Three-Quarters Hog Bipe
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Three-Quarters Hog Bipe
Winter madness has set in and I am building a reduced Sig Hog Bipe. I love the way the original flies but I like smaller planes and I wanted it to fit inside my station wagon without removing the wings. I took the plans to a blueprint shop and they did a perfect job reducing the plans to 75%. I am trying to follow the original construction as much as possible. The wingspan is 41". To keep costs down in this experiment I will install a Thunder Tiger GP-42 engine. First photo shows progress so far. On wingtip, balsa sheeting was omitted. Instead, 1/8" balsa doublers were glued to both sides of Lite-Ply tip plate.
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RE: Three-Quarters Hog Bipe
That is very neat. I hope to see more pictures. You are doing great. Keep up the good work. This would be a nice project for anyone.
Mark Shuman
Mark Shuman
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RE: Three-Quarters Hog Bipe
What was I thinking when I started this project? Oh well, the field has been too soggy to fly all winter anyway. Making the cabanes was a challenge but the Higley book "Bipes" gives a method to make them precisely. Finding the 1/16" strips was hopeless but a friend cut them for me with industrial shears.
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RE: Three-Quarters Hog Bipe
Beautiful looking work Dsegal, keep posting the pictures. I have to agree i really like smaller planes too in the 25-40 size, it's always nice to be able to take the plane to the field in one piece.
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RE: Three-Quarters Hog Bipe
First photo is of the finished fuselage with raised turtledeck. This allowed me to omit the nuisance headrest of the original design. Stringers are spruce to survive hangar rash.
Second photo shows wings in place with completed I-struts. What an agony trying to align the top wing and hold everything exactly in place while drilling holes through the struts.
Second photo shows wings in place with completed I-struts. What an agony trying to align the top wing and hold everything exactly in place while drilling holes through the struts.
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RE: Three-Quarters Hog Bipe
Very nice. Would you be so kind as to post some pictures of the cabane struts, attachment, wing stagger (directly overhead), and the airfoil? I'm scratching one, and could use the info. Thanks.
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RE: Three-Quarters Hog Bipe
Any new progress? You may have inspired me to do the same
Which size hog bipe would be best for a Saito .72? The original, or a scaled down version? One other thing, how does the hog bipe compare to the super sportster bipe?
Which size hog bipe would be best for a Saito .72? The original, or a scaled down version? One other thing, how does the hog bipe compare to the super sportster bipe?
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RE: Three-Quarters Hog Bipe
I am sorry but I can't answer your questions. I have watched Hog Bipes fly many times but I have never seen the Super Sportster in the air, although it does look like a very nice design. As to the engine, I have little experience with 4-strokes, but I think the .72 would be much too big and heavy for the 3/4 version. Progess at this point means that I have only the upper wing left to cover.
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RE: Three-Quarters Hog Bipe
At long last the 3/4 Hog is finished. With the TT GP42 engine all-up weight is 70 oz. The plane was taken up today for a test flight by a very experienced fellow club member. After getting it trimmed he did triple rolls, a reverse split-ess and then handed the box to me. I was suprised at its speed but pleased that it is a steady flyer and that it looked great in the air. Five minutes later I landed gently with my heart-rate at the red-line (G). I will re-prop it to reduce speed and adjust the control throws to suit my style.
The red plane is the full-size Hog Bipe.
The red plane is the full-size Hog Bipe.
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RE: Three-Quarters Hog Bipe
Looks great! Excellent project, i'm looking forward to hearing more about how it flies. Hope it slows down nicely for you with the different prop.
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RE: Three-Quarters Hog Bipe
I now have about a dozen flights in and have gone from a 10x6 to 11x5 to an 11x4 prop. Definite improvement with this last prop. It flies nicely at half throttle and really moves out at full throttle. Probably would be nice with a 4-stroke but I don't want to hack up the nose to move the firewall back and be in a squeeze for fuel tank space. It looks good now and I think I will enjoy it that way.
