Author Topic: Build threads look fun (Read 60809 times)

Dave_Trible · « **Reply #150 on:** July 07, 2013, 04:41:29 PM »

I finished the center section sheeting and put the wing tips off the hanger queen on it. It's set aside to dry and now I'll start the stab/elevators the old fashion way of wax paper over the plans. I know Ty is talking about this on another thread. I use the store brand ( HyVee) paper. I've noticed stuff sticks more to it these days than before but didn't know why. Not to worried, it's one- time use and if it peels off in shreds I don't care. It still comes off. Now if it got through and stuck the plans.....

Dave_Trible · « **Reply #151 on:** July 07, 2013, 06:30:53 PM »

Here we've got it mostly together and drying. When I can lift it I need to sheet the bottom center section and put tip blocks on. The geodetic construction gives the stab a bunch of torsional rigidity to resist warps and twisting in flight. The first three Desperados had built- up and fully sheeted surfaces here. They are larger units so I was getting 4 ounce assemblies when finished. To cut weight here I went open bay stabilizer and solid, very light 3/8" elevators and trimmed out nearly two ounces. I was actually shocked how heavy those tails were. I'm not actually trying to build feather light with this design but THAT weight was in a bad and worthless place. Still had to be stiff tho. Twisty tails or rear fuselages are bad news.

Tim Wescott · « **Reply #152 on:** July 07, 2013, 06:52:18 PM »

Quote from: Dave_Trible on June 28, 2013, 07:41:18 PM

One last look inside. You can see the overflow way in there running up to the top front corner to get max fill with the airplane sitting normally on the ground.

No baffles? How does the thing do at the end of the engine run?

Dave_Trible · « **Reply #153 on:** July 08, 2013, 05:02:08 AM »

Hi Tim. For me, baffles went out with bell bottoms. Never saw a benefit. In fact my last experience with them made me think it was blocking fuel entry. The run is very solid up to the last lap or two with a short speed up and cut off. Seldom ever a burp. There sure are a bunch of other tanks out there and no baffles. Also these planes are moving right along with a pretty consistent centrifugal force on the fuel. Baffles were more common with the old Fox where the airplanes seemed to almost stop in the air at times like the crowns of wing overs and overhead eights. Here the fuel might fall away from the feed line for a microsecond creating a burp or worse. The baffle in theory would hold a little fuel in the pocket.

Dave_Trible · « **Reply #154 on:** July 08, 2013, 06:29:18 PM »

Stab is dry and ready to complete. I'm showing the shaping lines I've drawn on the edges. It's too easy to mis-shape these edges causing flying trim issues. Guide lines for carving and sanding are a little more accurate.

Dave_Trible · « **Reply #155 on:** July 08, 2013, 06:36:18 PM »

For cutting hinge slits (not slots, I don't remove any material) I've made a simple wooden guide to center the slits and make cuts. Though this spreads the wood slightly a sanding block fixes the issue latter. I have a small assortment of these guides for different thicknesses of wood. Somebody should make and market sets of these.

Dave_Trible · « **Reply #156 on:** July 08, 2013, 07:45:21 PM »

Remember these? I need to finish up a tail horn so it can be buried in the elevators soon. These were brazed from 1/8" music wire and Dubro steel straps I reworked a little including installing a brass bushing for the pushrod. I then plastered this up with some JB to keep the bushing in and fill pre drilled hole in the strap I don't need.

Dave_Trible · « **Reply #157 on:** July 08, 2013, 07:47:11 PM »

I bent the arms as I needed in the wire bender and tweaked them up for alignment.

Dave_Trible · « **Reply #158 on:** July 08, 2013, 07:48:50 PM »

Finally blew on a little chrome paint for rust proofing and its ready to be installed.

Derek Barry · « **Reply #159 on:** July 09, 2013, 05:29:47 AM »

You have as much scrap granite hanging around as I do. You in the countertop business?

