1:3 Bohatyrew 'Motyl' of 1925

[ARUP]

Wrocitem! The rear spar is angled where the ailerons start so a nice accurate cut was made then epoxy used for the joint. The angled portion was jigged to induce washout. The front spar was partially assembled so that everything is square as it holds the socket. Shear webs get added after the ribs are threaded in place.







wiecej...

[ARUP]

Wiecej! Before the ribs can get threaded onto the spars the front spar cutouts need to be made in the ribs. The rear spar cut outs have already been done for they were used to locate the position of the LE and front spar. Also, the TE need to be finished. The aluminum tube capture the wire TE that will be added. The tubes need reinforcement so 1/64" ply added each side of the 'regular' ribs. The 'special' ribs next to the inboard portion of the ailerons are longer so have angled wire pass-throughs on their tube ends. They also have hard balsa segments on their inboard side to help prevent the covering from pulling them inward. A couple of pictures show the wire TE through the tubes. The covering will pull a nice scalloped curve effect in them!







Pozniejsze dni!

[Gene C]

Outstanding!

[ARUP]

Thanks, Gene!

[ARUP]

My brother and I went to hear the Pixies in concert last night and it was great! Back to sailplane stuff. Here's a start on the wing construction. The main 'Hershey Bar' portion of the wing has all of the ribs ready to receive spars.



PA pa!

[ARUP]

Czesc wszystkim! The root rib was used to mark the position of the wing socket carry through. 1/4" ply supports were cut and fitted for spruce diagonals. Balsa support blocks were put across the top of the tube inside the fuselage. These were capped with pine stock. Now you know why I made this one bulkhead from lite ply wood. It is for torsional rigidity but thin so that 'stuff' can be added to it. The CF in the laminations help spread loads. That socket ain't coming out! Epoxy is curing as I type!









Wracac!

[ARUP]

Csesc modelarze! Here is the wing tube socket carry through and bracing without all of the clamps. The small piece of spruce to the right of the socket is to receive the anti-roation pin's socket. I left it long enough that any decalage misalignment issue can be rectified by moving the socket. The anti-rotation pins are 1/8" music wire and the tubes are brass. The wing roots will have aileron servos mounted to their exterior side so a recess will be made in the fuselage to clear them. Scrap balsa elevates the servo from the root rib surface and two wraps on masking tape gives a little 'wiggle room' side to side for mounting. The epoxy is curing for the servo rails as I type. I gusset will get added to each side. I'm giving these new 'Pro Modeler' servos a try.







Wroce!

[Gene C]

Ah! good old masking tape. The one item a shop can't be without. Interesting servo setup.

[ARUP]

To znowa ja! the root ribs were finished along with the fuselage to receive them and the wing construction has started...yippeee!





Do nostepnego razu!

[ARUP]

Gotowy na wiecej? The main ribs were put on the spars and glued after alignment ensured. When the glue dried the outermost rib was put in place using a jig then glued. The other two ribs were then fitted after measuring and cutting the ribs for the spars to pass. Fiddly but easy. The fore curved LE was fitted and glued. A spar extension piece had to be custom made to anchor the curved LE. From there the swept portion of the tip was added. It will get joined to the TE. While glue was drying the stabilizing strut anchors for the wings were made. Sheet steel was cut, drilled, filed, sanded, cleaned and painted. The parts were mounted to their blocks which will get glued into the wings. The nice thing about these stabilizing struts is they will also serve to keep the wings from sliding off the wing tube! My feet hurt... since I've worked on this model almost all day!









Dobranoc!

[ARUP]

Dzien dobry! I did a little planing therapy. I love my new planes! They beat the tar out of sandpaper and my arms and shoulders aren't so tired. Each wing panel was flipped over in turn so the aileron spars could get started. A straight edge was secured then the lower part of the aileron spar's slots were cut. The lower part of the spars were glued in place then the wing was flipped upright. This made the ribs a little more robust so that the aileron portion of the ribs could get leveled. I had to block the wing stable so the plane and 'T' sander could do their 'thang'! The straight edge across the top plus some pencil marks helped guide the razor plane and 'T' sanderWhen that was done 1/64" rib doublers were glued in place. Now the upper aileron spar parts can get 'cut-in'.









more...

