Standup quad/golf buggy/beach cart slow speed query

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electricboard1

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Joined
Nov 17, 2010
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I am currently building a multipurpose utility vehicle, which is an electric standup quad/scooter which can have a golf bag attachment on the back for the golf course and then doubles up as an electric powered beach cart with drop down handlebars and a cage which then bolts onto the back for hauling stuff to the beach.

My issue is..
obviously for the golf course I want it to cruise at around 18 miles an hour and have enough torque to power up slight hills but when I attach the cage onto the back and drop the handlebars for it to become a beach cart I want it to cruise along at walking pace.
I am running a 48v 1000w Brushless Escooter motor and had it geared so it would do around 15mph top end at first, however this made the acceleration far too aggressive and fast to walk along with in cart mode.
So I changed both sprockets to a 15 tooth front sprocket and a 68 tooth rear which according to the online gearing calculator says it should now do 23mph top end. (My thinking is make it faster top end to slow down the acceleration)
This new top end speed has slowed down the acceleration slightly and seems a little bit better to walk along with however the throttle still kicks in a bit too violent for me to use effectively.
After some research I found the posts regarding putting an inline trim Potentiometer in-between the black throttle cable and turn it til the motor spins then back it off slightly so the throttle is then set much closer to the start point of the trigger (so no more dead band at the beginning of the throttle) to smooth out the initial acceleration of my throttle and this seemed to work pretty good until I switch the quad off, then when I reconnect the battery to go again nothing works at all. What I have found is I then need to dial back the little potentiometer way back til it comes back to life and the motor works again, but then I have lost my setting and the throttle is aggressive again.
Am I right that maybe the speed controller isn't switching on when I have the potentiometer set so close the the beginning of the throttle band, does it maybe "think" someone is giving it a small amount of throttle and so not switching on??
Is there some kind of a throttle safety limit before the controller will power up?
As when I dial back the trim Potentiometer it then operates again but then is no good for me

Has anyone any ideas as to how I can set this trim Potentiometer close to the edge of the throttle starting point so it is smooth at slow speeds yet still be able to turn on the controller?
I used a 200ohm 10 turn trim Potentiometer as one of the posts suggests.
I'm just running out of ideas how to get this to work,
I didn't want to use a gearbox on the motor as I still want to have a bit of top end speed for the golf course yet need it to go slow speed for in cart mode🤔

Any one have any clever ideas to get this figured out?
 
VESC would be my goto, easy to set a speed limit (and about a million other things). It's by no means the only controller with that option though, I know Votol's have 3 speeds that can be set but I don't think they do any around the 1kw range. Do you have any details for your controller? Could be it has a programmable speed limit.
 
stan.distortion said:
VESC would be my goto, easy to set a speed limit (and about a million other things). It's by no means the only controller with that option though, I know Votol's have 3 speeds that can be set but I don't think they do any around the 1kw range. Do you have any details for your controller? Could be it has a programmable speed limit.
Click to expand...
Ok thanks I was wondering about maybe getting a programmable controller price dependent.

I don't know much about the controller I have other than I think it is a fairly cheapish one from AliExpress it came with the motor for about £150 (I think) I will try and find a link.
But pretty sure its just the basic type which comes with those MY1020 motors
 
I know some of those are re-flashable with open source firmware and that would allow setting speed limits but I'm out of my depth beyond that, I've used them but never needed to dig beyond plug-and-play. If you can find any markings or a few pics it would probably help anyone familiar with them. Any interest in programming? It wouldn't... well, shouldn't really be all that hard to do with an arduino. YMMV with resistors, many (most?) controllers operate in a mixed balance of torque and speed rather than simply x resistance = y RPM but it's certainly worth a try, if it slows off on slight hills and doesn't hold back on slight descents then it's mixed mode or x throttle = y watts.
 
If you’re using a hall sensor throttle, this thread helps point out the safeties of most controllers.
Using an On/Off-Momentary Push Button Switch that’s normally open to replace a hall throttle.

This thread will show you how to modify the output, as well as the particulars of the hall throttle.
Guide to Hall Sensor Throttle operation, testing, and modification. - Electricbike.com Ebike Forum

What stands out to be right now is the small resistance of the pot you’re using. I’ve always recommended a 10K as you’ll see in the thread above under modifications.



Regards,
T.C.
 
I did a similar beach cart to drag my kayak and fishing gear to the beach. I had a 350w geared reduction scooter motor then another 4/5:1 reduction on top of that to do a max of 5mph. Acceleration was crazy until I got a controller with a ramp up to control start up. I used a robot control, but would use vesc now. You could easily just switch pulleys based on daily use with belts. I had a live axle to splined hubs for the soft sand. Plenty of torque moving along at 2mph, just a bit noisy.
 
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TommyCat said:
If you’re using a hall sensor throttle, this thread helps point out the safeties of most controllers.
Using an On/Off-Momentary Push Button Switch that’s normally open to replace a hall throttle.

This thread will show you how to modify the output, as well as the particulars of the hall throttle.
Guide to Hall Sensor Throttle operation, testing, and modification. - Electricbike.com Ebike Forum

What stands out to be right now is the small resistance of the pot you’re using. I’ve always recommended a 10K as you’ll see in the thread above under modifications.



