Author Topic: Blueprint discussions  (Read 2997 times)

Offline rich pierce

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Blueprint discussions
« on: July 24, 2017, 06:05:52 PM »
In the stock shaping thread there were questions on how to make a blueprint for building a rifle based on an original, so one can build from a blank versus using a precarve. There are lots of previous discussions.

http://americanlongrifles.org/forum/index.php?topic=22617.msg216223#msg216223
http://americanlongrifles.org/forum/index.php?topic=37493.msg360287#msg360287


I will edit this one from time to time.

I'm building a fowling piece based on work by George Fainot. Here is my process. First I gather all photos, descriptions and measurements available. I decide which common and specific features to incorporate. From fotos and measurements available I realize he went with the flow while maintaining a classic Lancaster profile. His guns vary some in drop, length of pull, barrel length, length of forearm, etc. Just as we would expect depending on customer and available parts.

PARTS DETERMINE MUCH of ARCHITECTURE
Lock: He seems to have favored flat faced English locks on fowling pieces so the Chambers Early Ketland was chosen.

Stock: he was more likely than some to use walnut on a smoothbore and I have a nice blank. Walnut it is.

Barrel: I have a 20 ga octagon to round Getz barrel 46" long. That will work.

Trigger: make a simple trigger  and plate from various mild steel stock laying around the shop.

Buttplate:  buttplate has a huge impact on your architecture so think about this one. I chose a Reeves Goehring English styled small musket buttplate 1 and 15/16" wide by less than 5" tall. It will be easy to modify the top extension to match one Fainot used.

Guard:  I don't personally like acorn guards so chose another Reeves Goehring early English fowling guard. Not too fancy. Fainot was not a prolific engraver.

Sideplate: to make from 1/8" brass flat stock. I do this after drilling lock bolt holes.

Thimbles: to base on originals using 0.040 flat brass stock.

Nosecap: to make based on originals from 0.040 flat brass stock, after shaping fore-stock.

Patchbox:  yes he often put patchboxes on fowling pieces. His are unique side opening boxes in a surround. Make from 0.062" brass stock. Wait on this until the buttstock is largely shaped.

Starting the blueprint:

Lay the barrel on a long sheet of paper and trace it. Mark where the breechplug face is and mark the fore and aft location of the touchhole. If using a liner make sure there's room for threading it ahead of the breech plug and draw it on the barrel.

Web:  add a web of wood the barrel sits on, above the intended ramrod hole. I make this 1/8 to 3/16" at breech and muzzle and draw it in cross hatched.

Ramrod: draw the ramrod in place on your blueprint. Same thickness as you plan the hole to be.

Lower forearm line:  allow 1/8" or so of wood at the entry thimble below the ramrod. Use the same or a little more at the breech. Rough outline this in now on your drawing and finalize later after you know precisely where the entry thimble will go and how much "rise" the tail has.

Lock: mark with a magic marker where the sear arm is. Transfer that to the lock face so you can see it. Then strip the lock to the plate. Center the touchhole in the pan on your drawing. If using a liner you've taken that into account when locating the touchhole. I'm double checking. Now locate the nose of your lock based on the web. You have some small amount of play here for locating the forward lock bolt. That allows you to adjust the lock tail to look good. Don't draw the final lock location yet but do mark where the sear will be, by drawing a small arc.

Trigger: now you get to decide where, fore and aft on your drawing, to place the simple or double set trigger to give the performance you want.

Buttplate: know your intended length of pull from your or customers preferences. Draw an arc from front trigger to locate where the center of the buttplate can go.

Now the real design begins because you have the constraints set.

DECISIONS based on DIMENSIONS and PHOTOS

Length of forearm. Did this builder base forearm length on barrel length or buttstock dimensions?
Length of wrist, arc of wrist. Will this be dependent or independent of the guard length?
Length of comb and where the comb line "points".  Is there a clear trend with this builder?
Does the lower line of forearm break toward the toe line at or behind the trigger? What sort of arc?
Lower buttstock line: is it curved or straight or step-wristed?  If curved, where does the "action" happen?

At this point you may choose to "blow up" available photos by printing at whatever percent enlargement works to give you the scale you need. This will rarely work perfectly unless you replicate or modify parts to very closely match original dimensions.  But a cutout of such a buttstock "blowup" will surely help you see where your plan matches and differs from that specific original as you develop your blueprint based on parts and dimensions from originals.