Derek

Dave_Trible · « **Reply #160 on:** July 09, 2013, 06:11:05 AM »

Derek not me personally. My employer ( the big orange box) does. My specialty is home appliances. Think of me when you grab your next cold one or wash your socks. Once in a while they change out the granite samples......

Dave_Trible · « **Reply #161 on:** July 09, 2013, 01:41:58 PM »

Working on the elevators; blocked up while still square for drill horn holes.

Dave_Trible · « **Reply #162 on:** July 09, 2013, 01:45:26 PM »

Marked showing slots for horn wire.

Dave_Trible · « **Reply #163 on:** July 09, 2013, 01:46:41 PM »

Groovin'.....on a Tuesday afternoon.....

Dave_Trible · « **Reply #164 on:** July 09, 2013, 01:47:45 PM »

A trial fit before shaping the elevators.

Dave_Trible · « **Reply #165 on:** July 09, 2013, 01:51:41 PM »

Though I don't always do it this way, I'm glueing on plywood strips 1/32x3/32" to the trailing edges. This gives something solid to sand to and will help withstand banging into doors frames and warpage.

Dave_Trible · « **Reply #166 on:** July 09, 2013, 03:44:30 PM »

Oh, there he goes off the reservation again. Hinges shoved into the slits. Absolutely NO glue or epoxy. Drilled vertical holes through the hinges where tooth picks will be glued in to retain. Nothing in the hinges to bind them up. Pockets are for money not hinges. The airplane will be covered and finished with everything already joined. The hinges can self-align when worked a few times then the finishing dope will lock them from twisting. Dope doesn't stick to nylon.

Dave_Trible · « **Reply #167 on:** July 09, 2013, 06:59:55 PM »

Good to go. 2.5 ounces with horn and hinges.

john e. holliday · « **Reply #168 on:** July 10, 2013, 09:16:29 AM »

No glue on my hinges either. Only CA on the toothpick to hold it in place.

Dave_Trible · « **Reply #169 on:** July 10, 2013, 03:55:19 PM »

Quote from: john e. holliday on July 10, 2013, 09:16:29 AM

No glue on my hinges either. Only CA on the toothpick to hold it in place.

Yeah John I've done it that way as long as I can remember. The time or two I tried to glue them in the epoxy went where I didn't want it. Since I have the airplane all together from the first drop of dope it's very easy to pin the hinges. Where the trailing edge is a quarter square there is plenty of hinge sticking through the backside I'll glue those from the back or inside (wing trailing edge) and not weaken the 1/4 sq. by drilling it.

Dave_Trible · « **Reply #170 on:** July 10, 2013, 03:59:54 PM »

The car is loaded and killing time till I head for Muncie in the AM. Sanded up the wing and put it on the scale. As shown complete with landing gear but no flaps 11.5 ounces. Not too bad. Not trying for an ultralight but when I can keep the weight down I have room for a little more finish.

Randy Powell · « **Reply #171 on:** July 10, 2013, 08:53:39 PM »

Good luck at the Nats, Dave.

Dave_Trible · « **Reply #172 on:** July 11, 2013, 02:59:23 AM »

Quote from: Randy Powell on July 10, 2013, 08:53:39 PM

Good luck at the Nats, Dave.

Randy Thank You so much. Lots of work to do.

john e. holliday · « **Reply #173 on:** July 11, 2013, 09:46:28 AM »

Well Dave depending on when you finally got on the road, you are closer to the NATS than I will be. Just have a safe trip there and back. Don't forget to have fun and say hi to all the guys/gals.