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RE: Three-Quarters Hog Bipe
After two dozen flights I have concluded the plane is over powered. If this was a monoplane sport model I would be happy with fast cruise speed and terrific vertical climb. But that is not the reason I built this plane. A small 4-stroke would probably be OK but that would mean chopping up the nose of a nice looking model and perhaps serious nose-heaviness. It looks like I could use the same type engine mount to hold an OS.25FX and I may pull one from another plane and give it a try.
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RE: Three-Quarters Hog Bipe
Well, I have done the unthinkable and put a smaller engine into the bipe. No one in my club has ever changed to a smaller engine in a plane before! (G) Despite doubts from the sidelines, an OS25FX with 10x4 prop lifted it up nicely and provides speed more appropriate to an oldie style biplane. A small 4-stroke would probably be nice but I used an engine that I had available and which required little modification to the nose.
#18
RE: Three-Quarters Hog Bipe
Congrats Dsegal. The 3/4 Hog looks sweet. I also applaud you for realizing that it was over powered with the .42 and making the switch to a more appropriate motor in spite of popular trends. The .25FX is a great motor as I am currently flying one in a scratch built original design.
bdb
bdb
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RE: Three-Quarters Hog Bipe
I opened up my wallet and went for for a lovely Saito .40 4-stroke. Having used a Great Planes 2-piece motor mount meant that I could use the same holes in the firewall and just drill out a new mount for the Saito. Now the plane flies more like its big brother. Steady flight like a biplane should have and that great 4-stroke sound. The only difficulty was trying to get the throttle linkage to work in the tight space available. Three days spent on that with a roll of wire, pliers, soldering iron and many connectors. I finally learned that the carb arm could be rotated 180 degrees which put it close to the throttle tube and now I have a decent setup with proper response to the throttle stick.
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RE: Three-Quarters Hog Bipe
ORIGINAL: Dsegal
The only difficulty was trying to get the throttle linkage to work in the tight space available. Three days spent on that with a roll of wire, pliers, soldering iron and many connectors. I finally learned that the carb arm could be rotated 180 degrees which put it close to the throttle tube and now I have a decent setup with proper response to the throttle stick.
The only difficulty was trying to get the throttle linkage to work in the tight space available. Three days spent on that with a roll of wire, pliers, soldering iron and many connectors. I finally learned that the carb arm could be rotated 180 degrees which put it close to the throttle tube and now I have a decent setup with proper response to the throttle stick.
PS This works on two strokes also, just do the 180* bend right after the threaded part of the rod.
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RE: Three-Quarters Hog Bipe
Rich, I like your arrangement. Unfortunately my photograph is misleading as that setup did not work. It was a braided metal cable connected to a piece of hardware store wire with a soldered coupler. The top end then had a shortened brass coupler and nylon ball coupler. It looked great but the offset from the throttle tube was so great that for half of the servo travel the u-bend just rotated but did not provide linear movement to the throttle arm. AARGH!
I called Saito and learned that the throttle arm could be rotated and by lowering it there was now only a small lateral offset to the throttle arm. But on such a small plane there was still no space aft of the carb for my usual threaded coupler on the braided cable to clear the firewall. Your setup with the threaded rod going into the nylon pushrod is nice but I had already installed a small nylon tube to carry the cable and could not do that. In the end I used a solid length of .047" music wire with EZ connectors at both ends. I really only like to use one EZ connector on a cable for security. Thanks for your suggestion
I called Saito and learned that the throttle arm could be rotated and by lowering it there was now only a small lateral offset to the throttle arm. But on such a small plane there was still no space aft of the carb for my usual threaded coupler on the braided cable to clear the firewall. Your setup with the threaded rod going into the nylon pushrod is nice but I had already installed a small nylon tube to carry the cable and could not do that. In the end I used a solid length of .047" music wire with EZ connectors at both ends. I really only like to use one EZ connector on a cable for security. Thanks for your suggestion