The 4-120 Bipe was a kit manufactured by Ace RC. \u00a0In 1993 RCM published a plan called the Ultimate 120. \u00a0To use the plan, the builder would purchase the 4-120 kit from Ace, modify some of the kit parts as directed, fabricate some other parts, and assemble the parts over the Ultimate 120 plan. \u00a0The result was a big plane that looked a lot like an Ultimate Biplane. \u00a0It\u2019s not really a scale project, but it\u2019s a pretty convincing fake. \u00a0My short kit is a partial substitute for the Ace 4-120 kit that you were supposed to have. \u00a0It\u2019s pretty much like my other short kits, with fuselage sides, doublers, 48 ribs, bulkheads, and a few other doo-dads. \u00a0It has a reasonably high parts count.<\/p>\n
The plan has some issues that should be noted. \u00a0The scaling of the plan that I found online was way off, so I rescaled it to what I believe to be the correct dimensions. \u00a0However, even after I corrected the dimensions of the plan there were still some serious drafting errors in the original plan. \u00a0In particular, on the fuselage sheet the top wing is smaller than the bottom wing, and the bottom wing is smaller than what\u2019s shown on the wing plan sheet. \u00a0Also, the bulkheads are not depicted correctly. \u00a0If one were to cut out the bulkheads as shown on the plan, some problems would be encountered during fuselage assembly. \u00a0So I made some executive decisions and designed the parts to produce a workable fuselage.<\/p>\n
Other than that it\u2019s pretty straightforward. \u00a0If you\u2019re doing this project you should\u00a0be able to figure it out. \u00a0If you have questions, feel free to ask.<\/p>\n
I submitted my corrected version of the plan to Steve at Outerzone, and he posted the updated plan there.<\/p>\n","protected":false},"excerpt":{"rendered":"
The 4-120 Bipe was a kit manufactured by Ace RC. \u00a0In 1993 RCM published a plan called the Ultimate 120. \u00a0To use the plan, the builder would purchase the 4-120 kit from Ace, modify some of the kit parts as … Continue reading