RE: WACO YMF
 

I get it. I'm a little slow on the uptake. :)

RE: WACO YMF
 

Bill,

The following book on eBay may interest the Brotherhood. Decide who is bidding if you want it. I don't advise bidding against each other.


WACO - Symbol of Courage and Excellence - Vol.1
Item number: 290119148170






WACO Brotherhood No. 14.


old git - - - - - - -aka John L.

RE: WACO YMF
 

Sounds like you're having too much fun. It's killing me to get mine back in the air, I just haven't had time to really get in there and finish up this landing gear replacement, but, its coming along.

John and I noticed something at CCA on several UPF's; the entire vertical tail on at least four was offset to the right, to counter the torque reaction and P-factor. Even the headrest extension was offset to meet the extended centerline of the V stab. Oddly enough, there were others (majority) that had no offset. When we asked the owners, noone had a really good answer about why the difference. Our Brother WACO Joe's UPF was not offset, and he was interested to look at the ones we saw that were. His comment was that they wer apparently rigged that way to counter the torque, etc. Another owner siad that the airframe structure determined the angle the V tail mounted at, that it was not something that could be changed.

I noticed that mine also flies with a bit of right trim to keep the tail straight, otherwise it looks like you're in a bit of crosswind. I try to just fly it, and lean on the rudder a tad to straighten it out, rather than crank in a lot of trim, because the trim screws me up on approach and when doing loops. But you're right about one thing, it's a real sweetheart otherwise.

Don't know if you can see the offset in the right side view, but you can in the left side

RE: WACO YMF
 

It's a gorgeous plane. Congrats!!

Joe

WB #54

RE: WACO YMF
 

Ken,

Did these two planes with the offset vertical stabs have the trim tab on the rudder as well? I'm planning to make the rudder trim tab completely adjustable on this one. Not in flight, but statically. Seems as though this would preclude having the entire tail skewed>

Bill, AMA 4720
WACO Brotherhood #1

RE: WACO YMF
 

I hate to butt in, but you might try calling around to the different hvac places around your town. Im a tin bender myself and it wouldnt be any problem at all for me to make a tank out of copper and sweat it togather. in fact im probably going to build a tank for my 4 star 40 this weekend. Im kinda dumb so if I can do it shurely there are other tin benders who can.

Possum

(didnt realize the way this forum worked. this post was meant for a guy named chris who had a tank question)

RE: WACO YMF
 

Yeah, Master Chief, these UPF's still had the trim tab on the rudder. It differs from the YMF tab; instead of a discrete piece that fits within a cutout in the rudder as the YMF has, the UPF has a bendable tab riveted to the trailing edge. At any rate, both are ground adjustable only.

How will your trim tab work? Will it be sufficient size to cause the tail to deflect by itself? Certainly it can't work like the full scale does, by creating a force to move the entire rudder in the desired direction. Your servo would keep the rudder centered, or wherever your servo trim point was.

RE: WACO YMF
 

Bill,

Good question, but it seems there were at least 4 different rudder trim tabs used by Waco and were only ground adjustable.

P1 – None - ASO, CTO, QCF-2, RNF, UBA and UBF-2 (UBA, NC 9220J shown)
P2 – Small Metal Tab – UPF-7, QDC and ZQC (UPF, NC 39727, shown). All the UPFs that were at the Fly In had this tab. **
P3 – Large Metal Tab – QDC and UEC (UEC, NC 13050 shown)
P4 – Inset Rudder Tab – YMF, UKC, UKS-7F and YKS (YMF, NC 14081 shown)
Bill, this is the style that would be correct on your plane.

**According to some of the owners, there is a notch in the fuselage former for the front of the vertical stabilizer to fit into and the exact placement of the notch varied slightly due to hand cutting of the formers.

Also note the various stabilizer thicknesses and rib shapes.

RE: WACO YMF
 

John--- why don't you buy it, and read it to us. I just love a good book in a British accent.

"This is WACOpiece Theatre; I'm your host, Alistair 'old git' Cooke. Today, we shall discuss the totally arcane and mysteriously indecipherable alphabet soup of WACO model codes."

:D:D

RE: WACO YMF
 

OK, here's my attempt at posting the "before" pics.

RE: WACO YMF
 

Gentlemen.

Went away for a week vacation in Los Angeles, return to find about 5 pages of posting.
Some body sure likes typing.
Regarding the corrugations. I built a 1/5 Pica Cessna Skylane and used plastic " L " angles, not triangles as mentioned on a previous post, probably the same brand name and bonded equally spaced with super glue, filled the edges with primer paint and sanded smoth.
It may seem like a lot of work, but I think it was worth it.

If super glue gets on your skin, use acetone, it disolves it right away.

Angel
B 58

RE: WACO YMF
 

Scott,

Definately worth bringing back. Just as I thought, even then they were UMF's too.

