Anatomy of a micromatic head: how it works

[amishmotorboat]

For informational purposes only. I do not recommend that anyone try to disassemble one.

The knob is connected to a rod with threads, so that when you turn it, the top of the unpictured rod (1) pushes in the direction of the arrow, making contact with this little toothed piece (2) forcing it in the direction of that arrow. The teeth on the top of (2) run across a splined shaft (3), making it turn. This also compresses the spring (4).
The shaft turning like this closes the door. This shaft isn't actually the hinge. The hinges are pins that come through the door and are connected to the shaft, but offset from the shaft's axis. Because the pins are offset, when the shaft turns, the door first closes, and then when it cannot move downward anymore, further turning of the shaft draws the door forward securing the blade.
When you turn the knob the other way, the rod (1) recedes, leaving that tiny little spring (4) to do all the work of opening the door again.

 

[Aberneth]

It's amazing that such a complicated mechanism can function after 70 years of use and abuse. I did eventually get my oiled, though, with red gage oil.

 

[MrGuy]

Very cool info! Love the arrows for reference of movement direction. So, can a disassembled Micromatic ever reassemble?

 

[amishmotorboat]

Very cool info! Love the arrows for reference of movement direction. So, can a disassembled Micromatic ever reassemble?

Reassembly is the part I doubt, hence the warning.

 

[Darjeeling Express]

Amish, this is an excellent thread, thank you for posting it. I have always been fascinated by the movement of the Micromatic's opening and closing mechanism. The way it rises and moves forward is fascinating. Unable to contain my enthusiasm I have shown it to my wife who merely tolerates my shaving related obsessions was equally impressed.

 

[the beav]

Thanks for this. Just looking at a Micromatic, it seemed so simple that I never considered how it actually worked.

 

[Sledgehammer39]

I know some folks don't like the MM but I own a Clog-Pruf and a Bullet-tip/Guiding Eye and I like the Clog-Pruf better. Holding one of these models and you just gotta appreciate the engineering and tolerances they achieved back in the day.

 

[sffone]

I just happened to come across this thread and am so glad I did. I just finished taking a Micromatic apart and was going to post some pictures, but I see that it has already been done. Good job.

 

[Haiku]

One thing that sets the Micromatic apart from all other TTO designs is the fact that the thing is built like a rock. There are simply no other such razors on the market that are that solid. When they decided on the Micromatic line, they also clearly decided that the quality was going to be world-class.

 

[DamnFineBob]

Thank you! You had no idea how often I watched my Micromatic's door close and slide forward, wondering just how it works.

 

[kimfella]

The rod ("1" in the picture above) has a series of "step-downs" taking it from about 1/4" dia. at the base of the handle to approx 1/8" at the end of the rod. There is a split ring riding between one step-down and a flange (step-up?) about 1/4" further along (this flange on my MM got a bit chewed up when I took the handle off) There appears to be a groove in the barrel for the ring to seat into. Beyond that is a threaded section on the rod which mates with a threaded section in the barrel. (Who was it said a picture is worth a thousand words? He sure got that right! I wish I had a camera to show what I mean)

On my MM there are two square "spots" on the (top side of the) base of the head. I'm guessing these are two pins from the conical section housing the traveling knob/lever/thing (part "2" in the picture in the first post), and that the head is basically press-fitted onto these pins. I tried heating the razor in the oven to see if the heat would expand the pins and the mating holes in the head at different rates, loosening the fit. No joy.

I'll have to try tapping a little harder on a wrench holding the handle. If that still doesn't work I may try to tap/punch out those two pins directly. If I can get it apart without breaking the pins I may be able to reassemble it, even if I have to use Weld-Bond (or whatever that metal/epoxy product is called) to hold the parts together securely.