Acroprint Motor and Cam Replacement — Models 125 & 150

Replacement motor and brass cam assembly for Acroprint 125 and 150 mechanical time clocks.

Description

This Acroprint motor and cam replacement is designed for mechanical Acroprint models 125 and 150. If your clock is losing time, failing to advance minutes, or operating with excessive noise, the motor and brass cam are typically the cause.

After removing the minute hand, hour hand, and the four screws securing the clock face, inspect the brass cam. If a deep groove is worn into the cam surface, the minute overthrow will not travel far enough to grab the next tooth on the minute gear. In this condition, the motor may continue running, but the clock will slowly lose time.

Replacing both the motor and cam restores proper minute advancement and ensures consistent gear engagement. This assembly is intended specifically for Acroprint 125 and 150 models.

Installation Overview

This is a straightforward mechanical repair for someone comfortable working inside a punch clock.

Tools Recommended

• #2 or #3 Phillips head screwdriver
• #2 flat screwdriver
• Allen wrench set
• Magnetized screwdriver (strongly recommended)
• Patience

During reassembly, a light application of WD-40 can help ensure smooth mechanical operation.

Service Option Available

If you prefer not to perform the repair yourself, you may send your clock to our service shop. We offer professional motor and cam replacement with a typical 1–2 day turnaround.

What This Fixes

• Clock losing time
• Minute hand failing to advance
• Noisy or weak motor operation
• Worn brass cam causing missed minute changes

FAQ

How do I know if the cam is worn?
Remove the clock face and inspect for a deep groove in the brass cam.

Will a new motor alone fix the problem?
Not if the cam is worn. Both components should be replaced together when needed.

Can I install this myself?
Yes. Basic to moderate mechanical ability is sufficient.

Do you offer repair service?
Yes. We provide in-house service with a typical 1–2 day turnaround.

Click here to download the Acroprint owners manual

To change the motor and cam:  

You will need either a large flat bladed screwdriver, or a medium Philips driver.
And a small one of either.
Unplug the clock.
Remove the ribbon.  The Pentagon hole goes in toward the wall, round hole out to you.

Set the clock for any time, as long as the minute hand is straight up on 12.00
Remove the minute hand.  Keep the nut, hand, and washer in order.  That's critical.
Remove the hour hand with the flat screwdriver.  Wedge it in between the face and hand,  twist and wiggle it off.  You will press fit it back when you reassemble.

Remove the face. Remove the screws holding the motor and dial plate assembly.  Four large screws between face positions 7 and 5.  This normally takes a little "whack." it tips back and up, then lifts out. It goes back together much easier.

Disconnect (or cut) the motor wires.  It's easier to cut and make new ends on the wires, then twist them together and wrap with a wire tie or electrical tape when done.

Using an allen wrench, you will back out the cam locking screw, and put it in to the new cam.
Remove the motor, and replace it.
Put the cam back on, with the cam's knob, called the minute impulse cam, facing out.
Align the locking nut with the flat spot on the motor shaft and make it tight. Not killer tight, just tight.

Put the dial plate assembly with new motor and cam back on, put the 4 large screws back in, and snug them up.  It should reassemble smoothly.  Shorten the motor wires so there's not a lot slack, you have to make it easy to take off the cover and put it back on now and then. You can use a plastic wire tie to hold the wires in position - that's what we do.  Wrap the wires.

Put the face plate back on.  Press the hour hand back in to position.  Keeping the screw, minute hand and washer (or lock washer) in proper order, put the minute hand back on.  Aligned to 12, like it was before.

Make sure the ribbon is installed correctly.

Test it.

How to replace an Acroprint 125 / 150 punch clock motor
Photos below.

• 1) Unplug it, remove the case
• 2) Tools needed: 
  Size 2 phillips screwdriver, Size 3 phillips screwdriver
  Thin flat blade screwdriver, a new time clock ribbon
  Two wire nuts, new Acroprint motor and cam
  
   
  
     
  
     
  
   
• Set the clock so that the time shows any hour, and the minutes on 12 - straight-up.
• UNPLUG the CLOCK
• Cut the motor wires about an inch away from the motor
• Remove and discard the ribbon
• Remove the minute hand.  Note that there is a locknut underneath the hand, and a very small, specialized screw for the hand.
• Using a flat blade screwdriver, get under the hour hand right at the center and wiggle it up and off.  It's on a sleeve.
• Remove the 4 face screws and the face.  This exposes the frame.
• Using the allen wrench, remove the cam and put the allen screw aside.
  --  Note:  You will be reusing the allen screw.
• It's okay to force (twist and turn) the cam position, the motor is going away, anyway.
• Remove the 4 large screws on the fork. 
• Wack the back side of the motor frame assembly to release it.
• That big gear controls the minute alignment.
  --  It is adjustable after you put it back together to center the minutes
       if you need to.
• See the allen set screws, it's easy to figure out.
• Remove the motor screws. Sometimes there is one long screw and one short.
   Note that the long screw goes at the bottom.
• Replace the motor.  We put a drop of locktite (or nail polish) on the motor screws. Replace the cam.
• When replacing the cam, make the cam flush with the end of the motor - closest to you, not the frame.
  Leave just the siightest space between the cam knob (minute impulse knob) and the motor frame.  It should not rub.
                        Nearly.....Done!
• Put the motor and gear assembly back on.  Lower it in place with the black gear centering in the movement.
• Put the face back on.
• Slide the hour hand back in place.
• Put the minute hand back on, straight-up.  Lock nut, hand, screw.  In that order.  Plug it in and test, then set the time.