1:4 1928 RRG Professor

[ChrisL]

Mad Modeling Mike! Can't wait to see this one in person.

[JimD]

Very clever...you are the master of detail illusions!!!

[kjkavaney]

Mind Blowing...I needed some inspiration about now Michael...thank you for the GIFT !!!!
kevin k.

[lenb]

That looks really great Michael. The seat is exceptional.

[ARUP]

The weaving class is so a nice period correct pilot's seat can be made for the intrepid pilot! He needs to be able to work in a comfy office! Who knows what the 'real deal' looks like but this is fun stuff, man! A paper pattern was cut using TLAR technique. Stand offs were made and screwed to the seat bottom and the assembly was epoxied to the rudder tiller support rail. When the epoxy cured the seat bottom was removed so the back rest, as cut using the paper pattern, could be added. The edges were trimmed with stained manila folder stock so they don't 'unravel'. The seat keeps the pilot's 'bum' from interfering with the servos. Don't want a 'goosey' pilot on approach! The pilot likes it!









Dobroy nochi!

[ARUP]

Kevin K... this post is for you, good buddy! The pylon was set up with incorrect incidence as noted early in the build. Balsa was glued as 'backing' inside the pylon then more balsa scarfed in place against the backing. You can see the untrimmed backing and scarfed wood in the background and the finished result in the foreground of first pic. The ply skin will reinforce this fix. This exercise was so the wing sits flush on top of the pylon. The next pics show where balsa was scarfed to the former so that the ply will have aligned seams when added, later. One is of the wood 'before' and the other is 'after' the stain added. The switch mount was made from ply, stained then glued in place. The pilot's right arm will cover it. It's fun to hide the electronic stuff as much as possible so that the casual inspector won't see it and spoil the illusion! Manila folder card stock was folded then strips were cut. The odd ones... or was it the even ones... were removed and saved.
The strips were weaved together then they were stained. When the stain dried thinned wood glue was painted onto this then allowed to dry. What in the world...?









More...

[Tango Juliet]

Maybe it's just the photo. There might be some parallax contributing to the illusion that it's not all square.

[ARUP]

TJ, yessir! The servo arm is 90 degrees from the link to the tiller. If the tiller and servo arm were parallel to each other, which might 'look' better, then the throws would be more differential. If the servo arm was a lot longer then you might get some 'wonky' throws at the extremes of travel but for such a short moment it is pretty much equal. Don't over think these things! The 'computer' radio is your friend (even though I have my doubts at times)! lol

[Tango Juliet]

Are you getting equal rudder deflection with that linkage? Something about it just looks a little off to me.

[ARUP]

Wanna see some 'skin'? More ply skin that is! A better pic of the compass is shown. Too bad it doesn't have a German face dial. The rudder pull-pull cables were run and structure was 'clearanced' for the cables to pass freely without rubbing. While putting ply on the fuselage it was realized it might be problematic getting to one of the skid anchor bolt/nut assemblies. It would be difficult to get my hand inside the fuse to turn wrenches. What to do? A guide tube was rolled from paper using a suitable mandrel (a K&S Wire Bending Tool handle, in this case) so that a 1/4" socket with attachment and extension would fit. Access will be from above inside the pylon. Balsa guide tube supports were made from balsa. The socket was used to align the guide tube while the glue dried. More ply skinning can commence!

[ARUP]

More pics!









The pics are a little blurry... sorry. The rudder cables are going to get installed then the sheeting can pretty much get finished. The fin and tail skid will need to be built in order to finish the ply sheeting.

Frohliche Weihnacten!

[ARUP]

Christmas Day has been a good one! It even snowed a little bit! After visiting with family and friends more was done to the Professor! More ply added. A couple of large gussets were added to reinforce the aft section of fuselage to the 'backrest' front portion. The instrument panel a it's items were fabricated. There are no photos of it so basic instruments were put on it. The tow release knob was turned using a drill and sandpaper, drilled for the pull rod then dipped in orange dope a few times. The variometer face was drawn onto paper then cut free. The needle was from brass parts included in an 'instrument kit' purchased many moons ago. The other two instruments, altitude and speed, were salvaged from that same kit. I had to paint over English words on them. The needles are free to move. A brass pin was used to capture the needle. The pin was bent downward on the back side of the instrument and excess length cut. The end of the brass acts as a weight to hold the needles fairly stable around the 'zero' mark on the face of the instrument. The glazing was put into a frame overlay then captured by the instrument panel. Holes were drilled in the fuselage bulkhead to receive the instruments before the instrument panel with its glazing was put over them. The holes were painted with black dope. The functioning compass was obtained from a sporting goods store.









More pics to follow.

[ARUP]

Thanks very much Kevin! I hope the information contained within this thread is enough that anyone can use it to build vintage sailplanes! The more vintage sailplanes flying the better as far as I'm concerned! (I'm good at dodging snowballs thrown by glass sailplane fliers! )

I had some 'split sinker' lead weights lying around so decided to use 'em. Some got pounded with a hammer to various degrees of 'flatness' then they were 5' epoxied into the upper recesses of the frame's nose before the ply put in place. The fuselage sides were used as 'weight receptacles', also. A piece of plastic bag was laid down then some lead pellets were poured in place. A scrap piece of balsa was used as a scree to level and make sure they didn't sit proud of the level of the ply, once added. The lead was (about 100g each side) mixed with 30' epoxy then put back into the fuselage recesses. Once the epoxy cured for each the ply was added. The goal is to maintain room inside the cockpit for some 'spurious' detailing. The full scale plans for the Professor are available for a price tag of around $7K. If I'd hit the lottery I'd get 'em. As it stands there is no room in the budget for that kind of acquisition! A Coverite iron was used to shape the gentle curve in the ply after it was cut and sanded to fit. Paper and light card stock is used to make patterns for these ply parts.







Joyeux Noel!

[kjkavaney]

Michelangelo at work here...beautiful stuff Michael...you put the rest of us to total shame....damn..
kevin

[ARUP]

Hillbilly white tie? Could be! The first pic is the paper pattern made to fit the nose. 1/64" ply cut a little large, the release area cut into it and fitted then the ply was cemented in place with Ambroid. Wow! The first bit of ply going on the model always gets me pumped! Once the glue dried a scrap bit of ply was abutted to the proud edge of the nose ply then the nose ply sanded down to the level of the scrap. Fitting the top and bottom ply pieces against the nose ply will progress quicker! I had to make sure the nose ply piece was square to the datum line (which is parallel to the top longeron) of the fuselage. Don't want seams 'running downhill' or 'uphill'! The last pic shows the skid patiently awaiting installation! It has three coats of pretty varnish!





Boa noite!