Making Cannon Carriages, Part 1
There will be times when you want to do some scratch building on your model to make it more accurate or historically correct. One feature found on many model ship kits today that can use such an upgrade is the cannon carriage.
The procedure I will show you today requires a miniature table saw such as the Byrnes table saw or the older Preac table saw. I made the carriages shown in this article using the Preac table saw.
The first step in making cannon carriages is to choose the wood that you wish to use. A common wood available to model shipbuilders has always been basswood.
Basswood is a soft wood with very little visible grain making it ideal for model shipbuilding. Because of its softness, it is easy to cut and carve making it somewhat ideal for making all kinds of model ship parts. However, its soft nature also is a deterrent for making many parts because it does not hold a good, sharp edge well.
The most desired wood that model shipbuilders like to use is boxwood. Boxwood is the wood that many old model ships found in museums were made of. It is a hard wood, with a cream yellow color. It has no visible grain pattern, holds a very nice sharp edge, carves nicely, and turns an even darker golden color as it ages.
However, for my cannon carriages I chose to use bloodwood. Bloodwood is a very hard wood that is red in color, similar in color to the color its name implies - blood. It does have some visible grain structure to it. It can dull sharp tools also because of its hard and grainy properties.
Many modelers like to simulate certain colors of a ship using different colors of wood. Bloodwood is commonly used in model ships to simulate such things as the red bulwarks found on most warships, and since cannon carriages were often painted red, it is a preferred wood for making these details.
The carriages I made for this project were actually used to replace the carriages found in the Mamoli kit, Rattlesnake. This particular kit is in 3/16” scale, meaning that a measurement of 3/16” is equal to one scale foot. The carriages I made measured 5/8” in length and 9/32” in height (not including the trucks and axles).
To create a series of parts such as the cannon carriages from scratch so that each carriage is identical in its dimensions requires the use of some technique. Unless you have skills and access to CAD software and a laser cutter or CNC milling machine, the best method to use, and the one I will be covering in this article, is what I call a profile blank.
A profile blank is a piece of wood that when viewed from the end, has the profile of the part you are going to make from it. When the entire length of this piece of wood is sliced up in to thin slices, each slice has the exact same shape or profile of the part by itself.
I often use this technique to make different parts for a model that need to be identical in look as well as in dimension. You may not realize it but just making individual planks from a certain dimensioned thickness of wood is done so by applying this same principal. It starts by taking a billet of wood and milling the profile of the part into the billet from end to end.
The carriage in this demonstration measures 5/8” in length and 9/32” in carriage height (does not include the trucks and axles). A piece of bloodwood is milled to a length of 6” using these dimensions.
When finished, the block of wood will have the profile shown in Photo 1.
Photo 1
To create this profile, you will need a miniature table saw such as the one made by Byrnes Model Machines. I used an older saw known as the Preac Table Saw which is no longer in production.
The blade I used has a width of .057” or approximately 1/16”. It is a slotting blade. Such blades can also be used on the Byrnes saw.
Photo 2 shows the milled billet of bloodwood and the Preac Table Saw. The blade height has been set so that 3/16” protrudes through the slot in the table. This height is used to cut through the bloodwood to create the lowest step in the aft end of the carriage side. This is the step on the left shown in Photo 1 that sits above the notch for the rear axle.
Photo 2
Dial calipers were used to measure the height that the blade was set at. Photo 3 shows how this measurement was take. First the dial calipers were opened up with the width of the calipers set at .187” or 3/16”. Then the calipers were locked in this position.
By opening the calipers to .187” and locking them in this position, the movable rod is extended that distance from the end of the calipers. That enables you to measure the height or thickness of something such as the height of the saw blade shown in Photo 3.
Photo 3
With the extended end sitting on the table top of the saw, the blade is loosened and raised so that the blade touches the end of the calipers. Then the blade is locked thus setting its height to .187”. Now when the blank of bloodwood is run across the blade, a notch will be cut into the wood that is .187” deep.
Looking back at Photo 2, the saw fence is set at a distance that will put the outside edge of the blade, that is the edge facing you in this photo, a distance of 1/8” from the edge of the fence. The wood billet is then run across the blade for the full length of the billet. Photo 4 shows the resulting cut.
Photo 4
To make the next step, the blade is lowered, and the height is set to 1/8” or .125” using the calipers to measure the blade’s height. The fence is moved so that the outside edge of the blade is a distance of 1/4” from the fence edge. This is the distance from the outside edge of the second step. The billet of wood is run across the blade to create this second step. Photo 5 shows the profile of the billet after making that pass.
Photo 5
The third step requires that the height of the blade be adjusted again this time setting the blade height to 1/16”. NOTE: All of these height settings were obtained from the original drawing I created in AutoCAD. If you hand draw your carriage profile, you will just need to take these measurements with your ruler. In doing so, the top of billet surface as shown in the Photo 4 and 5 will be the point you measure from and the step will be the point you measure to.
Getting back to that third step, once the blade height was set, I adjusted the fence again so that the distance from the fence to the outside edge of the saw blade was 3/8”. Then I ran the billet of wood across the blade to make the third step as shown in Photo 6.
