Patriot XL modifications
 

Well I just bought my first set of Spring Air retracts for a GP Partiot XL that I'm building. I'm an experienced builder, but this is my first attempt at putting retracts on a plane. The retracts were used, but looked in great shape. Just by fiddling with them for about 5 mins, I was able to hook everything up and get them to work properly.

1. Is there any important information that I need to know when installing these?
2. Where is the best place to install the air input nozzle on the plane?
3. Would retract covers make that much of a difference on the performance of the plane?
4. What is the best way to "beef" up the retract area?

Thanks for your help
-Troy

RE: Spring Air Advice (Patriot XL)
 

tmproff..., I recently built the Patriot XL and the 40 size,, the XL was by far alot easy-ier to build ,,, but i used fixed gear, from what i can tell the retracts should be easy to put in and beef up too. I didn't get retracts because they were too expensive for the larger size. Show us some build picks:D.


--------------VAROOOOM!!!!------------->

RE: Spring Air Advice (Patriot XL)
 

Troy:

I assume you also have the mounting template for the 1/4 ply mounting system. You can use a little thinner ply, but not by much as blind nuts are the best way to go. Have seen some use Sheet metal screws with no problem. To transfer the mount stresses to the wing, you will need to back each of the ribs the mount attatches to. The best way is to build light ply ribs and ca/epoxie them in place. Some triangle stock from the rib to the mount also helps. You want to keep your glue joints and joining surfaces tight as possible.

You want to keep the mount plate as close to the main wing spar as possible in a taildragger configuration. You may have to go with a trike system if you can not get the wheel to miss the main spar. You can bend a small angle in the LG wire to help miss the spar, but not much, th wheel needs to set relatively flat in the wing and be angled correctly for taxiing . Some toe out is ok, just not a bunch. The smaller wheels you use, the easier the install.

Ok, wheel/opening covers (doors) do help with the airflow and drag and also make things look nice. Most newbies will try to produce a cover that works well. They are a mechanical problems in keeping them adttatched to the LG wire as the air pressures on them in flight when coming down are high, and they tend to slip around like a sail. No big deal flying when both do the same thing at the same time, but when one slips into a sail position and the other does not, its almost like trying to fly a twin with one engine out. Its dooable, your chances improve with 3D experience. Also each time you land and bend the gear a little, you have to re-allign the system so it does not hang up. More difficult with a door attached to the LG wire. Yes, ypou can reinforce the wire so it does not bend, but those forces have got to go somewhere. Suggest you leave the door to a future time when you can devote time to building a CF composit door and get some experience with the things under your belt. My first retracts were hand built in the 60's on a bench vice, hack saw, drill press and good files, took around 6 months of R & D, better called trial and error, somehow got all 3 to work off one standard Pro-Line servo. Did wow the guys at pattern contests and cop some wins when points were close. Also embarrassing when your gear falls down on takeoff or landing.

There is some build pics around on the forum that may help. Do a search. ENJOY

RE: Spring Air Advice (Patriot XL)
 

Here ya go...I haven't finished sheeting the bottom yet because I still need to run the servo wires for the flaps and ailerons.

RE: Spring Air Advice (Patriot XL)
 

80 psi is what Bill at Spring Air says should be the pressure to pump the air tank to. Some other brand systems use more psi.

RE: Spring Air Advice (Patriot XL)
 

Very nice work Tmproff , you will love this bird, i have the OS 91 fx on mine and it flys great, i took her out yesterday and buzzed around, flys straight and true , lands exellent also.:D

RE: Spring Air Advice (Patriot XL)
 

Mine has Robart, but should be similar.

1. Is there any important information that I need to know when installing these? Watch the axle length on the main gear. This is a thin wing and the axle needs to be cut as short as possible to let the mains retract fully. Put a shim on the nose gear to get the nose higher; otherwise you have a tail high stance and the plane doesn't want to rotate.
2. Where is the best place to install the air input nozzle on the plane? I have mine on the side just behind the wing.
3. Would retract covers make that much of a difference on the performance of the plane? I didn't use any but I did wrap some balsa around a spray paint can and used that for wheelwells. Otherwise, the wing is open and bugs and other foof will get into the wing.
4. What is the best way to "beef" up the retract area? I just followed the plans; other than the wheelwells, it went fairly smoothly. The tubing is a tight fit.