Regards,
T.C.
Click to expand...
Thanks I did see that thread regarding modifying the throttle and I did wonder about the 10k pot Vs the 200ohm one I have used
Would changing mine to a 10k help do you think?
 
electricboard1 said:
Would changing mine to a 10k help do you think?
Click to expand...

From your description it would seem to be suspect…

But why speculate? I would recommend taking a voltage reading of the output of the throttle. And see if it is steady. Is the pot making it jumpy, is the voltage staying at the same set point, or drifting? Where it trips the controllers lock out, and if the throttle is reliably and accurately returning to the home position.
 
TommyCat said:
From your description it would seem to be suspect…

But why speculate? I would recommend taking a voltage reading of the output of the throttle. And see if it is steady. Is the pot making it jumpy, is the voltage staying at the same set point, or drifting? Where it trips the controllers lock out, and if the throttle is reliably and accurately returning to the home position.
Click to expand...
Thanks I will try and get a tester on it to check (might be tricky as soldered and heat shrink all my connections)

I have ordered some 10k pots so will change mine to rule that out and see

Failing that I will probably look at a vesc controller or Votol

Any advice for which Vesc or Votol controller would be suitable for 48v 1000w in a mini quad?
Just not sure if some are designed more for ebikes or Eskateboards with bigger or smaller wheels/gearing
Or will they all work the same?
 
TommyCat said:
If you’re using a hall sensor throttle, this thread helps point out the safeties of most controllers.
Using an On/Off-Momentary Push Button Switch that’s normally open to replace a hall throttle.

This thread will show you how to modify the output, as well as the particulars of the hall throttle.
Guide to Hall Sensor Throttle operation, testing, and modification. - Electricbike.com Ebike Forum

What stands out to be right now is the small resistance of the pot you’re using. I’ve always recommended a 10K as you’ll see in the thread above under modifications.



Regards,
T.C.
Click to expand...
A 10k pot seems to have fixed the issue I was having with the controller not starting up👍

However seems like the dead band is a bit larger with this pot than the smaller one, even if I adjust the pot right to the edge where the motor starts, there is still about an inch of play on the thumb control before the motor kicks in and it's still a fairly violent kick not really smooth at all, it is smooth with wheels in the air with no load it feels good and can ease the throttle on, but on the ground with my weight on it it is quite jerky still

I have just ordered a Flipsky 75100Pro V2 controller so hopefully that will be better
 
electricboard1 said:
However seems like the dead band is a bit larger with this pot than the smaller one, even if I adjust the pot right to the edge where the motor starts, there is still about an inch of play on the thumb control before the motor kicks in and it's still a fairly violent kick not really smooth at all, it is smooth with wheels in the air with no load it feels good and can ease the throttle on, but on the ground with my weight on it it is quite jerky still
Click to expand...
Curious, how many turns is your new pot?
That much play would certainly be bad. :confused:
Would love to see a plot of the output... but good luck with the Flipsky.

Thanks for the update.
 
One of these might be suitable if you're going the VESC route:
flipsky.net

Flipsky 75100 75V 100A Single ESC Based on VESC For Electric Skateboard / Scooter / Ebike Speed Controller

Warm tips: It is recommended to keep firmware 5.2 from factory ship, the new firmware upgrade may damage the ESC. Remark:Please be careful to limit the Absolute Maximum Current below 200A. HERE Specs: Voltage:14-84V (4-20S) Continuous Current:100A Max Current:120A Firmware: latest (firmware...
flipsky.net flipsky.net

I've never used that model before so I'd suggest double checking beforehand, there's a long thread on them somewhere here. IIRC they cant sustain max values for long but you're well below those limits (about 7.5kw max). Bare in mind there are other options and probably at less than half the price, if you're into tweaking and tuning then they're like a dream come true but if all you want it set and forget then they might be overkill. Maybe check a few vids on setting them up beforehand too, the setup software (VESCtool) is slick and very well finished but some folks find all the options overwhelming.

edit; "sustain max values for long", as in duty cycle.
 
Last edited:
Last edited:
stan.distortion said:
One of these might be suitable if you're going the VESC route:
flipsky.net

Flipsky 75100 75V 100A Single ESC Based on VESC For Electric Skateboard / Scooter / Ebike Speed Controller

Warm tips: It is recommended to keep firmware 5.2 from factory ship, the new firmware upgrade may damage the ESC. Remark:Please be careful to limit the Absolute Maximum Current below 200A. HERE Specs: Voltage:14-84V (4-20S) Continuous Current:100A Max Current:120A Firmware: latest (firmware...
flipsky.net flipsky.net

I've never used that model before so I'd suggest double checking beforehand, there's a long thread on them somewhere here. IIRC they cant sustain max values for long but you're well below those limits (about 7.5kw max). Bare in mind there are other options and probably at less than half the price, if you're into tweaking and tuning then they're like a dream come true but if all you want it set and forget then they might be overkill. Maybe check a few vids on setting them up beforehand too, the setup software (VESCtool) is slick and very well finished but some folks find all the options overwhelming.
Click to expand...
Thanks
Yes that similar to the one I have ordered, however I got the Pro V2 model as after doing some research on them apparently the V2 is much better and doesn't overheat and is supposed to be much better overall

I've watched a few videos on setting them up and they look good so will give it a go, and like you say hopefully it should be ok as I will be setting it well under the max limits of its capabilities
 
TommyCat said:
According to its specs, it looks like a one turn. Hence the lack of fine tuning. You could verify if desired.

