spyder0069

Even though I told myself no more small planes somehow I ended up buying one of these Global AT-6 Texan ARF. The reason was my buddy built a HOB texan which is the same plane so I figured I'd match him and we could fly together on similiar planes.

So....
Built it up and I had a extra .15LA and HS-81s ect. I know the LA is a hot engine in the combat circuit so I figured it would do the trick for this plane. Step one was unfortunately opening up the wings to put in two aileron servos (hs-81s) becuase the stock nyrod did nothing but bind. Used the nyrod tube to run the servo wires through (just had to remove the connector, route the wires, and insert them back into the connector). Patched it back up. Ok, wing is done and the two hs-81s weigh the same as a standard servo. Next I moved the servos into the area right behind the tank as far forward as I could. Made new dowel / control rods. Using a 4oz tank. Mounted everything up and put it on the balancer and the tail hit the floor. Hmm. My 300ma battery was no where near enough to balance. I had to add a 1oz spinner weight and then put a AA 4cell pack under the tank and that got it balanced at 2 3/4 back from the leading edge. The instructions call for 2 1/4 back but others on RCU report 2 3/4 to 2 7/8 being about right. So I am comfortable with the balance now. HOWEVER, even with all hs-81's the planes all up weight is 2lbs 10oz dry. I am a little concerned if the LA will pull this plane. I will be using the 8x3 MA prop since on the previous plane the LA really liked it. Its only had about 10 tanks of fuel through it so it should be finishing the break in. My intentions with this plane was to have a sunday flyer but I want to be able to pull a loop every now and then too. I realize the plane has a lot of wing area but wanted opinions on the weight and capability of the LA .15. I hope to fly this plane this weekend and I really don't want to cut a new cowl (I have an extra on the way) or remount for a 25 size. Expecting problems I just ordered a O.S. CV-A which hopefully is a drop in for the LA as far as muffler height, ect. I still would like to try the LA first though. For those who have tried the .15's with this plane what were your results.

Ken Erickson

Spyder,

Mine had a .15 Magnum with BB. It would take off decently from short grass. Would loop. Heck of a time traking off from hard surface.

The balance point suggested on the instructions was WAY too far forward.

I sold the plane before moving back to Texas, so I can't balance and measure, Forgot where it balanced when it did fly nicely. Find an old timer who will guess at average chord and balance on the spar at that point. I'm thinking 4 inches from leading edge at the fuselage, but then am not sure. I called Global, the guy said he did nolt know but the HOB balanced at the point the instructions said. He thought that little planes were just different. They are not!!

You will get it. They do, however, fly much better with a .25.

Ken, AMA 19352

spyder0069

I maidened my buddy's HOB texan and have flown it a few times. He is a new flyer so I take off and land and buddy box him in the air. The only place to fly where he lives is a huge asphalt parking lot that is empty on weekends. It is always a challenge to get it into the air without ground looping and it lands hot and of course the rollout on the asphalt is long and full of pole position trying to avoid the light poles. His plane definately is on the nose heavy side so I am hoping with a little tweaking I can get mine to take off better. I have flown cubs from this lot which also are challenging with the ground loop situation but not as challenging as his plane. I may pull the fake gear door covers off mine since they weigh an ounce by themselves (made from heavy ply) and will probably also create drag. I have a new mecoa .28 as well so if the LA and the CV-A won't cut it I guess thats the next step. I was trying to keep this with the park flyer feel that I have had with other .15 size planes. Years ago I had a Global FW-190 arf that was great on a AP .15. I was able to slow down and fly stable with my buddies electrics and speed up for some fun. Wanted to recapture some of that.

P.S.
I did eventually put a .25 bb on it which was a blast until it self destructed mid air from speed and flutter.

Ken Erickson

You have my empathy.

This one never seemed like a park flyer. I didn't mention the NC racing of these planes. Too much power was not good. The .25s I was thinking of were bushing engines.

I'm not doing another. Got other fish to fry and planes to fly.

Ken, AMA 19352

spyder0069

Actually I am feeling more positive today. Took the plane in the yard to run up the motor. 8x3 on the .15 LA was taching at 17,500 rpm even with the 1oz spinner weight. Holding the plane verticle it would almost hover. So if I have a close to a 1:1 power to weight ratio it should fly fine on this LA. That doesn't mean the cv-a won't make it in but not as urgent. So as long as the cg being at 2 3/4 back doesn't kill me it should fly nice.

spyder0069

Oh, and I use the "park flyer feel" loosely. The close by parks here in Illinois have 5 soccor fields joined with 6 baseball fields. Probably not so roomy in other parts of the country.

spyder0069

Had the maiden flight today!

