Allen, I liked your reply...... however.... I think your formula will
result in an extractor running too fast.  Here is an alternate
suggestion.
 
1.  Turn the extractor by hand and have someone count the rpms of the
baskets at the speed that you have found works well.
 
2.  Find any low speed motor (1725 rpm) and mount as suggested.
 
3.  Select your two pulleys to drive the extractor at the selected speed.
 
As you will be using only one speed and it will be easy to let the
machine run longer than when turning it by hand you may want to try a
lower speed.
 
 
Eric Abell                           email: [log in to unmask]
Gibbons, AB, T0A 1N0
Canada
(403) 998 3143
 
On Mon, 11 Sep 1995, Allen Dick wrote:
 
> > Allen; I just read your post to the bee-list and am interested in
> > the details for motorizing a hand crank extractor using a fan or
> > other small motor.  I have a small, four frame Dadant stainless hand
> > crank that, as I get older would like to motorize.  Your help would
> > be appreciated.
>
> Just remove the mechanism from the top of the centre shaft, and find
> an 'A' belt pulley to fit.  About 6 inche diameter is right as I recall.
>
> Then arrange to hang a 1/4 horse two speed furnace fan motor on one
> side so the the shaft is also vertical and poking up enough so that a
> pulley placed on the shaft will line up with the first pulley. The
> smallest pulley available at a hardware store will be appropriate.
> If you can rig a mount that allows some adjustment towards and away
> from the centre shaft to allow for belt variations or pulley changes,
> so much the better.  A simple L shaped piece of 3/16 steel with slots
> in it works well.
>
> Then find a belt that fits between the two pulleys, and then wire a switch that
> permits two speed operation.
>
> The RPM selection of the motor is usually 1140 and 1725.  The RPMs
> of the (two speed) extractor will be P1 / P2 X Ms.  Where P1 and P2
> are the pulley diameters and Ms is the motor RPM at the moment.
>
> A 60 inch radial runs about 250 RPM, so for a tangential type, you
> would likely want a target top speed ofsomewhere in the range of
> D60 / Dyours X 250 where D60 is the speed of the large machine and
> Dyours is the diameter of your little machine measured across the
> baskets, not the tank.
>
> I extracted 125 hives one year in a converted school bus with such a
> machine and did not find it wanting.
>
> Regards
>
> Allen
>
> W. Allen Dick, Beekeeper                                    VE6CFK
> Rural Route One, Swalwell, Alberta  Canada  T0M 1Y0
> Honey. Bees, Art, & Futures <http://www.cuug.ab.ca:8001/~dicka>
>