Don't forget that unless you figure way more power than needed(like a starter motor) the listed RPM of a motor is not the actual speed it will turn at the load rating. Motors like the Maxon style inline gear motors (which is what I'd use for doing this) have in their specifications the RPM at load ratings. The Maxon style motor is expensive when bought new but Googling for them gives a lot of them on the surplus/new market much cheaper. But even new prices arre pretty close to a car starter motor price.

A few pluses for one of this type motor is they have gearing built in, they are made for continuous duty and the don't draw as much current as a starter motor, which is way overkill for this project.

one place that has the motors I'm suggesting - http://www.jameco.com/1/3/dc-gearhead-motors

 

If it was me I would just buy the correct tool for the job like small 12 volt winch.

 

I would use gearing to help the motor match the ratios to get 25 sec .

There are two types of starter motor out there especially for the smaller size application, some now are permanent magnet field which controlled virtually the same as any other DC shunt motor, the traditional series wound starter motor should only be used under load due to the runaway condition it operates in, and can only be precisely controlled, rpm wise, by using feedback.
Max.

 

I like Benards numbers.
I'm an obsolete inch guy so...
100mm = 4 in X 3.12 is about a foot per revolution, about 3.3 ft per meter so 50 ft. In one minute would take 50 rpm so in .42 minuets 118 rpm.
10 kg = 22 pounds so if it were a 1 inch radius wheel 22 inch pounds, but since it's 2 inch radius 44 inch pounds.

 

Closest motor I could find: Surplus Center NE, PN: 5-1800, DUOYOU 200-1091, inline gear motor, 179 RPM 12V DC, 12A, 35 in-lb. Shipping wt- 11 lb. US $ 79.95.
If gear ratio was a bit lower torque would be around 50 in-lb. 2 motors should work at slightly reduced V,
Does battery ride along with motors, or is there a long umbical cord??

 

Closest motor I could find: Surplus Center NE, PN: 5-1800, DUOYOU 200-1091, inline gear motor, 179 RPM 12V DC, 12A, 35 in-lb. Shipping wt- 11 lb. US $ 79.95.
If gear ratio was a bit lower torque would be around 50 in-lb. 2 motors should work at slightly reduced V,
Does battery ride along with motors, or is there a long umbical cord??

Thanks for the suggestion!
But, it is looking pretty expensive.. 4 times my budget!!

 

Windscreen wiper motor = Cheap+lots of torque+12V+suitable rpm+compact+relatively light+Ok for continuous running

 

Window lift motors are another, they come with a reduction G.B.
Max.

 

Wiper motors mostly oscillate. Window motors generally too slow, 60- 62- & 88 RPM
If I had to do this proj & got despirate, I'd buy 2 ea CAT # DCM-565 from All Electronics, 12V, 3.5 A no load, 88 RPM, US $ 14.95, & use a 5.5 in drive wheel. Then test.

 

Wiper motors mostly oscillate..

No. The oscillation is achieved mechanically, the motor itself does not change direction.

 

How about a cordless electric drill/screwdriver with a chuck-mounted small-diameter winch drum?

 

Starter motors are not usually geared down, and the one you reference appears not to be geared either.

Yeah most starters anymore are direct drive or Bendix Drive.. But they do supposedly make geared starters for replacement of the Bendix Drive but I have yet to see one or buy one..

 

Hi,

All the starter motors i have seen to date are direct drive, but have a very small gear on the shaft which drives a very large gear on the motor so the gear ratio is quite small which gives it a lot of torque on the engine itself. You'd have to know the exact model to be sure though.

The required power of the motor is derived from the work that has to be done and the time it takes to do it.

 

Have you taken into consideration the weight of the motor? What are you going to use as a brake to hold it at the top?

 

Wiper motors mostly oscillate. Window motors generally too slow, 60- 62- & 88 RPM
If I had to do this proj & got despirate, I'd buy 2 ea CAT # DCM-565 from All Electronics, 12V, 3.5 A no load, 88 RPM, US $ 14.95, & use a 5.5 in drive wheel. Then test.

Thanks for the info Bernard.
I did not understand what is 2 ea CAT # DCM-565. Can you please explain?
Also, for lifting 10kg calculated power is 120W. So probably I will be needing 10A current rating motor correct?

 

How about a cordless electric drill/screwdriver with a chuck-mounted small-diameter winch drum?

Can you please give me some ebay or any other reference? I searched a lot for cordless drill motors also, but could not find a suitable one. Also they were costlier.

 

I did not understand what is 2 ea CAT # DCM-565. Can you please explain?

They appear to be window lift motors I mentioned earlier.
Torque increases at the ratio of reduction.
Torque = current, RPM = voltage.
Max.

 

Have you taken into consideration the weight of the motor? What are you going to use as a brake to hold it at the top?

Yes gerty. I have taken the weight of the motor into consideration.
But, for braking, i thought if the stall-torque/current ratings are more, then it is enough.
Please suggest me.

 

I am thinking an alternate solution.
Can I use AC motor instead of DC and a 12v to 220v inverter?
I was searching for 100w motors. Found ac motors are cheaper.
Also, a regular sewing machine motor would do the work.
Inverter is also cheaper. (ebay)
Would this strategy work?

 

You can buy cheap PWM DC controllers on ebay ~$4 to $5.00.
Depends what kind of AC motor.
DC motors are often very cheap if you have an auto wrecker where you are, especially if it is a strip-your-own yard.
Max.