This was with the cg at 2 3/4 back. STILL TOO NOSE HEAVY! Flip inverted and it would drop like a brick and the landing was fast. I took my 1 oz spinner weight off the engine and flew again. MUCH better! I expect it to drop some in inverted since its a flatbottom wing and this time I only had to add a little pressure. Landings were nice and slow without signs of tip stalling. Three mistakes up I stalled it out and it just mushed right along straight forward. The .15 LA was plenty of power. I tried the the 8x3, 8x4 schmitar, and 8x5 props. All master airscrew. The 8x3 had great climbout. The 8x5 seemed to be the best speed / pylon prop and both I and the engine hated the 8x4 schmitar prop. I'll have to dig through my pile and see if I can find a 8x4 apc which will probably be the best all around. All up weight (without fuel) is 2lbs 9oz. Unfortunately I had tank problems with my 4oz hayes. During a roll, inverted, or a extended dive the engine would lean out and almost kill. I had checked this tank before putting it in the plane and the clunk was working fine. It wouldn't quite touch the top of the tank when flipped but it was close. Of course afterwards I remember where the tank came from. The plane I previously had the .15 la on and it had the same problems so I had swapped that with a 6oz which had solved the problem. Doh, poor memory. From now on I am throwing away suspect parts instead of putting them back in the pile. Ha ha ha So I have to pull my servos and front servo rail which was directly behind the tank, move them back, put the larger tank in, remake dowel pushrods for the tail so they fit the new servo locations, and rebalance. Its just another couple of hours of work to put into my ARF.

AND IF YOU READ THIS FAR...
Before I pull all that stuff I checked my balance (fuel tank empty) where the plane flew great and the perfect CG is....
3 inches from the leading edge measured at the fuselage sides.

So hats off to the guy in one of the other threads that mentioned this cg. He was right on the money. My buddy brought over his HOB texan today and he was also nose heavy so we are matching my results.

NOW. My CV-A .15 should be in by Friday.

spyder0069

Had another flight on the Texan with the new tank and cg at 3". I think the cg still could go back just a hair and I have to hold some elevator into the landing to slow it but that could also be due to the minimal low rate throw they suggest as I can hold full elevator on low rates through a loop without any snap and its pretty large and round. I think the engine problems were less with the tank and more with the setting/prop. Using the 8x3 that engine was screaming. Although I set the mix for about 300 rpm drop from peak(noticable audible drop) and it was still spitting a little raw fuel on the ground I think it was leaning in the air where it unloaded more than most engines. Then once inverted it was too much. I noticed a little on a test flight with the new 6oz tank so instead of the 8x3 I switched to a 8x4 to load the engine a little and keep the rpms down (still have to tach it) and ran it a little extra slobbery on the ground and then seemed to have no issues in the air. I am also running a hot plug with 15% fuel which might be too much so I will probably also try a A3 plug or similiar. I've come to these conclusions also in part because although I had a engine on landing before this flight the glow plug was shot when I got to the field. So I think the hot plug, high nitro, and semi-lean high rpm run killed it. I dropped the heavy AA pack and installed a AAA 700ma 4 cell pack on a aluminum bracket under the engine (away from the heat) and moved the engine out by adding 3/8" spruce stock behind the stock mount. This allowed me to move the servos back to the place they were originally intended, lose weight, and still keep the balance. I am really impressed with this little LA and probably won't replace it with the CV-A unless it cranks out some impressive numbers on the bench. The LA is still getting better every flight as if its finishing a break in. The plane flys great on it, have plenty of power, and pretty good speed with a light wing loading. I did some yanking and banking with no snap tendencies. When I pull a loop its mostly straight but I think it needs a quick check of the lateral balance to perfect things (not sure how straght you can get a plane that has its two elevator halfs connected by a wire). The 6oz tank seems to be the ticket. The 4oz tank would last through a 30 second startup and tune, 30 second taxi and 8 minute flight at 3/4 to full throttle. It was bone dry when I landed. 8 minutes is a little short for me but I think the pylon races or combat are only 5 minutes so it could fine for that.

One trick for anyone using these LA's. Since its a airbleed carb when you fill the tank and it tops off the pressure will push fuel through the carb and flood the engine. Before fueling close the needle, once topped off hold the plane up and make sure any overflow that is in the muffler is dumped, open your needle to 3.5 to 3.75 turns (yep these require much more than most engines) and don't prime it. Just make sure the engine isn't hydrolocked with a flip and then attach the glow and hit it with the starter.

garrett490

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I am going to put a OS .25 in mine. And I am going to take off the landing gear and make it a belly lander. I am still confused about one thing though. What is the difference between the HOB and the Global????

spyder0069

The House of Balsa is a kit and the Global is a ARF. Other than that they are the exact same plane. Nice thing about the global arf is that it comes with the cowl. The HOB kit has you find your own. They suggest the bottom of a pop bottle but companies haven't put those covers on pop bottles for a decade. However, HOB owners can buy the cowl cheaply from Global / Hobbypeople and it will work fine. Oh, and you can't build the HOB for less than the Global ARF.

garrett490

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WOW. Thank you so much. That was an AWESOME description. OK....I am definately going with the Global ARF!

AllTheGoodNamesAreTaken

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Here ya go Garrett490...

garrett490

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OMG HOW did you get those Decals?????!!!!!!!!!!!!!!!!!!!!!!!!! I HAVE to have some
TELL me everything about your Texan...How,What,Why,When,Difficulty...Everything! ???

spyder0069

Looks like his is a nicely finished HOB texan. Great job!

