Plans for a Coeharn Sled Base

[CrufflerSteve]

I just got one of Powder Keg's beercan Coehorns and its the greatest looking mortar. I already have one of the Hern Coehorns and I build the traditional SOLID base out of ash and the base weighs more than the barrel. My son calls it the Hernia mortar. That's what got me thinking about ones that are easy to move.

I'd like to put this one on a sled type of base. Thats where there's two side pieces resting on the ground and two or more cross pieces. The mortar goes in trunnions and is often adjustable for elevation. There's a cool old design for one at http://www.cannonsonline.com/product_pgs/carriages/features/britishSaltern_mortarBed.htm
I'm open to more modertn ones also. I just don't want one that weighs a ton.

Steve

[GGaskill]

One thing to consider with a sled type mount is the recoil force has to be carried by a narrow part of the side rails versus the whole base with a block mount.  So the rails need to be fairly deep and thick to prevent breakage.  I'll send a plan for your review after I get home.

[HotGuns]

Heres one that I built form oak, its pretty solid and seems to take the recoil well.
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Dosent weigh too much...

[CrufflerSteve]

Heres one that I built form oak, its pretty solid and seems to take the recoil well.
Dosent weigh too much...

That looks pretty good. What did you use for the elevation screw?

Steve

[HotGuns]

Its a piece of 1/2-13 all-thread that is 6 inches long.

You can buy a stick of "allthread " at any Lowes and cut to length with a hacksaw.
I turned the knob on a lathe and milled the notches in it, but just about any knob would work.

I belive that the "sled" design was favored by Northern troops and the base design was more of a Confederate thing.

In any case, its not hard to build. I put it together wil lag Bolts and its solid as a rock.

[Double D]

I belive that the "sled" design was favored by Northern troops and the base design was more of a Confederate thing.

I don't think that is totally supported by history but that is a neat looking base.

The Union Mortar had reinforcing bands and a base block.


The Confederate mortar has a straight tube and it also had a solid base block.  


The heavy solid base was need for stability in the field.

Now the large siege mortars had bases like those in pictures.
Ft. Moultrie


If course now someone needs to come up with a picture of an original and blow this theory out of the water.

[Santa Dave]

I just looked at that British "sled" and I can't see what holds up the muzzle! Am I missing somthing? I also wonder about the scale-- two handles on each end pretty well limits the total weight to 80 -90 KG, not much when arrayed against a hard target!
Santa Dave

[GGaskill]

The barrel support is parallel to the side rails and painted pink, too, so it doesn't stand out.  If you look under the front of the barrel, there is a curved piece that rises up from the transom and apparently swings back down parallel with the line of the barrel.  A little bit is sticking out behind the barrel, too.
 

[Medbill]

Great thread!  I have one of  Powder Kegs babies on the way to me as well.  I can't wait!!!!  Please keep us posted on your sled work.  This will be my first time building one of these so I will be on here with a magnifying glass!

Billy

[GGaskill]

Here is a drawing of the mount for the above mortar.  It is 1/4 scale so doubling it should give good dimensions for a half scale tube.

[Double D]

I know I am sometimes a stickler for the "original" look, but I realy like the look of the angled front screw elevator base.

Here is a pictrue from the original drawing of my first mortar.  The Mortar was called a Tin Can Mortar and appeared in the March 1974 edition of GUNS magazine.  



Pretty crude compared to the things the folks here are build,

I will have another mortar but with this fancier carriage.

Also Steve, for the record about the Hernia Mortar, why else would we have sons but to do our light work in our retirement.   My son doesn't visit this board...I hope

[Tropico]

I too am in Powder Kegs  waiting list for a bronze.,I do believe I will be building the sled as opposed to the base carriage. The screw part is the toughy for me since I am not a machinist to make a know or levered wheel crank for the all thread.., anyone here offering services for such an elevator?
Tropico

[Cat Whisperer]

Tropico -

Welcome to the board!

Send us pictures when you get to firing it!

[Tropico]

Thank you Cat Whisperer.,I will I will.,I cant wait to get this jewel.

[GGaskill]

Coehorn sled mount here.