spitfire66

Another note. I am using a plastic spinner and I am done with that. There is quite a bit of vibration and I am going to have Dave Brown make me a custom order. The vibration is also causing my factory metal wing bolts to losen up a little in flight. Has anybody had this problem? Any suggestions? I was thinking about using locktite on them every day at the field, but don't know if this is the best solution. The locktite wouldn't be that big of a deal, other than forgeting to do it. Nylon Anyone?

maverick11359

G'day spitfire66,

Sounds like your getting similar performance that I have been getting from my Saito 125 with incredible vertical performance and speed .I've also use to use a Master airscrew 15x7 3 blade but these days i'm using a 16x8 2 blade boly look alike composite from china . From memory also around 9,000 rpm for the 3 blade ,but now a constant 8,600 for the 16x8 2 blade . Fuel will change its performance as well, I use 10% nitro ,17% klotz and 73% methanol . I use a plastic spinner over the aluminum 3 blade because it keeps its overall the weight down .I save around 5 ounces of the nose with the plastic spinner and 2 blade prop.

jim pettis

In the entire 57 pages of this thread (and I've read every one of them) there has not been a single reported incident of the wing bolts loosening up. I use simple washers between the bolt head and the reinforced area the bolts go into, and have never had them loosen up. I would suggest before going to locktite (which takes a few hours to set up and become effective) that you try some lock washers. Just my opinion. Nylon won't solve the issue either I think.

Did you check all your engine mounts? Firewall bolts? Maybe that beast of an engine is just too much for this plane and its frame?

LeeHunt

Hey mate try the rubber backed washers that are around I have found them to be really usefull for things that vibrate or come loose.
While Iam here i notice that mast of you are using epoxy for glue, have you heard of Hysol it is a wonderful product and has very unique features, such as ,you can run a bead upside down and it will not run, it seems to adhere to almost anything and really stands the test of time.
Just a couple of thoughts thats all!
Lee

Smoky

congrats on your flight. I am using 1/4 inch nylon bolts on mine. I have had no issues with them yet.

wingco

Have you tried using split washers on the wing bolts? They'll keep them tensioned.
Wingco

spitfire66

I think I wasn't tightening the wing bolts all the way. I overtightened once and cracked the wood and had to repair. I like the rubber washer and split washer idea. I need to do some recovering this week if I have time.

maverick11359

G'day guys,

             Finally  got to fly the Spit again last weekend ,its been a couple of months since i had the chance. Well i nailed it twice with two good landings with flaps and the third just ran of the runway into tall grass and stopped ( no nose overs at all even on the last).The trick with lifting the rear of the electric retracts with 1/8 inch with ply  angles the undercarridge forward about 5/8 of an inch. This helps stop the nose overs. The advice on landing approaches with flaps sure helped too.. Thanks guys.. cheers mav.

da Rock

Got a picture showing that sucker on the ground?

Good news about your ground handling. 5/8"..... hmmmmmmm good info

N1EDM

My Feedback: (2)

Maverick, are those Lado retracts that you're using? If so, did you have to do any modifications to the LG pockets to get them to fit???

I have a set of Lado's and will try to install them but would like to know about this ahead of time.

Thanks,

Bob

maverick11359

No not the lado's . Quote from my earlier post :-" These electric retracts are rated upto 9lb or 4.7kg and take standard 5mm piano wire undercarridge.They  come from Hobbyking online store   http://www.hobbyking.com/hobbyking/s...dProduct=14838  and look identical to the Lado aluminium electric retracts,but fo a fraction of the cost but made from a composite plastic. So far I have broken the replaceable mounting plate on only one of the plastic retracts and that was from the last pancake landing (which was easily unscrewed and replaced)on the Spit ..I have them in my 46 size 6lb  P51  mustang and they work perfectly .My 46 size  Mustang came with identical retracts to the H9 Spit ,with only 4ml piano wire , it bent even on the good landings which became a pain in the butt straighting them all the time to fitt back in the wheel wells.. Best thing I ever discovered elecrtic retracts easy refitt and remove the old  mechanical retracts".

maverick11359

PIc of the spit at Archville field .. Mav.

N1EDM

My Feedback: (2)

Thanks, Maverick. That tells me what I needed to know. I appreciate the info.

Bob

modelflyer5

The problem with the wing bolts is not how much or how little your tightening your wing bolts. All fasteners that are in your plane that are metal on metal. (metal nut, metal bolt) will loosten up because of the harmonics caused by your gas engine. Gas engines will shake the fillings out of your teeth if the engine was strapped to your jaw.

