moto-x

Dubs. Mine is at 23lbs without the batteries.The c/g right now is at 7 inches back from leading edge.Wow,quite nose heavy ya think.I will put the battery packs as far forward as I can get them,even if I have to cut a slot to put them behind the firewall. I still do not think that will put me up in the 4 inch range.Very disturbing for me as I have built several kits and assymbled many ARFs and have been able to build around the c/g and have never added weight to balance. Just lucky I guess.

lovehydro

Every thread I have ever read about the Pica Spitfire talks about all the led it takes to balance this plane. It is wonderful flying plane, however it has a problem with CG.
When I rebuilt the Spit, I replace the broken engine rails with an engine box, I built compartment on the side of the box (access through the top of the engine box) for the batteries. I am going to build a platform from the top engine bolts going forward towards the spinner. I built the engine stacks on heavy duty wood so I could support the platform over the crank shaft in front of the motor. This gives a platform for my lead in front of the motor head just behind the spinner. I did this on another plane and it work well. I hope it will help minimize the lead. When I got this plane it had a 4 lbs. block of lead bolted to the firewall plus there was lead on the broken engine rails.
Lovehydro #39

shanksow

My Feedback: (2)

Recently, a Royal kit of the (small size) Spitfire landed in my lap and now I am in the process of restoring it to a flyable condition. The fiberglass covering was cracking, but I (re) wet sanded the whole fuselage and wing and now it looks good again. Just have to spray a new coat of primer on the old girl. Other things that have to be done to her are bending a new set of Landing gear wires, cutting a exit for the elevator push rod and re-connecting the internal rudder pushrod. I'll have to wait on a 2-stroke motor and radio gear to stick into it.

My question to the Spitfire brotherhood is if any of you have ever flown this old Royal Spitfire kit before? Tip stalling, etc???

dubs1946

Hi lovehydro, i put my 1/5 Pica spit back on the balance board today and it needs 4 Pounds to get it to 4 1/2 inches back from the center of the leading edge that would make mine
32 and 1/2 Pounds and its still in undercoat, i always test fly in undercoat.
For me that's to much added lead weight.
What i have done is cheat i have extended the nose by 1.5 inches and now it only needs
1 Pound to balance at 4.5 inches
I will start at that and reduce the weight as it will allow on the test flights.
It is not going to be a high end scale aircraft any how and the extra 1.5 inches on the nose turns it into a MK.9 with big fat cannons.
Its hard to tell by looking at it unless you are a Spitfire Guru.
Dave.

FireBee

My Feedback: (34)

Dubs1946, LoveHydro, others on Pica Spit.

I have flown two of the Pica 1/5. Spit. I started at 4.75 but settled on 5 inches back for the CG.
I also report with that large wing area you could go to 32-33 pounds and still fly well if you have power.

details:
#1 overall Silver in Belgium paint scheme. CG used was at 4.75 inches, took 6 lbs of lead to balance. That brought my weight overall to 27.5 lbs. I had a supertiger 3000 for power which gave pretty good top end speed but lacked pull for larger loops. I replace glow with a Brison 3.2 (50+ cc gas), shimmed the gear so axels were closer to the leading edge as only issue was its Take-off handling (felt like I was on a teeter tot (Fulcrum).
I then rebalanced at 5 inches back and she was now a WARBIRD.


#2. American camo in North Africa. Same as your gents, redid the landing gear to move forward and match the angle better. LArger Yellow Aircraft wheels required me to cut through the main spar so added a connecting spar across the front of the Wheel wells and tied it back into the main spar. Alos added rear spar across 2-3 ribs to tie in the landing loads to the main mount wood rails. CG 5 inches. about 3.5 lbs of lead (about 3.0 lbs in box attached to the spinner backplate former and remaining 0.5 lbs along the engine mounting rails as far forward as possible. Moki 2.10 for power. this kite really moves out now.

Two thoughts before test flight:
- I added 2 oz of lead to the starboard wingtip on spit #2: based on a magazine article on how to tame the warbird. It definatly worked and helped counter stall and torque.
- Flaps. I found about 25-30 degrees and she was rock solid. I always try for a main wheel touch down vice 3 pointer. Too much Flaps and I had to "fly her in" on power and thus landings were a bit fast. You will know if you are getting slow on final if the wings start to rock back and forth. Add a couple clicks of power immediately and she steadies out nicely.

