Cushman 3 wheeled Truckster conversion Build Log

[drewjet]

I bought a 3 wheeled Cushman Truckster to convert a few years back. The engine didn't run, but I was told it did. I got it running within a few hours of getting it home. It never idled right and though I though I knew why, I never really messed with it much. I knew all along I wanted to convert to electric. I have slowly worked on it over the years but no major progress.

Here are some pics

As received


After Painting

 

[The fingers]

We have had quite a few of those at work for many years. The gas engines ran better when the blow by was disconnected and left hanging down to drip oil on the street. The starter made a distinctive noise when cranking, so you always knew when the boss was on the prowl. :lol:

 

[drewjet]

The motor I will be using is a D&D 6.7" Series motor powered by a Altrax 72V 400 Amp controller. This is replacing the 2Cyl oppossed Onan 22HP engine. It rated rated for a peak of 40HP and 10HP continious. Which should be more than enough for me to cruise at 40 to 45 MPH

Batteries are going to be 6 of the 7S3P Fisker units from Victpower. For a total of 75V and 120AH.

 

[Jeremy Harris]

Neat project, I like it.

I keep looking around for a fairly small vehicle to convert, to no avail. Ideally I'd like one of the replica bubble car trikes, like the Messerschmitt KR200 or KR175 kit cars that were available here years ago, but they are way out of my price range. If we had light utility vehicles like this Cushman truck that would probably mean I could get by with no car, maybe just a hire car if I needed to go more than around 20 miles or so. Unfortunately I don't think we've ever had anything like that in the way of a road legal vehicle here, at least not made in the volume where there might still be some around for a reasonable price.

 

[drewjet]

Motor is in A D&D 6.7" Series with a Alltrax 72V 450 Amp controller.


My buddy is building the frame for the batteries, hope to have it in by next week.

 

[drewjet]

Battery box going in

 

[dnmun]

if the old onan engine still runs, it may be more valuable than you expect. it was commonly used as the power unit on vermeer trenchers, and so there maybe someone out there who needs it to get an old trencher going again. on mine the valve seat came loose on one cyclinder, so that may be a common cause.

 

[drewjet]

I already sold the engine. I got $200 for it.

 

[drewjet]

I have been putting some miles on the Cushman. I start from a dead stop and cruise in 3rd gear and acceleration is great up to about 32 MPH. I can beat most cars off the line. The acceleration is way better than when it was gas powered. Top speed on the flats is 38 MPH, which is a bit slower than I want. I have one of the higher rear end ratios available at 4.7:1 There is supposed to be one higher at around 4.3:1 but is quite rare and probably expensive. To solve this I can go up in voltage. I am currently at 75 volts off the charger with 21S A123. I bought a founding Power BMS which is capable up to 24S, So I may try that. My controller is good up to 90 volts so no problem there. The other thing I can do is to go to a larger rear wheel, Currently is is a 17" diamater, and I think I can fit a 20.5" tire on there, By my calcs if I do both is should get me to 51 MPH.

I have done a 22 Mile trip and as I recall every cell was above 3.2 volts, I need to get my CA connected so I have a better idea of power usage and range. The motor was warm after that trip but not hot, I could hold my hand on it for 5 seconds, the controller wasn't much above ambient.

 

[The fingers]

Video would be uber cool!

 

[Jay64]

Super cool Drew! Stoked u let me know about this thread. I definitely want to check this out next time I'm up there. You should bring it by Off The Grid and we can do another video day w all the electric toys. That is so awesome that you got a track one. Sooo useful.

 

[burner1]

Drew, interesting build. I am looking at doing something similar. I have a Haulster I use here but would like to make a nicer vehicle. I have a Truckster I pulled the drive train from. I ams ourcing electric motors now so your information is quite helpful.

It looks like you are using the transmision with all the gears. Do you still use the clutch and how well does it work? Overall what do you think of the geering? I am considerign weather I should use the trans or just hook it to the 2-speed transmission.

The Halster BTW I pulled the industrial leaf springs and built a triangulated 4-link with airbags:

 

[drewjet]

Burner1, you got a nice looking Haulster there.

The transmission is totally unneeded. It was the easiest way for me to adapt the motor, and retain the emergency brake. I did remove the clutch, totally unnecesary. If you have the skills and the time direct to the driveshaft is the way to go.

My top speed is right around 40, I have the 3.7:1 rear end in it, I may still up the voltage to around 80 and that should get me close to my target of 45 MPH, Larger tires would help, but then I think it would look funny with the stock one on the nose. The acceleration to 30 is fantastic. At most stop lights I am the first car accross the street, by at least a car length.

If your interested I have an extra motor and controller, exact duplicates, that I may be interested in selling.

 

[burner1]

Thanks Drew, I will send a PM

 

[oatnet]

Hey Drew nice build! Did you get a CA hooked up, and get any wh/m stats? Those look like the a123 7s3p packs - have you put many cycles in them, and how are they holding up?

-JD

 

[drewjet]

Sorry Oatnet, been a bit out of the loop for a while.

