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-   -   A Ringmaster Bi-Plane (https://www.rcuniverse.com/forum/control-lines-231/11585751-ringmaster-bi-plane.html)

flyingagin 12-01-2013 05:35 PM

I will have to modify my attach plates in the wings slightly to accommodate a blind nut. I think 4 40 will suffice.


Do some dry fitting of the N strus. Then I can cut the streamlined aluminum tubing to fit over the carbon rods. I reckon at that point I can epoxy the 4 40 steel rod ends into the carbon rods.


I have to credit John aka Namvet on the Ringmaster site for this ideal. It just made life simpler.


Ken

flyingagin 12-08-2013 06:58 PM

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It has been a busy weekend, so not much accomplished.


I am changing the strut attach points in the wings. So I have a grand total of two done. These are the bottom wing inboard side. The 4 40 wire pieces simply bolt to the new attach pads i made. I have to make similar pads on the bottom of the top wing. Then remount the wings on the parallelogram jigs. Then it will be a case of fussing with the angles of the 4 40 wire pieces and the lengths of the carbon rods. The the wire pieces can be epoxied into the carbon rods.


A whole bunch of fussy work.


I may have more building time coming up soon (if I feel up to it). My understanding is that my upcoming implant surgery is going to have me off work for 3 weeks. Hope not, I don't get paid when I don't work.


Ken

flyingagin 12-15-2013 12:26 PM

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All the mounting pads are in and the blind nuts as well. The blind nuts are also secured with epoxy and and micro balloons.


I have cut and bend up some more 4 40 wire pieces. Then the annoying task of bend them to the exact angles. Then on to sizing the carbon rods and aerodynamic aluminum rod covers.


I will be working on the 4 40 wire pieces. We will see how long and frustrating that is today.


Ken

flyingagin 12-15-2013 09:39 PM

Well I will take this in sequence


Wings are back on the parallelogram jigs. Started bending the 4 40 rods to their correct angles Inboard rear (bottom and top wing) rods are now correct, and the N part of front top wing rod is also correct. Was not to hard. I used several 1/4" sticks of balsa (different lengths) to check the angles, just laid them flush on the rod. When the angels had the stick in alignment with it's opposite rod on the other wing, I called that good. I had to remove the rod pieces to bend them, and then remount check and repeat till they aligned.


Then we (wife and I) headed off to the grocery store.

Then we (wife and I) headed off to the grocery store.


NEVER MADE IT. WE WERE REAR ENDED AT A LIGHT.


Just got home from E.R. We were back boarded out of the car. Poor Penelope, yes we named our little PT Cruiser.


WE ARE OK PRAISE GOD. We were immediately in a lot of pain with our bad backs. X Rays and pain meds.


I was stopping at a light on the way to the store that had just turned. And then WHAM AND WHAM AGAIN. Full size pick up rear ended us. The police was there within seconds as he he was across the street hiding watching for violators. He was there before the red light cycled to green. I was checking my wife as it was obvious she was in a lot of pain, she usually endures pain in silence. Not this time. When the officer opened my door and I started to move, Well I changed my mind and sat still.


My seat back collapsed in the first impact and the second knocked my glasses off. One of the paramedics found them all the way in the very back of the car by the rear hatch. Obviously the second impact knocked them off after my seat back collapsed.


No airbag deployment, a bit of a surprise there.


They took my wife out first then me on back boards and then transported us to the hospital.


There were we checked out and X Rays done. Pain meds and muscle relaxants given. The finally released.


We are OK, just hurt and will hurt for a day or so.


Got to make appointment with our primary care doctor and I have to notify my pain management doctor.


Already called my insurance company. Notified my work while I was still on the back board (dang man those thing are heck on the back).


Our dear friends from church got to the accident scene as the paramedics were getting me out (maybe live 1 or 2 miles from the scene) then they followed us to E.R. Took us to Denny's on the way home and bought us dinner. They have been so good and loving to us since we moved to Texas.


So now we are home in our recliners relaxing.


Ken

flyingagin 12-17-2013 04:56 PM

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We are feeling much better now. My insurance company provided a rental car. We have follow up appointments with our primary care doctor tomorrow. The car has been released for repair It is not as bad as we thought it would be. We took a drive to Galveston and no undue pain. Necks are still rather sore. The wife is rather gun shy about lights turning and clobbered again. And I expect to return to work Thursday.

OK here is an update on the bibe. I got a little done on the struts today.

I epoxied the carbon rods to the lower inboard 4 40 rods. I first sand the 4 40 rods and then started mad a bunch of small nicks all over them in a random pattern with my Dremel and cut off wheel. I cut some of the streamlined aluminum tubing and test fitted it over the carbon rods. Fist thing I noted is that this will not be straight forward. Second thing I noticed is that the tubed at least doubled the wight.