Dave_Trible · « **Reply #174 on:** July 26, 2013, 08:20:16 AM »

We will be getting back on this build real soon. I've got a couple things to whip up for some others real quick and after test flying the green Desperado this week with the Jett .76 I'm so taken with it that I'm converting the red one to .76 by just lengthening the pipe tunnel and the rest of the fleet is retired. After flying both engines back to back AND watching video tape for the first time of my flying it was immediately obvious how the .61 ships slow down on the tops of loops and consecutive intersections, affecting shape. The bad part is now I have to learn to fly again. The amazing part is the .76 isn't really using much more fuel so I'm still pulling fuel out of the 7 ounce tank. I can slow my laps a little and still get much better drive through maneuvers-win- win. The one we are building now I will try to cut weight enough that it should work much better with my .61's but can easily take the .76 from the start.

MarcusCordeiro · « **Reply #175 on:** July 26, 2013, 01:04:46 PM »

The bigger, the better, when it comes to engines.

Marcus

Dave_Trible · « **Reply #176 on:** July 31, 2013, 08:45:38 AM »

Well at least maybe I found it. (&$!??x). The red airplane now has the .76 and is truly now a point-and-shoot airplane, me likes a lot! This ship always flew superb, mostly better than the rest except for one bad flaw which kept it home for this Nats. Without fail the third turn in the hourglass I'd see the bottom of the airplane suddenly and it would head for green acres. Tried everything. Thought more power might solve it. Nope. Now remember my shpeel about ribs crushing with shrinkage? Once again. Can you see it in the photo? I think it's causing a tip stall at a bad time. So next project is to fix this by cutting the covering on the last bays and tips both sides and shoring up the ribs. This one could make the team trials so best get with it.

Dave_Trible · « **Reply #177 on:** August 02, 2013, 07:10:27 PM »

What it looked like under the silk span.

Jeff Traxler · « **Reply #178 on:** August 03, 2013, 01:52:01 PM »

Wow,That looks ugly.A piece of 1/16 x 1/8 or even 1/4 with the grain going the other way will fix it.I always thought that was a weak point in almost all built up wings.I wonder if building up the ribs like a full size aircraft would be worth the extra effort.It would eliminate that problem and might be lighter to boot.Trax

Dave_Trible · « **Reply #179 on:** August 03, 2013, 08:19:43 PM »

Hi Jeff! For me this issue began with this v- tip in that before I usually had some hollow block or thick sheet tip which supported the airfoil at the tip rib. With this design that last rib is rather unsupported and needs to be beefed. I have a fair amount of finish here which may be causing a little more shrink, even with the non- tautening Certified. The fix this time is to replace the lightened 1/16" ribs with mostly solid 3/32" and a little webbing between the spars. Since this is the third one I've had this issue with I'm going back to the new one I'm building to beef it up and changing my drawings likewise. My theory is the solid thicker ribs will do the job without adding much weight or extra work. Hope you got a new project on the table. It's only about 49 weeks until the 2014 Nats fella!

Jeff Traxler · « **Reply #180 on:** August 03, 2013, 11:34:39 PM »

Dave,For the short term I am whipping up a simple Fuselage for my SV22 wing and tail.Dayton is next week,Detroit the week after,FCM next.I definately want a good flying ship by the team trials.While I'm helping out I am going to input as much stunt info as I can and try not to explode

Oh Yea,I wanna do a bunch of flyin' too.I have most of the components framed up for my Shark 45.That is my main project for building season.I'm really going to try for a nice finish.Don't know if I'll ever get one of those Concourse trophies but I don't want to be in the back row with brother Dan's Vista again next year!!Trax

Dave_Trible · « **Reply #181 on:** August 23, 2013, 09:40:47 AM »

Boy this is terribly slow right now. After the TTs next week it will start rolling again. I started getting the fuse together. Here I'm using epoxy to assemble the front end. The mounts and spacer block were made as an assembly down on the flat granite to ensure the mounts are flat and square. Team racers Jim Dunkin and Bill Wright drilled this into me years ago. A hot engine case can be warped if screwed down unevenly. Then I drilled the mounting holes and lightening holes on the drill press. I use 1/2" sq. mounts because the nose is short and I need the fuselage width to get enough fuel tank in. Then I've put temporary pins through the fuse to lay and position the mounts correctly. These are pulled later.

