# A little CNC work



## JimDawson (Apr 4, 2020)

These are some hinges for what we call break down tubes for our truck camper stabilizer product.  These are really for a particular camper model that has limited storage space, so the hinge allows it to fold for storage.

Sorry about the picture quality, I just photographed the screen







And the layout for machining.  The raw stock bolts down to the fixture plate then is machined into the form you see in the next pictures.

The raw stock for the piece with the two protrusions is 1x1.75 6061 bar stock.  The flat pieces are made from 1/2 x 14 6061 plate.  Haven't made any of the flat pieces yet.



And 36 pieces in process.  About 45 minutes from raw stock to roughed out as below in the next picture.



And a close up of the roughed out pieces.  The thread is 1 1/2-16, threaded with a thread mill.  We chose 16 TPI for the best compromise between thread strength and thread depth.  We only have so much wall thickness to work with.  



And a wider view.  And an old style hinge with tubes screwed in shown.  Current production is the new style, easier to manufacture.  These will be cut apart and finished in a second operation.  I'll post the second opp when we get to it.  The raw stock is shown for comparison.



And this is how we thread the tubes.


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## BGHansen (Apr 4, 2020)

JimDawson said:


> These are some hinges for what we call break down tubes for our truck camper stabilizer product.  These are really for a particular camper model that has limited storage space, so the hinge allows it to fold for storage.
> 
> Sorry about the picture quality, I just photographed the screen
> View attachment 319534
> ...


Jim,

Looks great!  Looks like you are chamfering the inside of the 6061 tube with a center drill?  I've been using a small carbide one for engraving, works great.

Bruce


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## JimDawson (Apr 4, 2020)

BGHansen said:


> Jim,
> 
> Looks great!  Looks like you are chamfering the inside of the 6061 tube with a center drill?  I've been using a small carbide one for engraving, works great.
> 
> Bruce



Thank you.

Yup, makes a nice chamfer, live tooling is wonderful.  I have done some engraving with a center drill also, and have used a sharp pointed countersink.


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## JimDawson (Apr 9, 2020)

As promised Here is the second opp on the parts.


The soft jaw drawing



And the finished soft jaw.



The left part is radiused on one side, then flipped over radiused on the other side drilled & reamed.  Right part is profiled on the right side, then flipped over and profiled on the other side, then drilled and reamed.  The parts were cut apart on the bandsaw rather than build a big fixture to hold a length of them.  Just didn't have enough parts to justify building a more sophisticated fixture.  The hundred parts is most likely at least a year's supply.  Next these will go out for anodize.


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