Everytime that you fasten the wing to your plane, you need to blue locktite it. Any other fasteners on your plane that are metal to metal should have lock tite on them. You should also check these fasteners before every day of flying. Metal gear servos that have a metal fastener screw should also have locktite put on them. I have many friends that have lost planes just for that reason.

Blue locktite everything metal to metal.

Matt R

spitfire66

Thanks for that info. I wasn't sure if using that would be a good idea or not just because I would have to do it everytime and wasn't sure if it would mess things up. I guess we are only talking about the wing bolts that have to be fastened and loosened everytime.

modelflyer5

Yes, Lock tite your wing bolts. Make sure that you go through the whole plane and do the same to all metal fasteners that are screwed into metal.

Matt R

maverick11359

Good idea modelflyer5, I just pulled the cowl of my Spit before it takes to the sky tomorrow morning and discovered one engine bolt missing from the mount to the fire wall . Just shows how they vibrate loose and the plane god smiling at me for your timely post...Thanks.. I've put a little 271 loctite on all bolts..

Also guys I found loctite 271 does not stand up to the heat from our engines or mufflers after acouple of days flying cut short due to loose mufflers on my saitos, I did a little researched into loctite and found that at 150 degrees celcius loctite 271 looses 50% of its strenght. I now use loctite 263 which has a higher heat tollerance than 271..To undo any thread though using 263 you need to use heat (above 180Degrees C ), gas bottle or heat gun direct on the joint.

Thanks Mav,

spitfire66

Flew the spitfire today and had a pretty good flight. I am in the process of breaking in the dle 20 and it is running great. I am spinning the 16x8x3 blade at 8400 static rpm and the engine pulls the plane around great. Unfortuately I beefed up the retracts with 3/8" music wire and had a bad landing which ripped out 1 retract. O well, just a little glue and I'll be back in service by tomorro afternoon. Are most of you using flaps for landing? It seems when I use flaps I always let it hang there until it stalls and just drops without warning. I had better luck with no flap landings at this point and just keeping it fast. I have mentally had hard time keeping up the speed until in the landing flare thinking I will land too long. Just need more experience. I think repairing my airplane everytime will help expunge the habbit. Happy flying!

N1EDM

My Feedback: (2)

Sorry about your issue with the retracts, but they will be fixed OK.

I was going to install some Lado retracts in mine temporarily, to try them out before putting them in another plane (OK, so I wanted to play with them ). You said that you changed to a 3/8" music wire gear. Did you perhaps mean 3/16" instead??? Were these the stock retracts?

I did some mods to my plane and haven't flown it yet. I put in a 95AX (hasn't been run yet) and some Robart Robo-Struts on 3/16" wire. I hope that, besides looking really good, they will smooth out the bumps on the landing...

Bob

maverick11359

G'day spitfire66 and N1EDM ,

Lifer

My Feedback: (1)

Have you tried the flap-to-elevator mix? Add some down elevator to maintain airspeed.

spitfire66

I think mixing in down elevator would be a great solution to MY individual problem, but I don't really know how to do that on my jr sx600. I can look through the manual. I am just letting it get too slow. I like Maverick 11359's method and will try that. I just keep chopping the throttle instead of flying the airplane to the ground. I have 300 feet of runway to work with surrounded by tall grass if I go long. I have thought about what I'm doing wrong quite a bit and I think I would rather come in fast and use the whole runway and potentially runoff the runway or go-around than stall and plop the thing in again. I'll get it figured out, I just wanted to see if I was the only one having problems with landing.

Yes, 3/16 music wire not 3/8. I have to recover the monocote where the damage was done, redo the retract wire setup with the servo and I will be ready to go.

N1EDM,

Be careful about have an aft cg. The elevator is extremely touchy and will shoot toward the sun. I can't remember my exact cg, but I think it is slightly less than 5 inches, I think 4 3/4. I posted my cg earlier in the thread. Good Luck!

Lifer

My Feedback: (1)

Your experiences parallel mine. I really abused my first flap equipped model.Now, on test flights, I take it up high, drop the flaps, and have my buddy input down elevator on the elevator-to-flap mix til it has a pronounced downward glide. Why don't you swing over to the Sunchasers field and I can help you. PM me for a phone number.

maverick11359

G'day spitfire66 ,

                  As lifer  stated  it will help if you use down elevator mix with your flaps, I do  ... 

              We talked about it back a couple of pages ago on this thread..If you use the same throws , 1 inch down on full flaps and 1 inch up/down elevator  (full rates ) and mix 15 %  down mix elevator ,you will have the same throws as I use .. 

                  I experimented by trial and error in flight too and like lifer stated  you need slight down glide decent with the elevator mix in.  15% mix seemed to be right .

Lifer

My Feedback: (1)

I'll be at the Sunchasers field tomorrow morning at 10am if you'd like to come out.