I may rethink these. I am thinking I might glue some balsa to the carbon rods and the sand to the correct shape. I can then cover the balsa with some aluminum or silvery tape or coat. Wife says paint them black, but I am not real keen on that. I wanted some bling here.

I am still going to use the aluminum tubing for the cabane struts..

So here are some pics.

The 4 40 rods that epoxy inside of the carbon rods The shiny spots are the light nicks I dremeled into the rods

The mounting of the 4 40 rods

The aluminum tubing

And aluminum tubing covered carbon rod struts

Ken

flyingagin 12-18-2013 05:35 PM

I removed the aluminum tubing from the strut assembly.

Then I finished epoxying the top 4 40 rod to the carbon rods, so the strut is now glued together as a one piece unit.

I will glue some balsa to the carbon rods and sand that to shape. I have some aluminum tape on the way courtesy of a brother on the ring site. I will cover the struts with that. Stuff is strong, and shiny. BLING!!!!

I will use the aluminum tubing for the center struts sans the carbon rods. I can put some brass in it at the center and ends so it will hold the 4 40 mounting bolts.

Ken

flyingagin 12-25-2013 08:52 AM

An update on the car crash. Our car is being totaled out. And I lost my job over it. So busy hunting for one and dealing with all the other problems from the crash. If you pray I could sure use some.

Ken

flyingagin 12-25-2013 08:54 AM

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Going to Christmas dinner at some friends from church this afternoon. And I am totally dead in the water getting anything else done today (tomorrow and the next few days will be very busy indeed), so I worked on the last inter-plane strut.

During this I completely snapped the L.E. at the last two ribs off the bottom wing. I epoxied it back. Good as new.

Cut and bent up the 4 40 rod attachment pieces.. Then a couple of short sticks laid against them (after bolting them down) to check angles and re bend till they lined up with the opposite piece. Went relatively fast this time, as I could almost guess close on the angles this time. Then cut the carbon rods to size. That went faster and I got better fits to boot as well. I have to disagree with the old adage that practice makes perfect, but it sure does help a bunch.

So then I epoxied the 4 40 rod pieces into the carbon rods I confess to laying the two end carbon rods down in the wrong sequence, and when I already had the glue all the rods, going what the heck, they don't fit now??????? DUUUUHHHHHHH STUPID; switch the ends!!!!! Yep I really did call myself stupid. But anyway the 2 inter-plane struts are glued up.

Now I have to wait till I can get my spectral fishing line (30# test) out of my smashed up car and warp the carbon rod ends. The filaments in the carbon rods are all uni directional. No spirals or winding's or anything else. So the ends can split real easy. The answer for that weakness is to wrap the ends of all the carbon rods with the spectra and then some thin epoxy. I don't think they will then fail. Heck the warping may not even be needed, but I will sure feel a lot better knowing I went the extra step. I would prefer to use Kevlar thread, But I be darned if I can find my bobbin of it.

I can begin roughing the ply gussets that fits where 2 carbon rods com together ie. the N parts of the struts.

Merry Christmas every one!!!!

Ken

flyingagin 12-25-2013 06:04 PM

Houston WE HAVE A PROBLEM


THE BOTTOM WING IS UPSIDE DOWN


OH CRAP I REALLY DID IT this time CRAP CRAP CRAP CRAP


Ken

flyingagin 12-25-2013 06:09 PM

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When I put the wings in the parallel jigs I put the bottom wing in upside down. So the strut mount pads are now on the bottom of the wing and the struts are fitted that way. Stupid mistake just stupid. There are keying strips on the inside of the bottom wing to key it squar into the fuse when bolted on. I forgot those and thought it was upright.


So remove the keying pads, sheet the top of the bottom wing, realign and re add the keying pads. Redo the bilt pads on the bottom wing. By thay I mean just add some more ***** ply to the bottoms of the holes to key the bolts. and oh yeah I removed some of the ply bolt plat at the T.E. so it now can fit inside of the fuse. So I will need to add a new plate to the T.E. as well.


OH MAN I AM SO GLAD THESE WINGS ARE SYMMETRICAL. SO DARN GLAD. Otherwise it would be extremly difficult to redo at the point.


So the bottom wings top now becomes it's bottom.


Well I sure hope it is this easy.

Ken

Jim Thomerson 12-25-2013 06:56 PM

For 1/2 square, I glue two 1/2 triangular pieces together, and attach them to something straight while the glue dries.

Ammonia works by softening the lignin and subrin in wood. There is little or no lignin or subrin in balsa. I use water with a little simple green in it. I think it is a matter of removing a little oil or wax, or whatever, and allowing the water to wet the wood. I'll try water with a little vinegir in it next time.

flyingagin 12-26-2013 07:35 AM

Yeah Jim I have read that vinigar works really good. Now if you could steam the parts, that should turn stick peices almost to wet noodles. I have seen that done on hard woods and they bend like crazy.

