tfarmer96

I put my complete spit on the CG machine last night and WOW its tail heavy. I cant believe it. I even put a super tiger 75 in it for extra non lead weight. Im not sure where to put on the lead. Can anyone give me a little direction? Without lead the plane weights in at 9.6 lbs

saramos

If you can, put the weight in front of the firewall. I would think there would be space around the engine mount box. The farther forward, the less weight you'll need to add. When it comes time for me to make weights, I'll probably do a mix of lead shot and epoxy.

Scott

tfarmer96

that was my next question how in the world do you get 19 oz to stay on a firewall?

Blue_Moon_

the best thing to do is to add a heavy spinner. My stang was tail heavy so i made a new prop nut, of steal.

FrankRC1

My Feedback: (5)

What I did is make a box above the firewall and add a mix of epoxy and lead shot. I have also seen a box added to the engine mount and filled with lead shot and epoxy. You can see this on the construction book on a ARF Great Planes Super Stearman. You can down load it off tower hobbies web site info about the kit. I havent tried it but looks like a good idea.

jamie_duff

Just whatever you do don't add any weight to the cowl - it'll start cracking as soon as you fly it.

I sometimes use car wheel balance weights, and capture them on the engine mount using excess thread from engine bolts, but I think a lead box would be the tidiest way

tfarmer96

well i took it to the LHS and those guys helped me out. Looks like a total of 11 oz total.

flapper

Hi,
I am still building my TF spit and have looked at ways of moving dead weight further forward of the CG. I have moved the retract servo/valve/receiver tray right up to the firewall area. Have fitted the pressure valve and fill valve up as well. The suggested position for the air tank was too far back. I have made set it up further forward as well.

The extra tray on the engine side of the firewall holds the throttle servo. Above that I have a 4.8V battery pack. Whilst I plan to glass and paint the plane, at this stage I am able to balance the CG at the suggested point with the need of only an extra 3oz up front. Not sure how I will go once finished though. I am seriously considering using plastic film on the fuselage to reduce tail weight and glassing the wing only. That 1.5mm blasa shheting on the wing is so thin and fragile. I have a fibreglass cowl now to replace the ABS plastic one. It is slightly heavier than the plastic so sholuld help as well.

jaka

Hi!
Building light from the start is very important...that means asking yourself all the time when you glue in a part: Do I really need it ...or Does it really need to be this strong ...Most of the time you don't need all the wood and you don't need the strenght.
But it's not that easy when you are a newcomer.

The thing you can do is to take a Dremel with a drumsander and sand away part of all the oversized formers in the fuselage and sand away all the heavy plywood sheets and balsa blocks in the fuselage...and also replace a heavy tailwheel ...and replace Anything that looks heavy.
Nearly half a kilo upfront sounds just crazy.

Regards!
Jan K
Sweden

tfarmer96

Just got it off the scales the whole plane totals 10 lbs. I can live with that.