bending a patch box

[billd]

What's the secret to not have the hinge bind up when you bend a patch box to match the contour of the stock? I did a banana box tonight and just bent it the slightest bit and now the hinge is not free. This has been a re-occuring thing with me.
Thanks,
Bill

[Bob F]

Bill, I cut some relief cuts in the underside to give it some room when I bent it.

[tallbear]

Bill
I bevel the back of the hinge knuckles .Just the back part that won't be seen.As you bend the hinge they get closer together but don't bind.I also stop and work the hinge a little as I go.

Mitch

[billd]

This last one I tried the beveling trick but it still binds. This one was from MBS. It seems like they should make the hinge a little sloppier. Too much quality, rare in todays world.   I just worked it back and forth while watching a hockey game but it still isn't as free as I would like.

There's got to be a better way.

Bill

[Z. Buck]

well, ive  never used it for this exact problem but a little bit of relive and some mothers chrome polish, and work it back and forth she free it up much faster than without any sort of abrasive

[J. Talbert]

This has always been a problem area for me, and I don't have the magic formula yet.  Some have worked better than others, but a couple things that I have tried include:

Trying to concentrate the bends torward either end of the hinge keeping the center as straight as possible.

If not copying a specific design that's made otherwise,  I make the lid with just two knuckles (one either side of center) with the outer portions of the lid "free floating", keeping most of the movement close to the center.

Even so,  sometimes I've been happy with the results and other times, not so much...

Jeff

[billd]

Thanks everyone,  I thought of the abrasive as suggested by Zack.  I have some lapping compound. That outta work.  This one's tighter than most I've done, and it's iron.


Bill

[Nate McKenzie]

I've had success with valve grinding compound if its not binding too badly.

[Hoot AL]

You need to remove the hinge pin. Then bevel the lower inside of each knukle at about a 45 degree angle. This way you and almost make a half circle of the hinge and it will still not bind.

[George F.]

Here's something else I do. I do releave the under side knuckles. I put a tapered point with a slightly rounded nose on a hinge pin that is about 3" longer than I need. Then I liberly spray WD40 on the hinges. Next I chuck the hinge pin in an electric/ cordless drill and I run the  pin in and out with the drill  running. I also operate the hinge as I'm doing this, also spraying more WD40 as I do this.   ...Geo

[wmrike]

Beveling, lubes, and so forth provide some relief, and you do indeed need some side-to-side clearance.  But the real culprit is that once the hinge pin is bent, each segment of the hinge is working on a different axis.  Imagine an engine crankshaft with each of the mains bored and ground on a different axis from one another and you'll get the picture.  Ultimatley, the little fingers for each segment will have to be sprung open to provide the necessary clearance.  The most straight forward way to do this is to just open and close the lid through enough cycles to free it up.  I think this is a reason why the originals tend to incorporate narrow lids - it minimizes the the discordant angles through the working portion of the lid.  At any rate, this breaking-in process is a distasteful way to treat a nice, shiney new patchbox lid, but somebody's got to do it. 

[flintriflesmith]

If you are making your box, just bend the lid and finial before you fit the hinge. Cut the knuckles parallel to the axis of the door opening.

Gary

[David G]

If you are making your box, just bend the lid and finial before you fit the hinge. Cut the knuckles parallel to the axis of the door opening.

Gary

                                                                                                                                                                               Yep, and it also eliminates the knuckles from opening up at the top.

[Pete G.]

The secret is to bend just the outer knuckles of the hinge, which are attached to the finial and don't move anyway. The center portion of the hinge should remain flat, which is the only way a hinge can work properly. The door and final are both be shaped toward the edges, and unless you point out that the middle portion is actually almost flat, no one will ever see it as such. A lot of the architecture of longrifles depends on illusions, which is just one of the things that make them so fascinating. Look closely at some of the photos available with this in mind and you can start to see it. Sit down and really study what happens when the barrel flats transform into the round wrist or look at the carved areas that are actually flat, but carving and moldings make them appear otherwise. There are many places that things aren't really what they seem at first glance. These are the kinds of things that give the handmade longrifle a soul that a production made rifle can never match.

[J. Talbert]

Gary,
I've contemplated that method previously but never tried it because of concern about matching the curvature of two separate pieces before they're mated, and installing a curved pin.  I take it that this is the method you use.  I suppose that explains my hit or miss results in the past.  I'll definitely give it a try next time.

Thanks,
Jeff

[Roy S.]

Gary,
I've contemplated that method previously but never tried it because of concern about matching the curvature of two separate pieces before they're mated, and installing a curved pin.  I take it that this is the method you use.  I suppose that explains my hit or miss results in the past.  I'll definitely give it a try next time.

Thanks,
Jeff

You can get the curve fairly close just by eye and I use a 1/16" pin so it will follow it.

[flintriflesmith]

Gary,
I've contemplated that method previously but never tried it because of concern about matching the curvature of two separate pieces before they're mated, and installing a curved pin.  I take it that this is the method you use.  I suppose that explains my hit or miss results in the past.  I'll definitely give it a try next time.Thanks, Jeff

It is the method I have used since forever and have taught it in a number of Bowling Green classes on box making. Some students have told me that a well known book on building says what I do is impossible--good thing I don't read that stuff!

Make the initial bend with a pin in place in each piece. I used soft coathanger wire for years but have come to like the tempered "music wire" a lot of folks use for barrel pins. Since the wire is steel it will need to be pulled any time you heat the brass to anneal it.

Pull the pins and start the knuckles--I cut the door first and use it to scribe the location for the corresponding voids in the finial. When you get them where they just begin to fit file a long taper on a pin and use it to draw the door and finial together (sort of like timber frame house construction).

Polish and lube the pin as you drive it in and out.

Gary

[Larry Luck]

I use Gary's method.  And I find that making a patchbox is one of the more pleasing parts of the process.
With respect to the final curvature, even if the arcs of the finial and door are slightly different, fitting then together will bring them pretty close and the final filing will line everything up.
Larry Luck

[Rich]

If making the patchbox from scratch, bend the door and finial before cutting the hinge. After it's bent, cut the knuckles at 90 degrees. I know this sounds like it won't work, but it does.

[rick landes]

The secret is to bend just the outer knuckles of the hinge, which are attached to the finial and don't move anyway. The center portion of the hinge should remain flat, which is the only way a hinge can work properly.

Ditto!
Makes the hinge work nice and smooth, no tight spots either!