Yerf-Dog new build

[Jaz]

First post here. Going to convert go-kart to electric for kids to ride in. So far I’ve purchased the frame, 48v 1800w motor kit, and group 24 battery boxes. I’m going today to purchase four maintenance free U1 batteries (of which two will fit in each battery box. Bought a cheap 48v 2.5Ahr charger. Will build/weld custom motor mount and hopefully be good to go.
Thanks for the good info here.

 

[Functional Artist]

Sounds good!

Keep us posted

If ya have any questions
...just ask

 

[landuse]

Welcome! Looking forward to this one

 

[Budget GoKart]

That looks like a repainted yerfdog 3202 heres mine

 

[Jaz]

Got the batteries and charger.

 

[EpsilonZero]

Got the batteries and charger.

Are those deep cycle batteries?

 

[Jaz]

No these are just the higher capacity lawn mower batteries. U1 size. There aren't any easily available U1 size deep cycle batteries. These rural King batteries are about 22Ahr and cost $29 each.

 

[Jaz]

Ugh, wiring

Why don’t they make the wiring labels easy to understand in English? Well other than the three speed switch and braking it’s tested good.

 

[Jaz]

Wiring done. Temporarily held with duct tape. Need to mount motor then test out!

 

[EpsilonZero]

Wiring done. Temporarily held with duct tape. Need to mount motor then test out!

If you can get some Velcro strapping, it is fantastic for cutting into fasteners. You can use it temporarily or permanently and it doesn't leave residue.

 

[Jaz]

So no luck on this build. I’ve worked the controller and hall wires in most combinations but can’t get anything to actually work.

So no luck on this build. I’ve worked the controller and hall wires in most combinations but can’t get anything to actually work.

Posts from functional artist and mfg

So for some reason when i try to hook up controller directly to positive it arcs badly. (Bypass 40a breaker). Even when everything else is disconnected (phase wires, everything) it still arcs when trying to attach them directly.

 

[Functional Artist]

I thought you said that it was testing good (post 8)

Well, the pics don't show much of your wiring

So, maybe let's start off with ya drawing us up a wiring diagram
...of exactly how you have everything connected
...& what you have connected to what

More pics may be helpful too

 

[Jaz]

Here’s the hall and phase.

“Power lock” goes to keyed switch
Astern goes to three way switch

Switched key and forward/reverse switch

Throttle wiring

Controller wires.

Finally a schematic of wiring

Forgot to add to schematic black to negative red to positive 48v(actually 51 charged)

 

[Functional Artist]

Your wiring diagram looks correct

Well, I guess, your gonna have ta do some testin'
...& record the readings, for us

First, using a MM (multi meter) check the batt pack voltage

Then, connect the batt pack, to the controller

With the controller still switched "off" all plugs should show 0 VDC
...except the on/off plug (labeled "electric lock")
...& the charge port plug
(they both should show pack voltage)

Next, connect a switch to the "on/off" plug
...& switch the controller "on"

Now, with the controller switched "on"
...the Battery Indicator plug show pack voltage (of course)
...& the Indicator Light plug
...& the Brake Light (lever) plug
…& the Brake Light plug
(all should show pack voltage too)

The other control circuits
...the Reverse plug (labeled Astern) should show 4.6VDC
...& the 3-speed plug should show 5VDC/0 VDC/ 5VDC
(same as the throttle)

Then, let us know what your findings are

* The "arc" you see, when the power is first connected, is normal
...it's happens when the capacitators in the controller "draws power" to initially "charge up"

 

[Jaz]

So, the real problem I've been having is lack of power, it'd barely move under its own and you could stop the kart by holding it back. The kart originally had a #40 chain with 62 tooth sprocket on live axle. It would have been a major pain to change out the rear sprocket to a 8mm chain sprocket. I couldn't easily find a "dual D" bore #40 chain sprocket, so I welded an 11 tooth #40 sprocket to the 9 tooth 8mm dual d sprocket.

I now believe the problem isn't with electronics, but a nonlinear load placed on the motor due to a not quite sqare weld of the two sprockets.

PERHAPS this is my problem...

 

[Brianator]

Perhaps.... lol.

 

[Joe-405]

I don’t know a lot on electric stuff but it sounds like the gearing might be off also.

 

[landuse]

I don’t know a lot on electric stuff but it sounds like the gearing might be off also.

I agree 100%.

Please give us the tooth counts on all the sprockets, as well as tyre height and weight of the kart.