DIY Electric Car Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter #1
Hi There,

Yes you read correctly, i am trying to move 3000kg with a 48v system. I do understand how difficult/inefficient that is.

To make it even more interesting i would like it to move up a 30 degree incline and have a top speed of 25mph on the flat. It is on 32" diameter wheels with an acceleration of 5s.

I have come to this with a small amount of experience, but have been hopefully doing the correct research.

Using the equations that are present in

http://www2.mae.ufl.edu/designlab/motors/EML2322L Drive Wheel Motor Torque Calculations.pdf

I have calculated that the torque required for a 30 degree incline = 11241 Nm.

I have currently looked at;
Lynch 2 x 200 (127)
Ashwood IPM-200-66
MotEnergy ME1002
HPEVS AC-50
HPEVS AC34x2

I have also contacted Saietta and D&D. Currently waiting on a response with options from them.

I have attached screen caps of a quick excel spreadsheets showing the required gear ratios and their top speeds.

The calculations i have used for those are;
Gear Ratio = 11241/Diff Ratio/(Max Motor Torque Nm x Efficiency)
I have set Efficiency at 0.9

Top Speed in MPH =( RPM / (Gear Ratio x Diff Ratio) x (PI x Tire Diameter) x 60) / 12 x 5280


As you can see nothing is quite up to it, with the closest being the HPEVS 34x2 with a top speed of 11MPH.

So the question is does anyone know of any other motors i can look at before i say it is not achievable at 48V??

If you require any more information please just ask, or please let me know if i have calculated anything wrong.

Thanks
Madmonkeyrtu
 

Attachments

·
Administrator
Joined
·
6,111 Posts
You need a forklift motor - buckets of torque and relatively low rpm

I paid $200 for my 11 inch Hitachi motor - 48v and 10 Kw
But I'm feeding it 340v and 1200 amps

You won't need anything like that I would suggest a P&S 500 amp controller and stick to your 48v
 

·
Registered
Joined
·
18 Posts
Discussion Starter #3
Thanks for the reply. I have had a quick look on ebay for forklift motors but we don't seem to have too many in the UK.
Seems to be plenty in US, but i am reluctant to commit to buying a motor across the pond without having looked at it first.

I think the other option would be to start scouring scrap yards for anything suitable. I did find a few websites selling used forklifts but they are all abit too much money.

Also i have a quick question about the netgain motors if anyone has the answer. Only the warp 7/transwarp 7 seem to have any info about them running at 48v (not that i can find them available to purchase anywhere), are they the only netgain motors that can be run at 48v?

thanks
 

·
Administrator
Joined
·
6,111 Posts
You need to
(1) find out who is using electric forklifts - normally food or furniture places where a light dusting of soot from the gas powered forklift is not acceptable
(2) call them and ask who repairs them
(3) drop in and see them with cash money
Ask the repairers if there is somebody who acts as a graveyard for them

An 11 inch motor will weigh about 100 kg and be worth about 70 pounds as scrap metal

Dropping in is important - the guys you want to talk to are NOT the office staff

As far as the Netgain or Warp motors those are just ordinary forklift motors but with the brushes advanced for higher revs
If you do get one you will probably want to go back to neutral timing

My 8 degrees advance costs me about 20% of my Torque at zero revs -
 

·
Registered
Joined
·
1,551 Posts
Names to look for: Raymond, toyota, hyster, komatsu but those are American brands.

Used to be a serious scrounger here named Woodsmith, but he has a different name now "Maker of things" if you can contact him, he may be able to offer some assistance
 

·
Registered
Joined
·
4,779 Posts
Names to look for: Raymond, toyota, hyster, komatsu but those are American brands.
I guess they're brands which are common for forklifts in the U.S., but of course Toyota and Komatsu are Japanese companies - perhaps their forklift products are worldwide... and so still names to look for.
 
1 - 8 of 8 Posts
Top