Improving a Marx Windup Motor

[wallyworld]

Brilliant...

[servoguy]

If you wanted to make these parts commercially, I would recommend you get them made by a CNC machine shop and wholesale them through the parts guys.  There is probably a good market for these pieces.  This approach keeps you from doing any realy work.  Just ship the parts and put the check in the bank.

[JamesP]

Thank you!  I like to work on clockwork motors, but I wouldn't want to do it for a living... ha!

If anyone from Kalmbach should see this, I don't know why my initial text is fine, but subsequent text after the images has the red underlining.  The underlined text was red when I first posted, even though I did not do anything to the color or format of it when I typed it.  I was able to select a black color for it, but cannot seem to get rid of the red underlining.  Hmmmm....

Thank you,
James

[Firelock76]

Brilliant!  You may just have the makings of a little side business here.

[JamesP]

Marx windup motors have a lot going for them; they are durable, perform well, plentiful and affordable.  However, like any mechanism with an age that is measured in decades, they can develop problems.  Over the years I have learned how to deal with the normal Marx issues such as loose wheels, broken mainsprings, malfunctioning governors and slipping ratchets.  But, the die-cast mainspring hub will occasionally break, and the only fix I had for that was to find a donor motor with a good mainspring hub.  I decided that I wanted to be able to make my own hub in case I couldn't find a replacement, and while I was at it, I wanted to develop a more durable ratchet, too.

The mainspring hub itself wasn't an issue except for the square hole for the key.  The new hub was machined out of 360 brass, and a 1/8" hole was drilled through it for the keyhole.  I made broaches to cut the square keyhole out of the original 1/8" round hole.

Here is a picture of the new brass mainspring hub on the left and an original Marx mainspring hub on the right:

 

The orginal Marx ratchet uses a plate with pawls stamped into it that engage matching holes in the big gear.  Over time, the pawls and the mating edge of theholes get worn out, resulting in a malfunctioning ratchet.  It can be repaired, but just for fun I wanted to try my hand a making a more durable ratchet.  I soldered a new drum for a ball & ramp style of one-way clutch to an original Marx big gear, then machined a center ramp that pressed onto the new springhub.  Commercial 3/16" diameter ball bearings were used in the ratchet.  Here is a picture of the new ratchet assembly:

 

I did have to rework the ramps to make it engage properly.  I also had to make a few other modifications to fit the new ratchet in the motor; I will redesign it so the next time the additional modifications aren't needed.  Here is a picture of the ratchet motor with the new assembly in place:

 

The rebuilt motor was installed in a Commodore Vanderbilt shell and has been undergoing test runs on my clockwork layout:

 

So, the new mainspring hub and ratchet project was a qualified success... it was a good learning experience, and hopefully the next one will turn out even better!

 - James