My July adventures started off with a trip to Cupertino, California to help my good friend Todd Bridges (another crazy RC airplane pilot) finish up a neat little RC plane that he has been working on for several months. The plane itself is a 2.3m (91") wingspan all composite scale model of an Extra 330SC made by Composite-Arf. The airplane arrives from Thailand at your doorstep in a large wooden box with fabrication of the main parts done. You, the builder, are required to install and rig the necessary inner structures and equipment to make the aircraft flyable. That doesn't sound too hard, right? It's normally not a big deal and one can build this type of an airplane in a week without too much trouble. However, being crazy rc airplane guys, Todd and I had talked about using a Desert Aircraft DA120 engine in the plane, purely to make it *more exciting*....and to avoid adding dead weight to the nose of the plane to make it balance.....
The recommended engine for a CARF 2.3m airplane is a DA60.
Specs for DA60:
*3.1Lbs
*60.5cc Displacement
*around 7Hp at 7200RPM
*3.1Lbs
*60.5cc Displacement
*around 7Hp at 7200RPM
aaaand here's the DA120.
Specs for the DA120:
*4.95Lbs
*121cc Displacement
*121cc Displacement
*14Hp at 7000RPM
So.....maybe a bit overboard...nahhhh it'll be fine.
So a few months passed after we had jokingly discussed it on the phone and little did I know Todd was serious.
"You don't think I'll do it...I'll do it!" - Todd Bridges
"You don't think I'll do it...I'll do it!" - Todd Bridges
one day I received a picture of a perfectly shortened engine dome from Todd. This is when I knew he was srs bdns.
Over the next month or so I received a steady flow of progress pictures until finally the airplane was nearly ready to fly, only a few things were left to do and we were both getting excited....until the airplane had to be shelved for a month do to important things that needed to be taken care of first.
fast forward to Tuesday, July 13th when I arrived at San Jose Intl Airport with a suitcase full of airplane stuff.
(side note: people look kind of concerned when you pull your RC transmitter out at the airport security checkpoint...I've never actually been questioned while going through security at an airport.)
fast forward to Tuesday, July 13th when I arrived at San Jose Intl Airport with a suitcase full of airplane stuff.
(side note: people look kind of concerned when you pull your RC transmitter out at the airport security checkpoint...I've never actually been questioned while going through security at an airport.)
Todd was there to pick me up and we quickly went back to his house to start on the plane.
The goal was to get it finished by Wednesday morning in order to go test fly it later that day, however that didn't end up happening. We had a few setbacks, namely the engine didn't actually fit inside the cowling.... so Todd had to (painfully) cut some holes in the sides for the spark plug caps to pass through. The rudder servo was moved from inside the airplane near the fuel tank tray to the rear of the fuselage so it could be hooked directly to the rudder with a Push-Pull linkage. I prefer to use this type of linkage when I can, I think it's much more solid feeling in the air than a Pull-Pull setup with identical servos.
The goal was to get it finished by Wednesday morning in order to go test fly it later that day, however that didn't end up happening. We had a few setbacks, namely the engine didn't actually fit inside the cowling.... so Todd had to (painfully) cut some holes in the sides for the spark plug caps to pass through. The rudder servo was moved from inside the airplane near the fuel tank tray to the rear of the fuselage so it could be hooked directly to the rudder with a Push-Pull linkage. I prefer to use this type of linkage when I can, I think it's much more solid feeling in the air than a Pull-Pull setup with identical servos.
(as long as the geometry is correct)
Todd had backed up the cutout with good quality 1/8" plywood to stiffen the rear of the fuselage as well as providing a good material to drive screws into in order to hold the servo in place.
Next we made a carbon tube X-brace to support the canopy opening, which is usually where planes of this type fail. Todd used 10mm diameter tubing with a 0.5mm wall thickness, we then inserted balsa wood dowels into the tubes so they could be drilled through and screwed to the underside of the canopy frame as well as epoxied in place.
Todd had backed up the cutout with good quality 1/8" plywood to stiffen the rear of the fuselage as well as providing a good material to drive screws into in order to hold the servo in place.
Next we made a carbon tube X-brace to support the canopy opening, which is usually where planes of this type fail. Todd used 10mm diameter tubing with a 0.5mm wall thickness, we then inserted balsa wood dowels into the tubes so they could be drilled through and screwed to the underside of the canopy frame as well as epoxied in place.
(I actually forgot to take pictures of the work we did because we were in such a hurry to finish)
I then started playing with the elevator/stab assemblies because I thought the Phenolic/Steel wire pin hinge was sub-optimal. There was more slop than I wanted between the phenolic horns and the steel hinge pin.
The solution is to drill out the phenolic horns and insert bushings. Seems simple enough...until you realize modern hobbyshops don't seem to carry much metric tubing..if any at all. :( We ended up driving to three different shops until we finally arrived at a vintage style shop, which had of all things, many control line models, slot cars and all sorts of vintage RC abnormalities and memorabilia which you don't normally see in what has come to be the standard hobbyshop of the 2000's.
