Father, Son GP .40 Cub build..
05-17-2016, 07:36 AM
#52
Thread Starter
Started covering the wing now, the last section of the build! We are hoping to have the maiden flight on Saturday!
Wing struts being covered..
Wing struts being covered..
Last edited by MFIGHT43; 05-17-2016 at 01:52 PM.
05-22-2016, 03:46 PM
#53
Thread Starter
She's finally done! Just waiting for a less windy day to get it airborne. Although it's far from perfect, we are happy with how it came out. Stay tuned for pics and video from the first flight!
Last edited by MFIGHT43; 05-22-2016 at 03:55 PM.
05-23-2016, 06:59 PM
#57
My Feedback: (1)
MFLIGHT43, Suggestion.......don't move your pilot to the rear seat, add a second pilot (he would be the PIC in the back) to the rear seat. I fly most of my cubs and other aircraft with more than one person onboard. It is different than what most modelers do, and adds a little bit of realism to your model. Also FWIW, I install most of my pilots using velcro so they can be moved around to different models of like size as needed. Just do all the hook and loop the same, either all on the bottom of the pilot or all on the pilot shelf. A few female pilots/passengers is also good.
05-29-2016, 06:15 PM
#59
Thread Starter
Maiden Flight Accomplished!
Well we finally got her in the air! So far flies really well too. Only a couple clicks of elevator to trim for level flight. My son and I each got a flight in today with her! It weighs in at 7.25 lbs dry. My ASP FS61AR does not like being inverted though. A bit finicky. Also, this thing is a ground loop machine! Really tricky on the ground.
Last edited by MFIGHT43; 05-30-2016 at 02:28 AM.
05-29-2016, 10:35 PM
#60
My Feedback: (1)
MFLIGHT43, Congrats on the successful maiden. I'll bet both you and your son were grinning ear to ear on those first fly bys. Great looking cub! FWIW on the "ground loop machine", yes a Cub can be a handful on the ground especially on a paved runway. They take some getting used to, and some takeoff technique adjustment. Don't know your flying experience and I don't claim to be the second coming of Charles Lindberg but let me say how important it is to start your takeoff run with a very gentle application of throttle to get the plane moving forward and establish the plane's direction straight down the runway. Start your gentle throttle input, holding up elevator to plant the tailwheel, continuing to slowly add throttle, releasing the elevator to allow the tail to come up and now steering the plane with the air moving over the vertical stab and rudder, slowly continuing to add throttle and by now the plane should have lifted off at a nice shallow climb angle. If you're not at full throttle by now go ahead and squeeze the throttle to full and continue your climb out. The key IMHO is not slamming the throttle to full right at the start but rather get the plane moving, get any direction corrections done when your going slow and maintain that direction using rudder as speed increases. You will need left rudder to counter the P factor and will find the sweet spot for that rudder input by not upsetting the plane with too much throttle to quickly. Slow and smooth. If you are chasing the plane with more than two direction corrections at the start, abort the takeoff, turn around and line back up for another try. Grass fields are a little easier for Cubs but you still have to be smooth on your throttle and rudder inputs. Once again, great job on the Cub and may you have many happy flights.
05-30-2016, 10:37 AM
#62
Thread Starter
Thanks everyone for the support! We are looking forward to many years of flying with this plane. I think the only thing I'm not doing is holding up elevator during the roll. I have many tail draggers and this is the only one that does whatever it wants! Haha
05-30-2016, 12:48 PM
#63
Join Date: May 2003
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The ground looping is a characteristic of all Cubs. Even full scale (although not quite as pronounced). A cub will teach you the value of the rudder more than any other airplane on the ground and in the air.
05-30-2016, 08:06 PM
#65
My Feedback: (1)
MFLIGHT43, Double check the main gear wheel alignment. Either both wheels dead straight ahead, or both with just a very little "toe in". Then recheck that the tail wheel is not steering the plane left or right with the rudder exactly straight ahead. I do this check with the wings off on my shop floor by locking the rudder in place with two large popsicle sticks clamped on the vert stab with plastic spring clamps (sort of like "gust locks" would be on a full scale aircraft) and just pushing the fuselage across the shop floor and watching it's path. Adjust and repeat until the plane rolls straight every time. On holding up elevator to plant the tail wheel, the trick is to learn when to release the up elevator so the tail can come up and be able to now steer with just the air moving over the rudder. Don't ever hold up elevator all the way to lift off or you will take off already in a stall and have "your hands full" trying to save the plane in a stall just a foot or two off the ground. Don't ask me how I know not to do this 
. (yes, I saved it)
. (yes, I saved it)
05-31-2016, 08:31 AM
#67
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This has to be one of the BEST recommendations I've read so far. Given the plane might have some "Toe Out" or even very straight, the planes end up with a mind of their own. Larry hit the nail on the head. Also the alignment of the tailwheel with the rudder is a common issue with a lot of planes. Especially the ones with springs driving the tailwheel... Very easy to have a tailwheel that has a mind of IT'S OWN... All of these items together make for very exciting take offs and landings! Good Luck and Have Fun!
Weav
Weav
MFLIGHT43, Double check the main gear wheel alignment. Either both wheels dead straight ahead, or both with just a very little "toe in". Then recheck that the tail wheel is not steering the plane left or right with the rudder exactly straight ahead. I do this check with the wings off on my shop floor by locking the rudder in place with two large popsicle sticks clamped on the vert stab with plastic spring clamps (sort of like "gust locks" would be on a full scale aircraft) and just pushing the fuselage across the shop floor and watching it's path. Adjust and repeat until the plane rolls straight every time. On holding up elevator to plant the tail wheel, the trick is to learn when to release the up elevator so the tail can come up and be able to now steer with just the air moving over the rudder. Don't ever hold up elevator all the way to lift off or you will take off already in a stall and have "your hands full" trying to save the plane in a stall just a foot or two off the ground. Don't ask me how I know not to do this . (yes, I saved it)
. (yes, I saved it)
05-31-2016, 11:23 AM
#68
My Feedback: (1)
MFLIGHT43, I just went back to some of your Cub photos and see that you have an aftermarket tail wheel with the 2 springs. That is a great upgrade, but, you must be sure that both springs have the same tension on them and that they both have enough tension to make the tail wheel follow the movement of the rudder. On my 91" Phoenix Super Cub that I maidened 2 weeks ago (on grass) I didn't have enough spring tension and the plane wouldn't turn much at all on the grass. I since jacked up the spring tension in the shop and when reflown yesterday the ground steering was fine. Your left hand spring looks slack in one photo. Check those too. Cheers.
05-31-2016, 12:51 PM
#70
Well done. Warned you about the gound looping. You can do as much toe-in as you like, but it won't change much until you discover the real secret of keeping it straight: Use very little throttle! It's a brisk walk type of speed. If you're about to break into a gentle jog... you've over nailed it. I had a little LA .40 in mine. Never got above 25% throttle on take off. Once you break ground, slowly advance the throttle forward to "model flying speed" Try it. You two have done a great job with the build.
Last edited by David Bathe; 05-31-2016 at 12:55 PM.
08-24-2016, 06:31 PM
#72
Thread Starter
Well, so far we have about 8 flights on the cub and it flies really well! We took the advice of David Bathe and no more ground looping! Just nice and easy takeoffs! I also installed a SwitchGLow onboard system and that solved the engine issue. No more Ni-Starter required!
06-29-2017, 08:38 AM
#74
Thread Starter
Quick update, still flying well!! I put a couple flights a week on the cub now. Really enjoying this airplane and its scale flying looks and behavior. Early morning flights are sublime.
