Using small flywheel with ring gear and a starter motor as a slew gear?

[Renze]

Does anyone have experience with using starter motors for 10 to 15 minutes continous ?
My pal asked my advice on how to make an irrigation hose reel on the back of his pickup, to move the firehose feed hose to the self winding spray reel.

I suggested a starter with flywheel, and a slack V belt around the drum so that it slips when overloaded, instead of smoking the starter. I just wonder if a starter gets hot at light loads too...

 

[davedj1]

When you think about it, 12v hydraulic power packs like used on dump trailers etc and even snow plows are not much more than a starter motor. I would start with something heavy duty if possible like one for a diesel. I think it would hold up fine.

 

[davedj1]

Just a back of the envelope calculation, starting at the working end:

@ 1 RPM of the 10' boom, its tip is moving at about 1 ft/sec, which isn't exactly slow for up to 400 lbs, plus the boom's mass.

With, say, a 5:1 sprocket ratio reduction, your drive motor would only be turning at 5 RPM to achieve that somewhat fast boom tip speed.

I'd also be concerned about controlling acceleration and deceleration of that much mass, and at what side load on the boom. Seems like finding used or salvaged components to thread this design needle would take awhile. Earlier responses suggesting using a worm gear reduction might make component selection more flexible.

Thanks for the feedback, I think you are correct, it would be too fast, hard to control. I think I have decided to go with a hydraulic motor and large sprocket.