I see that I just mention using “multi turn mini potentiometers” in my write up.
I’ll update to be more specific!

Guide to Hall Sensor Throttle operation, testing, and modification. - Electricbike.com Ebike Forum
Click to expand...
Oh I see, yeah maybe that's why it's not quite the same as before that would make sense.

I've just re read the description on Amazon and see it says one turn I thought they were multi turn pots when I got them.

So does that mean this one turn pot just wouldn't be able to get as close the starting point as a multi turn would or just harder to get it near?

Just looking at pots again now on Amazon with next day delivery and they have a 25 turn version, would a 25 turn Pot work? Rather than 10? Or would 10 turn be better?
 
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electricboard1 said:
Just looking at pots again now on Amazon with next day delivery and they have a 25 turn version, would a 25 turn Pot work? Rather than 10? Or would 10 turn be better?
Click to expand...

I look at the total over-all resistance capability, and then divide by the number of turns to see the resolution.
I.E. 10K divided by 25 turns is 400 ohms per turn.
10K divided by 10 turns is 1000 ohms per turn.
The smaller the ohms per turn, the more precise you can get. But takes you more turns to get there…

I got these when I started… 25 turn mini pots.

https://www.amazon.com/dp/B0711MB4TL?psc=1&ref=ppx_yo2ov_dt_b_product_details

But doing an actual turn count on a 10K one, I counted 28 turns or about 357 ohms per turn. These work very well in this application. I.E. No problem to get within .5 of a volt and have it accurately stay there.
 
TommyCat said:
I look at the total over-all resistance capability, and then divide by the number of turns to see the resolution.
I.E. 10K divided by 25 turns is 400 ohms per turn.
10K divided by 10 turns is 1000 ohms per turn.
The smaller the ohms per turn, the more precise you can get. But takes you more turns to get there…

I got these when I started… 25 turn mini pots.

https://www.amazon.com/dp/B0711MB4TL?psc=1&ref=ppx_yo2ov_dt_b_product_details

But doing an actual turn count on a 10K one, I counted 28 turns or about 357 ohms per turn. These work very well in this application. I.E. No problem to get within .5 of a volt and have it accurately stay there.
Click to expand...
Excellent thanks
Have ordered the 25 turn will see how that goes 👍
 
Would a bias help, an additional (fixed) resistor on one end of the pot?
edit: or on both ends, a narrow voltage range.
 
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electricboard1 said:
Excellent thanks
Have ordered the 25 turn will see how that goes 👍
Click to expand...
Ok have soldered in the new 25turn pot, the only strange thing is the new one has exactly the same code on it and they look identical as the other one which according to Amazon was a single turn pot, does the code on them mean anything with these trim pots? Both say 3296 and W103 on them

It does seem to be alot better now as I am able to feather the throttle at low speed much better (still not perfect but hopefully the Vesc will help with that) but is useable now at least and the controller seems to stay active when turning it off and on again with these 10k pots👍
 
electricboard1 said:
Ok have soldered in the new 25turn pot, the only strange thing is the new one has exactly the same code on it and they look identical as the other one which according to Amazon was a single turn pot, does the code on them mean anything with these trim pots? Both say 3296 and W103 on them
Click to expand...
Seems to…

3296 Trimmer Potentiometer

Perhaps a bad one? Did you test it?



electricboard1 said:
It does seem to be alot better now as I am able to feather the throttle at low speed much better (still not perfect but hopefully the Vesc will help with that) but is useable now at least and the controller seems to stay active when turning it off and on again with these 10k pots👍
Click to expand...

Thanks for following up with the great news! Job well done.
Looking forward to your Vesc build.



Best regards,
T.C.
 
electricboard1 said:
Sounds good, but how you mean by that? do you mean put it on the red wire as to limit the top end also?
Click to expand...
My bad, I wasn't paying attention to what you're using the pot for. I had a switch set to a certain speed in my head for some reason, "flick the switch and it'll do a steady 4mph", not dead zone removal. At a guess your controller thinks the throttle is held on when starting up so disables output for safety. Does the controller have pins that are only powered once it's fully started up? Could stick a relay between the throttle output and earth if so.
 
TommyCat said:
Seems to…

3296 Trimmer Potentiometer

Perhaps a bad one? Did you test it?





Thanks for following up with the great news! Job well done.
Looking forward to your Vesc build.



Best regards,
T.C.
Click to expand...
Just wondering as I am now in the process of installing the Vesc controller instead, do I still need to fit the 10k Pot?
As it is Vesc does this mean it is all adjustable within the app now? or would you still install a pot for adjustment?
 
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