I'm looking for advice on attaching anhedral stab halves to a fg fuse. Got an old Vertigo II kit, foam stabs with 1" anhedral, fg fuse with stab base molded in, plans show lots of detail but nothing on how stabs are attached.

My best thought has been to make up a plywood anhedral brace, cut slots through fuse sides to slip the brace through, slots in stab halves to receive the brace, put everything together with epoxy.

I'm sure better minds than mine have wrestled with this, and I'm looking for any tips I can get.

As I recall (it's been about 10 years since built) on my old Tiporare with anhedraled stab, I simply joined the sheeted stab halves as usual, then placed them in thru the cutouts I made in the fuselage tail area. I left the balsa tail post uninstalled out of the vertical stab until after mounting the stabs, so I had good access to the inside of the joint. The holes were cut using the root shape of the stab as a template, using a Dremel. Open the holes up a bit as necessary. Rough up the inside of the fiberglass at the glue joint a bit for good adhesion, and wipe down with alcohol. Place the stab in the hole, and tack glue in place and in proper alignment, using small shims as necessary. I then sealed around the outside of the joint with 1/4" wide masking tape for the next step. Epoxy the stab in place from the inside, using 30 minute epoxy with micro balloon filler added (if your holes aren't real precise this helps), and some small strips of lightweight glass cloth laid into the joint, top and bottom. Remove tape and you should have one neatly and strongly mounted stab. Fill the outside of the joint as necessary.
This made a very strong and secure mounting.

Good luck. Hope this helps.

Rick

OK Rick, that makes good sense. Thanks for the help.

To add to what Rick said, there is no need for an anhedral brace, but it is advisable to wrap a light piece of fiberglass around the joint just like you would for a wing center section. If you do not wrap the joint, you could end up with a broken stab inside the fuse. I've seen this happen a few times and you have to remove the rudder post to fix it. It doesn't take much glass. A 1" wide strip of 2 oz. glass will be more than enough.

John

I'd be more inclined to run a strip of glass tissue (if you know about it, it's great stuff) or 3/4 oz. cloth out past the fuse/stab connection.

The stress point is where the stab connects with the fuse, this will either break the stab or act as a lever for to break it at the centre section.

I assume that this is a 60 size pattern plane. What engine are you planning on using. I am currently building a plane called a Cure Air that was kitted by Farnworth and Elroy. I am thinking of putting a saito 100 on this. Any thoughts?

Anyone know anything about this plane?

Thanks

Doug

My Vertigo II is a 60 size pattern plane. The fg fuse has hardwood beams glued in as for a side-mount two-stroke, and not a lot of room for improvising. Trying to set up a four-stroke throttle linkage, for instance, or putting an engine mount on the firewall, looks like more trouble than it's worth. So I will be thinking of a two-stroke of the .72-.75 displacement range. Or I might go classic and put an HB61 in there. I have three of them, one is old stock new in box, and I will probably never have a more appropriate plane to put it in.

I don't know the Farnworth Elroy Cure Air. I presume it's a cousin of the Curare. I would think a Saito 100 ought to go well with a 60 size pattern model, but that's just on general principles. I do like my Saitos. If you don't already own it and are going to buy, I'd be more inclined to buy a YS (91 or 110 if you crave power). With the integral fuel pump and tank installed at CG you have consistent pitch trim throughout the whole flight. With my non-pumped models, if I fly too long, I know it's time to land when the model starts getting squirrely; I have to really concentrate to get it down in one piece.

I would be very hesitant to mount a 4-stroke on one of the old 70's/80's era pattern ships, simply due to the relatively small size of the airframe and wing (usually around 650 sq.in. compared to the larger, late 80's/early 90's designs around 750-850 sq.in.). These older ships were never designed or intended to have that kind of power or WEIGHT in the nose. As such, the plane becomes very noseheavy, needing lots of balancing weight. This aggravates the already high wing loading problem caused by the 4 stroke's weight. These old birds will fly very well on just about any 2 stroke .60 you can put in them. With a 4 stroke, extra tail weight, and limited wing area, they would fly like a brick and be pretty unforgiving.

But, this is my opinion. Do what you will. I'll be the one standing over on the side saying "I told ya so!".

Rick

Many of these older pattern planes weighed 9+ lbs. due to heavy glass and paint finishes as well as electric retract systems like the Kraft units. I see no reason why they would not be able to handle a light 4-stroke like the Saito 1.00. Also keep in mind that the Saito, while a powerful engine, will not fly the model at the speed any of the Rossi or OS VF engines did so the stresses upon the airframe will actually be lower with the Saito.

John

The saito weighs about 20 oz with muffler. Most of the older pattern 60 engines were around 24 oz and then you add a 3 to 4 oz exhaust system.

I have an old curare and agree with almost everything that everyone has said. Leave the tail open, tack, glass, microballoons, but I didn't run the glass cloth past the sides of the fuse. Just flush or there abouts, I think I put a 1 inch strip on, and it has never ever even started to break at the fuse line. It's still holding fine after many years and still flying. Well it's in the hanger, but it still would. The anhedral stab always looked good in the air. Always liked it. Just my opinion on it. Paint it light as possible though. They're real bullets to land. Good luck