Cushman based build

Think about this. 12 batteries at 60lbs each. Along with motor, trans, relays, that's about 800lbs all by itself. Frame is all heavy steel.

1640lbs
 
1500
 
That's not bad considering you are using lead and have 4 wheels, and a real suspension
 
I am surprised it does as well as it does with the weight. It glides over rough terrain quite well but since the motor is not part of the rear suspension the percentage of un-sprung weight is small which helps.

I did get a chance to check top speed and on level road it is 28mph in low gear. I am looking at maybe setting up a belt reduction in place of the motor drive adapter. It vibrates a bit; especially under deceleration. I really don't need to go faster then say 35 and it would be nice to have a little stronger low gear for pulling loaded trailers.

When traveling over bumps fast the back rattles when it floats. I am looking at adding limit straps to stop that. I got a couple straps from the MGB dealer. I can see how I am going to attach them. I just need to do it.
 
When I put the triangulated 4-link suspension on the 3 wheel Cushman it would flop left or right; because it was 3 wheel. I ended up cutting up and welding a sway bar. Once mounted that problem was solved.

With this vehicle, I built a pretty similar 4-link suspension. Since it is 4-wheel the problem is not bad but there is still a little. If you sit in the left seat, the left is slightly lower then the right. When you drive it is level. It's not bad but it gnawed at me.

At first I thought sway bar but I have a second issue. When my axle unloads the shocks rattle a little when they get slop. So instead of a sway bar I used rubber limit straps from an MGB. It loads the axle just enough to level it out when sitting still and solves the rattle when driving:


Strap1.jpg



Strap2.jpg
 
That's interesting...since I know so little about suspension systems (even after years of reading around), would something like that work to help damp a leaf-spring system?

I've been looking at redoing the back end of my SB Cruiser trike to put leaf-springs on the rear, but this would make it pretty bouncy when not loaded down. Would a strap like that work to dampen this? (I'd probably be using the rubber cargo tiedown straps I sometimes find on the side of the road).
 
It depends what your intentions are for the straps. These are not functional in respect to noemal suspension travel. These are more to limit the over travel in droop when the suspension is unloaded.

These you can find at victoriabritish.com
 
In my case they'd be being used as semi-active parts of the suspension, in that they''d provide a bit of preload on the leaf springs at the center (axle), and that when I hit a bump that further loads the springs, the rebound would be limited by the straps, so they'd have to take that "negative load" momentarily, every time.
 
Man that think can haul some wood!

Kind of hard to do that with a Polaris or golf cart!


Fire.jpg
 
I applied for a Manufactured VIN. I had it inspected by the State Police and filled the paperwork. A VIN number was issued and I attached a VIN tag to match the issued number. I then had it inspected by local Sheriff and then finished the paper work to get a title. I finished the paperwork at the license branch. In a week or two I should get a title to the vehicle and a DNR tag which allows me to drive it on the county roads here.
 
I am working to fine tune the drive. I did not hook up the 2-speed transmission because low speed had me at 28mph. I never brought it into high gear.

After feeling things out I decided on about a 32mph top speed so that I could comfortably cruise at 25. rough numbers here.

I also had vibration problems with the misalignment adapter so I decided to move to a belt reduction to conquer the vibration and gear ratio. It should not only give me the top speed in HIGH gear (not low gear) but should also give me a low gear with more TQ for different jobs.

Hopefully this weekend I should get it all buttoned up so I can try it.

EVBelt.jpg
 
Well the belt drive is a no go. I was concerned about belt strength but that turned out not to be a problem. Slippage did though. It is a cogged belt but once it slipped it was all over. Buggy was going no where; even with a tight belt.

Plan B....Chain. Works great but noisy:

Chain.jpeg


Stopped it on a very steep hill. Took off in low gear. Just about pulled a wheelie. I got low end TQ now.
 
I am working on a dash. It is ready to go to powdercoaters. It should help close some loose ends on the project:


Dash.jpg
 
Dash came out well. Turn signal and light system, relay system. All negative based. No shorting out switches under dash.

Plugs for easy dash removal, install and maintenance.


EVdash1.jpg



EVdash2.jpg



EVdash3.jpg



EVdash4.jpg
 
Dash looks good, nice job! :D

-JD
 
I finally did what I should have done from the beginning. I moved the transmission back to the axle. Since it is being driven the correct direction it does not jump out of gear. There is no gear reduction so the drive is cleaner. All vibration gone and drives like it should now. Darn thing will pop a wheelie in low gear! I can even pull cars around the yard:

Final%20Drive.jpg


Photo2.jpg




The final thing I wanted to do was to get the Jib crane set up. I got the Jib crane from Harbor Freight. I set it up so it drops into a vertically mounted trailer hitch so it comes off very easily:

Jib.jpg


Jib2.jpg
 
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