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Good morning Forum readers. I’ve just finished building an 1/2A Geodetic Galaxy. I used to fly one of these back in the 60’s at the Sepulveda basin and if I remember correctly it was a great flyer. Any suggestions on triming out this plane? My memory is lacking!
Scott
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Probably nothing new to tell you but it should go right/right, start with stab tilt about equal to inboard wing panel’s dihedral and adjust as required to get glide circle. Set the GC according to plans, tweek incidence for nice glide with proper turn. Be sure you have at least 3/16″ wash in on the right inboard panel of the wing, and about the same washout(3/16″) in both tip panels.
Everyone has opinions here, but I have found that once the CG and glide is set-up, it usually does not need adjustment again, leaving you to just dial in the power pattern with thrust and tab adjustments. Unless you have the CG and/or the incidence way off, it should come in and transition nicely when you apply full power with the prop on forwards.
If it tries to go too hard to the right and wind in under power, use some left thrust rather than opposite rudder tab. I use very short 3 second runs to observe this. Don’t be surprised if it takes alot of left thrust, some models need more than others.
The TD .049, depending on how good it is, will require that you creep up on the run times slowly unitil you are sure it will not tighten up and begin a spiral under power, just take it slowly and you’ll be alright.
If you change to a stiffer prop ( I see you have a black flexible one on there now) it will affect the speed of the climb, be sure to do some short runs to make sure the power trim is safe before cranking in ten seconds….good luck! Nice Plane, love the colors.
Thanks for the response. I’ve already changed out the prop to a 5.75×3 APC. I’ve also got a COX 6×3 and a 5.5×4,s available. But I’m starting out with the APC. The TeeDee I’ve got on it is a very strong runner. It’s one I used prievely in the late 60’s and I’ve switched to the Galbreath head and the glow plug, runs great. I’ll let you know how the trimming works out.
Scott
Start with a 2.35 to 3 second engine. use the APC prop. Consider a 6×2 APC. Its a good prop. Make sure the stab is keyed. Also the wing.
If you have fast DT capabilty, use it. Otherwise , cross yor fingers.Most good flying planes have a lot of patches. You might try poking 6-8 holes into the wing with a screwdriver and apply the aforementioned patches. this would eliminate step. That’s a good looking plane.
What’s the weight?
Fuel draw might be a problem. That’s a long bit of tubing to and from the timer. Bladder would solve that problem.
Dan
I’ve used the same timer location that I’m currently using on my 250 ramrod, Pic under Ramrod forum. It works fine with the Ramrod but I have a different tank on the R’rod than on the Galaxie. To your comment I am having some issues keeping the engine running with the Cox tank. Even after I’ve shortened up the length by more that half to see if it would run better. So far no luck! I’ve modified the Cox tank to more simulate the Competition tank on the R’rod. But allas my battery has weakened and no fire for trial. New battery on order. Will let you know of the modified Cox tank works. If not I’ll have to jump into the pressure bladder seen. I’ve already purchased on the goodies from Hank!
Scott
Well, I finally bit the bullet and moved the timer 2″ forward and have starting the trimming process. First 2-3 second run plan dove right into the ground 🙁 Raised the engine attitude. Next test flight better pwr. pattern but transition, i.e. lawn dart with no glide turn 😡 Added 1/32 shim to stab tilt and 1/16 shim under TE of stab. Next flight Pilot error, lawn dart! Next flight launched with slight right turn and 60 degree angle climbed great perfect transition. 😀 🙂 Flew one more time with longer engine run and leaned the engine out a little more and it was great! Nice right turn pwr. pattern and a perfect transition into a left had glide. Stopped there before lost temp shims. Took it home and replaced shims with permanent ones. Will probably fly again this evening to make sure everything has stayed the same. If same will turn up pwr. and light DT and enjoy.
Scott
Welp, flew last night with all the hard shims in place at 95% pwr. on the first flight and was great! 😀 Next flight wicked up to max. rpm’s and set DT and watched it float! I do love to watch a good pwr. pattern, and flat transition into a floating glide. Can’t wait to see it in lift! 😀
Scott
The Galaxy was the model that my son started with back in 2000. He had great success with it and it is still around but in not as good of shape. He was able to trim it fairly easily and even used it to fly F1J at the 2000 NATS. I tink he took second in senior (or maybe junior) and won 1/2A with it. You should have fun with it…
We always trim with the engine at max rpm’s. If you are concerned about too much performance in the beginning, just use a shorter engine run. Plus the engine likes it much better- nothing worse than the engine stopping at the wrong time.
Another update on the flights of my Galaxy. Went to Muncie for a contest there a couple of weeks ago and flew 1/2A classic gas with the galaxy/minipearl design to a 2nd place. But while I was there I continued trimming the Geo Galaxy. With the wind at Muncie I had to do some additional trimming of the right hand pwr. pattern. After getting this right Lee Campbell suggested I change out the prop to an APC instead of the black plastic prop I was using for triming (doesn’t break!). Mounted a 5.5×2.5 APC and what a difference in rpm’s 😯 Plane flew with much more authority during the pwr. pattern! Can’t wait to get back to Muncie for some more flying. Maybe this weekend at the NOFFA meet. Weather dependent.
Scott
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