Sheeting the open side of the bottom (center section) wing (new top of bottom).


Carved off the alignment taps from the center section of what is now the bottom of the bottom wing. That is going to need some sanding and puttying. No big deal.

I test the two wings assembled to each other. They are very stiff laterally. There is virtually no give at all when I try to push the top and bottom wing in opposite directions. Much stronger than I expected. I think offsetting the struts top to bottom by one rib bay (2") was the key. Not only does it look better, but it is way stronger for not more than a very few grams of wight. But it sure made it a lot harder to do. Everything became compound angles. Worth it though.


Ken

flyingagin 12-26-2013 10:18 AM

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I have the bottom wing re mounted, a bit rough yet as it is still not perfectly aligned, just close. I will fix that later. And then I will add alignment tabs to insure it goes on in perfect alignment.


So here are some teasers. The stab is not yet glued in, just a press fit into the slot for it. Lots I want to do to the fuse first.


Ken

flyingagin 12-27-2013 08:19 PM

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I wanted some BONES in the fuse.


So the turtle deck is ribs and stringers


I cut the 2 ends ribs to shape and gluued them in with out the stringer notches. The back one is 1/16" birch ply. the front is 1/2" balsa. I then added three more ribs equally centered in between. They are two layers of 1/8" balsa at right angles to each other sorta of making a balsa ply.


I first glued the center rib. It was cut well oversize as well as the other two. It was then block sanded to size and shape. I use a long bar with about a 3" piece of sand paper glued onto it's middle. I then shape the rib. Next I did that back center rib, followed by the front center rib, all the same way.


Then it was time for stringer slots. The center stringer is spruce. The outer 4 stringers are balsa. I made stringer slots in each end rib. Laid a piece of spruce stringer into the two in slots and then marked and cut the other 3 slots for the center stringer. I the repeated this process for the outer 4 stringers.


When covered the shape of the stringers will show through the covering, giving me some bones in the fuse.


At some point I will make a head rest for the front turtle deck rib and extend in backwards 2 or 3 inches.


The aft fuse really stiffened up a lot with the turtle deck installed. It is one very rigid fuse, but still seems to be quite light.


Ken

I keep forgetting to add that all the stringers all 1/8" square stock.

flyingagin 12-30-2013 02:06 PM

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I roughed in the top block over the fuel tank compartment. I felt I needed some ideal of how it might interface with the cabane struts.


Speaking of cabane struts, I am in the early process of working on them.


I installed the mount points and blind nuts in the top wing. There are only two attach points and nuts in the top wing. The cabanes will bolt onto the center line, one forward and one aft. The opposite side will make an inverted V, and will be in the usual N layout. The bottom ends of the struts will be epoxied into the fuse. Seems simpler and maybe lighter.


The Struts will be built just like the other two were, 4 40 rod into the same size hollow carbon fiber rods. Well on the top any way. The 4 40 rods are bent into a V, for both the front and back. The front 4 40 attach rods exactly the same as all the others were, But then soldered together to give me the needed four legs.


Ken

flyingagin 12-31-2013 02:19 PM

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It is starting to STRUT it's stuff. :p Bad pun, intentional too. Hahaha

The Cabane struts are roughed in. Still have to epoxy the 4 40 rods into the top and bottoms of the carbon rods. And then glue the bottoms to the fuse.

These have been real son of a guns to do, far more difficult than the inter plane struts were. The angle were harder to get correct. The 4 40 rods had to be removed to make a bend then a correction bend. and repeat several times. Then trying to bend the other leg would knock the first bend out of true. a course after each and every bend everything had to be re bolted and check, and then repeat again several times.

I also made the bottom front fuse plate that makes the bottom of the fuel compartment, and serves as the landing gear mount. At present I do not have correct sized gear legs, a future buy. I will most likely use 3" wheels.

Ken

flyingagin 12-31-2013 03:08 PM

Now to take the Cabane struts apart. Only 2 bolts. Because of all the angles and stuff they dont just come apart, the angles prevent that, and that is a good thing.

Prep the 4 40 rods for epoxy and glue them up permanent.

Ken

flyingagin 01-01-2014 07:45 AM

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I temporally mounted the engine, and the carving for the top of the tank compartment. I had to split it and relieve it for the front strut legs. I also removed the wire landing gear legs from a RC Kadet Jr, that is not being used, and mounted it to the bibe. Need to bend the legs back in as it was an over sized gear, and I had bent, and spread the legs out a lot. But I think once I bend the gear back to it's original angles it will work just fine. I have to sand the rust off it and then paint it.