Averaging about 200 wh/mile

It is the A123 7S3P packs. They are doing great. a few cells are not as good as the rest, but not by much. Sure wish I would of bought more when they were available. I would love to double up what I have currently in it.

 

[goatcoffeegirl]

I very much appreciate your posts here @drewjet! I bought this red Cushman Truckster (1991) (images attached below) but didn't realize that the previous owner put epoxy on the cracked engine block to hide the leaking oil long enough to sell it to me... so I've been trying to decide whether to try to fix (or replace) the cracked engine or go ahead and convert the truck to electric (EV). I would love to convert it to electric to avoid more Onan 22HP engine issues in the future but I've never converted a vehicles to EV before and don't know where to start. Your posts have given me hope and made me realize it doesn't have to cost $10k. We live in St. Petersburg, FL (about 2 hours from you). I'd love to know where you purchased all of your parts for your EV conversion? Did you buy from a local shop or through eBay? Also, are you ever available for mechanical (or EV conversion) work to make extra $?

 

[gakmon]

Nice,I was wondering have you decided to convert to elec.?

 

[gakmon]

i just bought 1 too.Thinking about doing the same

 

[DaLanMan]

there are 2 similar units up at a govt auction site in Cali :auses to check internet history::
Click this
And with the right hat you could play a sexy meter maid for Halloween

 

[goatcoffeegirl]

@gakmon Nice blue! I haven't decided to convert to EV yet. I wish there were some great YT videos out there on exactly how to do it for an old Cushman like ours. I personally am OK with going slow (keeping it at 45-50mph) to save money but don't want to end up wasting a lot of money on eBay parts I can't return because I don't have a clue what I'm doing (or exactly what to buy).

@gakmon or @drewjet If you end up finding the perfect solution for our collective 91' Cushman trucksters (and a kit to buy) please let me know!

 

[amberwolf]

Well, this post

Cushman 3 wheeled Truckster conversion Build Log

I bought a 3 wheeled Cushman Truckster to convert a few years back. The engine didn't run, but I was told it did. I got it running within a few hours of getting it home. It never idled right and though I though I knew why, I never really messed with it much. I knew all along I wanted to convert...

endless-sphere.com

states which parts were used.

The motor I will be using is a D&D 6.7" Series motor powered by a Altrax 72V 400 Amp controller. This is replacing the 2Cyl oppossed Onan 22HP engine. It rated rated for a peak of 40HP and 10HP continious. Which should be more than enough for me to cruise at 40 to 45 MPH

Batteries are going to be 6 of the 7S3P Fisker units from Victpower. For a total of 75V and 120AH.

Based on a quick google for phrases out of that, and matching up images in the results to those in this thread,

the motor is this

Affordable Electric Vehicle Batteries & Components from Electric Car Parts Company

Electric Car Parts Company is your one-stop-shop for affordable electric vehicle parts and components including batteries. Shop our selection and order now!

www.electriccarpartscompany.com

but you'd have to make or have made an adapter plate and coupler to connect to your drivetrain.

The controller appears to be the 7245 on this page

AXE Products – ALLTRAX

but I dont' think they make those anymore; you'd be best to ask them which current product is the best match for whatever motor you end up choosing.

The batteries used may not still be available after this many years (and probably wouldn't still be all that good after so much aging), but there are lots of batteries out there depending on what you want to do / how much range you need. Given the ~200wh/mile that Drewjet reported for his usage at some speed below 40mph (his reported max speed, since the wh/mile usage doesn't have a speed or conditions associated with it, we can only guess), then for your higher speed desire you should guesstimate 300wh/mile just to be sure you will have enough capacity for the range you want.

What he used was 75v x 120Ah, which is 9000wh. At 200wh/mile that would give him a possible range of around 45 miles. (assuming that 75 he reports is "average" or "nominal" voltage--if that's his full voltage the Wh and range would be less).

You need higher speed, so you will either have to use proportionally higher voltage, or different gearing between motor and wheels to do that. It will also take more power to go the higher speed (quite a bit more than you'd expect given the apparently small difference), so you'll probably need a bigger controller and battery, too.

So if you wanted, say, a 10 mile range, you would need at least a 300wh/mile x 10 mile = 3000wh pack. For a 72v system that would be 3000Wh / 72v = 42Ah. If you need more range you'd need a proportionally higher capacity pack.

Which specific battery to use would depend on your budget and your DIY skills. It's unlikely to be cheaper to build your own pack from separate new cells, but it probably is far cheaper to buy used large-EV modules from places like BatteryHookup, etc., and use a separately-purchased BMS (like the contactor based units from JBD), as the one that comes on them (if any) probably isn't usable outside the original EV they were for. (used EV cells is what Drewjet used)



Whether his solution will work for your needs depends on what they are. For instance, if you have to add much extra weight to your Cushman, such that it has something like this one does built in

Did I kill my 60v controller with a new 60v 150Ah lithium battery?

