Make a speed controller less sensitive

[abunaitoo]

Gang here seems to be a vast collections of information.
Thought I'd see if anyone here knows.

So I'm trying to make a treadmill motor variable speed.
I got an AC to DC speed controller.
chinese junk, but it works.
It works, but I need it to be more gradual.
It comes on to fast and is to sensitive.
This is what I have..............
QWORK AC 110V 400W Knob Motor Speed Controller,
2 Pack DC 0-90V Variable Adjustable Speed Regulator
for 90V DC Motors.
Anyone know if it can be made less sensitive, more gradual????

[MaryB]

I am guessing the knob sits on a variable resister(potentiometer), you could measure the resistance end to end(middle terminal is the wiper and gives the variable resistance output) then get a 5 or 10 turn variable resistor of the same value. Requiring more turns would mean finer speed control... may require mods to how stuff is mounted in the box because they are 3-4 times longer...

https://www.amazon.com/Onwon-Potentiometer-Wirewound-Multi-Turn-Adjustable/dp/B07M7GDC1D?th=1

[abunaitoo]

Uggg!
It sounds like the way to go.
Only thing is if opened, warranty is void.
Has that warning tape on it.
But was cheap enough to give it a try.
Thanks.

[JonB_in_Glencoe]

You need a controller with Accel control.

[abunaitoo]

What is that????

[abunaitoo]

Opened it up and it has a B10k pot.
I have a B10k, so I'll try and see what that will do.
I know the bar type of pot can be found with more turns to reach full power.
But what are they called?????

[MaryB]

you want a 10 turn pot, means it takes 10 turns to reach full value...

[JonB_in_Glencoe]

What is that????

Acceleration control/deacceleration control
https://www.youtube.com/watch?v=teO5qz3gLtQ

[abunaitoo]

Tried to watch it, but it's waay over my head.
Understood some of it, but.............
What do they call one of those pot that have lots of turns.
I've used them in a couple of tools, but I never knew the name of them.
I thought it was a linear pot, but it's not that.

[JimB..]

I’ve been thinking of using an old treadmill motor to run a small wood lathe, but was planning to scavenge all the electronics from the treadmill as well. You on a similar path?

[JonB_in_Glencoe]

Tried to watch it, but it's waay over my head.
Understood some of it, but.............
What do they call one of those pot that have lots of turns.
I've used them in a couple of tools, but I never knew the name of them.
I thought it was a linear pot, but it's not that.
It's called a Rotary Potentiometer (10-Turn)
BUT, personally I don't think that will give you a more gradual "start" with such a cheap DC drive. The potentiometer sends a small voltage signal to the Drive and the Drive kicks out a starting voltage to the motor. If there is no adjustment on the circuit board for the starting voltage, usually labeled as MIN, the drive doesn't likely start at 0.0 volts...and it's not a pure DC voltage, it's a choppy DC voltage. You need a drive with an Accel/Decel option to achieve what you are asking for. OR, you could use some sort of mechanical friction control, basically a fake load.

[popper]

Real problem is the motor. It requires an amount of torque to start, after which it 'runs'. Run speed is higher than start speed. Aka, you'll never get there without gearing down the motor.

[phantom22]

Maybe an doing an old rotary airplane propeller style spin at the beginning would get it going. Maybe not that exactly, but some kind of manual start assistance.

[farmbif]

might need something like this;

https://www.surpluscenter.com/Electric-Motors/DC-Motors/Motor-Speed-Controllers/90-180-Volt-DC-Variable-Speed-Control-w-Potentiometer-Minarik-MM23001C-000D-11-2269.axd

it usually comes down to you get what you pay for. ive tried different speed controllers and most economical solution was to get ones that are not mounted in a box and make my own box for it.
im not sure how these things work but ive connected them before and made them work. ive even recycled dc motors before cleaning them out and putting in new brushes and resoldering wires but that the extent of any expertise I have. we used to get crate fulls of dc motors into the scrapyard that were changed out on regular basis at different manufacturing plants and usually need to be cleaned out from working in high dust environments and maybe brushes replaced and a new coat of paint and they would work good as new.

[MaryB]

Best DC speed control is pulse width modulated. Motor get full voltage but it is pulsed to control speed. Gives full start torque that way.

[popper]

His motor is probably PWM anyway but stall torque is the problem. If it's a 3 phase brushless there is a chance but still have the stall problem. Most brush type motors don't have much speed range. 10 turn pots are for better resolution, probably not needed here. Might look at new washing machine motors. 3 phase PWM motor that will handle a heavy load.