Now your buttstock profile is ready to be drawn, keeping your needed drop at comb and heel within 1/8" of customer preferences OR closely emulating your original. I always try to evoke, not copy architecture.

Move your buttplate around to set the drop at heel and angle of comb, while maintaining length of pull. Draw it in place. Double check pitch.  A bought buttplate may be the right height and width and look generally the same, but is the pitch of your buttplate similar enough to the original to give you the look and pitch you want?  If not then you may choose to bend it now if it's soft yellow brass. 

Using the buttplate top surface, length of comb, and desired angle, draw the comb line and work on the wrist profile and transitions. Very few comb lines are perfectly straight.  Most have at least a subtle arc.

Knowing your desired height of wrist, and where the forearm breaks toward the toe, sketch in the lower profile of the wrist. Realize this vertical wrist height is impacted by your choice of barrel diameter at breech, web thickness, ramrod hole diameter, and trigger design. Re-configure the lower forearm line from trigger plate to entry thimble as needed.

Complete the lower buttstock line to the toe of the buttplate.

Step back.

Now that you have the general profile, study photos of originals again. Make adjustments till it looks "right".

Re-position the lock till it looks right. Draw in the lock, sear location, and lock panels. You may change some things later but design time is well spent.

Make decisions on underlug and thimble  placement. Draw them and their pins in place. Finish drawing the fore-end and nosecap.

When you are satisfied with this lock-side profile, copy it, flip it, and work on drawing the cheekpiece if any, and sideplate and lock panel.

Even though some thing are likely to change, you can now position your profile on the stock blank and cut to the upper profile line. I like inletting the barrel into a big solid chunk and being able to make needed adjustments before cutting the bottom profile.

« Last Edit: July 25, 2017, 06:20:56 AM by rich pierce »
Andover, Vermont

Offline Mauser06

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Re: Blueprint discussions
« Reply #1 on: July 24, 2017, 07:08:45 PM »
Thanx Rich!  Good threads! 


Maybe we can do gather up some info/old threads in this post on blueprints and shaping and send it to the tutorial section so we can find them easily in the future.


If I get time I will do some searching too and posts the links to the old threads here. I have been running the search function quite often...lots of the questions I have have been hashed out lots of times...

Offline Mark Elliott

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Re: Blueprint discussions
« Reply #2 on: July 24, 2017, 10:49:46 PM »
Assuming that I have all my parts, I start with a blank that has the top and lock side square and then I draw the plans right on the top and lock side of the blank.   Then I can cut to those lines.   I will have to redraw the lines on the top once I cut the profile.     If  I am doing a new profile,  then I slab off about 1/8" once the profile is cut to give me a template for future use.   That is,  I cut off 1/8" if I have an 1/8" to cut off.   Otherwise,  I transfer the profile to acrylic.   

Offline rich pierce

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Re: Blueprint discussions
« Reply #3 on: July 24, 2017, 11:00:54 PM »
I love the idea of cutting off a slice for documentation and future builds. If I had a bandsaw lol.
Andover, Vermont

Offline oldtravler61

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Re: Blueprint discussions
« Reply #4 on: July 25, 2017, 04:31:05 AM »
  Rich thanks for this info it is much appreciated by many of us. Oldtravler

Offline PPatch

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Re: Blueprint discussions
« Reply #5 on: July 26, 2017, 03:04:10 AM »
Thanks Rich, good info - I hope it ends up in the tutorial section.

dp
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Offline Ray Settanta

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Re: Blueprint discussions
« Reply #6 on: July 27, 2017, 02:07:18 AM »
Very helpful information. Thank you.

Offline jerrywh

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Re: Blueprint discussions
« Reply #7 on: July 27, 2017, 05:18:16 AM »
 I do it the same way as Mark Elliott. I have a 4' ruler that I mark out the forearm with. You better get the math right when you mark it out. I mark it out with a felt pen and cut outside of the lines. The slab it of as Mark said. I save every piece ontil the gun is done and some later.
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Offline Mark Elliott

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Re: Blueprint discussions
« Reply #8 on: July 27, 2017, 05:31:38 AM »
I love the idea of cutting off a slice for documentation and future builds. If I had a bandsaw lol.

Whatever saw you have obviously works.   I have cut out a stock using a hand(rip) saw.   Once you get it started, it works pretty well.