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Discussion Starter #1
There's something I've been wondering about . . . Since it sounds like some people run DC series forklift motors up to 10x their rated voltage, would it be too unreasonable for to operate two motors (placed in mechanical series) each at 200V? Using a leaf battery system, at about 380V (unless I want to really get in there and rewire everything) it seems like running these motors off of this battery in ELECTRICAL series as well would place both motors near 200V ~ within the reasonable realm?
 

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There's something I've been wondering about . . . Since it sounds like some people run DC series forklift motors up to 10x their rated voltage, would it be too unreasonable for to operate two motors (placed in mechanical series) each at 200V? Using a leaf battery system, at about 380V (unless I want to really get in there and rewire everything) it seems like running these motors off of this battery in ELECTRICAL series as well would place both motors near 200V ~ within the reasonable realm?
Hi Meni,

This sounds like a bad idea for multiple reasons. But the killer is the motor controller. Unless you're prepared to custom design the controller, forgetaboutit. Even then, you'd soon realize it best to keep this each motor controller circuit separate but powered from a common source.

Off the shelf, the Zilla will accept nearly 400V and allow motor limit to 50, 100 or whatever. I'd look at that approach.

Regards,

major
 

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Thank you Major.

Those Zilla's look pretty spendy at over $2k. But they do seem like a really clean/easy solution!

I've seen a lot of people talking about making a DIY motor controller being the cheapest way to go, and also not terribly difficult (mostly solder monkey?) But I don't know that I have the confidence to do this. Would a controller to pair with two motors in series be that much more complex? Or perhaps just not as much information about the design for said controller?

To be clear about your suggestion. . . I would have two motors in mechanical series, electrically powered in parallel from a single Zilla?
 

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Thank you Major.

Those Zilla's look pretty spendy at over $2k. But they do seem like a really clean/easy solution!

I've seen a lot of people talking about making a DIY motor controller being the cheapest way to go, and also not terribly difficult (mostly solder monkey?) But I don't know that I have the confidence to do this. Would a controller to pair with two motors in series be that much more complex? Or perhaps just not as much information about the design for said controller?

To be clear about your suggestion. . . I would have two motors in mechanical series, electrically powered in parallel from a single Zilla?
My recommendation is a controller for each motor. However some drag racers have the Zilla option which runs two motors in series from a single Zilla. I don't think it is a good idea for a beginner.

What is mechanical series vs mechanical parallel?

major
 

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Discussion Starter #5
some drag racers have. . .

What is mechanical series vs mechanical parallel?

major

That is a great question! I have been discussing putting two motors in mechanical series by attaching the drive shaft together, so both motors are powering the same shaft. I would assume mechanical parallel would basically mean something like a motor on each wheel. . . ? Probably not the best idea in most applications~



btw~ not trying to drag race or anything. Just trying to power my 6,000 lb Winnebago LeSharo up to about 50 mph. . . could it be done with a single forklift motor? Maybe a single beefy one (150lb, 9.5" x 11") ?
 

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Hi Meni

could it be done with a single forklift motor? Maybe a single beefy one (150lb, 9.5" x 11")
I would call that a "small" forklift motor a 9 inch motor!

I'm using an 11 inch motor - 102Kg

I would think that putting two 11 inch motors together - the Hitachi I'm using has a double ended driveshaft so that would be easy - would be easy from a mechanical POV

Basically you end up with an 11 inch motor that is about 40 inches long! and about 210Kg

Electrically - if you connected them in series then the same current would go through both and your controller would control the voltage to control that current

For my Hitachi I found that I needed about 150v to get adequate performance at the top end
A 130v system gave me a top speed of just 100 kph

So your system would need about 300v

A Paul & Sabrina high voltage controller would be fine for that
 
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