Marsilly carriage for golf-ball caliber cannons

[Cat Whisperer]

I've been looking at lots of pictures of Marsilly carriages on the net.

(Planning on building two of them - one for Dale's new cannon and one for my Napoleon.)

Is there a reason for not having the sides parallel?  Were some parallel and others converging?

[GGaskill]

The sides of naval/garrison carriages are not parallel because the breech ring is usually a larger diameter than the width of the rimbases and the breech ring is usually still between the cheeks.

[Zulu]

It is much harder but is much nicer when finished.
Zulu

[Double D]

The set of plans I have of a Dahlgren shell gun on a Marsilly carriage does show draft front to rear.

http://www.fototime.com/E1166DF35C07A50/orig.jpg

[Cat Whisperer]

Ahh what a resource!  (DD himself that is)

The cad work begins ....

 

[Double D]

Tim,

Didn't you buy a set of AOP plans with a gun mounted on a Marsilly that day we hit sutler's row at Fort Shenadoah?  I thought you did because I always kept it in the back of my mind to borrow then from you.

[Cat Whisperer]

Tim,

Didn't you buy a set of AOP plans with a gun mounted on a Marsilly that day we hit sutler's row at Fort Shenadoah?  I thought you did because I always kept it in the back of my mind to borrow then from you.

I did buy a set of plans.  But since I couldn't put my fingers on them last night I don't know which one.  AutoCAD copying the general shape and adjusting the scale will produce what I need - adjusted for each barrel for looks.  Will do in both 3d and 2d and make available.

[Max Caliber]

The top view on the Green plans show the cheeks at an angle but the cheek drawings show the trunnion recesses and the side bolt holes perpendicular to the sides of the cheeks. The cap square drawing has the same problem. The side bolt holes and the trunnion recesses in the cheeks, as well as the rounded part ot the cap square that fits over the trunnion must be offset at the same angle as the cheeks (usually around 2.5 degrees). If someone were to make all the parts from the Green plans, then try to assemble them they would have problems. Best to fit the parts as you make them.

[Zulu]

The top view on the Green plans show the cheeks at an angle but the cheek drawings show the trunnion recesses and the side bolt holes perpendicular to the sides of the cheeks. The cap square drawing has the same problem. The side bolt holes and the trunnion recesses in the cheeks, as well as the rounded part ot the cap square that fits over the trunnion must be offset at the same angle as the cheeks (usually around 2.5 degrees). If someone were to make all the parts from the Green plans, then try to assemble them they would have problems. Best to fit the parts as you make them.

Max,
You are correct.  All holes have to be drilled at an angle including the trunnion holes.  The cap squares also have to be fabricated at an angle.  The recesses where the axles go into the cheeks also have to be cut on an angle.  It is a lot more work and a little tedious.  This is why most of the carriages we see here have parallel sides.
I use 3 degrees.  It adds many hours to your carriage build but sure looks nice.
Zulu

[Double D]

The  difference may not be that significant, depending on how big the carriage you are building is. On a big carriage the dispersion and draft would be significant.  Small ones not a so much

If you built to the scale of the Green drawing it would amount to less than 1/8 inch over the 2 23/32 inch  length of the carriage. Up scale 4x and the draft is 1/2 inch over 10 7/8 inches.   The difference for the angle of the holes drilled in the side of  the 1/4 inch thick cheek  would hardly be worth the effort to set up.  I course you could do the math and make a drill platform with the right angle.

I had to deal with this when I built the SAMCC.  I did not have to drill the holes at an angle in the little over 6 inch long cheeks.  The dispersion over the 5/8 inch diameter of the trunnion recess  was such that one  light pass of a round file  gave relief.  For the axle relief it was snug  fit that was relieved with a pass or two of a flat file.

The larger the carriage the more this is a factor.

[GGaskill]

For the Constitution 24 pounder carriages on the NHC CD-ROM, the rear width is 33 1/4", the front width is 30 1/2" and the length of the cheek is 71" (5' 11".)  Cheeks are 5 1/2" thick and barrel is about 17" in diameter at the trunnions and 21" at the base ring.

[Cat Whisperer]

Good info - slight taper.
THANKS

[Double D]

Good info - slight taper.
THANKS

Some where and don't remember where is was identified as draft.  Like inletting wood it needs draft.

[Cannoneer]

Cat,
There are line drawings of the side elevation and top view of a wooden Marsilly carriage for the Dahlgren IX-inch shell gun on the (Diagram G) page that follows p. 52 in this U.S. Navy ordnance book. Open as PDF (right hand corner) and print the drawing. Ordnance Instructions For The United States Navy by J.A. Dahlgren, 1860.

[Max Caliber]

If making a carriage with angled cheeks, here is a handy three piece jig to help in the layout of the axle recesses and trunnion sockets. Also, by standing the center part of the jig on it's edge along with one of the outer parts with a cheek piece on top, the bolt holes can be accurately drilled in the cheeks. To make the jig, glue two pieces of 3/4 boards together, or more if required, square up the sides then saw at the required angle. Simple and quick to make.