Jason Greer · « **Reply #182 on:** August 23, 2013, 10:56:55 AM »

Good luck at the team trials Dave.

Bill Little · « **Reply #183 on:** August 23, 2013, 11:54:53 AM »

Yes, Dave, Good Luck at the Team Trials!

BIG Bear
RNMM/AMM

Dave_Trible · « **Reply #184 on:** August 23, 2013, 04:15:56 PM »

Thank you guys. We'll sure have a good time. I'm not happy with how little flying time I've gotten since the Nats but I'm sure liking the .76. I'm going to dedicate a major effort to find a new place to fly. Getting tired of fighting the soccer bunch and schools around who choose the park for gym class instead of the school grounds. Must be something better.

john e. holliday · « **Reply #185 on:** August 24, 2013, 10:00:45 AM »

Hey Dave I too have been looking around for places to fly as the circle at Shawnee Mission Park is too small with that hedge tree on the back side. Can't wander hardly three feet. Don't ask me how I know. Have looked at the ball diamonds down in the park. Don't see any lights and the one ball field is away from the road. Have also never seen the ball diamonds being used. May try it out after the Topeka contest. Haven't flown since Memorial Day weekend.

Dave_Trible · « **Reply #186 on:** August 24, 2013, 02:48:34 PM »

Let me know. There are a couple industrial parks down my way and a big sports park out south where my daughter's new house is I'm going to check out. Tempted to Google maps the area and try to spot some places. If need be we'll restart the old club for creds. (You pick which club: Sky Devils, Sodbusters, Super Tigers, Knights......)Four clubs at one time. Now us and no place to fly.......see you in the morning John.

john e. holliday · « **Reply #187 on:** August 24, 2013, 09:24:23 PM »

On the way home from my granddaughters birthday party, I passed the sign, Fleming Park this way. It is the KCRC flying field in which some of the guys are now coming around to CL activity after the fun flies that have been held there. It is an area marked for CL and helicopters. There is a pave square big enough to make decent take offs and the rest is grass. Yes it requires a permit to fly there unless there is a special sanctioned contest. The Minors just had a F2D meet there. Great turn out and a lot of combat. saw Jim Piscetto there that weekend mowing the grass the KCRC group has to maintain. I guess you have to be a member of the KCRC to get a park permit and also an AMA license. Thought of that for 2014 with one day set aside during the week for flying. Of course Sat and Sun would share with the rotor wing group. Now I am in full retirement I wouldn't mind driving out there to fly. Also no keys needed to get access is my big draw to the site as well as the safety of a fence. I know that there are more than just the two of us. Problem is getting all the KC area CL people together. This could become another Buder Park on a small scale.

Dave_Trible · « **Reply #188 on:** September 08, 2013, 07:00:59 AM »

Just wanted to add a note. I'm putting this particular build on the shelf for now. Having flown the TTs and working some with my new (for me) .76/.75 power packages I really think the standard Desperado is just a little too small for it. It's very hard to keep this and a credible finish on 650 sq.s and still keep the wing loading within competitive limits. So I'm starting a pair of new 105% Desperado. When I get the wings built and up to the same building stage we were on here I'll pick up from where we left off. The new version pushes the area up to about 700 squares which I believe is better for this design, power, and weight. Frankly the rather still air this time in Muncie showed me I didn't allow every situation. I built for wind and it didn't happen. That's why we keep trying I guess.

Randy Powell · « **Reply #189 on:** September 08, 2013, 05:01:00 PM »

Well, the StarGazer isn't very big. Neither is Jim Aron's hot rod and both use big blocks.

Will Hinton · « **Reply #190 on:** September 08, 2013, 08:22:39 PM »

Dave, I agree with Randy - I'm running my PA75 in a Trivial Pursuit based airframe and it's just a wonderful combo! Finish this one and "big block" it!

