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Building Tips and technical articles. => 1/2 A building. => Topic started by: Steve H on January 22, 2014, 02:38:16 PM
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I know, it's sacrilege but these cold winter months with no flying/crashing have laid my hands idle. So, to help pass the time I started cloning from DT foam board a copy of my Musciano hollow log. all parts have the paper removed. The wing is just a flat sheet with a balsa leading and trailing edge. The fuselage is the same foam laminated and sanded to shape. All is covered with coffee filters and WBPU. I still have the firewall, tail and the control hardware to fabricate but it's still just at 4 oz with motor battery esc. I plan to hack away some of the foam once I find the placement for the battery and esc to obtain the proper balance and recess them flush with the sides. So far, it's great fun relearning the limited skills I had in my youth.
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I like building with foam myself but a Musciano out of foam just doesn't feel right, but it should fly great. good luck
john
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Yeah...Classics.
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Yeah...Classics don't seem as 'classical' in foam...but a great shortcut!
Foam 'Perky'? Maybe not.
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Looks like it might be a a little Devil(of which there are variations). I plan to build one in my near future to mount my RR1 on. Mine will be a balsa log with a Sig 4"x1/4" balsa airfoil though. It ought to be a rocket with the RR, that's a great running engine.
Here's my old fuel soaked one:
(http://i166.photobucket.com/albums/u116/rknrusty/Airplanes/LilDevil.jpg) (http://s166.photobucket.com/user/rknrusty/media/Airplanes/LilDevil.jpg.html)
Rusty
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Looks like it might be a a little Devil(of which there are variations). I plan to build one in my near future to mount my RR1 on. Mine will be a balsa log with a Sig 4"x1/4" balsa airfoil though. It ought to be a rocket with the RR, that's a great running engine.
Here's my old fuel soaked one:
(http://i166.photobucket.com/albums/u116/rknrusty/Airplanes/LilDevil.jpg) (http://s166.photobucket.com/user/rknrusty/media/Airplanes/LilDevil.jpg.html)
Rusty
Rusty, is that Sig 4" airfoil wing still available from Sig??? (my right arm hates longboard block sanding!)
I built a copy of a Musciano Little Mercury with a Sig airfoil in Santa Cruz in...'73? Can't remember exact date, but it flew great!
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Rusty, is that Sig 4" airfoil wing still available from Sig??? (my right arm hates longboard block sanding!)
I built a copy of a Musciano Little Mercury with a Sig airfoil in Santa Cruz in...'73? Can't remember exact date, but it flew great!
Yeah, Mike, I just bought one a couple of weeks ago.
Here ya go:
http://sigmfg.com/cgi-bin/dpsmart.exe/ThumbsV7.html?L+Sig+ofrl1693+_Ddp_5fSearch1_02a46WoodSig36BalsaSt_01Search_02Index_01Menu_02CatProd_01SubMenu_02NONE_01Thumb_02Balsa_20Wood_01Manu_02SIG_01
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Rusty, you might be right about the original being the Little Devil. My original had been repaired many times, mostly the tail area so none of what I still had was even close to the original, just the body and wing. The clone is sporting an early Ford Flivver tail section to try an keep it close to how these were designed.
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It's getting there, but still some hacking, measuring and studying on it to get the electronics in place.
It flies really nice on the work bench. :)
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Nice bright shiny paint job. I like it. Be sure and give us a flight report.
Rusty
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It is looking nice so far. Now me, I do more damage in the shop or on the bench than at the field flying.
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Rusty, the paint/covering is only the coffee filters and a couple coats of the WBPU. I am experimenting with a number of different techniques I have found browsing these and other web sites. This is one of those a few minutes of work here and there planes.
John, There will be some serious damage on the bench when I cut the fuse up to accept the battery but that wont happen until I make the motor mount which I think I will be able to put the ESC inside of.
If it didn't seem like it was going to be below freezing and either raining or snowing here for the next couple months I'd be working this one a little harder.
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Closer to completion however I have a question. This being a low wing would there be any benefit to having the weight of the battery below the wing?
I built the box on the nose to get the prop out to about the same position as it would be with an extended tank Bee. This is also part of the plan to make something that will house the motor and speed controller semi-permanently so it can be moved from plane to plane just like I did with my old Cox engines back in the day.
