Waco YMF-3 (oz3269)

About this Plan

Waco YMF-3. Radio control scale model plan, includes all formers and instructions. Scale is 1/5.

This planfile is a large filesize since it includes 3 large sheets of the actual plan plus another 44 (yes, 44) A4 pages that show all (hand-traced) formers and include 15 pages of text instructions.

Quote: "I saw the 1/6 scale plan that you now have and it reminded me that I had a larger version from Pica that may be of some interest. I got this from another site: www.houseofmoy.com but it no longer seems to be online."

Direct submission to Outerzone.

Update 18/06/2018: added kit review from R/C Scale International, November/December 1998, thanks to RFJ.

Quote: "Kit Review. Pica Waco. Clifford Mcllwee builds a classic kit from the USA

Why the Waco? The Pica Waco is, in my opinion, a beautiful aeroplane and one of the prettiest 'bipes' to take to the air. It is also fully aerobatic which helps when deciding which schedule to fly. The Pica kit of the Waco comes in a very large box with loads of strip and sheet wood as well as mouldings and an extensive fittings kit. One thing I did notice, however, was the suggested weight of the finished model, so even before I opened the box I was thinking in terms of keeping the building light. The packaging was first class with all the pieces in separate bundles, all labelled, with the cowl very well protected at one end. A forty-four page instruction manual, two full-size plans for the wings and fuselage plus a decal set are provided.

Building: The wings are built first and use balsa spars. The wing ribs are 1/8 die-cut, so I lightened them with 13mm holes (five holes in each rib). This did not weaken the ribs in any way, and I lightened the bottom ribs in the same manner. The die-cut ribs do require a little sanding, possibly reflecting the kit's age, but they all fit nicely on the plan and the wings really do go together very quickly and no problems were encountered with the alignment of any parts. The selection of balsa for the finishing of the wings was first-class in this particular kit.

On page twenty of the instructions it shows a bell-crank arrangement for the ailerons, but I decided to go for a separate servo in each wing, however, the hardware provided (bell-cranks, all the bearings, etc) are good quality and strong mouldings and perfectly good for their purpose.

One other really nice touch is a set of aileron covers , which are supplied as ABS mouldings which have scale riblets on them, it's just a matter of scoring them off their moulding, cleaning them up and cynoing them in position. These are provided for both wings.

Once I had the two wings built I gave them a careful sanding and put them away on a flat surface. The top wing is 72 in, so if you work in a small workshop like I do, you must treat them with extra care.

The changes I made to the wings were only to mount 4mm captive nuts on the top wing mounting blocks instead of screwing the wings on with No.8 sheet metal screws as the instructions suggested. This modification makes for a far more reliable method of holding a top wing onto a plane of this size and weight.

Fuselage: This is the area which required the most work and modifications. The changes were, however, purely a matter personal preference as all the die-cut formers were a good fit. Page twenty-three shows all the necessary laminations that are needed and these have to be labelled by the builder to save trouble in understanding later pages.

The fuselage is built upside-down on the 'plan view' along two crutches..."

Update 29/9/2022: Added kit instructions, thanks to JeffGreen.

Quote: "Revised by the WACO Brotherhood (a collaboration of dedicated modelers interested in keeping these planes and kits alive and flying)

Introduction: The WACO F-3 models were first introduced in 1930, and it is felt by many that the 1934 F-3 version was one of the most attractive of all biplanes. This elegance combine with excellent handling and flying qualities made it a much sought after aircraft.

There has been some confusion about the difference between the F-3 and the F-5 models. Essentially the only difference was that the F-5 was a little more plush in its appointments. When the Continental engine was used the designation was UMF, with the Jacobs engine it became YMF. All F-3 and F-5’s were constructed with two cockpits and a cover was provided as standard equipment for the front cockpit. When used, this gave a single-cockpit appearance to the ship.

Since the real aircraft has all of the necessary areas and moment for an excellent flying model, the model portrayed here, has a 100% scale outline.

Before You Start: Most problems which arise in building kit models are the result of inadequate instructions and/or lack of attention to the instructions. We have provided this booklet in order to have more space for written instructions and diagrams. It's a good idea to read the booklet through, referring to the plans, before actually cutting or gluing anything.

Top Wing: The rear spar is made first. Take (1) 5/16” x 5/8” x 15” and (2) 5/16” x 5/8” x 30” strips, cut to the lengths shown and Join with ply braces W-11A. (W-11A - make new ones from 1/8" ply, only make them go from the center of the wing, out at least 3 ribs into the wing. (you will need to cut the spar slots in these ribs to allow the longer wing joiners to fit.) Make sure braces are flush with top edge of spar as shown. Check dihedral 2° at each end, Cut and shape into spar ends.

Pin assembled spar down over wing center panel plan. The ply braces face the rear. Glue and join the center sheeting using the bottom center sheet layout. Pin the sheeting in place on the front side of the spar. Now using a W-1 rib to insure perfect spacing, add the 5/16’ x 5/8” x 15” L.E., the 5/16” sq. x 15” bottom spar, the 5/32” x 5/8” x 15” L.E. backup, and the W-11, W-11B plywood braces. (make new ones from 1/8" ply, only make them go from the center of the wing, out at least 3 ribs into the wing. (you will need to cut the spar slots in these ribs to allow the longer wing joiners to fit)..."

Supplementary file notes

Instructions.
Review.

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