hot rod golf cart

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been sdoing research and found a similar brain power controller with three speed.
The speed wires for the 3 speed are black, grey, white
the 1800 w controller only has 2 speeds?
black is ground
black + grey = LOW
black + white = HIGH
black not connected = medium
so maybe by having disconned we are in MEDIUM or LOW gear?
I ordered a 38t and 11t sprockets which should increase my speed.
still figuring out the mph but getting lost.
using existing sprockets the final gear ratio = 20.25:1 or 716 feet per miniute?
 
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using this caculator Gear Ratio Calculator my present speed at 2000 rpm = .41mph
raising gear ratio to 16.95:1 = .49mph
I really wonder what speed the motor is running?
Need to reassemble the 8t sprocket back on and find a tachometer or?
 
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using this caculator Gear Ratio Calculator my present speed at 2000 rpm = .41mph
raising gear ratio to 16.95:1 = .49mph
I really wonder what speed the motor is running?
Need to reassemble the 8t sprocket back on and find a tachometer or?
I don't understand.
Doesn't your motor specification label tell you the RPMs it runs at? The calculator has a space for that.

I guess I don't see what you are trying to achieve.
Exactly how fast do you want this vehicle to go?
How fast is - TOO FAST?
Will your brake setup stop it at your desired speed?

I thought this was an 'electric' powered vehicle.
You speak as if it has changeable gears/speeds.
My setup uses a throttle (potentiometer) More like a variable speed transmission.
Push a little-go slow. Push a lot - go fast...😱

Seems to me you are making this much more complicated than it has to be.
It looks like you are using a calculator designed for fuel vehicles not electric vehicles.
The calculators I suggested are primarily for electric vehicle applications.
When I used the calculators (I suggested) I could care less what the gear ratios were.
To me, it's just gee-whiz minutia information that I really don't need to be concerned with.

I needed to know just two things.
How fast I wanted/needed to go and what size gears/sprockets would get me there.
In my case I limited myself to going no more than 25 MPH.
I input the known parameters, and looked for the unknown. Which was what size sprocket/s did I need for the jackshaft.

I looked at the Speed and Gear Ratio Calculation Results until I achieved the right gear/sprocket combo to achieve a maximum of 25 MPH.
For example: My motor runs at 4500RPM. My Sprocket sizes are; Motor 9T...jackshaft input 24T, output 11T...Rear axle will be 54T
That combo gets me to 24.62 (+/-) mph. Exactly where I need to be, to be DMV NEV compliant.

I let the calculator do all the brain work. Nothing more, nothing less.
 
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I am using same motor as your hot rod. My desired speed is 20mph max.
your total gear ratio from motor to axle is 7.56:1
my issue is the differential is 13.5:1 to begin with.
going to raise my gear ratios c;oser to 10:1 (the fat tires must be included.
Got to looking over project and realized the old motor was 24v 500w 9:1 gear ratio
IF I get close to 10:1 I will be happy
 
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confused if the differential is 13.5:1 then multiply 13.5 x 13.5 = 182.25 for sprocket # of teeth?
this can't be right?
 
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Last night while laying in bed it dawned on me, Looking at this gear ratio all backwards.
I need to overdrive the differential from the motor to the differential input sprocket.
a 1:1 ratio would give me a 13.5:1 ratio on the axles.
Then figure out about the two or three speeds.
Ed pedal car may need to use the two speed wiring to obtain the desired 4500rpm?
 
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According to the calculator I use my gear ratio is 13.09.
As I stated before, I'm not really needing to understand what [my] ratios are.
Maybe I should, but haven't found the need.
That all assumes that the information I get from the calculator is correct.
If not then a redo will be required.
I still need to use the GPS speedometer to verify my speed.

I did find online at TDPRO99 on ebay, they are now offering a switch with their motor packages for changing motor speed.
To the best of my understanding, my motor label states it runs at 4500 rpm. I'm assuming that is no load rpm.

Nowhere do I find that my motors are multi-speed motors. Or am I missing something?
 
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on the layout showing what wires go where there is one with 3 wires marked speed control
curious what size are your wheels with tires (diameter)
found an online program called SPROCKETEER 2.0
trying to print out a 14t sprocket
 
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on the layout showing what wires go where there is one with 3 wires marked speed control
curious what size are your wheels with tires (diameter)
found an online program called SPROCKETEER 2.0
trying to print out a 14t sprocket
I'm aware of that on the controller but since the motor wasn't sold as a multi-=speed I'm just not using that lead.
Not really sure if it is any advantage for my needs.

Sprocket-making program, Great now I learn of such a thing.
And my neighbor across the street has a CNC in his garage.
Send me the link to the program.
Some don't seem to work.

Where was that program when I was making my own sprockets??

My rear tires are 23" (22 1/2 actual)
Tire size 23x10.5x12

I'm actually looking to upgrade to 24x12x12
 
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I pulled the sprocket off the differential and see a 1/2" shaft that is splined. I figure I can just get a 1/2" sprocket with 8 teeth and grind a flat spot in the shaft.
apply some loctight and should be good to go.
famous last words.
 
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Think, think and think again before you go modifying the differential.

If you haven't already a check of how Brad did his might help to guide you on your build.

Anyway here is my 2 cents
Not sure I know what I'm doing but this is what I get.

Note:
these numbers can be changed slightly to get the sprocket tooth count close to what is available without having it specially made.