Bill, AMA 4720
WACO Brotherhood #1

RE: WACO YMF
 

Ken and John,

John, thanks for the pics that you e-mailed to me. I will make the trim tab inset, and adjustable via a pushrod and link that can be adjusted for flying trim. The tab will be hinged, and the horn will have a clevis arrangement so the rod can be either shortened, or lengthened as necessary. I don't think that this tab will overcome a 133 in/oz digital servo, but I could be wrong. What do you guys think?

Bill, AMA 4720
WACO Brotherhood #1

RE: WACO YMF
 

An oiffset fixed trim tab on a servo driven control is of no value at all. You'll end up fighting the servo's neutral if the tab is offset to any degree....a linked, moveable tab (as in full scale called a servo or anti-servo tab ,depending on the linkage) could work on a model but in this case it's not scale. I suggest cutting the tab out of the rudder trailing edge in a scale fashion and reattatching the tab in a neutral position and use rudder trim on the transmitter as necessary for yaw free straight and level hands off flight at low to medium power settings. For all other speeds and maneuvers fly with the rudder stick as necessary.
Not bragging but I'm a very long time modeler as well as a full scale pilot, instructor, and mechanic. Mitch

RE: WACO YMF
 

So I guess what you are saying is that even with the holding power of a digital servo, the trim tab will overcome the servo's ability to hold center.....right?????

Bill, AMA 4720
WACO Brotherhood #1

RE: WACO YMF
 

Angel,

"If super glue gets on your skin, use acetone, it disolves it right away."

It is better not to get the super glue or epoxy on your hands by wearing latex/nitrile type gloves. The acetone will enter your body right through the skin and could cause problems in the future. I use carpenters (yellow) glue for most of my building (comes off with saop and water) and only use CA (super glue) and epoxy when necessary. Stanley makes solvent (nitrile) gloves in a package of 12 (I think) for a few bucks. Found mine at Wal-Mart in the paint section.

RE: WACO YMF
 

Bill,

What you are proposing with a push rod sounds a lot like a boost tab arrangement. The full size trim tab just had a nut and bolt clamping the curved track on the bottom of the tab to a small tab attached to the rudder. The trim tab is hinged at the ends (no Dubro or Robart type hinges) with a pin and socket type arrangement. I think I would go with Mitch and set the trim tab neutral and use the servo trim as required.

RE: WACO YMF
 

Sorry if I'm not clear....the tab will only FIGHT the servo. Use the trim function on the tranny so that the SERVO holds the proper neutral. Ground adjustable tabs on full scale planes are set to take rudder pressure off the pedals (or in our case, the servo) at cruise airspeed. At all other times it's up to the pilot to perform coordinated or by choice uncoordinated flight using the pedals (our servos) as necessary.
Whay I'm trying to say....forget that there's a trim tab back there. Make it look as though there is one but don't use it. Trim the plane to fly yaw free at cruise flight the way us RC pilots have always done it....with the xmtr trim function.

RE: WACO YMF
 

All clear now Bill? The trim tab will have no effect on the airplanes trim, it's just too small. But it could make the servo work just a little harder to hold the nuetral you have set on the tranny. If you are using a Digital servo, this could lead to an increase in battery consumption. but that's about all it will do.
Evan, W.B. #12.

RE: WACO YMF
 

Well, It seemed like a good idea though. I suppose that I'll actually hinge the tab, and lock it with a bolt through the slotted tab. What do you guys think about doing the offset vertical stab ala the full scale, as in the pics that John posted? Another exercise in futility, or what? I'm hoping that the adjustable incidence H-stab does not turn out the same way.[:@]

Bill, AMA 4720
WACO Brotherhood #1

RE: WACO YMF
 

I came to the conclusion awhile back that about 2 degrees of right thrust will be my plan to help negate the rudder trim issue. Am I on the right track here?

RE: WACO YMF
 

The offset does not affect a thing while flying. Even take offs are nice, I wouldn't put too much energy into it!
Like I mentioned before, if my cowl was off, I would put a degree or two of right thrust in it!

RE: WACO YMF
 

I'm just not into having a prop that sits gillhooley to the cowl on a scale airplane. I do fly with the rudder, and I have been trimming models successfully for years. I just wanted to be able to add a little more scale realism with the trim tab. I guess I will make the tab look realistic, and not functional.

Bill, AMA 4720
WACO Brotherhood #1

RE: WACO YMF
 

I'd set the vertical stab straight with the centerline and use a couple of degrees of right thrust at the firewall. Mitch WB #100

RE: WACO YMF
 

Actually, I have built and flown several of these with different powerplants. The only significant place that I have seen where right thrust offset seems to help is on the up-lines and loops. You should be flying with the rudder, and you do your own corrections to the yaw axis. The up lines are made easier with built-in right thrust. The one with the MOKI 1.8 actually needed the built-in offset. So far, none of the rest have.

Bill, AMA 4720
WACO Brotherhood #1