Ken

flyingagin 01-01-2014 09:53 AM

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I just realized I have been at this plane for 3 months now. But I have sure enjoyed it. I am thankful for the time I have spent on it, knowing I still have a long ways to go.


I thought I would try to better show the construction detail of the cabanes (cabane? since it is one piece). I really enjoyed making it, but it was brain wracking, time consuming tedious work. Way more than I ever thought before hand. Would I do it this way again. IN A HEARTBEAT! Just invent better techniques!


And 1 picture of the mount points on the bottom of the top wing.


Ken

flyingagin 01-01-2014 10:01 AM

Wow I just added up all the wing(s) mounting bolts. This bad boy will take a while to assemble and disassemble at the field.

The are for 6 32s mounting the bottom wing to the fuse. Each inter-plane strut has 4 bolts and the cabane has 2. All 4 40s. So that is 14 bolts. And I will have to come up with something for the lead out guides. Have not even thought that far yet.

Ken

flyingagin 01-02-2014 02:06 PM

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I was very unhappy with the cover over the tank compartment. I also thought it was going to make the are right behind it difficult to do.

I had a piece of 3 x 3 x36 balsa that I have been storing for something like 20 to 30 years, A darn baseball bat almost (well a bit lighter and softer). haha. So i thought why not make that whole are as one piece. So finally time to use the big chunk of balsa. I got out the band saw, and set it up to re-saw the block of wood. The little band saw gave me a very accurate cut. after measure and marking then checking it I cut the piece I had ripped to length with my Zona saw and cut some slots for the bulk heads. I the just chiseled out the grooves. I ended up with a very good fit.

So next lots of carving. a bit of sanding. Looked good to me. Now it needed the headrest. Shaped anf glued it on. Man it sure needs a windshield. A 32 ounce water looked like it might just do the job.

All of this sort of sets the height and fills the gap between wings.

The block on top that I carved will be permanently glued on. All access will be from the bottom, through the bottom wing opening and the plate that the landing gear fastens to.

I am trying to see the kind of access I am going to have to install and service (if ever needed) the bell crank and push rod. And also since this bird is going to have 2.4 radio for throttle, I have to get into the fuse for installation and service.

All of this has to be taken into account now as the top is permanent as well as the cabane struts will be permanently epoxied to the fuse.

I have to figure out the cabane struts and windshield conflict. Just sort of testing and adjusting.

So several simultaneous jobs just to get every thing to work together.

Ken

flyingagin 01-02-2014 02:10 PM

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And two more pictures as RCU would not let me add anymore to the last post.

Ken

flyingagin 01-11-2014 06:54 PM

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I got some time in on this bird


I have been fussing with the windshield. 2 attempts to mold one. 2 different molds.


And ya know what? Forget about. That dog ain't gona to hunt for me. I used my mono coat hot air gun to shrink the plastic. First attempt was a sprite bottle. Second was a plastic milk shake cup. I think the plastics are PET. Shrinks real good. The first mold was balsa. Flared my carpal tunnel like crazy. The shape was really not big enough to fit with a good look. I was just trying to learn.


I mounted the molds to a dowel and clamped that to my table.


The second attempt I put off and put off. The carpal tunnel was really bothering me and I was not willing to carve another mold. So I finally thought let's try a mold out of foam. That should be easy on me. It was and went fast. The plastic shrank fairly good (plastic milk shake cup) but my mold melted when the plastic started to form around the mold. I thought it would but I just had to try. In truth I did not like the shape anyway.


So the next attempt (3rd) is a go. Just some flat clear plastic bent around the fuse. I made some marks with a magic marker and cut a bit. Tested and marked and cut a bit more.


So now the windshield issue is solved. A little more trimming to get the exact shape I want is all that is needed other than gluing it on. I think I will also use some .5 round head Allen head screws. I think they will look good, and they will really help hold the windshield.


I also glued the top blocks on. First I hollowed them out a bit. Had a very minor oops moment that was almost a major oops ouch moment. I was using a 1/4" router bit in my Dremel to do the bulk of the hollowing out. I went through in one spot. Just barley and I do mean barley missed my hand on the opposite side. That scared me. But I did miss myself. I plugged the hole in the top block and trimmed and sanded it flush. So no harm. I followed up with a ball mill bit. Removed a lot of weight.


Ken

flyingagin 01-11-2014 06:59 PM

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More pics for the last post. It would not let me add the last 2 pics.

Ken

flyingagin 01-11-2014 07:01 PM

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Finale shape for the windshield.


I also made slight groove in the top block for the bottom edge of the windshield to sit in. That will help lock it in.


I have to cover the cockpit area with some 1/16" sheet balsa. And all this area has to be have the covering applied before I glue the windshield down.


Ken


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