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Another Mark VII Speed Cam Question

Posted: Sun Jan 22, 2012 2:51 pm
by chucks
How do you remove the Speed Control Cam? Have the parts list....see how it goes together...not sure of how to take it out.(I to have a possible source of a cam...(underline possible)

Posted: Sun Jan 22, 2012 3:53 pm
by JPG
chucks wrote:How do you remove the Speed Control Cam? Have the parts list....see how it goes together...not sure of how to take it out.(I to have a possible source of a cam...(underline possible)

Assuming your 'parts list'/exploded view is the same as I am looking at:

Before doing any of the following, remove the motor belt from the motor pulley, and position the belt away from the idler pulley. That will allow free movement of the control sheave and cam.

Pry out/off (24) to get access to the shaft retaining ring.

Remove the retaining ring (25)

Remove the dial (23). Take care to not lose (20) & (26)!

This should give you access to the three screws and lock washers (27,28).

Before removing those three screws, rotate the cam so the follower (17 - different drawing) can be moved off the cam. I believe that is possible at the outer end of the cam. Note the positioning of the follower to the cam. The pins are not centered and it can be reassembled bas ackwards.

With the control sheave and follower moved off the cam, remove those three screws(27,28), and the entire outer assembly should be removable. The cam and shaft etc. may not come through the hole, but should be removable through the access hole(25,26 - different drawing) on the back side of the headstock.

The cam is retained to the shaft by a tension pin.


One Caveat! I be working only from the drawings. Never actually feasted my eyes upon these parts!;)

Posted: Mon Jan 23, 2012 7:41 pm
by chucks
That's what I was afraid of.......looking from the back of the machine at the cam it's right there....was hoping for a quick extraction. Thanks for the info...I will use it. It will be my first excursion inside any of my machines. Was hoping to get practice on one of my Mark V's before breaking into the VII. But this will definitely be worth it!

Posted: Mon Jan 23, 2012 11:26 pm
by JPG
chucks wrote:That's what I was afraid of.......looking from the back of the machine at the cam it's right there....was hoping for a quick extraction. Thanks for the info...I will use it. It will be my first excursion inside any of my machines. Was hoping to get practice on one of my Mark V's before breaking into the VII. But this will definitely be worth it!
The cam and shaft may come out the back without removing the three screws etc.