Рет қаралды 2,808
As a result of the needed compromises between scale size/detail and practicality of injection molding/strength of finished parts, mud flaps provided in model truck kits are often over size in thickness and the mounting brackets tend to be simplified.
0:20 Many 1:1 trucks use a mud flap bracket made from square steel bar, formed into a coil at one end to absorb vibration and road shock. Bent flat bar tabs provide attachment points for the rubber mud flap.
0:50 In 1/25 (or 1/24) scale, 1/32" square brass bar (from K&S Specialty Metals selection) is a close to scale match. Begin by annealing one end for a couple of inches to soften the brass. This is done by heating the brass carefully with propane torch until it reaches "red hot" (really more of an orange). Let it cool on its own. This makes the brass soft enough to easily be formed into a coil around 3/32" brass tube. Make the coil 3 full wraps, and put 90 degree downward bend in the short end. A left and right hand version is required to locate mud flaps properly in relation to tire.
1:29 .005" shim brass is cut into strips .060" wide for the flat bar tabs. This image shows all of the pieces tinned with a layer of solder, ready to be assembled.
1:46 Cutting shim brass strips is easy to do with straightedge and hobby knife. The fixture shown is copper sheet with brass strip soldered at one end.
2:00 This makes a stop against which the brass shim is placed, along with spacer of required thickness and the straightedge. I am using .060" square styrene strip here.
2:17 Remove spacer and cut strip with several light passes of the hobby knife.
2:35 Magnets on steel surface are a great way to hold parts for soldering. Place tinned surfaces together and apply heat for a few seconds. Solder will melt and flow together, joining the two metal surfaces.
2:52 Finished assembly will, at this stage, look like a small brass centipede.
3:06 Bending the flat bar tabs is done using styrene strip of appropriate size to ensure consistency. .030" x .060" is used for this application, one set of bends has been completed and next step is to cut each tab to length with chisel blade in hobby knife. .005" brass cuts easily with light downward pressure. Next operation will be bending other side of tabs down, then flipping bracket over to make the "plunge cuts" on tabs.
3:48 1/25 scale version of the coiled bar stock with flat bar mounting tabs.
4:00 Kit mud flaps with logo molded in, such as these Ford ones, can be used by cutting away mounting hardware and sanding flap down to .030" thick.
4:16 Drill through tabs and mud flap for .020" brass wire pins.
4:30 These not only look like bolts, they act like bolts by providing a mechanical connection that is much stronger than four small glue joints. CA glue is used to secure the pins in place, after which they are cut to length with flush cutting pliers for a smooth finish - no filing required.
4:48 Frame bracket is a short piece of 1/16" square brass tube soldered to a piece of 1/64" brass flat bar.
5:27 is a better view of frame bracket, 1/64" x 3/32" flat bar with piece of tube cut 3/32" long. Two styrene rivets represent fasteners. AMT Kenworth mudflaps were used on this model...
5:44...with a small "cheat" of placing reflectors over the two prominent ejector pin marks at lower corners! Another advantage of the brass square bar with brass tube bracket is mud flaps can be removable and taken off the model if travelling long distances such as going to a show. Eliminates the chance of a mud flap breaking off in transit.
6:00 Mud flaps can also be scratch built with styrene, .015" sheet and .015" strips of suitable width. The .030" finished thickness matches the 1/32" square bar.
6:17 Drill and pin mud flaps to brackets in the same manner as when using kit mud flaps.
6:33 Many tractors have the mud flap bracket angled down 45 degrees at outside top corner to reduce the likelihood of mud flap snagging trailer on sharp corners, especially on uneven terrain.
7:08 Make model angled mud flap hangers the same way as shown on this Peterbilt 378.
7:29 Scratch built mud flaps were used on this model, you can also cut kit mud flaps off at a 45 degree angle just like it is done on the real trucks.
8:00 A great advantage of making separate mud flap and bracket is the ease of achieving clean colour separation between the parts as shown here with white mud flaps on blue painted brackets. Mounting pins are easily touched up with brush after final assembly.
With some basic scratch building, more realistic mud flaps and brackets can easily be added to your scale model trucks!
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