Pazmany PL-4A. Scale model for radio control. For K&B .40 power. Scale is 1/5. Planfile includes detailed build instructions.
Quote: "Contruction Sequence. Pazmany PL-4A.
WINGS: As the wing is a constant chord, you can manufacture all the ribs via the sandwich method by assembling sixteen of 1/16 and four of 1/8 balsa blanks between two 1/8 ply templates. These are cut to comply with the W2 rib shape. After shaping the ribs to the ply template you can now separate the ribs and, using the drawings, add the additional cutouts and slots to suit the total wing requirements. Note: The two ply templates used are now altered to become the two W1 ribs. Join the 1/16 sheet for the bottom wing skins. Cut out and shape the 1/4 sheet braces which are used to hold the bottom sheet to shape against the ribs. Mark out the spar and rib positions on the bottom sheet for the outer panels.
Pin the braces and bottom sheet to a flat surface, add spar, ribs, leading edge and 1/8 x 5/8 aileron spar. Add both triangular sections, shape and install the aileron leading edge, followed by the aileron ribs W6 and W7. Add the dihedral braces W13 and W14 followed by riblet W5. Mount the aileron crank in its ply base and install. When dry, set aside and repeat for the other panel.
Set out the centre wing panel in similar fashion. However, do not glue down center undercarriage assembly, consisting of ribs Wl, U/C braces W8, W10, W12 servo mount W9 and riblet W15 since these are all assembled as a separate unit with epoxy. Spar stiffener W11 is glued to the bottom of spar only at this time.
The ailerons are carefully cut out and hinged. Cut is slot in the aileron leading edge and relieve the immediate area to allow for link adjustment and epoxy aileron horn in position. Do not glue hinges in position at this time. Install aileron pushrods and terminate the pushrod about 1 in outside the outer panel. Using the dihedral jig, join the two outer panels to the center section.
With the ailerons taped in position, brace up the wing and pin one outer wing panel down on the wing bracers. Now cover the top of the wing with pre-joined 1/16 sheet. Repeat on the other panel.
Cut slots in center section panel to accept the undercarriage. Carefully place the undercarriage through the slots and bolt the assembly with 4-40 bolts and nuts. Brace up the center section and epoxy the undercarriage assembly to the wing. Now add upper brace W11. Fill the area at rear of ribs W1 with scrap so it will not compress when the wing bolts are installed.
Trial-fit the aileron servo and join the pushrod with split brass tubing. Now cover the center section with pre-joined 1/16 balsa. When this is dry, cut out the aileron servo access. Cut the top skin to release the ailerons and inset the 1 mm ply shroud. This ensures minimum clearance to allow proper aileron movement and it will not curl.
Glue on soft balsa wingtip blocks and carve them to shape. Cut off the outer curved section as per plan and hollow the inner section. Re-glue the outer section on and install the 1/16 soft wire to protect the tips. Use epoxy glue here as this not only protects the tips, it also ensures that they will not curl out of shape.
STABILIZER: Cut two 1 mm ply rib templates and, using the sandwich method once again, make eight of 1/16 and one of 1/4 soft balsa ribs. Using the 2 mm ply templates, open the spar holes to 1/4 and face the two center section 1/16 ribs around the dowel spar and after appropriate bracing up of the lower skin, glue the assembly in place. Add the 1/8 and 1/4 balsa center section fillers plus the tab spar and 1/4 square tab hinge supports. Cover the stab top with 1/16 soft balsa. When this is dry, sand it to shape and add the tips..."
Direct submission to Outerzone.
Planfile includes build article.
Did we get something wrong with this plan? That happens sometimes. Help us make a correction
Do you have a photo you'd like to submit for this page? Then email email@example.com
* Credit field
The Credit field in the Outerzone database is designed to recognise and credit the hard work done in scanning and digitally cleaning these vintage and old timer model aircraft plans to get them into a usable format. Currently, it is also used to credit people simply for uploading the plan to a forum on the internet. Which is not quite the same thing. This will change soon. Probably.
This model plan (like all plans on Outerzone) is supposedly scaled correctly and supposedly will print out nicely at the right size. But that doesn't always happen. If you are about to start building a model plane using this free plan, you are strongly advised to check the scaling very, very carefully before cutting any balsa wood.
© Outerzone, 2011-2019.
All content is free to download for personal use.
For non-personal use and/or publication: plans, photos, excerpts, links etc may be used, provided that full and clear credit is given to Outerzone with appropriate and specific direction to the original content i.e. a direct hyperlink back to the Outerzone source page.
Unauthorized use and/or duplication of this material without express and written permission from this site's owner is strictly prohibited. If we discover that content is being stolen, we will consider filing a formal DMCA notice.