You can see mine on the Jett site in the Hall of Fame. It's the black and gold one. It's a fun plane, but is very nose heavy and a bit of a sled. The flaps and retracts are neat, but I don't fly mine much anymore.

RE: Spring Air Advice (Patriot XL)
 

Well I got a little more done on mine last night. I finished sheeting up the bottom (still need to cut holes for the wire part). Also, I am modifying mine a little by putting both the flaps and ailerons inside the plane to reduce drag. You can see the oval ply pieces beside the retracts I'm going to use for the flaps.

RE: Spring Air Advice (Patriot XL)
 

Looks good sar far. I like the idea of putting the ail and flap servo in the wing.
Looks much cleaner that way.

RE: Spring Air Advice (Patriot XL)
 

Well, here is the flaps / aileron servos placed into the wing. All screws are recessed so I'm hoping that this little mod didn't add much weight and help with the overall look and drag of the airplane. I should be doing the final sanding and start covering this weekend. More pics to come!

RE: Spring Air Advice (Patriot XL)
 

Wheel wells have been added. Elevator was glued into place last night and rudder should be going in this afternoon. I'm really liking how this plane is turning out :)

RE: Patriot XL modifications
 

Tmproff:

Great job so far. I like what you did on the inboard servo's for the ailerons and flaps. This is just a suggestion; this kit has a weak rudder setup, I have flutter at high speeds on my XL. I'd test your rudder before sealing up the rear.

Frank

RE: Patriot XL modifications
 

Did you seal your hingeline? What would you recommend to strengthen the rudder?

I am using some Hitec 645MG's (133 oz torque on 6v) on elevator and rudder and using ball links.

RE: Patriot XL modifications
 

Make sure your nosegear strut is plenty long so your plane does not have negative angle of attack sitting on the ground. Otherwise, you may have trouble taking off, especially grass runway. I solved my nose down attitude problem by throwing in 15-20 degrees flaps for take off. Minimize epoxy in low stress areas to keep flying weight under 11 lbs and you will have more fun flying. I used the Titanium struts from Central Hobbies, cheap/light/strong, rather than the standard metal wire struts to keep the weight down. I think gear doors look nice but a bit more hassle to maintain, did not bother with them on mine.

RE: Patriot XL modifications
 

Tmproff:

The issue is with the rod that connects to the rudder,the design is very poor and flimsy. Go up to the next size rod!

Frank

RE: Patriot XL modifications
 

I got her all covered (yes it's a shameless copy of speedboy's 40 sized patriot....it's such a great look!) I still need to install the servos (waiting on tower shipment) and put the engine on a test stand and tune the header to the correct length. Also need to cover the control surfaces and hinge them to the plane.

Also, I decided to put the engine upright so that the muffler won't be interfering with the wing if I need to take it off

RE: Patriot XL modifications
 

Sweet!

RE: Patriot XL modifications
 

Does anyone know what prop I should start with while tuning this? It's an OS .91 with tuned pipe.

RE: Patriot XL modifications
 

Very nice job, that is a great design, i wanted to do mine like that but i am not too good with covering jobs, your plane looks great.
I broke my OS 91 fx in on a 14x6 apc.,------ but with a tuned pipe i'm not too sure about, if i had to guess , i would guess mabey use a 12x6 or 11x6 i could be wrong....... I don't think tuned pipes do much good for the OS 91, mabey a few hundred rpm's.

RE: Patriot XL modifications
 

apc 11x9 will be good starting point

RE: Patriot XL modifications
 

11x9 is about right to start with......

12x8 would be the next step ---- perhaps 11x10 too.

Depends 100% on how you tune the pipe system.

RE: Patriot XL modifications
 

Ok, Patriot is just about done. have to set up the pull-pull for the nosewheel, but other than that, all I need to do is balance the plane. Hopefully I can maiden her in the next 2 weeks. Here are some final pics:

RE: Patriot XL modifications
 

Hey tmproff I like alot the scheme and the colors hehe :D:)

Good to me to see that you did a copy of that [)]

And what about the prop 12" , 11" , did you tuned it ??? could you please tell us more about that :D

RE: Patriot XL modifications
 

Thanks a lot Speedboy! I loved your scheme, and I thought it'd look great in the air. I tuned the engine to 11X9. Next time I run up the engine, i'll tach it and report back.

RE: Patriot XL modifications
 

Thanks to you tmproff and yes I bet you will love the look once in the air :D

11x9 good!! I think you will have the peak of rpm from this engine but please tell us what says the tach [)]