I am soooo disappointed!

[Brady Watson]

Slick hinges, boys! Thanks for posting.

-B

[Bob Eustace]

The almost invisible hinge also needs perfectly square ends on each end of the dowel. A simple sled is all that is needed (made on a Shopbot of course)! I use this thing for heaps of other jobs (like small 1" feet and toy cars sand trucks) and its so much safer than the cut piece flying off into outer space!

[barrowj]

Hi Bob,

I am always on the lookout for items like your sled, any chance you still have the cut file for it and would be willing to share. I think we need a place to share these type of production aids. I will start posting any that I make for the group to use if they want or even comments on improvements. If we already have a place for that I would really like to find it...

[shilala]

I have the Incra, and when I drill I run that bit in and out and in and out until it's not touching anything. It gives just enough slop to get the brass in.
If the brass rod is the least bit tight, I chuck it up in a cordless drill, hit it with some sandpaper (400 or 800 or whatever is laying around) and then shine it with a scotch-brite pad.
It takes very little work to change the diameter of the rod that tiny little bit if I need it.
Running the rod in the drill also shows me if the rod is true. Sometimes there'll be a little whoop or hogleg that's a problem and I can straighten it out or grab another rod.
I buy them in lots on ebay for next to nothing, so I don't mind chucking one. Not at hardware store prices.

[Bob Eustace]

This is a superb example of how good the hidden hinge looks on a very high end box by Rob Cosman. You just cant see it! The lid is on the left and is 5/16" thick.

[Burkhardt]

This is a superb example of how good the hidden hinge looks on a very high end box by Rob Cosman. You just cant see it! The lid is on the left and is 5/16" thick.

Ha! That looks really great! Something to strive for.....

I still have my sights set on machining it out of one piece. The first attempt was actually not that bad until I screwed up with the CA glue.

Obviously, when using a ball end, the hinge barrels can not be square and all edges must be beveled at least with the ball end radius. But I designed the 3d-model with a CAD system that allows me to do that in a fashion that there is constant clearance between all surfaces of the hinge. For now I am planning to use 0.01" clearance. If I can machine that precise enough (will use 1/4" bit instead of the 1/8" bit next time) the hinge should be almost as invisible as with the glued-in dowels, I hope. I also bought a few 1" abrasive buffing wheel brushes for gentler sanding of the hinge inside corners. I will post if I am successful. Oh well, maybe I will even post again, if I am not.

[Burkhardt]

....I still have my sights set on machining it out of one piece.........

Oh well, I give up on the one-piece design. I have been playing a bit more with the CAD and I get everything to fit without voids and machinable with a ballnose bit. But there is an unavoidable interference of the top and bottom part bevels when opened fully.

So, I will try to stay closer to the proven invisible hinge concept. To simplify the fabricating of the dowels I made them on the CNC with the additional advantage of integrating alignment tabs to help with the assembly. These tabs will be machined off after glueing (if I don't screw it up again....).

End grain strip of maple. The area where the dowel ends is recessed 0.004" to give the hinges a tiny bit of play.


Dowels with assembly tabs drilled and machined free 7/8" deep




Lined up on the stainless steel hinge pin (0.08") and temporary brass rods.
The dowels are not totally symmetrical. One half has 0.004" larger radius where they are to be glued.


So far so good. I will try to cut the box body tomorrow and glue it in. I just wonder what will now go wrong.

[Bob Eustace]

Gert I'd kill to have your ability to think outside the square like you seem to do weekly coming up with such original stuff! A MASSIVE advantage you have over the Buddy and Desktop brigades is you can clamp vertically. On the invisible hinges its a real bummer having to do them on the router table. I have "dug" a well in the table down to the power stick but it is horribly limiting particularly when I see what you and Brian get up too!

[Burkhardt]

Bob, that is probably a professional affliction. I have been the R&D manager for my company for 15 years and they paid me to come up with new stuff. For the last couple of years I am responsible for Operations and need another outlet for ideas

Actually, my machine does not allow vertical clamping. But I do have full 8" clearance under the gantry as well as 8" z-stroke. That allows for some pretty tall parts and long bits or, like in this case, the use of a sturdy machinist vise to clamp smaller part solidly.

[scottp55]

Lookin' Good G. !