[ARUP]

...more! While letting glue dry the aileron bell cranks were started. Rough blanks were cut from phenolic then measured for drilling cable attach holes, pivot hole and clevis horn hole. The cable hole spacing is 80mm as will be the aileron surfaces' horn spacings. Then they were dressed on the belt sander and mounting blocks were made and epoxied in position. A segment of brass tubing is the pivot and is a very slight interference fit on the bell crank. The tube pivot is glued into the mount blocks. Not shown is a stick of hard balsa glued to the rib from main spar to TE where the aileron's horn will be located. This will keep the wing from compressing locally under the action of aileron input and its flight loads. I don't have enough pulleys so McMaster Carr to the rescue... I hope! I'll make an order tonight!







Do widzenia!

[ARUP]

Csec modelarze! The top parts of the aileron spars were added. Scrap was used to maintain even spacing from the wing to aileron. Cap strips for the aileron were added so the tip could get sanded fair. Once the other wing is done then all cap strips, drag and anti-drag bracing and aileron pull-pull cables get installed before the final LE sanding. It's near the home stretch with major construction almost done!







Kolejny dzien!

[ARUP]

Witam ponownie! Work progresses on the 'secret project' and the Motyl! The left wing's aileron LEs were let into the ribs and the LE of both wings sanded to rough shape. Once the cap strips are installed the LE will fair into them. One aileron was cut free and the hinge line drawn onto it so the center of the horn could be located. You can see the wash out built into the aileron. The wing has no dihedral so it will be nice to have wash out. The bell crank has a span of 80mm hole-to-hole so the horns will be the same. The start of the aileron horn fabrication has started. They are wires bent and soldered and will have brass tubes epoxied onto them. The brass tubes will be flattened and drilled to accept the pull-pull cables on their end.





PA pa!

[gunny11]

Coming along nicely.. Keep it up.

[Gene C]

I'll second that. Looking great.

[ARUP]

Thanks, Gunny and Gene!

[stihac]

Loving it! Your builds are the best. Those of us relegated to be "virtual builders / flyers" enjoy your posts. Thank you for doing it.

[ARUP]

Hello Peter! It's so good to hear from you and I hope you and your family are well! Did you ever finish that neat Avia?

[stihac]

Hello, all is good here. thank you for asking. Just too busy with daughter's activities. Unfortunately the Avis is still unfinished together with other projects. One day they may be done...

[ARUP]

Witam ponownie! A 1/32" marine ply shear web was glued to the spars where the pulleys will get mounted. The ribs at the same location were reinforced with 1/64" ply. Triangles of 1/16" marine ply were cut and drilled to receive aluminum tube axles for the 1.25" pulleys. Aluminum cable guide tubes were mounted on 1/16" balsa stand-offs using epoxy. The exit guides will get built next. The aileron wire horns have been fitted with brass tubes, their ends flattened and drilled to accept detachable cables. The ailerons are getting hinged. Once that is done aileron 'throws' and clearances can be arranged. As in some of my other models, the ailerons will be removable.





Dobry wieczor!

[ARUP]

Toznowu ja! The aileron horns were painted then guides were fabricated for placement of the horns onto the aileron ribs. Dummy cables (fishing lines) were used to place and epoxy aluminum ferrules onto the ribs. A spacer block was put between the pulleys to keep them in place while setting up cable runs. The cables and respective guide tubes will keep the pulleys in place after everything is connected and in working order. The next order of business is drilling holes in ribs for cables to pass. The length of the bell crank hole to pulley was measured and drawn on the board. The height of the bell crank was measured and this put on one side of the drawing then the height of the pulley guide tube put on the other end. Rib stations were drawn onto this between the ends. A line was drawn connecting the two. A dummy cable was put across the wing. Then a triangle was used to know were to transfer the rib hole heights, as measured from the drawing, onto the ribs for drilling. It takes longer to type this than it does to do it! The ailerons have their hinges epoxied in place. I am holding one of the removable hinge pins.





Spotkamy sie znowu!