Shorting a motors out to keep it from spinning question?

[supak111]

Hey guys quick question here I'm not sure about. I use a DC gearbox motor to move something and when the motor is not is use I have the 2 terminals shorted together so that its harder to move the motor by hand. Kinda like the circuit on a car window.

My question is if I have two exact same gearbox motors, (both same gear ratio) only difference is one motors internal resistance is 15 ohm and the other is 30 ohm, which motor would be harder to move by hand when shorted?

Or is it not possible to figure out just by knowing the resistance?

 

[Minder]

Generally the lower resistance, other factors are the generated voltage at the same particular RPM.
The higher the rpm the more resistance to back fed rotation when shorted.
Max.

 

[supak111]

So lower resistance is the way to go? Not sure about generated voltage but this info might help...

Device I'm using uses 2 motors and I'm using 12v. I have two options of motors both are same gear ratio:
1) I can either run 2, 6v motors, each is 30ohm, 30rpm, wired in series
2) or my other option use 2, 12v motors, each 15ohm, wired in parallel or series. Doing it in parallel gives me too fast of movement. In series it spins about same as the option 1, about 30rpm

 

[Bluejets]

Kinda like a window winder in a car , use a worm drive gearbox.

 

[supak111]

for what i'm doing worm drive would be best but space is limited and there are no cheap good quality worm drive motors. This is why i must use one of the 2 motors mentioned above. just trying to figure out which one has more resistance when moved by hand than the other. Might just end up making one of each and doing some test to find out

 

[Kiwi]

I would not have thought that shorting the motor terminals together would have had any effect on the force needed to turn the motor by hand.
The force required would be due to the reverse ratio through the gearbox.
The motor wouldn't be turning fast enough to generate voltage.
It would certainly make it stop in a hurry when running.

 

[supak111]

Makes a huge difference shorted or not, try it on any gear motor.

PS motors I'm using are using gear ratio 300 to 1 so its really noticeable