Assembly jig for cannon carriages

[DBorgens]

I purchased Syren canons and carriages for my Pegasus build and needed a jig to assemble consistent carriages. This article describes one method of making a carriage jig. This jig is sized for the smallest of Chuck's carriages. (Disclaimer; I considered making a jig when a club member pointed out Chuck's jig shown in his Winchelsea build log. Chuck's is similar to the one I planned.)

Before building the jig, separate the sides and axles from the laser cut carriage kit and sand the laser char off from these parts.

The first block is a trapezoid that sets the taper of the carriage sides (the center block in picture 1). The shape of this part is set by the width of the axles and the distance between the axles. Record the width of the lengths of the center portion of the axles as well as the distance between the axles on both sides of the carriage. In this case the front width is .19 in (4.8 mm), the back width is .22 in (5.6 mm) and the length is .40 in (10.2 mm). [The taper measured 2.25 degrees on each side, which is easily cut using a Byrnes saw taper gauge.] Block height is .125 in (3.2 mm) then raised to .25 in (6.4 mm) is better to help keep the carriage sides vertical. This block is cemented to the base along the center line. The higher block works much better than the original.

 

 

Picture 1 - jig layout

The front block (left block in picture 1), is also tapered to clear the carriage sides. Place this block using the front axle to ensure a close fit to prevent movement of parts when assembling the carriage. Be careful to ensure the axle is set wide side down as it is not square.

The back block (right block in picture 1) is set with a small gap to the axle. This will allow the carriage sides to set the exact axle location.

The side blocks (top and bottom in picture 1) are set using the axles in place to ensure symmetry (a small piece of double backed tape under the axles will prevent movement). Ensure that the axles are centered on the jig and parallel. I used one block for each side, then cut out the center of each side after gluing them in place. This allows use of a square (or short scale) to keep the carriage sides vertical when assembling.

 

Picture 2 - partially assembled carriage in the jig.

Remove the carriage from the jig before installing the front and back braces, the supporting wire and bed.

 

Picture 3 - carriage out of the jig.

Add the front and back braces (carefully trim to fit), the supporting wire and bed.

 

Picture 4 - carriage ready for painting.

Picture 5 - carriage ready for painting.

Dave B

Edited April 3, 2021 by DBorgens
Revised center block and figure 1.

[allanyed]

Dave,

Your jig is similar, and better, than what I have used in the past.  Very nicely done.  

Your axles appear to be hand carved and not exactly round.   You can do this and leave them a little large to start or just leave them square to start.  Then, if you have or can get a small piece of brass or steel rod, you can drill a hole in the center the diameter of the axle that you want then file or hand saw slots to create cutting blades.   Once done, chuck the cutter in your drill and round out the axles.   A small drill press is easiest to use, but a hand drill will work as well.  Photo of one that I made from a piece of scrap brass rod in a about 20 minutes is below.

 

Edited April 2, 2021 by allanyed

[DBorgens]

Allan,

Great solution! Sure beats trying to make them round with a flat file.

Thanks,

Dave B

[dvm27]

If you have a lathe it is also very easy to turn the axles from square stock then reduce the width to size. Literally takes 30 seconds per truck.

Edited April 2, 2021 by dvm27

[DBorgens]

Unfortunately I don't have the proper tools now to for these good ideas. I did file another set using a lighted magnifier and a magnifying visor. Was able to make the axles round by working slowly. Found it somewhat relaxing which is good as I have a few dozen axles to file. 🙂

 

Dave B