Vintage Safe Restoration

[PeterT]

I did not have a good way to set up the angles on the surface grinder (no sine bar)

You likely have seen this method but just in case... You can make quite accurate sacrificial custom angle jigs using a piece of metal with one good edge & some dowel pins.
Example shows a layout to get a desired 3.50 degree angle relative to horizontal. How accurate? 2nd example shows same jig with RH hole out by a thou (yellow shade now a driven dimension), results in the angle being off my only 0.02 degree (purple shade). This is just a positioning device of course, you still need a way to clamp the part, kind of like how a parallel positions. The nice thing is you can use this to hold stock at oddball orientations, could be upright or relative to some other angle. Or incorporate 3rd dowel to act as a stop, now you have 3 contact positions for repeated operations.

 

[Dabbler]

@RobinHood, I should loan you some of my grinding tools! Nice work with the T&C grinder!

 

[RobinHood]

Thanks @PeterT, that’s an excellent explanation on the accuracy of that method. yes I did use that principle when I milled the new lathe compound gib on the mill table supported by a chunk of cold rolled and a dowel pin. The gib was super glued to the top of the billet.

I should have been more specific: since I was going to use the surface grinder, the pin method does not work as the magnet won’t hold down the vice any more. So I would have had to use a vice on the mag chuck, then another (smaller) vice inside the bigger’s jaw and use the pin method on it to get the angles. Head room quickly becomes a problem. Plus the blade has tapered sides - tough to hold onto it in the first place.

A “magnetic sine bar“ is what I was referring to. It could have held the blade fine for grinding... maybe I should buy all of Bert’s surface grinder accessories, if he were willing to separate them from the grinder? What you think @Dabbler?

 

[Dabbler]

@RobinHood You could borrow my multi-axis sine table at any time, put the pin in a V block, and you are away! You found a perfect solution using your T&C grinder - great thinking!

- You and I should talk about the SG and accessories. Give me a call when you are able.

 

[RobinHood]

@Dabbler , I will call you.

only small progress today. Broached the three key ways. Worked very well.




key is next...

 

[PeterT]

That turned out very nice. So are you stroking the quill like drill press mode? About how much DOC per pass? Do you select a low gear to minimize spindle rotation or does it even matter? I have yet to broach but I'm sure I will have to cross that bridge one day.

 

[RobinHood]

@PeterT , the actual broaching was anticlimactic, almost a let-down.

After using the little flat on the front of the tool to indicate it square to the part, and centering it in the hole, i just moved over in Y for touch-off. Yes, i just moved the quill up and down with a DOC of 2.5 to 3 thou. It was mostly done by feel (i know super precise, hugh?!). No seriously, i could feel the broach engage and take a chip and just went with "about that amount of down pressure on the quill handle feels right". I could feel / hear the chip being taken. Having done some metal scraping probably helped as i have a pretty good feel for what is too much/not enough pressure.

The mill was in low gear with the variable speed selected to lowest (~40 RPM) and the spindle brake engaged. So the only movement is the little bit of backlash that my machine has in the spindle drive gearing (i have not measured that, but being a spur gear, i would guess no more than 2-3thou between the teeth). I called that good enough. One could build a real spindle brake to engage where the spindle protrudes the quill - that would result in zero rotational movement.

Here is a picture of the little ships.

 

[RobinHood]

The Finishing Touches

The key is 50 thou thick. I found a washer of suitable thickness ~49 thou and did some rough grinding with the Dremel and finish shaping on the mill. Work holding was the biggest challenge as the height of the key is less than 1/8”, the thinnest parallel I have. I used some steel strapping underneath the part to raise it high enough to allow the machining without cutting into the parallel.



here is the finished key


the spindle, knob and bezel were assembled next. Made a new brass pin after using a 1/8” end mill as a drill to make the hole at 45* to the shaft axis. This was done originally to prevent the spindle from unthreading and to hold the bezel. They had a steel pin, the new one is brass, I think plenty strong enough. Used some low strength locktite for added security.




after final assembly and a little tweaking (filing) the lock is back operational.



the combination is 37, 4X, XX, XX, in case you are wondering... I’m sure Kelly will change that....

 

[Cap'n Kelly]

Wow, super impressed with all of the detailed workmanship! I am super stoked to pick this up and re-install in the safe body.
Now for some historical perspective for what it is worth in closing this off. I had alluded to the age possibly being from 1948 and have attached the related advertisements from https://archive.org/details/PopularMechanics1948 . Contact with several safe forums, antique safe dealers, and even Underwriters Laboratories did not reveal any further evidence but I will continue that quest. I have also exhaustively researched where the safe may have come from, I have really only a single piece of an old news article https://www.coloradohistoricnewspap...--1--img-txIN|txCO|txTA-safe+burglary-------0-- so this is highly speculative but the time and proximity seem plausible (attached below).
Thank to everyone for their interest and assistance with getting these parts replaced. I am completely humbled not only by the precision of the newly manufactured pieces but also by the corrections made to make this piece better than when it came from the factory! A huge thank you to RobinHood for his meticulous work!!!