First Patchbox, need some help re: bending etc updated with progress

[Chowmi]

I'm building a Chamber's Isaac Haines, and have chosen to copy the patchbox off of #80 in RCA. 

Essentially, I have two questions:

#1.  Does it look like I have scaled the picture up correctly, resulting in the right size patchbox?
I scaled up a photocopy from RCA, using the butt plate height measurement from RCA compared to the butt plate on my rifle.  My length of pull is about 1/4" to 1/2" less.  Maybe I should have tempered the measurements from that. 
It looks a bit big, but when I compare it to the RCA gun, it seems about right.

Here is a photo where  I have roughly traced the outline of the patch box to get an idea.  The outline is rough, but dimensionally accurate.

IMG_3541 by chowmif16, on Flickr

#2  I was surprised at how much I would need to bend the hinge and finial in order to make it fit.  I've done all the reading in Gunsmiths of Grenville, and understand that I do not want to bend the lid hinges, only the outer sections.  It also says in Grenville that you can flatten a portion of the stock under the hinge, and you will end up with the illusion of the correct profile.  I know that you do not flatten the whole section as you would for a sliding wood patchbox.
When I lay the finial on the stock, it looks like I would really have to dig in there to get it in. 
Also, on this particular patchbox, it appears that the outer hinge points on the lid are quite close to the edge of the lid.  That leaves little on the sides to bend. 

Here are a few photos of the finial on the stock ( with no flattening yet), to show how much curvature would be required:

IMG_3544 by chowmif16, on Flickr

On this one, the finial is balancing on the stock and so one side is higher than the other:

IMG_3545 by chowmif16, on Flickr

So is that normally what it looks like?
Or:
Have I not shaped that area of the stock correctly.  Have I maintained the curve of the butt plate too far forward?   I don't think I have dished the transition from the comb too much.

Here is a picture that might help show the profile of the stock at the hinge/finial:

IMG_3547 by chowmif16, on Flickr


The tracing is rough, there will be a daisy head on it!

Thanks for the help in advance,
Cheers,
Norm

 

[Hungry Horse]

How thick is the patch box material? It may be just the photograph, but it looks really thick. I usually use recycled old brass door kick plates, which are around forty thousandths thick. Thinner metal makes it easier to roll the hing, and bend the contures.

 Hungry Horse

[Chowmi]

How thick is the patch box material?

 Hungry Horse

Good question, it's .060.  It's a Chamber's patchbox kit.  I bought it over 3 years ago when I bought the gun kit. 

Cheers,
Norm

[Mike Brooks]

I always bend the whole thing, I assumed everyone else did too.  Anneal your brass and then bend it around your stock. Then screw it down to your stock and trace around the edge. Then start the inleting process. Does Gunville really say leave the lid straight?

[Nordnecker]

As I've only made one brass patch box, and my hinge was on the side, I'm looking forward to the responses you get here. You've certainly done a nice job describing and photographing your situation.

[SingleMalt]

After bending it to fit, the hinge knuckles will probably have to be filed so the door will open and close.

[n stephenson]

I agree with what has been said , you will have to bend it . I do like Mike said I screw the box to the stock and trace , inlet , etc.   When you bend the hinge you will create tightness in the knuckles on the inside of the bend " underside" of the hinge . Pull the hinge wire out and file the interference between the knuckles on the bottom side mostly that way you won`t have large visible gaps between the knuckles on the top surface "the side you see " . I always anneal my brass first, to me it makes  it easier to get it to lay down flush .  This is just the way I do it and I`m sure there are other methods that will work as good or better. I think it looks like your doing fine  keep us posted . Thanks Nathan

[Chowmi]

I always bend the whole thing, I assumed everyone else did too.  Anneal your brass and then bend it around your stock. Then screw it down to your stock and trace around the edge. Then start the inleting process. Does Gunville really say leave the lid straight?

Mike,
it doesn't say to leave the whole thing straight, and I didn't mean to leave the impression that I was going to do that.  Essentially it says that you don't bend the middle part of the hinge that has the knuckles from the lid portion, or you don't bend it very much.  The reason he gives is that of course the hinge won't work if it is curved (or curved too much). 
I kind of figured that most people did indeed bend the whole hinge, and then file the knuckle joints as stated by everyone above.  I also took a look through the ALR library last night after posting this and it looked to me like the old builders bent the whole hinge to a certain extent.

Does it look like I will have to bend it more than normal?  In other words, is the stock too curved?