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My solution to getting low (and high) wingers to fly is to mount the bellcrank on the engine/fuselage centerline. I add a second plywood support to double-shear mount the controls.
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Paul, how much of a difference does mounting the bell crank on the engine center line make?
You just sparked a whole lot of thoughts as to how future builds will go.
Many thanks!
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Finally had a chance to get this airborne. After a couple unsuccessful one man launches and a couple minor repairs I engaged the services of my oldest grandson (9). He has done many other perfect launches for me so the following isn't due to pilot or launcher error but oversights on the builder.
I laid out the lines, connected and triple checked the controls. Inserted the battery and double checked with the ground crew all protocols for launch. With the handle in my hand, the signal was given to start the motor. All is good and the motor revs to max rpm. The gesture is made to launch and away it goes. No lines tangle in the grass, a perfect release and I watch as the plane begins to roll to the inside of the circle. As speed increases the bend or arc of the planes path lessens as it flies 15 or so feet above my head and begins to descend, still banked to the left. What a thing of beauty, right up to the moment of impact. Kind of a large horizontal figure 9.
So, why so different from the old beat up log I copied??
Torque, as best as I can figure. First of all my prop was a tad heavier than the one I used on the balsa log and second, the battery was mid ship, none of it on the outboard wing like the balsa log. Oh, and tip weight? whats that??
Live an learn and break out the epoxy. :)
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Are you using a pusher prop with reverse rotation? Tends to turn the airplane out instead of in.
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John, the prop is just a standard rotation one I had on an old cox .049. I need to get some of the reverse/pusher props but I'm just using what I have on hand while I'm relearning.
It's fun being 11 years old again but why cant I remember everything I have learned from these wonderful forums until after the crash.
:)
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John, the prop is just a standard rotation one I had on an old cox .049. I need to get some of the reverse/pusher props but I'm just using what I have on hand while I'm relearning.
It's fun being 11 years old again but why cant I remember everything I have learned from these wonderful forums until after the crash.
:)
Cox Has some LH 1/2A props. http://coxengines.ca/propellers/ Whatever the source a LH prop is the way to go.
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Aw man I hate it when that happens. I watched my big Shoestring fly over my head one day after a weed snag. I didn't know whether to run or wave at it. I'll be awaiting your next flight report when the epoxy hardens.
Rusty
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Tip weight and LH prop cure all
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The reason you are having trouble is that these hollow-log models were designed before "'lektrik" was invented. It's the engine noise and vibration that keeps them flying on the end of the lines ;D.
On a more serious note, add some thrust line offset to the outside of the circle. This usually cures any desire the plane has to fly horizontally over your head. Also, make sure that your wing isn't warped.
Orv.
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The repairs are complete, I am beginning to like the Elmer's Glue-All Max polyurethane stuff for building and repairs. A rubber band is enough pressure to keep the foaming from pushing the pieces apart and the foaming helps to fill the gaps from a less than graceful landing.
I'm thinking I will put the ESC inside the fuse cutout I made for the battery and hang the battery out on the wing more like the old balsa one I cloned from.
I have some motor offset but a little more wouldn't hurt.
Hummm..... Maybe an unbalanced prop might bring back some of those good vibrations and noise and keep it in the air better. :)
Many thanks for all the suggestions.
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The clone is a success!!!
Added some more motor offset, stuck a nickel on the outboard wing tip and used a lighter weight prop.
Flew pretty nice, was able to pull a few loops and fly inverted. Now it's time to make it a wall hanger and continue the next project.
I reduced the plans for a white lightning by 25% or so and am using (free) Styrofoam panels for the fuse and wing. Investment so far is less than 25 cents. My hope is that I can find some building methods that fall within the budget but will produce decent and durable planes.
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I'm glad to hear you got it flying right, Steve.
Also there is some wisdom in what GGeezer says about electric models.
The reason you are having trouble is that these hollow-log models were designed before "'lektrik" was invented. It's the engine noise and vibration that keeps them flying on the end of the lines ;D.
On a slimer, any minor hitch or stiffness in the controls will be shaken back to neutral by the engine vibration during a loose line incident. On an electric its critical that your controls be 100% free so they fall back on their own.
Rusty