Author Topic: Proper cap box construction  (Read 3161 times)

Red Owl

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Proper cap box construction
« on: October 16, 2010, 07:53:57 PM »
The only cap box I ever put on a rifle came as a completed kit where the parts all fit together. I recently ordered a brass cap box where you have to install a pin in the lid and holes in the tabs of the surrounding border piece. In any event I'm not sure how to proceed. I can drill a hole cross wise through the tab on the lid for the pin but should I file a slot for the pin to rest in the tabs and use the spring to hold in place, or drill a hole through the tabs? On the originals- how was it done?  Any help appreciated.

Offline okieboy

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Re: Proper cap box construction
« Reply #1 on: October 17, 2010, 06:37:56 AM »
 Red Owl, I am not a capbox expert, but I will tell you about the ones that I have handled, and I made you a little sketch to illustrate.
 The first thing you have to do is get a good fit between the lid and frame.  This is just a stain transfer process using a needle file or a scraper (a bearing scraper or an old pocket knife thatcan be abused). You probably want to smooth one piece first then do your fitting on the other piece. Then when you are happy with the fit, clamp the two pieces together and drill your pin hole thru them in one shot.
 Then inlet the frame, remove wood for the cavity, then remove wood such that the lid cam has a unobstructed travel. Finally, cut a narrow mortise for a spring. This spring can be simply flat; screw it in place with a screw. The screw in the drawing looks like a flat head as that is my standard symbol for a wood screw, but a round head would probably work better here.
 The important thing is the cam. The top of the cam has to be on the spring side of the pin centerline so that the spring keeps tension on the lid in the closed position, and holds the lid open in the open position.
 I'm sure there are other ways of doing this, but this is what I am familiar with. Hope this was of some value to you.

Greg Newcomb
Okieboy

Red Owl

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Re: Proper cap box construction
« Reply #2 on: October 17, 2010, 10:30:29 PM »
Thanks, helps a lot.

Offline kentucky bucky

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Re: Proper cap box construction
« Reply #3 on: October 18, 2010, 06:19:44 AM »
I learned the hard way about thinking these things through before you drill. I ruined an really nice and expensive (for me) cap box. I drilled 3 holes and never did get it to work right. I realized too late what I was doing wrong, so I had to order another one and start over. I was drilling the holes in spots that wouldn't allow the lid to pivot without moving rearward.  The spring would work but it wouldn't open all the way unless I was willing to file an opening behind the cam making an eyesore opening behind the lid when closed. I found out that I was drilling the hole too far down on the cam area, and I needed to drill as close to the top and in the middle as I could so it would pivot on it's axis without moving backwards. Then I ould have no gaps when the lid was closed. Hope this helps.

Offline Dave B

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Re: Proper cap box construction
« Reply #4 on: October 18, 2010, 06:53:25 AM »
KB is right on about the hole being critical in its placement. Getting a hold of a long drill bit helps I broke several trying to get in tight with a regular length bit and broke it off  in the hole because of the binding. I ended up drilling from the other side to punch out the drill piece stuck from the other side. Once apart I silver soldered up the holes and dug out the long bit and Viola. If you use one of the 5" long drill bits you will have no problems. You want that drill to be tight up against the plate of the lid. I would use a cold chisel to clean out the rounded edge at the base of the lugs to help with keeping the bit up tight to the plate while you drill.
Dave Blaisdell

Red Owl

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Re: Proper cap box construction
« Reply #5 on: October 18, 2010, 03:30:02 PM »
Well, it sounds like everyone drills a side ways hole through the downward tabs on the frame and a hole through the tongue on the lid (I hope I'm using the correct terminology) and then runs a pin through the entire thing.
The reason I asked is because the only other cap box I ever installed didn't work that way, the tongue on the lid had two prongs on either side- this could be accomplished by running a pin through the tongue and leaving short stubs on either side.  Then the downward tabs had slots rather than holes- so you sort of slid the tongue through the big opening in the frame and then up so that the stubs fit into the slots. Once the two parts were put into the stock the pressure of the spring held everything in place.
I hope I'm explaining it properly.