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  #11  
Old 09-28-2018, 10:26 PM
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Quote:
Originally Posted by digger doug View Post
It does ?

I dunno, the airco book I have that showed this machine calls the metal template that the magnetized roller runs against as a CAM.

You know, like the one in your car engine....

FWIW I have posted before, an old article showing a burning machine
run with paper tape, pre WW2.
The template being traced has been incorrectly described as a cam.

The cams mentioned in the OP control gas flow NOT torch movement.

Paper taper machines were classed as NC machines- Numeric Control (per Machinery Handbook and others) as opposed to CNC -Computer Numeric Control.

Because there is a cam (note lower case) somewhere in the mechanism does not make it a CAM (note upper case) process any more than having a cam in your car engine makes your daily driver a CAM machine....
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  #12  
Old 09-29-2018, 12:33 AM
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What about the fire control on the big guns of the Iowa class battleships . There was nothing better so they were left when the Missouri was rehabbed .
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  #13  
Old 09-29-2018, 05:17 AM
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Quote:
Originally Posted by camdigger View Post
The template being traced has been incorrectly described as a cam.

The cams mentioned in the OP control gas flow NOT torch movement.

Paper taper machines were classed as NC machines- Numeric Control (per Machinery Handbook and others) as opposed to CNC -Computer Numeric Control.

Because there is a cam (note lower case) somewhere in the mechanism does not make it a CAM (note upper case) process any more than having a cam in your car engine makes your daily driver a CAM machine....
Not all CAM's are round....

The airco book talks of both the CAM controlled valve set up (very common
back then BTW)
As well as the template called a CAM.

Airco's word's not mine.
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  #14  
Old 09-29-2018, 05:18 AM
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Quote:
Originally Posted by midmosandblasting View Post
What about the fire control on the big guns of the Iowa class battleships . There was nothing better so they were left when the Missouri was rehabbed .
Yup, there are "3 dimensional CAM's" out there, IIRC that system uses them.
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  #15  
Old 09-29-2018, 11:54 AM
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Quote:
Originally Posted by digger doug View Post
... Which gun were they making ? upper left of page 3 says "9mm Browning" ...
Top part says "Bren body", others Browning 9mm. Inglis was a manufacturer of the Hi-Power 9mm pistol.

The part on top looks like this but inverted.
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  #16  
Old 02-24-2019, 02:14 AM
Lantraxco Lantraxco is offline
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Quote:
Originally Posted by camdigger View Post
Definitely NOT CAM. CAM stands for Computer Aided Manufacturing. WWII pre dates the computer by 2 decades.

Besides, Page 2 of the article clearly says "tracing head"

My question is how did they manage to get the tracer stylus to follow the pattern. My own tracer suffers from lack of adhesion between tracer stylus and pattern.....
Yep, there's a chart near the end showing magnetic roller size versus corner radius. Looks like a 1/2" roller for the thicker plate sizes. I always thought thicker pattern plates would make for better traction. I have seen setups where a post was placed in the approximate center of the pattern and a long spring run out to the roller drive motor, adding tension to hold the knurled roller against the pattern helping the magnet out I guess.
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  #17  
Old 03-08-2019, 11:26 PM
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Quote:
Originally Posted by camdigger View Post
Definitely NOT CAM. CAM stands for Computer Aided Manufacturing. WWII pre dates the computer by 2 decades.

Besides, Page 2 of the article clearly says "tracing head"

My question is how did they manage to get the tracer stylus to follow the pattern. My own tracer suffers from lack of adhesion between tracer stylus and pattern.....
Tracer head was a term used back then for the system which provided a steel template that was smaller in real dimension by one roller diameter.

A required circle of say 12'' which have a template diameter of 11' if the roller was 1/2".The roller was a direct coupled to a variable speed electric motor.

The roller was also an switchable electromagnet. I virtually spent months on the multi cutting head units cutting bulldozer ripper components .Using the correct flame pressures and speed control settings,you would be amazed at the flame cut surface finishes that could be achieved.

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  #18  
Old 03-09-2019, 03:32 AM
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Quote:
Originally Posted by OZWELDER View Post
...Tracer head was a term used back then for the system which provided a steel template that was smaller in real dimension by one roller diameter.

A required circle of say 12'' which have a template diameter of 11' if the roller was 1/2".The roller was a direct coupled to a variable speed electric motor...
We have a Tanaka KT-350 magnetic tracing torch--we bought it in the late 70s. It still works although we haven't used it much in the last few years. Downside of course it that you must have a metal template for each part you want to cut. Once you've got the template the rest is easy.

In your example above I think you missed on the template size. If you want to cut a 12" circle (solid disc) with a 1/2" diam. roller your template would need to be 11-3/4" plus a little allowance for the kerf. An 11" template would cut a disc 11-1/4" in diam.

The pic is just one I found online but our torch is identical to it...
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  #19  
Old 03-09-2019, 01:31 PM
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I will stay with 11 1/2"
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  #20  
Old 03-09-2019, 02:19 PM
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Originally Posted by digr View Post
I will stay with 11 1/2"
Yup, you're right by gum. For some reason I was thinking of it as a straight line cut where your offset with a 1/2" roller is 1/4". When you cut a circle the radius of the template is reduced by 1/4" and thus the diameter is reduced by 1/2"...
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