torque, so bicycle gears (have plenty of them in the barn) could be used to take down r.p.ms

My idea:

-Angle grinder as motor, with bicycle gears in place or cutting disc.
-"Throtle" taken from 2.5KW driller, to adjust engine speed to road conditions.








-Twin 12V 125Ah pararell (that is, 250Ah) lead-acid tractor battery.
-12 to 220V DC to AC 2,5KW converter

As you see it will be quite simple set up, with no BMS or controllers

¿What do you think about this idea for my ******* electrobike?


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## Woodsmith (Jun 5, 2008)

o_teunico said:


> Oooooooooooops! Maybe I should have posted it in "Bike" section of forum.


I have moved your thread to the Bikes forum.


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## o_teunico (Oct 25, 2012)

Thanks Woodsmith!


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## o_teunico (Oct 25, 2012)

Have been looking Piaggio Ape´s brochure.

Vehicle plus cargo: 700kg (aprox. 1500lbs)
ICE: 50cc two stroke, [email protected].

Bosch angle grinder with [email protected]. could work fine.

Unfortunately I can´t find any "throtle" (prefereably with "reverse" function for future sidecar aplication) out from a driller that handles more than 1.5KW.

¿Any ideas for a reliable and cheap 0 to 6500r.p.m. plus reverse motor controller?


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## o_teunico (Oct 25, 2012)

While dish washig (yep, now I´m the housewife) I started thinking about POWER and WORK.

If the Piaggio has 1.8KW "power" and it´s "work" is hauling 1500lbs at 25mph...my ******* Electrobike will only need to haul half that weight...so will need half the POWER: 0.9KW...but will not travel on tarmac, only off-road, that is, half the speed of Piaggio, so again, half POWER: 0.45KW.

Are this asumptions correct? 

Rounding, 500Watt driller will do, and, as JRP3 said in it´s tractor proyect tread: "with an electric drill on the engine flywheel bolt it's already converted to electric, fastest conversion ever". 

This one will be even more than needed



0-to top rpm throttle, electronic reverse and even mechanical gearbos (top rpm 1300 in 1st and 3100 in 2nd).

I will measure wheel next weekend to see if this rpm range will do.

Any previous experiences with drillers as motor?


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## o_teunico (Oct 25, 2012)

Hi!

Yesterday I started thinking about gearing.

Good news are that chain/crown on moped are same teeth-to-teeth length than those on the bicycles I have to scrap. 

Bad news are that I will need more gear reduction than that of a bike.

3 1/4 x 18" wheel gives me about 0.11km/h for every engine rpm.
That means that the drill, with direct drive and at it´s higher speed of 3100rpm, will make the moped to fly at 340km/h (more than 200mph  ).

Obviously this is imposible (and insane!) with a 0.75kw motor.

A a top speed of about 4 to 6 mph means that I will need 90rpm at wheel, that is, 34 to 1 ratio.

Driller´s 1300rpm gear will make a perfect "crawler" ratio (about 2.5 mph)

Smallest bicycle gear is 10 tooth, but is plastic. Steel smallest one has a tooth count of 14. Bigest one is 46.

14/46 will make 3.29 to 1 ratio, and I need ten times that.

14/46 threesome should give about 35 to 1, but will be quite bulky.

¿Any ideas to help me with gearing?


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