Mortar block dimensions?

[flagman1776]

I am ready to start the base for my bronze mortar project.  Pictures to follow. 
Tube OD is 2".  The trunion shaft is 3" long.  I'm planning to laminate so I can start by boring the trunion recess.    That will take (4) 3/4" boards, plus (1) more to cap each side.  So a width of 4 1/2".
The tube is 4 3/8" including the trunions.  3 7/8" to trunion center line.  I'm thinking the length about 8". 
4.5" x 8"...  just seems narrow.  Is this right?  Should I add additional laminations to the width so it will look right?     
Thanks, guys!

[ironball]

Proportionally, it's wider than the Federal bases. 15x31" if I remember correctly.

[irishman]

Flagman1776,
 
     I look forward to the pics.
 
                                   Michael

[flagman1776]

I added the latest pictures on the build thread I'd already started:
http://www.gboreloaded.com/forums/index.php/topic,237958.0.html

[GGaskill]

Sounds like your piece is between 23% and 24% of a US 24 pounder Coehorn.  As mentioned by ironball, the Coehorn base is 15" x 31" and it is 9" high, with varying details of the top corner treatment.  Rather than adding a whole 3/4" board on each side, I would saw one in half the thin way (two pieces of 5/16" thickness) and use them for the outside pieces.  That would come out almost perfect in width.  The trunnion does not have much wood on the outside ends; remember, this was supposed to be a light weight piece that two men could carry (even if they had to strain to carry it; generals never carried mortars.)

[flagman1776]

Thanks George,  good tips!
Russ

[ironball]

To my eyes, the Federal base is too long in proportion to the tube. When I build mine, I will make it shorter. The Golden Ratio suggests 24" length for a 15" width. Some of the really nice ones I have seen here seem to be much closer to this size.  So maybe your width is OK, and just shorten the length?

[GGaskill]

While you don't have to copy the US Coehorn if you aren't making a model of it, you do want the axis of the bore (and the recoil) to pass through the bottom of the mount.  If it passes behind the rear edge of the mount, you may find your mortar turning somersaults when it is fired.

[flagman1776]

you do want the axis of the bore (and the recoil) to pass through the bottom of the mount.  If it passes behind the rear edge of the mount, you may find your mortar turning somersaults when it is fired.

This is a good point...   I was thinking the same thing.   

[flagman1776]

I scaled width x length & came up with 7.2" L.  I cut 3" maple last night & bored the center boards for the trunions.  More to follow.