Good luck and your Spits . They look far better than mine! nice job.

lovehydro

Mike,
Thank you for the specific information. This will really help all us Pica spitfire builders or rebuilders.

Lovehydro #39

Saburo Sakai

In the beginning....

moto-x

Well guys, here is what I came up with to get the spitty balanced. She was going to take 5lbs of lead behind the firewall. That would put me at 29lbs total ready to fly. I am running a DA 50 for power so I believe that would pull it around scale. As I said in post before , I do not like added weight. Here is my fix. I took a peice of 1 1/4 inch brass at 3.120 inches long. Put a radius on the end to fit flat in bottom of spinner. Turned down the other end 1/4 inch back to .840. That fit inside the prop bolt circle and flush with the head of the bolts. This spacer weighed 2lbs. mounted between spinner and front prop plate with clearence hole for spinner bolt. Still 4 oz shy of balance. Took that spacer and set it in the spinner.Melted 4 oz of lead and poured in the spinner. Put back together and she is balaned at 4 3/4 inch back from leading edge. This spacer is like a flywheel. Should give me a lower, smoother idle. It might affect ramp up time on rpm but I do not think I will notice. She is at 26lbs ready to fly. I will post some pics of the JEJ later.

Chad Veich

My Feedback: (60)

You might want to enquire with DA what that two pounds hanging on the crank shaft is likely to do to your engine long term. It may not be worth it. IMHO, the difference between 26 and 29 pounds on an 88 inch Spitfire is not likely to make a tremendous difference in the way the airplane flies but all that weight on your DA may dramatically reduce its life span. Just my .02 cents of course.

Duplicator41

My Feedback: (1)

That's a great way to really shorten your bearing life. As per Chad, check with DA.

Cheers,

hairy46

My Feedback: (1)

I do not think I would put the weight in the spinner either, I do believe you will be putting allot of stress on the engine front bearing as well. I know getting weight out as far in the front will reduce the weight needed but I never go out more then putting the weight on the motor mount or firewall. I do hope it works out for you but do think it will takes it toll on the engine!

moto-x

If a Zenoha or any other flywheel engine can carry the weight on the front,I would think a DA can. I can replace bearings if there is a problem or put a G-62 on it. The DA is well out of warranty but maybe a gallon through it. I have had it 3 years and run on test stand for custom pipe test. I had already took bearing wear in consideration but I believe that not being a everyday flier,I should be ok. Thanks for looking out for the DA though. They are great engines.

hairy46

My Feedback: (1)

Mr Moto, We here on the forums try to help one another out, It is not to pick or put someone down it is to help the person to maybe look at something they may have missed or to some of us that do not think maybe it will be a good thing. I hope it works out for you but I still have my doubt that in the long run it will cost you at very least the front bearing. Please let us know how it turns out!




SPIT75

moto-x

Hairy,I didn't take your advice as a thrash or bash. If I came off unappreciative I appolagize. I too have given my .02 cents worth on other threads and hope I have helped others. If I didn't want others thoughts on this I wouldn't have posted it. If this works out long term with no bearing wear, who knows, maybe I will market it. Again,thanks to all for your input.

markhamregular

My Spit is finished. My pride and joy. Cutting the cowl for the sideway engine was not that bad.

mad web tv scientist

dubs, all the discussion about front bearing life got me thinking about prop balancing that might be helpful. Do you balance a prop in the six o'clock position as well as horizontally? I sometimes have to glue weight on the light side of the prop at the hub to get an almost perfectly balanced prop. This may help clarify balancing concepts. I also sand the back of the prop when it is necessaary to make the tips track very close to perfectly in the same track.

Sakai, sorry about your loss. It's great to see you back with the products of your creative mind - lest we forget.

One of my sources shows a "Griffon" powered Spitfire with the gear struts noticeably angled more forward than is usual on some of the lower Mk Spits. That fits my own preference experience with landing gear.

Out.



Aim High, Fly, Fight, Win! (I fell in love with that motto when I first saw it on the Military Channel - fits fighter fantacy fun.)

