TF Spitfire kit elevator/stab question
 

I've started building a TF Spitfire and I'm currently working on the elevators. I noticed that the elevator LE is about 1/8 narrower than the stab TE. I'd expect them to be the same width and that's how it appears on the plans. Is this normal? I verified that the stab itself is built and shaped correctly. It is almost like the elevator LE provided is too narrow. I can easily fix it with some 1/16 balsa but I figured I'd do a little more research first. I don't want to fix it if it is supposed to be that way.

Thanks in advance for any input.

RE: TF Spitfire kit elevator/stab question
 

The stab's profile is curved. The stab as constructed right now is not. The stab is built up from flat pieces and right now is flat.

If you look at the plans, it shows the stab thickness tapering from it's point of maximum thickness. If the elevator were hinged right now with it's centerline matched up to the centerline of the stab, there would be an equal difference top and bottom, and it wouldn't be very much difference. The idea is to sand the shape of the stab to flow into the shape of the elevator both top and bottom. That's how they planned for you to get the symmetrically airfoiled shape.

RE: TF Spitfire kit elevator/stab question
 

I appreciate the input and I understand what you are saying but that is not the case here. The stab is constructed correctly. It is built up from ribs, similar to a wing then sheeted. It may not appear to be in the pictures but it has the correct shape. Curved or airfoiled just as you describe. This is determined by the ribs supplied in the kit and matches the plans and instruction photos exactly. You can clearly see this by looking at the tip block which has been glued in place but not shaped yet. It is still flat and the rest of the stab is clearly shaped properly.

It is clear that the elevator LE is narrower than the stab TE. I want to know if this is intentional or if the stab LE's supplied were cut incorrectly. They were laser cut from 1/4" balsa sheet. The cutting was pretty bad; very burnt and not perpendicular to the sheet (irregularly angled edges).

Like I said, I can easily correct it with some 1/16 balsa but I want to make sure it is really a problem before I do that.

RE: TF Spitfire kit elevator/stab question
 

You may have done this but check to be SURE you used the correct LE for the elev. measure the plan thickness and then the material you used. Quite possible the cutter used the wrong thickness for the supplied sheet if thats were the leading edge came from. If that is the case, the other parts on that sheet will be wrong. If the leading edge was a ship loose stick, check for the correct one.

RE: TF Spitfire kit elevator/stab question
 

Chuck,

It appears to me that whomever determined the thickness necessary for the elevator leading edges simply forgot to account for the thickness of the sheeting on the stab. It's an easy mistake to make, ask me how I know! At any rate I can't see any reason why this would have been done on purpose. Ideally you would want the elevators to be slightly thicker than the trailing edge of the stab, not thinner, as it helps to prevent flutter.

RE: TF Spitfire kit elevator/stab question
 

Chad, that's exactly how I see it. The elevator LE does match the stab TE if the stab sheeting were not there. I think I'll just add a little 1/6" balsa to the elevator LE & tips and call it good.

Speaking of easy mistakes... when I built the stab I forgot to add the hinge blocks before sheeting. I had to open it up and add them afterward. Not a big deal just stupid mistakes like that can make you nuts sometimes.

RE: TF Spitfire kit elevator/stab question
 

Chad is exactly correct. These parts were laser cut and that might have had something to do with the mistake since the rest of the kit is die cut. I posted what I did to fix it in this thread. The rudder had the same issue.

http://www.rcuniverse.com/forum/m_65...tm.htm#6569178

The rudder was a bigger problem and if you can cut out new parts before you build it you will not have the same issue.

RE: TF Spitfire kit elevator/stab question
 

Thanks. I went ahead and built it up with some 1/16 balsa tonight and all is good. I will keep the rudder in mind and fix the problem before it gets assembled.

RE: TF Spitfire kit elevator/stab question
 

Nice work! The other note to make for later is to cut out a new cockpit floor or add some wood to the part in the kit so it matches the outline on the plan. Lay the part included with the kit over the plans and you will see what I mean when you get to that point. It comes up short. It will save you headaches when you go to sheet the fuse. Nice to see another Spit going together.

RE: TF Spitfire kit elevator/stab question
 

Mine was the same, just added some 1/16 balsa also. You can see it here on the rudder.