#2024motorcyclegroupbuild
Hosted by @gi_mechanicsscalemodeling and @jamiegsscalemodelgarage3823
Even a simple subassembly, here the swingarm, can provide opportunities to add details - and some "engineering" as well.
0:12 Final drive housing is open on back side, and worth closing in because this is quite visible through spokes on wheel.
0:26 Diameter of final drive housing, 21/32" or 16.67 mm, is easily determined with circle template...
0:33...and marked on .010" thick (0.25 mm) styrene sheet. Mark centre of circle as well and drill to match molded in pin at centre of drive housing.
0:44 Cut circle from styrene sheet slightly oversize and glue in place.
0:56 Completed final drive side of swingarm.
1:09 Opposite side of swingarm is also "one dimensional" with good brake caliper detail on visible outside...
1:19...but no brake caliper represented on inner surface.
1:41 This is likely due to kit assembly sequence which has completed wheel/brake rotor subassembly "trapped" between axle pins on swingarm halves when those parts are glued together.
1:54 I added a small piece of .030" x .250" (0.75 mm x 6.35 mm) styrene strip as the inside portion of brake caliper. This now meant that swingarm could not be assembled per kit instructions with wheel "trapped" between pins, so the re-engineering of wheel installation began with removing molded-on axle pin.
2:15 #67 (.032" or 0.812 mm) hole was drilled for .030" (0.762 mm) steel wire axle. When drilling through an item with hand tools I find it works best to start from one side, drill partway through...
2:36...then finish drilling from other side. This minimizes the possibility of drill not tracking straight and coming out off-centre on side.
2:49 Do the same thing on other half of swingarm, removing molded-in pin from final drive housing then drilling through.
3:07 Kit provides "D"-shaped key and matching hole on swingarm halves for alignment but gluing surface is quite small so I chose to reinforce this joint...
3:25...with 3/16" (4.77 mm) aluminum tube cut to match inside width of swingarm. Inside diameter of this size tube is a perfect fit over kit swingarm halves. Brass tube can be used, the aluminum tube is easier to cut and file.
3:38 Glue swingarm together using .032" brass wire as an alignment tool through axle holes. Initial assembly was done using solvent cement, then joint between tube and swingarm halves was reinforced with thin CA glue (aka "superglue").
3:56 Smaller diameter steel axle requires wheel and brake rotor to be fitted with aluminum tube bushings. Wheel is drilled out 3/32" (2.38 mm) for 3/32" aluminum tube...
4:12...as well as brake rotor. This is a very slight increase in hole diameter over the kit part's molded-in holes.
4:23 K&S tube is made so that sizes telescope nicely together, here I used 3/32" (2.38 mm) and 1/16" (1.57 mm) sizes as the inside diameter of 1/16" tube is a good match for the .030" axle.
4:39 Bushing installed in wheel, projecting tube is where brake rotor will be installed.
4:48 Everything in place except for tire, ready for test fit.
4:57 Subassembly looks more convincing with final drive housing closed in, and even assembles more realistically because on a real motorcycle the wheel is installed by lifting it up into place and sliding axle through from one side of swingarm - just like the model will be!
5:15 An additional detail that will be added at final assembly is bolt castings on either side of swingarm to represent fasteners and "trap" metal axle in place.
5:29 Frame, engine and swingarm temporarily assembled shows that additional diameter of swingarm cross tube resulting from adding the aluminum tube sleeve does not create any clearance issues.
#yamahamotorcycles