Bronco Type XXIII Coastal Submarine

June 2025. Working on building up this page.

Click on the link to take you to the section of interest.

1 Sanding the Hull
2 Rudder Service Cover
3 Rudder
4 Rudder Shaft
5 Rudder Foundation
6 Rudder Installation
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Section Heading

Text and information, with pictures below

Sanding the hull

May 2025. The hull will need to be sanded now or later. Sanding now with the hull in smaller sections will be easier. I used 220 grit sandpaper and emery boards, getting into areas as close to the weld lines and other raised parts as I could. The hull will be treated with conditioner or solvent prior to painting.

Rudder Service Cover

May 2025. The area above where the rudder is located has a ‘hatch’ which needs to be cut out and cleaned up. The hull halves were clamped and held together with rubber bands. The backside of an Exacto knife was used to score the ‘hatch’ perimeter indentations to separate the hatch from the hull. Before starting I did a sample slice in scrap styrene to see how wide this cut will be. It amounted to about 20 thousandths. The only detail lost was the indentation indicating this was a hatch. The edges will be cleaned up and the method to keep the hatch in place will be done a a later time.

Rudder

May 2025. The rudder halves have nipples on either end to act as a pivot as a display model. These nipples were removed and openings were made on both ends and on both halves to accommodate a square brass tube. Spacers were applied to one rudder side as a glue point for the rudder tube then the brass tube was tack glued in place with CA. The rudder was held together and two 1/8″ holes were drilled into one end of the rudder. A mixture of epoxy was then applied to both halves and styrene solvent was applied to the edges. The halves were folded together and additional solvent was applied to help seal the joints. The rudder was clamped and held in place in a vertical position. A pick was then dipped into the epoxy mix and drops were placed in one hole until the remaining space inside the rudder was filled with epoxy. The other hole provided an escape for air displaced by the epoxy. Near the end as the epoxy filled the cavity, a pin was used at both openings to help any additional air escape. Then it was left alone overnight for the epoxy to settle within the cavity and harden. The next day, baking soda and thin CA was used to top off the hole and level it out with the outside of the rudder. Then it was sanded and Nitro-Stan was used to fill any small voids.

Rudder Shaft

May 2025. The solid brass rod I had on hand was metric so I had to ream out the inner square brass tube. With the limited rom available for the rudder arm, the arm was made from brass sheet. Two holes were drilled then the brass sheet was shaped with a Dremel abrasive wheel and files. It was then soldered onto the shaft. A small section of brass tubing was also soldered in place as a spacer. A brass mounting plate was made which had two holes, one for the shaft and one for a securing screw. A small section was also added as a guide for the the shaft. In the second to last picture you can see all of the parts. The last picture shows a partial assembly. For now the square brass tube slips onto the shaft with a friction fit. The outer brass tube is already fixed in the rudder during the previous step.

Rudder Foundation

May 2025. The lower foundation is three sections of glued styrene and shaped to fit. The hole was drilled and a brass tube was inserted. It was then glued into place.

The upper foundation has one hole for the shaft/square tube. The hole is big enough for the inner square tube to fit. It was adhered to on side of the hull with solvent.

Rudder Installation

May 2025. Installing and removal of the rudder into the hull is very easy. Insert the shaft through the upper mounting plate. Slide the inner square brass tube onto the shaft. Hold the rudder in position and insert the shaft assembly through the upper foundation, through the rudder and slide the shaft intot he bottom foundation. Then insert the screw to hold the mounting plate.