I have a three wheeled chinese electric foodtruck - like a Piaggio Ape. I was excited to upgrade range by adding a 60v 150AH Lithium battery pack from 60V lead acid. Custom made by Smart Propel but based on this 100Ah version. Charged the pack and installed it. It charged up to 73v. Managed to...

endless-sphere.com

then you may need a bigger motor, controller, and battery to do this. If you're just driving around with some small coffee deliveries, it's highly likely that his solution would work, if you only need the same speed / etc he had.

 

[PaPaSteve]

Should you decide to do a brushed DC golf car motor like the D+D shown in Amberwolf's post . . .
I have working Curtis 72V 400A controller that would be a match for that series motor.
It was removed from an Dynasty IT car when the car was updated to a 600A unit.
With the Curtis controller the field strength can be programmed to be strong for acceleration and then weaken for higher speed.
Also have a working Alltrax 48V 400A which will work for series wound or permanent magnet brushed motors. This controller has no field control.
Used electric golf car stuff may be a useful approach to a conversion.
As would retrieving parts from second hand NEV's (Neighborhood Electric Vehicle)

 

[goatcoffeegirl]

Well, this post

Cushman 3 wheeled Truckster conversion Build Log

I bought a 3 wheeled Cushman Truckster to convert a few years back. The engine didn't run, but I was told it did. I got it running within a few hours of getting it home. It never idled right and though I though I knew why, I never really messed with it much. I knew all along I wanted to convert...

endless-sphere.com

states which parts were used.



Based on a quick google for phrases out of that, and matching up images in the results to those in this thread, View attachment 345354

the motor is this

Affordable Electric Vehicle Batteries & Components from Electric Car Parts Company

Electric Car Parts Company is your one-stop-shop for affordable electric vehicle parts and components including batteries. Shop our selection and order now!

www.electriccarpartscompany.com

View attachment 345357
but you'd have to make or have made an adapter plate and coupler to connect to your drivetrain.

The controller appears to be the 7245 on this page

AXE Products – ALLTRAX

View attachment 345355
but I dont' think they make those anymore; you'd be best to ask them which current product is the best match for whatever motor you end up choosing.

The batteries used may not still be available after this many years (and probably wouldn't still be all that good after so much aging), but there are lots of batteries out there depending on what you want to do / how much range you need. Given the ~200wh/mile that Drewjet reported for his usage at some speed below 40mph (his reported max speed, since the wh/mile usage doesn't have a speed or conditions associated with it, we can only guess), then for your higher speed desire you should guesstimate 300wh/mile just to be sure you will have enough capacity for the range you want.

What he used was 75v x 120Ah, which is 9000wh. At 200wh/mile that would give him a possible range of around 45 miles. (assuming that 75 he reports is "average" or "nominal" voltage--if that's his full voltage the Wh and range would be less).

You need higher speed, so you will either have to use proportionally higher voltage, or different gearing between motor and wheels to do that. It will also take more power to go the higher speed (quite a bit more than you'd expect given the apparently small difference), so you'll probably need a bigger controller and battery, too.

So if you wanted, say, a 10 mile range, you would need at least a 300wh/mile x 10 mile = 3000wh pack. For a 72v system that would be 3000Wh / 72v = 42Ah. If you need more range you'd need a proportionally higher capacity pack.

Which specific battery to use would depend on your budget and your DIY skills. It's unlikely to be cheaper to build your own pack from separate new cells, but it probably is far cheaper to buy used large-EV modules from places like BatteryHookup, etc., and use a separately-purchased BMS (like the contactor based units from JBD), as the one that comes on them (if any) probably isn't usable outside the original EV they were for. (used EV cells is what Drewjet used)



Whether his solution will work for your needs depends on what they are. For instance, if you have to add much extra weight to your Cushman, such that it has something like this one does built in

Did I kill my 60v controller with a new 60v 150Ah lithium battery?

I have a three wheeled chinese electric foodtruck - like a Piaggio Ape. I was excited to upgrade range by adding a 60v 150AH Lithium battery pack from 60V lead acid. Custom made by Smart Propel but based on this 100Ah version. Charged the pack and installed it. It charged up to 73v. Managed to...

endless-sphere.com

View attachment 345364
then you may need a bigger motor, controller, and battery to do this. If you're just driving around with some small coffee deliveries, it's highly likely that his solution would work, if you only need the same speed / etc he had.

Wow! Thank you @amberwolf !!! I very much appreciate your guidance! I feel more confident about buying these parts now and think I can hopefully figure out other parts (BMS, DCtoDC, PDU, AEMcal software, adapter plate, coupler, etc).

 

[goatcoffeegirl]

I have working Curtis 72V 400A controller that would be a match for that series motor.

Thank you @PaPaSteve! I'll think about purchasing the Curtis from you. I need to budget out all of the other parts I'll need (including batteries) to make sure I can afford everything.


I see that you also know how to do 3D Cad work & 3D Printing. Do you think I could hire you to make me a custom adapter plate (to connect elec. motor to 91' Cushman transmission)? and coupler if I would also need that?