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MINIMOA 1/4 SCALE

Posted: 17 Nov 2020, 09:47
by chris williams
My personal history with the Minimoa goes back a long way. The b/w pic shows my 2nd version in the early 1980’s, scaled up from the Bob Banks plan, which was my 1st. (The gentleman holding that one is the Proto-Wookie version of Motley)
Unlike today, there was little around in the way of 3-views, so the accuracy of the models was not great. The recent ¼ scale version this log, (this time based on Vince's excellent 3-view) will describe is still not my last, as I have subsequently built a fifth scale version based on the same plan.
So, down to business…

Re: MINIMOA 1/4 SCALE

Posted: 17 Nov 2020, 11:25
by chris williams
Let’s start with the wings, as there’s a common misconception that gull wings are difficult to build. In the past, I have always built the wing in two parts, glueing them together at the gull join. As I have discovered with the smaller models, 5mm sq instead of 6mm spars are much easier to steam into a bend (applies to fuselage construction, too). So, the wing is built in one piece over a simple set of jig supports with single 5mm sq spars top and bottom. After the ply webbing is added to the front of spars, a secondary sub-spar is retro fitted in front, thus achieving a gull shaped I-beam, which is both strong and light…

Re: MINIMOA 1/4 SCALE

Posted: 18 Nov 2020, 11:23
by chris williams
With the top spar and aileron spar added, a handful of web plates are added to lock the main spars in place. At the same time, the 0.8mm ply triangles can be applied to reinforce the rear of the ribs. Note: the ribs are set at right angles to the lower spar...

Re: MINIMOA 1/4 SCALE

Posted: 18 Nov 2020, 13:05
by Christian Baron
I follow your build with interest.
Chris, airfoils are HQ35/xx I think?
When will the plan be available?
Regards,
Christian

Re: MINIMOA 1/4 SCALE

Posted: 18 Nov 2020, 14:42
by chris williams
Yes, inner panel HQ35/14, outer panel transitions to 35/12. Email me, Christian, and I will send you all the stuff... (Cliff is going to do a kit)

c_williams30@sky.com


cw

Re: MINIMOA 1/4 SCALE

Posted: 19 Nov 2020, 12:35
by chris williams
Once enough ply plates have been added to lock up the spars, the wing can come of the lateral jigs and the 15mm brass wing joiner box fitted, followed by the remaining ply webs ...

Re: MINIMOA 1/4 SCALE

Posted: 20 Nov 2020, 10:11
by chris williams
Retro-fitting 5mm sq spruce sub-spars in front of the web plates is a simple 10-15 minute job. The 1.5mm sheeting for the gull break is applied separately: the bottom sheeting is simple, but the top needs a little water and gentle persuasion. Note that the TE is clamped to a straight-edge to ensure that the spars remain straight as the rest of the sheeting is applied...

Re: MINIMOA 1/4 SCALE

Posted: 20 Nov 2020, 16:09
by chris williams
Yes, Adam, the details are on the plan...

Re: MINIMOA 1/4 SCALE

Posted: 20 Nov 2020, 20:52
by RobbieB
Ah, but it's not a cantilever wing and the strut attachment points are outboard of the gull break.

Re: MINIMOA 1/4 SCALE

Posted: 21 Nov 2020, 09:34
by chris williams
With the lower sheeting completed, the wing can be laid on the transverse jigs, weighed down, and the upper sheeting added. This time the straight edge is there to help ensure the inner panel TE is nice and flat...