Photo 6
Now let’s turn our attention to the arced area on the bottom of the carriage. This arced area is a concave cut that is centered side to side in the bottom of the carriage. To set the depth of this cut, the height of the blade was set to 1/32”.
The distance from the outside edge of the blade to the fence was set to distance of .284” which would put the cut in the center of the billet. I arrived at this figure by first dividing the width of the billet, .625” or 5/8” by 2 which equals .3125”. Then I divided the width of the blade, .057” by 2 resulting in a dimension of .0285”. If I subtract this dimension from the first, the result is .284”. Add it all up, .284” + .057” + .284” = .625” which is the width of the wood billet.
Now with the blade height set to 1/32” and the fence set to .284” to the outside edge of the blade, the cut is made. This can be seen in Photo 7.
Photo 7
If you look closely at this photo, you will see a pencil line drawn the length of the billet and parallel to the edge. This line represents the edge of the arced area. A second line is drawn on the opposite side to denote the complete arced area with the notch that was cut being the center of the height and denoting the depth of the arc.
In Photo 8, the arc is cut across the full length of the billet by first locking the billet in a vise. A gouge was then used to chisel out the arched area.
Photo 8
Photo 9 shows the profile after the arched was cut out. In this photo you can also see that the notch in the top of the carriage profile was cut. This is the notch where the cannon trunion will be fitted. This notch is also 1/32” deep so the only adjustment that had to be made was the distance of the saw blade in relationship to the fence.
Photo 9
The only thing left to cut now are the two notches in the bottom of the carriage profile where the axes will be fitted. By referring back to the original drawing show in Photo 1, you can take measurements in your CAD drawing or with a hand ruler to obtain the distance needed to set the fence to make the cuts. The cuts are 1/32” deep so no adjustment was needed for the height of the blade. Photo 10 shows the billet after cutting those two notches out.
Photo 10
Photo 11 shows the billet with the notches for the axles as seen from the bottom.
Photo 11
The profile of the cannon carriage is now complete. All that is left is to cut slices off of the billet, one for each carriage side. The blade is set at a height that will cut all the way through the thickness of the billet. The distance to the fence was set so that each slice would be 1/16” thick.
NOTE: This means that to make one carriage side, you will use approximately 1/8” of wood - 1/16” for the carriage side itself and .057” or approximately 1/16” for the kerf of the saw blade. By knowing this dimension, before you start you can count the number of carriage sides you need to make and multiply that number by 1/8” to determine the length of wood you will need to make your billet. Of course you’ll want to add about 1” to that length to allow for any mistakes made in cutting a slice and to give you some wood to hold onto when you cut the final carriage sides.
Photo 12 shows slices being cut from the billet. The cross slide is used to hold the billet perpendicular to the blade. The fence is used as a stop so that each cut creates a slice that is 1/16” thick.
Photo 12
I would like to point out a feature on the fence of the Preac Table Saw that does not exist on the Byrnes saw. Looking at the photo above, you see a bar attached with 2 screws attached to the fence near the center of the table and in front of the blade. By flipping the fence over, this bar will protrude into the cutting area in front of the blade.
This saw feature can be used in situations where you need to cut multiple parts of the same length, or as in this case, the same thickness. Photo 13 shows the use of this “stop” for cutting strips of wood that are angled but all of the same length.
Photo 13
There’s a very good reason for using such a stop. Any good woodworker with experience using a table saw knows all about kickback.
For example, if you wanted to cut a series of pieces from a 2 x 4 with each piece the exact same length, and you tried to use the fence as a stop while cutting these pieces, you might quickly get hit in the head with the piece of 2 x 4 you are cutting off due to kickback.
Kickback occurs when the blade binds with the wood you are cutting. Due to the torque in the electric motor that turns the blade, the blade will still try to cut the wood but at a point where the wood is nearly cut completely through, the torque will cause the wood part to break off, hit the blade at an angle and with such force that it kicks the wood back into your face.
It is a very dangerous situation, and woodworkers well know that you don’t push the piece of wood you’re cutting up against the side of the fence when you’re making a cross cut. Instead you use a block of wood clamped to the side of the fence and in front of the blade exactly like the special stop on the Preac Table Saw fence.
The torque in the Preac saw is nothing compared to the torque of a conventional table saw, so I chose not to use the stop to make the slice cuts. However, as I will show you in future articles, this stop can be used in quite a few situations where you wish to make repeated parts of the exact same length.
In Photo 14 you see the resulting slices of the cannon carriage profile blank. Each one is identical is size and shape.
Photo 14
This method can be used to make other similar parts where a unique profile is needed and each one must be exactly the same. If you plan to do any kind of scratch building in your model ships, a miniature table saw is a very good investment. I bought my Preac Table Saw about 27 years ago as of the writing of this article, and I still use it today. I also own the Byrnes table saw. Between these two saws, there’s virtually no limit to the small parts I can make for my model ships. Their constant use has more than paid for these saws over the years in terms of enjoyment in building and ease of use in making parts for model ships.
In my Part 2, I will continue the discussion on making the scratch built cannon carriages. There are still many details to add and make before the carriages are complete.