Dave_Trible · « **Reply #191 on:** September 09, 2013, 06:27:01 AM »

Yes I sure know that and in fact Uncle Jimby's airplane got me interested in going smaller. Perhaps it's airfoil but more likely just weight. Jim's airplane was 65 ounces last I knew. David's is in the same ball park. My last three were 70-75. The first three of these I built flew wonderfully at 61-63 ounces but were covered in jap and almost no finish. This later bunch I put on a Nats worthy finish and made one take-apart. I also have to fly off a soccer field with washboard landings and an occasional flip over so the airplane and landing gear are a lot more robust than a pavement airplane so more wood more epoxy ..... I wish I could build a hollow shell airplane but it would be splinters on my flying site so I just think I need to go a little larger with more area. I'm still going to try backing off on the finish a little but am going to have to chew at this a little from both ends. I find the Certified dope a great product but much more dense in filler and weight. I'm going to thin it much more and sand it better. Might go back to jap tissue too. Everything is compromise. If I were sticking with the wonderful .61s I have I would stay with the standard airplane but I seem to have endless power with the big blocks so I can afford more size with the plane. I could circle back in out years but going to try this path. Yesterday I took out my old Only Vegas airplane with a .76 in it for the first time. It's 716 squares and was super with the newfound power. I left those behind for smaller ships when I found the power limits of the .61. Those limits are gone with these truck motors!

Dave_Trible · « **Reply #192 on:** September 11, 2013, 10:10:08 AM »

Worked on control horns this morning. The photo shows horns in various stages. The flap brazements, the Delrin uprights and then riveted on. The very top are elevator horn brazements with a brass bushing installed. You'll notice I'm not much on slidy/adjusty/faily stuff. Most of these type adjustments can be made other ways without risking trouble.

Dave_Trible · « **Reply #193 on:** September 13, 2013, 07:39:24 AM »

Here the flap horns are finished at the top. The elevator horns are ready to bend and shoot with chrome enamel to prevent rust. I JB'ed the brass bushings in after the brazing was done to ensure they stay put. I flew one for years where the bushing had fallen out. More than enough slop in the controls but it flew very well and when finally salvaged didn't really find any extra wear. That area doesn't get near the abuse the flap horn does. That's why it's so much more heavy duty. I have at times put various bushings on before bending the wire ends but now simply use plywood traps glued to the fuse sides on the inside after assembly. This is a good place to shore up the fuse anyway so they serve multi purpose. With pipe ships you don't have any oil ingress in this area so the plywood holds up well. On a muffled or open exhaust airplane like classic I'd more likely slip wheel collars on the wire, then epoxy those to the fuse sides inside.

Dave_Trible · « **Reply #194 on:** September 13, 2013, 08:00:05 PM »

OK the winter building season control hardware supply is ready to go.

Dave_Trible · « **Reply #195 on:** September 14, 2013, 05:26:57 PM »

Have cut ribs and ready to start the new 105% Desperado wings. Took this day to re-connect with the fam and took my granddaughter to the zoo. It gave me a chance to reflect on the season which, for me was kind of a bear...

Dave_Trible · « **Reply #196 on:** September 14, 2013, 05:29:00 PM »

And I feel a little like I'm in the stunt desert....

Dave_Trible · « **Reply #197 on:** September 14, 2013, 05:31:47 PM »

But I got thinking about the coming Aussie world champs and decided to get back to the shop and work on new creations- like I found these guys today, on the left....

Dave_Trible · « **Reply #198 on:** September 14, 2013, 05:35:11 PM »

So lets get swimming....

Dave_Trible · « **Reply #199 on:** September 22, 2013, 09:18:08 AM »

Steady progress. The pair of new wings nearing completion. They are rougly 3/4" longer and wider in chord. To stiffen then some a pulled the trailing edge sheet further forward to a full 3" and added 1/8 sq. spars to support it. At this stage the first one with landing gear installed is 11.3 ounces.