You can get that scheme in a 46 size ARF from Hobby Lobby:

http://hobby-lobby.com/harvard-at6.htm

Its a Graupner ARF that comes as a glow version but Hobby Lobby also sells the equipment for a electric conversion. Very pretty plane.


P.S. be sure to check out their video on that page to see it in action. Beautiful plane in the air with the retracts up.

garrett490

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yeah I've seen the Hobby-Lobby version. It's a little big for a pylon racer that I am not scared to ring out. Thats why I am using the $90 Global .25 Texan ARF.

AllTheGoodNamesAreTaken

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Here is a build thread my friend Chris put together. We build these for pylon racing. The HOB's are faster (lighter) and usually build stronger than the ARF version. I assembled mine in less than a week.
[link]http://www.collectivelyspaced.com/modules.php?name=Forums&file=viewtopic&t=110[/link]

spyder0069

What is your all up weight on the HOB? I have since swapped my LA for the CV-A which spins every prop 1000 rpm higher than the LA. It screams and its light weight. The HOB's cannot be faster and lighter as they are the same plane. Even with wood selection I have a hard time believing that there is any significant difference if built stock. If you build in lightening holes then maybe. The big difference will be equipment selection. I used HS-81's in my At-6 as it looks like you used them in the HOB too. However, my buddy build his HOB stock and it calls for standard servos. So with four 1.5oz servos in that comes to 6oz where my 5 Hs-81's (two in wing) comes in at 3oz. He also had a four cell AA pack where I had a four cell AAA pack shaving a couple of more ounces (has a 2/3 AA pack but decided I wanted a bit more flying time). Then there is the tank. He has the 25 with a 6oz where my 15 cva will run with a 4oz. Thats another 2 oz shaved. The .25 LA / and TT GP 25 put out .6 HP while the CV-A puts out .5 HP but its also about 3oz lighter. Since flying both planes (but not at the same time ) I'd say that there is not a clear winner in the straight aways but mine will definately snap around a turn faster than the heavier HOB model. Mine lands slow and smooth and his comes in like a warbird. Hot and no three wheel landings. They have a very thin wing which means there isn't much drag to help you slow down and both fly like crap inverted because of the flat bottom wing. My arf had very nice glue joints which didn't require anything from me. Although I did have one problem. The landing gear included was cut too long and when inserted into the gear blocks and torqued down it punched through the top monocote. Of course I cranked both down before flipping it over and noticing.

garrett490

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That is funny that you know Chris. I have been communicating with him via email and he has agreed to making me a decal sheet. I am going to pay him in return. I assume your talking about Chris Wolfe. lol. This is awesome..Everything is coming together just nicely.

garrett490

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hello allthegoodnamesaretaken

How did you put Aeroshell on the bottom of the wing in white since ink jet printers don't print white?

WMB

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spyder0069- Did you notice a big improvement in performance when you went to the CV-A? How does the 1000 rpm increase work out in the flying of the plane?

I have been interested in the HOB AT-6 for awhile, except the flat bottom wing has dampened my enthusiam a little. Has anyone here also flown the HOB P-51 42-42" version? How do they compare?

I would really like to build both, but have deciced to finish my other started kits before tackling anything new.

That Areoshell scheme looks awesome!\

Thanks all, MikeB

spyder0069

There is a definate difference in takeoff. The cv-a jumps into the air. I was able to switch to a 8x5 for a little more speed and still retain a quick spinup. The LA was still a great engine and dollar for dollar is probably a better deal. But if you can splurge the cv-a is the hands down winner. The other big advantage is the cv-a has a twin needle carb instead of the LA's airbleed. This helps because whenever fueling the plane I always had to shut the needle off of the the LA so that the engine wouldn't flood and lock. The cv-a doesn't have this problem. Faster spinups too.

garrett490

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I am going to put an OS Max .32 SX in mine. Is that too much for the GLobal Arf???

AllTheGoodNamesAreTaken

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We run the SAT-6 rules for pylon racing these planes:
Global ARF, HOB or Rich Uravitch scratch built to plans.
Thunder Tiger GP .25
MA 9/5 prop
2 or 2 1/4 foam wheels
Min 4 oz tank
Pilot figure
Cowl - Rubbermaid #7 is acceptable
Min 4 servos - all surfaces must move

I don't know of anyone that uses standard servos. Most everyone uses the HS 81's or the Hobbico CS 12. Some opt for two HS 55's or 81's for the ailerons.
Mine weighes 34oz with the GP .25, 2" plastic spinner, 4 oz Hayes tank, 4 HS 81's, 600mA NiMh battery, Hitech Electron Reciever, 2" electric plane foam wheels.

Has anyone weighed the airframe of the Global kit?

Here is a photo from our last race. My Red Bull Texan is just in front of another HOB Texan. The 3rd plane in the race (Global ARF) is about a 1/2 lap back!

AllTheGoodNamesAreTaken

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I built / flew the HOB Mustang with a Fox .19. I highly recommend that combo! Great flying airplane - much more fun than the Texan. Getting the motor installed / tank height correct is the only issue since the fuse is really small and they call for the motor to mount inverted. If I were to build another one, I'd mount the engine 90 deg. or upright.