I will indeed screw it in, and then draw my lines for inletting.  The lines that you see were just simply to show the size for my question and to help align the finial for the picture. 

Thanks for the replies,

Norm

[bama]

Many of the originals have a flat section in the patch box area where the hinge is located. If that is the style of box you are building then do it that way.

The style of box you are doing I don't think was done that way so you will need to bend the whole box to match the contour of the stock. You may flatten out the area where the hinge will sit a little so it does not have a huge bend in it.

I build my patch boxes that have a curve in the hinge in this manor. I will make my hinge loops in the finial and the door then I will make a form from a scrap piece of wood that matches the contour of the butt stock where the hinge will be located. I bend the door and the finial separately in my form after I have formed the hinge loop and I make this bend with my hinge wire in the loop. After bending I pull the hinge wire and then layout my hinge knuckles in both pieces. I fit the knuckles as I go, insert the hinge wire as I go until I get a good fit and the hinge is complete. In doing this you can file your knuckles square and the door will open and close without binding.

[David Rase]

Here is a link that expands on     what Mike was saying earlier about bending, screwing, tracing and inletting.  http://americanlongrifles.org/forum/index.php?topic=37036.0  This is a hidden lid box but the inletting techniques are akin.
David

[Mike Brooks]

I always bend the whole thing, I assumed everyone else did too.  Anneal your brass and then bend it around your stock. Then screw it down to your stock and trace around the edge. Then start the inleting process. Does Gunville really say leave the lid straight?

Mike,
it doesn't say to leave the whole thing straight, and I didn't mean to leave the impression that I was going to do that.  Essentially it says that you don't bend the middle part of the hinge that has the knuckles from the lid portion, or you don't bend it very much.  The reason he gives is that of course the hinge won't work if it is curved (or curved too much). 
I kind of figured that most people did indeed bend the whole hinge, and then file the knuckle joints as stated by everyone above.  I also took a look through the ALR library last night after posting this and it looked to me like the old builders bent the whole hinge to a certain extent.

Does it look like I will have to bend it more than normal?  In other words, is the stock too curved?

I will indeed screw it in, and then draw my lines for inletting.  The lines that you see were just simply to show the size for my question and to help align the finial for the picture. 

Thanks for the replies,

Norm

Your stock shape looks good, exactly as it should. I always chop a ditch in where the knuckles go so you can screw your box down flush. I ought to write a book on how to build guns, there doesn't seem to be anything on the market that shows how to do it in the real world. Maybe I could retire then.......

[jerrywh]

 If you leave that much bend in the hinge you will have a very hard time opening the lid. The amount of bend in the hinge is very limited.  Think about it and try it out before you inlay it. 
  Go to DAVEC's post on the Chambers rifle he built.  That is the perfect way they should be.  I know that the old originals are not all like that but they were basically wrong.  BASPHEMY !!!!

[Mike Brooks]

Well, here's some with out a flat spot, although they don't look as curved as I remember them. Come to think on it, I probably haven't done a brass box in 4 or 5 years so forget everything I said. I wouldn't hesitate to put a box on Chow's stock the way it is....but I live on the razor's edge too.....


here's another un.

and another un

yet nother

[Chowmi]

Your stock shape looks good, exactly as it should. I always chop a ditch in where the knuckles go so you can screw your box down flush. I ought to write a book on how to build guns, there doesn't seem to be anything on the market that shows how to do it in the real world. Maybe I could retire then.......

Thanks Mike, you write it, I'll buy it!

Just saw your other post with pictures as I write this.  I'll have a look at them as well.  Looks like on some of those there is a little bit of play between the hinges that may allow for a curved hinge to open. 
I will also look at Dave Crisalli's post about the Chamber's rifle.  I've been following that one.

Norm

[Mike Brooks]

Your stock shape looks good, exactly as it should. I always chop a ditch in where the knuckles go so you can screw your box down flush. I ought to write a book on how to build guns, there doesn't seem to be anything on the market that shows how to do it in the real world. Maybe I could retire then.......

Thanks Mike, you write it, I'll buy it!

Just saw your other post with pictures as I write this.  I'll have a look at them as well.  Looks like on some of those there is a little bit of play between the hinges that may allow for a curved hinge to open. 
I will also look at Dave Crisalli's post about the Chamber's rifle.  I've been following that one.

Norm

I'm a lot more sloppy knuckled than dave2c and others around here.

