Next step is to remove the sheeting and the original retract mounts
Here Ive placed the retract unit and strut/wheel into the opening. Ive also cut new ribs out of 1/4 ply by using the old light ply ribs as a template. The outboard rib was moved about 1 1/2 in further outboard to accomodate the longer strut assembly and still keep the wheel in the same location. Black tie strap around strut is to hold the spring air retract in the retracted position.
New rails are cut from 1/4 ply and placed into appropriate cutouts in the new ribs. The rails will be laminated from 1/4 and 1/8 ply for additional strength. Next the rails and ribs will be epoxied in with triangle stock for reinforcement and the sheeting replaced.
Here it is with the wheel extended. Much more scale looking than the stock retracts.
Retract Installation.
I tried several retract combinations and this one seem to fit the best. Retract bodies are 400 series from spring air. I also used some robart P-51 struts that I shortened by 1 inch. This combination is lighter than a complete robart assembly and is also physically smaller and will fit into the wing. Follow along as I install these into the world models wing.
Retract rails epoxied into the wing. Now all thats left is to replace the sheeting and make a wheel well from balsa.
I fly from a short field so I decided to install flaps . I cut the flaps out of the trailing edge of the wing. Balsa blocks were installed at the hinge locations so the robart hinges could have something to bite into. The flap is hinged at the bottom to allow about 90 degrees of deflection.
The flap itself also has balsa blocks installed at the hinge locations.
I also added a small 1/8 plywood plate to the inside of the flap on the bottom surface to give a stable mount for the control horn.
Flap servo is a hitec 605 installed similar to the aileron servo.
Gear Doors 101
Follow along as I build "gear doors that fit"
1. The sheeting around the retract has been replaced and a new wheel well built from balsa.
2. The spring air retract is hooked up to an air source to hold it in the retracted position.
3. Clear monokote is ironed onto the wing bottom surface over the retracted gear.
4. Heavy fiberglass cloth is cut to fit over the intended area.
5. The wheel well comes back into view as you saturate the cloth with laminating resin.
6. 3 additional layers are added with more laminating resin. More can be added for additional strength.
7. Once cured, the fiberglass is sanded smooth and the outline of the gear door is marked with a sharpie pen.
8.The gear door is cut out from the fiberglass layup with a dremel tool and sanded to shape
9. The wheel well area is then recovered with matching covering and the balsa well is painted.
10. The new gear door also covered with blue oracover to match the wing and installed on the strut leg. The new door also matches the curvature of the wing perfectly.
11. Finished gear door.
Here she is , all ready to go. Finished weight is 16.4 Lbs. dry. Slightly over the reccomended weight but she should handle it nicely. One addition I did for strength was to remove the bottom wing covering and install full length sheer webs to the wing spar. The wing is now noticeably stiffer.
Head on view of the zdz 40 and new landing gear. Prop is a menz 20/8 for break in. I plan to use a menz ultra 20/12 later.
Flaps installed and covered and positioned at full throw which is approx 80 deg.
Another view of the flaps.
Another shot of the landing gear. Gear legs were painted white as per the full scale airplane. Stay tuned for inflight pics and flying impressions.