__________________________________________________ ___
FIGHTERS - AVIATION'S ULTIMATE CALL TO GLORY, HONOR, AND IMMORTALITY,
http://community-2.webtv.net/RICHARD...4/CALLTOGLORY/

__________________________________________________ ___
Spitfire Brotherhood (All Spitfires Welcome) # 64 - Post # 407 Battle of Britain & Winston Churchill relevancy to modeling

hairy46

My Feedback: (1)

No I did not take it wrong, I do hope it works out for you I really do! I to have learned so much from the forum's and am glad to have them on our side. We are a big club and RC family that wants nothing more then everyone to succeed! Great luck to you and please let us know yea or nea!

moto-x

Ok guys, here are the pics I said I would load. Notice the custom made exhaust. Three live with crossover tube to make six live.Six dummies. Very loud. I have test run this several times and it sounds good.

jet22b

markhamregular,
Your Spit look very good. Hope you have a sweet maiden flight.
Sad to report, I lost my Hangar 9 Spit yesterday on the last flight of the day. All day the wind was out of the east at 5 to 10 knts with gust up to 15 knts. My club field runway is east to west, so not a big deal. Setup for landing, gear down, flaps half way down, power set. Everything was looking good, then it happen. the wind shift from east to north and the speed went from a steady 10knts to over 25 knots. When you are less than 10 feet above the ground, you don't have much time to do anything but chop the throttle and watch it go in!! The fuse was toast, but the wings are okay. Now that Hangar 9 has them on back order, that give me more time on the build of the Top Flite kit. When they come back in-stock, I will pick up another one!!
I do have other warbirds to fly, but, I love my Spit!!!

Sonny
aka
jet22b

hairy46

My Feedback: (1)

Ouch! So sorry to hear that, Darn ground, it gets in the way of everything!








SPIT75

WARBIRDRCER

My Feedback: (22)

Jet22b,

Hate to hear of the loss of a great flying Spitfire[]. If we could discover how to overcome wind gust and gravity we all would still have some of our best. How is the TF Spitfire coming? My boy’s is still in the box. My wife has me detailed on finishing up her 1972 Mach I Mustang. Don’t know what the big deal is, I have only been working on it for 11 years on and off. I will be back on task soon, and maybe then I will get one of my Spitfires in the air.

flyntruk

My Feedback: (5)

   moto -x   nice bird    Can you tell me  what spinner that you are using , and where did you get your pilot ?  I'm getting close to wrapping up my spit, and these are some things I need to look at ... Thankyou ..

jet22b

WARBIRDRCER;
The tail is all laid out and I am thinking of staying with the wood that came with the kit. Some people have said to built light to save weight. The engine I am going with is a OS 120FS pump. I am hoping to keep the engine inside the cowling as much as I can. This is why I like to build, you can mod as you go to get what you want. As I go, I will post pictures for you and your son, ( in fact for everyone!!), to see how the build is going. I have a pair new in-box set of retracts that I pickup for the Great Plane Seawind, but, they was never install. I will have to lay them out on the plans to see if they will work.
Stay tune!!
Sonny
aka
jet22b

dubs1946

Hi mad web tv scientist Yes i do balance all my props, and i don't balance the hubs so all my props balance at the horizontal position.
I think that the hub is so close to the center of the circle that it should make little or no difference.
I have not run the engine yet with the spinner but its not far off.
I have just pulled all the Chinese servo's out and replaced them with HT.645's.
I thought i would give the Chinese servo's a look in to see if they were any good but no i could push them back even at 6 volts, so no more Chinese servo's for me, maybe i bought a dud brand, most of us use Chinese batteries etc. and a mass of other Chinese stuff but it does have a higher failure rate then radio control gear not from China.
I have a Smart fly in the Spitty and its about $200 landed from the USA and the Chinese equivalent is about $45 but some things you have to buy more reliable gear, and pay the money.
Dave.

moto-x

The spinner is a 5 inch aluminum spun from ibcinyourc.com. The pilot is from Bestpilots.com. The pilot is pricey if ordered painted. I bought the unpainted and had an airbrush buddy shoot it for me. They are great detailed pilots. They come in 3 pieces. I ran a tube up through the middle of mine and attatched the head of it to the rudder pushrod. When the rudder works the pilots head turns back and forth. It is like 60.00 dollars unpainted and like 180.00 painted.They are proud of there artwork. My buddy cost me 20.00. Looks as good as the one in the picture to me. Oh by the way. I bought the 1/5th scale pilot and it was a little tall in the pica spit. Had to put on belt sander and remove some a## from him to fit.