This particular shop carried a full line of brass and aluminum tubing in Metric and Imperial sizes.
I then started playing with the elevator/stab assemblies because I thought the Phenolic/Steel wire pin hinge was sub-optimal. There was more slop than I wanted between the phenolic horns and the steel hinge pin.
The solution is to drill out the phenolic horns and insert bushings. Seems simple enough...until you realize modern hobbyshops don't seem to carry much metric tubing..if any at all. :( We ended up driving to three different shops until we finally arrived at a vintage style shop, which had of all things, many control line models, slot cars and all sorts of vintage RC abnormalities and memorabilia which you don't normally see in what has come to be the standard hobbyshop of the 2000's.
This particular shop carried a full line of brass and aluminum tubing in Metric and Imperial sizes.
(however they happened to be out of brass tubing we needed unfortunately)
We decided Aluminum tubing would do for now, and purchased a pack.
Installing the tubing was easy and it improved the slop a great deal, enough to where I was very happy with the control surface operation. I decided to bush the rudder as well just to make sure it would continue to work correctly over the event weekend.
Currently it was Wednesday evening and we decided to delay flight testing until the next day in Santa Maria where we were meeting up with a few other competitors for pre-contest practice. This meant Todd and I had time to go meet up with some Friends,
Jordan and Joe, who happen to work in the area and are both MIT graduates and very interesting people...you might check them out!
Jordan's blog: http://t3chnolochic.blogspot.com/
Joe's blog: http://blog.jwcxz.com/
We decided Aluminum tubing would do for now, and purchased a pack.
Installing the tubing was easy and it improved the slop a great deal, enough to where I was very happy with the control surface operation. I decided to bush the rudder as well just to make sure it would continue to work correctly over the event weekend.
Currently it was Wednesday evening and we decided to delay flight testing until the next day in Santa Maria where we were meeting up with a few other competitors for pre-contest practice. This meant Todd and I had time to go meet up with some Friends,
Jordan and Joe, who happen to work in the area and are both MIT graduates and very interesting people...you might check them out!
Jordan's blog: http://t3chnolochic.blogspot.com/
Joe's blog: http://blog.jwcxz.com/
Anyhow, Todd and I finished up the plane that evening and got ready for our two leg trip to the Camarillo IMAC contest. We got up on Thursday morning, packed the trailer and headed off to Santa Maria where we had a semi-successful test day involving 4 flights on Todd's main precision plane, but none on the extreme 2.3m. We had issues with the battery tray operation, so Cameron and his father (other competitors) were gracious to let us use their shop to fix the 2.3m, as well as treating us to an excellent dinner at a secret steak house! (fun fact, lots of high level engineers and rocket scientists frequent this place)
Fast forward to the event
Friday morning we headed off to the event location, The Camarillo Condors model field. The field had been shut down for over a year prior to the contest due to a large fire which spread through the park burning most everything except the model field, it was the only structure/area not burned within sight. The field is located on university owned land, which means they control when we can and cannot fly. They felt it was for the best interest of the park that we shouldn't fly there in order to not hinder the growth of new plant life. They were gracious enough to grant us permission to run the contest albeit with a large amount of restrictions, but hey...I can understand their concern, and we're grateful they even let us fly there in the first place.
The contest went off without a hitch. There was a high level of participation in all the IMAC classed, plus freestyle. There weren't any crashes or any damaged aircraft, it was very professionally run and I'd definitely come to any contest run by Joe and Uncle Frank.
I didn't fly in the contest, I was mainly there to help Todd and his father in any way I could, as well as helping with the event if need be. I ended up flying a few planes and landing for a few people when the weather conditions became slightly adverse, I still had a great time though. Sometimes it's good to just go and help if you can...people in the hobby seem to genuinely appreciate it.
Cameron ended up winning both Unlimited and Freestyle with very high scores. I'd like to congratulate he and his father, as well as thank them again for letting us use their shop to work on the 2.3m.
after the event had been wrapped up and the trophies given out we were able to leave the field Sunday afternoon around 4Pm, which put us back in Cupertino around 11Pm, all in all a very fun trip, and I'm glad glad I went. 10/10 would do it again.
this concludes part 1,
check back for part 2 at a later date.
Part 2: The never ending layover + San Diego adventures.
I didn't fly in the contest, I was mainly there to help Todd and his father in any way I could, as well as helping with the event if need be. I ended up flying a few planes and landing for a few people when the weather conditions became slightly adverse, I still had a great time though. Sometimes it's good to just go and help if you can...people in the hobby seem to genuinely appreciate it.
Cameron ended up winning both Unlimited and Freestyle with very high scores. I'd like to congratulate he and his father, as well as thank them again for letting us use their shop to work on the 2.3m.
after the event had been wrapped up and the trophies given out we were able to leave the field Sunday afternoon around 4Pm, which put us back in Cupertino around 11Pm, all in all a very fun trip, and I'm glad glad I went. 10/10 would do it again.
this concludes part 1,
check back for part 2 at a later date.
Part 2: The never ending layover + San Diego adventures.
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