Trying maintain 20 MPH

With a jackshaft


4500 RPM
9 tooth motor sprocket
24 tooth input shaft
12 tooth output shaft
84 tooth wheel/axle sprocket
27.5 wheel diameter

Result

19.78 MPH
18.67:1 gear ratio

Without jackshaft

4500 RPM
11 motor sprocket
200 wheel/axle sprocket
27.5 wheel diameter

Result

20.31mph
18.18:1 gear ratio

With a higher speed

But to achieve your desired 13:1 gear ratio the below is what I get.
It also raises your speed well above your 20 mph.

With a jackshaft

4500 RPM
9 tooth motor sprocket
24 tooth input shaft
11 tooth output shaft
54 tooth wheel/axle sprocket
27.5 wheel diameter

Result

28.21 MPH
13.09:1 gear ratio

Without jackshaft

4500 RPM
9 motor sprocket
117 wheel/axle sprocket
27.5 wheel diameter

Result

28.41 mph
13:1 gear ratio
 
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Just for fun I input Brads numbers into the calculator (1000-15-60-15-32-32)

This is what it gave me.

8.53 gear ratio
11.2 mph

His calculations were 30:1 total gear reduction and 4.6 mph

So not sure what is what.
In my case, I still need to do a drive mph check to verify how close the calculations for my build are to reality.
 
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your cals look correct.
here is the site about DIY sprockets
How To Make An Electric Scooter Chain Sprocket With Nothing But Hand Tools | Hackaday
Issue I am finding is a t8f sprocket with a 1/2"bore and allen set screws
#25 sprocket is close but?
Thanks for the link
I downloaded it and discovered that I have viewed it before.
Somehow I didn't catch the Sprocket-making link.

I had to get my 24T sprocket made in England the first time.
No way could I find it in the U.S. of A
But it turns out, it was too narrow for a T8F chain.
It was slightly less than the 8mm/1/8th" it needed.

That is why I ended up making my own.
To date, it is working out just fine.
I used the sprocket I got from England as a template for tooth configuration.

After initial grinder cutting, it took a lot (a lot) of filing to get the teeth to seat in the chain without binding or catching in rough edges.
Very subtle filing and seeing where it was catching/binding was tedious, but in the end it paid off.

All of my sprockets have welded on shaft collars ( with set screws) because I'm using 3/4" axles.
You probably already know, that the set screws [will not] hold for very long. The shaft needs to be ground flat.
I learned the hard way when I had to get a collar that rotated and ground a grove, thus making it nearly impossible to get the axle out.
Getting them virtually dead center is problematic, but doable and requires jigging.

Just happened to recall, that the sprocket from England came as a 'pilot hole'.
Meaning the hole in it was only a beginning hole.
I had to finish drilling to the size hole I needed,i.e, 3/4"

So in your search, you may find the right gear but with a pilot hole.
 
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I found a #25 plate sprocket for the motor, a #25 sprocket w/ a 1/2" hub and 10' of #25 chain.
Plan now is grind a flat on the differential input shaft, install an 11t #25 sprocket, An 11t #25 sprocket on the motor. Now we are 13:1 ratio to the wheels 28" tall
need to caculate my speed but should be good
found all on the electric scooter parts site (same as the caculator.)
 
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QUOTE="MrIdaho, post: 12689, member: 825"]
using the caculator Motor and Gear Ratio Guide and Calculator for Vehicles with a Jackshaft - ElectricScooterParts.com
with 11t on motor and 11t on differential input - direct drive, motor running 2000rpm
now the differential is 13.5:1 and the wheels rotating at 148rpm (2000 / 13.5 = 148)
so every miniute the cart will travel 148 * 87(circumference of tire) =12876 inches which equates to 1,073 feet which looks like 4.92 mph
caculator or I am wrong???
[/QUOTE]

I can't say if you are right or wrong. I'm not sure I understand what it is you are doing.
Your method of arriving at your gearing is too complicated and complex for me.

Do I understand that you are using that little 11T sprocket fitted directly on the shaft to the differential?
You stated you used the jackshaft calculator. If so where is the jackshaft part?

Let me get this understood. You will use the 11T from the motor chained directly to the 11T on the input shaft of the differential?
And you are going to use a #25 chain to replace the T8F chain on T8F sprockets. Is that right?

If you are using the same motor that I have, how are you setting it up to only go 2000 rpms? Why?

Also, your tire measurement is probably off. The figures on paper are not what you may find by using a tape measure, therefore that can throw your hypothesis out of whack. I used the figure for my 23" tires and got another result after I measured them with a measuring tape.
They run 1/2" shorter than advertised, which made a difference in my calculator numbers.

 
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the differential has a gear ratio of 13.5:1
I made the error of not using tire rotations per hour.
Will get back after I look over my caculations and measurments,
the 2000 is basically half throttle IF the HIGH/LOW switch alters the rpm? going to test after I get my parts.
 
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found mistake using Gear Ratio Calculator
I need to input transmission type. Any transmission as long as it ends up 1:1 ratio
at 3000rpm the cart should go 18.51mph
differential is 13.5:1 ratio
now just wait for sprockets and start zipping down thee road.
My concern is wear and tear on differential parts.
 
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I am using 2000 rpm as a low reference point (this depends on the two speed selection) as 4500 rpm on the motor is probally dependent on the two speed selection.
this needs to be investigated. Will do when I get my new sprockets installed.

There is no jackshaft in my configuration, just the 13.5:1 differential ratio.
2000(rpm)/13.5(diff ratio)= 148.148 axle rpm. the fat tires are 87" in circuference so every miniute the tire rotates 148 rpm which equates to 148"/12=12.34 feet the cart moves per miniute at 2000 motor rpm.
hope this helps describes my configuration.
 
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