[Chowmi]

I'm a lot more sloppy knuckled than dave2c and others around here.
[/quote]

I'm such an idiot.  Didn't even occur to me that I might have appeared to be criticizing your work.  I gather you made those? 
I'll just shut up now.   

[Mike Brooks]

I'm a lot more sloppy knuckled than dave2c and others around here.

I'm such an idiot.  Didn't even occur to me that I might have appeared to be criticizing your work.  I gather you made those? 
I'll just shut up now.   
[/quote]
Oh hey, I took no offense what so ever, never even occurred to me. I was just stating the obvious facts. I'm well aware of my limited capabilities and am comfortable with them as compared to some of our top notch people here. My stuff is what it is, nothing more, nothing less.
All of those are probably patch box kits from  Chambers or elsewhere, I have never had much desire to completely scratch build parts that I can get already started by somebody else, saves me a bunch of time and my customers save money.

[jerrywh]

 If you look at the good originals you will notice two things. The hinge parts that are on the lid are best to be in the middle of the hinge section and not too  far apart. they are basically straight. A curved hinge cannot open unless it has a lot of slack in the pins. NO good. The section on the lid should be straight.

[Chowmi]

Jerrywh,
what you said was the same as my understanding from reading.  I've handled only a few originals, and should have paid more attention to that detail. 
The patch box I am attempting to re-create has 3 hinge points on the lid, and 4 on the finial. The 3 on the lid cover a fairly wide area of the hinge. 
I may have to compromise and do one of, or a combination of two things. 
Keep the lid hinge portion of the hinge line straight and hope for the illusion of curvature, as stated in Grenville,
And/or, re-configure the hinge points on the lid portion so that they do not cover as much area, which would allow me more room to bend the sides. 
I might also be able to bend the center section ever so slightly as others have posted. 

I will experiment with all of those.  This being somewhere between my second and third rifle (worked on several concurrently), it will never be perfect.  The key on this one is to learn how to do things well/correctly.

Cheers,
Norm

[Dave B]

If you go back to the photo layout page 338 you have two great shots from the top and bottom of the butt stock. Take note of the line from the butt plate to the tip of the patch box finial.  You can also see the flatter contour of the butt stock up to the point of the hinge section. You will see there is a divot in the line that coincides with the hinge.What this does is lower the point of where the hinge is no longer at such a height. This effectively decreases the arch of the center of the lid section of the hinge. Here is a shot of an original and you can see the hinge point is dropped lower than the finial.




This box hinge has been flattened slightly at the lid portion. The lighting gives the clue to the slight contour flatter section on the side of the finial.

[Bill-52]

Norm,

Gary Brumfield's website has an article on making a curved patchbox hinge, one key element being to cut the knuckles after bending the hinge to fit the stock.

http://www.flintriflesmith.com/ToolsandTechniques/making_a_curved_box_hinge.htm

Also, it may be the photos but to my eye, your stock seems to curve a bit much along the hinge, particularly as the curvature is greatest at the middle of the hinge. You may want to reduce that jus a bit.

Once you've made a working hinge with a slight curvature, you can enhance the illusion of a curved hinge by filing the tops of the outside knuckles.

Bill

[Mark Elliott]

I use a two piece hard maple form to bend my patchbox lid and finial.   Because the hinge knuckles are thicker, they never bend as much as the rest of the part and are usually a little straighter.   However,  there is always some bend in my hinge.   That is how I was taught to make them.  Because of that, they rarely open past about 60 degrees.     I usually use a five or seven knuckle hinge where only the middle three knuckles have to turn on the pin.    A tiny bit of curve in those knuckles is usually not a problem.   

[Chowmi]

Bill,
thank you for the point out to Gary's site.  I will go through that as well. 

Mark,
I had planned to make a bending form out of hard wood, as you describe.  And, I'm sure I will end up with a bit of curve as well on the center section.  That seems to be the consensus here.

Holidays coming up, probably won't really get to this till after Christmas, but I will post pictures of my progress.

Cheers,
Norm

[bones92]

Chowmi, is the intent for your hinge to run the full width of the patchbox outline, or just the section where the box will be inletted?

[Chowmi]

Bones,
on this particular patchbox from Isaac Haines, the hinge does run the entire width of the box.  I guess it depends on your definition of hinge though.  The hinge wire will run the entire width, however the knuckles are of course only within the width of the patchbox lid.  Essentially like the third patchbox in Mike Brook's photos, without the wood piercings. 
It's #80 in RCA.  I have resisted the temptation to violate copyright law and post a copy of the photo from the book.

Cheers,
Norm