Mussel Cap

[Bob Rearley]

I am in the process of bending over the end of a grooved brass cap.  The shaping has gone very well up to this point.  I am annealling frequently but my brain keeps telling me there is no place for this extra brass to go.  Am I missing something? 
Thanks, Bob

[rich pierce]

I learned to not leave the same amount of “face” metal at the edges as at the middle. I’m no good at drawing so will just try to convey the general idea.


It’s kind of by guess and by golly, but you can figure what you need under the bottom flat of the barrel by web thickness. Leave a bit extra for filing but not more than 3/32” or so. 

[Bob Rearley]

Rich,
i see what you meant but is this the case iwith the groved
 cap?

bob

[rich pierce]

Rich,
i see what you meant but is this the case iwith the groved
 cap?

bob

You might need a valley in the middle. But for sure little metal is needed at the corners. It usually takes me 2 tries to get a nose cap I like.

[smart dog]

Hi,
Here are some images showing making a one piece cap with a ramrod groove.


























dave

[P.W.Berkuta]

Nice tutorial Smart Dog

[Ken G]

Nice tutorial as well.  Thanks for posting.  Please move to the tutorial section.

Ken

[smart dog]

Hi Guys,
There already is tutorial there and my photos are mostly the same as Acer's and Rich Pierce's.

dave

[Bob Rearley]

A picture is worth a thousand words.  The end view of the brass peaned over the end of the form  tells me it can be done.  Very nice photos.  No further explanation needed.
Thanks to all for your contribution.
Bob

[smart dog]

Hi Bob,
Note, I don't use any special tools just the maple form.  The rest are just a drill bit, a ball peen hammer, a cold chisel to crease the outline of the groove more distinctly, and the hammer end of another bigger cold chisel as a anvil stake to final shape the front.  Of course a torch to anneal the brass many times.

dave

[Bob Rearley]

Thanks again Dave.  i haven't had much problem getting the shape I need.  Just with the face of the cap.Bob

[Darkhorse]

What you are talking about here is known as "Bend Allowances". When I worked as a toolmaker in the private sector we had "Bend Allowance charts" to go by when we were building forming dies. These charts showed the material size, length, thickness, etc. needed to bend a part and have it all come out right.
Do a google search for "Bend Allowance" and you will get a ton of data to keep you up late at night.

[foxm2015]

Try sheet aluminum to use for pattern development / practice / "disposable" general practice pieces as trial and error experiments.

Then move on to the "real deal" in brass after the unknown is somewhat defined.

This can take the "I have to get it right the first time" thought process down a notch or two. 

[smylee grouch]

How thick is the brass sheet?

[Bob Rearley]

I had not see any additional comments so I decided to go the two piece route.  I am using .04 brass so I soldered a piece of brass on the front of the tube.  You can hardly see the joint and I am very happy with the fit around the barrel.  while cutting the face plate to fit around the barrel I discovered one of my problems.  I was leaving too much stock wood under the barrel making it more difficult to pean the brass over the face.  i always expect to spend a great deal of time making the parts as I always know I can improve.  "Good Enough" is not good enough for me.  since the gun I am replicating has a 1 piece cap I now face the dilemma whether I should try again.  This will be #5.  This cap has two 2 brass rivets, however on the inside of the stock the rivets look more like nails than rivets.  Has anyone ever seen this an a circa 1800 northern Virginia, Sheetz gun?  Thanks for the reference on metal allowance  I know all you guys would rather be in the shop.  I always appreciate all you do to share your knowledge.  It is invaluable to all of us wannabes.

Bob