Miserable saw from hell

[Aunt Phil]

This fine precision saw comes from Germany, and looks very much like a wormdrive skilsaw.

Its purpose is to cut channels in concrete.   I always wanted to meet the blockhead who came up with it because he clearly never used his saw.

Note the instruction on the nameplate, do not  use in aggregate concrete.  Just what did he think floors were made with?

Actually it isn't too bad to operate in concrete that is less than a week old, but it is NOT for cured concrete.  The maximum slot is 1/2" wide and about 5/8" deep.  The cutter head rotates about 500 rpm, and the individual carbide cutters are replaceable. 

This was an early double insulated tool circa 1964, and was originally bought to cut slots in a floor to insert detection loops that caused a pneumatic door to open as a lunatic on a forklift came roaring toward the door.  The system worked well till an airline got shut off and nobody told the forklift maniacs.

[scottg]

Never saw that before!
 Green concrete is right. You'd raise enough cloud to make yourself into a floured doughnut if it was any drier. heehehe  I bet it was a mess to use even green.
 I can see the teeth are replaceable. Not easy to get now though I bet.
 
 I can't imagine very many of those were sold
  yours Scott

[pritch]

Holy Cow! As someone who has worked in concrete construction for 30 years, all I can say is Holy Cow! Check out how the teeth are facing-if they are in correctly, that would have to be rotating counter-clockwise and the operator would have to push against the cut. That groove would wind up being an inch wide by the time it got done blowing out the edges of the cut!

[Aunt Phil]

I hauled it around a while looking for a chance to try it, I ain't all that smart, and finally had a chance one evening.  I ran a few feet of cut across a pour that was a couple days old, a block wall was going where I made the cut so there really wasn't any damage. 

You're right on 2 of your observations, the teeth are in correctly, it rotates slow, but the kerf is about 5/8 wide.  It has a depth adjustment, so I made 3 or 4 passes to get to the full depth, probably 3/4".

Yes, you do PUSH it into the cut and you also HOLD it down.  It could use an adapter for a tractor seat so a small boy could hold it down. 
Dust isn't real bad on fresh concrete.

I also did try it once on cured concrete.  I quit fast.

The teeth are in 3 orientations, left, right and center, and you could extend the life by swapping positions if you ever used the dam thing long enough.

[rusty]

Hehe, monster machine. The fellow that invented it probably saw a chainsaw and thought 'hey , that would work great on concrete....

Back in the 60's it was more common to pour 'cheap' floors in supermarkets etc (no stone), before the idea of using forklifts became more or less manditory. I sure wouldn't want to hit a chunk of quartz with that thing...

>lunatic on a forklift...

Hehe, don't need a forklift, I fixed a glass/alumnium door on a cooler room a few weeks ago, the floor pad failed, the idiot with the two wheel handtruck smashed into the door that didn't open.....
Missed the crashbar on the door by 2 inches....