How much can you wind the crank of a Edison Model B Fireside phonograph?

[LyneisFilm]

After purchasing a new spring, on off brake, governor and a crank, I put the spring motor together and mounted it on the bottom plate.  I know the upper section works because I have tested it by driving it with a small DC motor. The reproducer was rebuilt my Wyatt Marcus and it sounds great.  The good news is without  cranking the spring too much, the mandrel rotates. 

 

Here is my question, how tight can the spring be wound?  The last thing I want to do is over crank it at this stage.  As I crank it of course I can feel the resistance increase and also the rotation speed of the mandrel increases.  How many rotations of the crank is needed for a 4 min playing time?  This may sound like a trivial question, but I have never cranked a windup phonograph.

[Valecnik]

You'll feel it noticeably tighten up when it's fully wound.  I just did a quick test on mine, 32 turns from fully unwound to fully wound.  Yours may be a bit stiffer with a new spring.

[phonogfp]

Around 30-35 revolutions is typical to fully wind an Edison single mainspring.  Don't worry about "overwinding."  Unless you apply significant pressure to a fully-wound mainspring (in good condition - and especially a new one), it won't break.  An old, tired, or damaged mainspring may break after only a few revolutions of the crank. 

 

Be sure the upper works and the motor are properly lubricated and you should be all set.

 

George P.

[LyneisFilm]

10 hours ago, Valecnik said:

You'll feel it noticeably tighten up when it's fully wound.  I just did a quick test on mine, 32 turns from fully unwound to fully wound.  Yours may be a bit stiffer with a new spring.

Excellent.  It turns the mandrel after just a few turns, which is a good sign that the gear train is functioning without too much resistance.

[LyneisFilm]

6 hours ago, phonogfp said:

Around 30-35 revolutions is typical to fully wind an Edison single mainspring.  Don't worry about "overwinding."  Unless you apply significant pressure to a fully-wound mainspring (in good condition - and especially a new one), it won't break.  An old, tired, or damaged mainspring may break after only a few revolutions of the crank. 

 

Be sure the upper works and the motor are properly lubricated and you should be all set.

 

George P.

Thanks.  the mandrel turns after just a few turns of the crank, which indicates the upper gear train is running freely.  I did find it was sensitive to how it sits on the lower plate, but found a position where it turned easily and then tightened the four mounting screws.