[Denzil68]

Hi,

If I can find the right forklift, Im thinking I can use the following....

1) The batteries

2) The controller

3) The accelerator

4) A motor (I believe some lift motors are bigger than traction motors?)

If the forklift was a 72volt, for example, am I right in thinking I can just add some extra batteries to over volt the motor, and the controller will be happy to deal with it?

I know the motor should be timed to match the new voltage.

Please advise if Im barking up the wrong tree with this.

Im hoping to connect the motor directly to the diff, and the van weighs 1700 kg as standard(with ic engine) , so with all the batteries added I think the voltage is going to need to be over 72v?

Thanks for any advice, Dennis

 

[Woodsmith]

The batteries will be very heavy, probably much heavier then your van can handle, obviously in a fork lift the weight is a bonus. However, if they happened to be there then they could be good for testing until you sell them or weigh them in as scrap. Clearly you would then want the charger to go with them.

The controller's usefullness will depend on its age. Old ones tend to be less useful but a modern electronic one might be usable. However, that would depend on its bulk and its voltage range. You would need to check the manufacturer's spec on it.
Old controllers, and controllers in general my provide useful components such as, cut off switches, relays, contactors, fuse carriers and fuses, big Anderson type connectors, etc.

The accelerator pedal may provide a useable throttle pot.

The motor will depend on what type and size it is and also how it is coupled as mentioned in your other thread.

The fork lift may also give up lots of cable that may help.

Do take the pump motor too as it could be big enough for a smaller project or be saleable as either a small eve motor or as a pump.

The rest of the fork lift may offer saleable hydraulics, rams, valves, etc.
The remaining parts will produce a sizable mass of steel for the scrap yard for you to recoup costs.

If you find a forklift to attack take some photos of the motors, controller and any specs or data plates and post in the forklift motors sticky in the motors forum. You will get advice as to how useful the parts are then.

 

[jackbauer]

Woody damn you i had a response all typed out!!

Just a few additional points. Forget the forklift controller. Voltages will be limited to the donor and with low frequency switched scr power stage it will make short work of your traction battery. Lots of cheap options exist for a modern pwm controller such as an altrax 72v or a diy.

As tempting as direct drive is from an assembly and simplicity point of view .........DON'T DO IT!! You will regret it. Here's a simple experiment. Next time you take your car or van out for a drive , try and take off in 4th gear

Only use the traction motor. yes some of the hydraulic pump motors are bigger and more powerfull but look closely at the rating plate. It will say something like "S2-5min". This means the motor can run at full power for 5 minutes per hour! A traction motor is rated to run at full power for an hour. Big difference.

 

[Woodsmith]

Woody damn you i had a response all typed out!!

Where do you think I am learning it all from?

 

[Duncan]

Hi Guys

Don't forget the mast and forks are worth a fair bit
Around here people adapt them for the rear of their farm tractors

 

[Woodsmith]

Hi Guys

Don't forget the mast and forks are worth a fair bit
Around here people adapt them for the rear of their farm tractors

Given a mast and orks I would install it in my house as a hydraulic goods lift to get stuff in and out of my basement workshop!

 

[Denzil68]

Thanks for all the advice, so in a nutshell....

The forklift controller is not suitable
The forklft batteries are too heavy
Therefore the forklift charger wont be of use
Going direct to the axle diff is not recommended

My 'simple' low cost plan is not so simple or low cost anymore!

More research is needed on my part me thinks!

 

[Woodsmith]

That's about right.

The issue of direct drive will depend on a lot of other factors, size of the motor, efficiency required, use of the vehicle and performance expected.

It is easier to have the gearbox as it solves a lot of drive issues, hill climbing gears, high speed gears to protect the motor from over speeding, reverse gear...

Unless you have a whole forklift available it is often easier to decide on the type of motor needed and then look for just the motor on its own.

You are in the UK aren't you?
Thy this place: http://www.forktruckbreakers.com/

 

[jackbauer]

It can still be simple and low cost. Couple the motor to the gearbox with a clutchless setup. Use 12v agm or flooded lead acid batteries as these will suit your minimal requirements. A homemade controller and charger and your set.

 

[jackbauer]

Some pictures in this thread:
http://www.diyelectriccar.com/forums/showthread.php/home-made-1500-amp-controllerii-49822p4.html

My two concerns about clutch based manual evs are firstly its way too easy for someone who is not familiar with the vehicle to push the clutch , rev the motor and bam! bye bye motor. Second , the amount of engineering required to mount flywheel etc can be prohibitively expensive for someone on a tight budget. Just my 2c. With the op's modest requirements from the van he would be doing very few shifts anyway.