Duane,

I may have misunderstood an earlier description and thought that both tubes were CF. If the sleeve you used was different than the tube, then it may very well have been a phenolic type. (According to the descriptions I found, the sleeve is made of paper or glass cloth impregnated with a type of resin made of phenol and an aldehyde and subjected to high temperature and pressure.)

Thank you,
Richard

Well I guess that's that then! Carbon Fiber tube andphenolic sleeve works for me. Been working on the lower fuse blocks today, fitting them and mounting them. Finished the stab and elevators this morning. All I need now is to makea control horn that will connect to the control rodinternally as per Duane'ssuggestion and Ed's practice. BTW are anyof you guys planning on coming to theVRCS event in Floridain October(Pioneers of Radio Control)?

Duane,

Sorry to mess up a build thread but I came across this to add to my earlier post (#69) This is the schedule Ed would have flown the Simla through at the 1965 US Nationals. It may be of interest to competitors at the proposed "Simla Supporters Super Shoot-out" which I hope you manage to hold some day (wish I could be there)

Manoeuvres were scored out of 5 points back then so this was some flight by the winner, Cliff Weirick. ( ref. MAN November 1965 page 33)

Ray

Impressive...sounds like a winner to me.

Mess up the thread....on the contrary...you got my not-so-subtle hint. This is just a little break to change the "tempo" a little before diving back into building.

Nice try at a name for the event, but I don't think we are going to "shoot" anything anytime soon. Maybe we ought to hold it in Belfast...what do you think? [8D]

No, I guess on second thought, it would cost a fortune to ship those "big puppies" over there. I guess it would cost less than staging the event in Germany, or even New Zealand however. Nice thought though.

Thanks as always for the documentation.

Duane

Metaphorically speaking of course - last thing we need over here is any more shootin'

You know I did read/hear something about Ed's shakes but darned if I can remember where. Perhaps he was just a very nervous flyer

Ray

I just heard from Tony at Radio South RC. He can supply a set of CF tube and CF sleeve for $75.84 per set, plus shipping. It does take about two weeks for him to get the set since it's a special order item. Now that sounds like a winner and a weight saver, and not that much more than the CF tube and phenolic sleeve set from TnT.

And I think I've beaten this poor topic to death.

Cheers,
Richard

This is an early version of how I did my stab so I would not have any problems cutting the elevator from the stab. Since the ribs have reference lines for the cuts, I sheeted the elevator up to one line and the stab back to the other line, leaving a gap. We'll see what happens when I cut the sections apart.

The stab is now going to wait for the arrival of the 1/4-inch CF rod to implement Bill's idea. I'll start on the fin and rudder while I wait.

Cheers,
Richard

Richard, I usually crudely test the rigidity of mystabilizers by grasping them at thetips and giving them a twist. In the case of this stab with the CF tube there was absolutely no discernible flex at all. It seems to be incredibly rigid. Assembled weight without the elevator and before finishing, 5.5 oz.

Great work. Now all we need is the description for each one.

I knew we could count on you to find such artifacts.

Kevin Clark

Bill,

When you built the fin, did your kit have a length of 1/2 X 1/2 stock for the trailing edge of the fin? The closest I could find in my kit was 3/4 X 1/2, and I just wanted to make sure I didn't miss another modification to the directions.

BTW, I would like to suggest that retired builders, no names mentioned, be allowed to work only the same number of hours as those of us who are still wage slaves.

;-)

Your Simla is looking really good. And another question: What do you use to fill in low spots when sanding?

Cheers,
Richard

Speaking of the fin, here is Jeff's final revision of the fin compared to the prototype. We decided to change it after carefully looking at the pictures vs the prototype/plans a number of times. Something didn't look quite right. We came to the conclusion the fin should be a bit taller, with an altered fin "rake". As I said, other small revisions were made to the fuse nose section, fuse thickness, to reduce the "tallness" of the fuselage rear section forward of the stab, and to raise the height of the wing about 1/2 inch.

We are happy with the final product, but we would never rule out other changes if they can be proven to be necessary.

Okay Richard here goes,I built my stab/elevator just as you did. After cutting them apart I used a 48" piece of aluminumangle clamped to a 48" building board as a guide to square up the stab trailing edge and the elevator leading edge. The guide was clamped over a piece of 180 grit 3M sand paper that comes in a 3" wide roll with an adhesive backing. I usually keep a roll of 180 and 320 around for any number of finishing purposes. Next, there was no 3/4 X 1/2 trailing edge stock for the fin, but I guess by now you already know that from Jeff's thread. I just went ahead and used the 3/4 X 3/4 piece by marking a center line on the inside and outside with corresponding center lines on the ribs. Line up the center lines and CA them together. Of course this requires a lot of sanding to taper the fin into shape, but who cares it's a Simla. Finally, I use an automotive product as a filler. It's Evercoat metal glaze, but don't let the name fool you, it's light weight, adheres well, and can be rough sanded with 80 grit paper and finish sanded with 180 grit paper. I usually brush a couple of coats of urethane clear over the area that I'm going tofill since the Evercoat glaze is much harder than the balsa. After the clear dries I scuff it lightly with 180 grit and then apply the glaze. Sand to finished shape with 180 grit and you are ready for primer.

Bill,

Many thanks for the tips. I just received Jeff's answer to my question about the 3/4 X 1/2. He suggested stripping it to form the missing 1/2 X 1/2 and again to form the missing 3/8 X 1/2. Not trusting myself to cut a perfectly straight and vertical strip with a knife, I will simply laminate some 1/4 X 1/2 I have. And I think I also have some 3/8 X 1/2, so I'll avoid having to perform that surgery.

Looks like a trip to an auto parts store is called for this weekend.

Cheers,
Richard

Duane and others, I have been wondering what you guys think of redundancy where your flight pack batteries are concerned. I have seen so many horror stories on low voltage disasters that I'm inclined to consider a two battery pack/double switch arrangement for the Simla. Which brings me to the question 4.8 volt or 6.0 volt packs and atwhat amperage? I'll most likely be using my Futaba 10 CAG system with an R6008HS receiver and S3050 servos with a HydriMax 5 cell 6 volt 2000mah NiMH battery pack (or two?). Any input would be helpful and appreciated.

I replace my switches at least once a year along with my fuel tanks if possible. Its cheap insurance. I like the switches that fail to on, and I like the two battery switches as well. It only makes good since to build as much redundancy into our equipment as possible. I think the switches that fail to on is the real deal though. The only problem I see with the two battery switches is keeping the batteries in balance, voltage wise.

Kevin Clark

Richard, I went to the Radio South web site but could not find a listing for the CF tube and sleeve. Is it necessary to contact Tony directly to place an order? I finished covering the fin last night and am currently working onfabricating an internal control horn for the elevators. So far it involves a piece of 5/32" landing gear wire, a 5/32" nose gear steering arm, and two pieces of Sullivan blue control rod sleeve as bearings. With a little more research I may down size the whole thing to say 1/8". This set up, regardless of size, will be simple, easy to make, and very effective. Photos to follow.

For digital servos I routinely use the 6 volt, 2000mah, and use a voltmeter to check. I wouldn't add extra weight. The Simla is a transition kind of plane between the small, conventional pattern planes, and the big 30-40% ers with multiple servos/receivers which would absolutely require multiple packs. The major change I made was the use of 4-40 fittings on the control surfaces instead of 2-56. That's just me.

Duane

NEXT: the fuselage, (or would people prefer the wing)?

My vote would be for the fuselage since some of us will be awaiting delivery of the CF wing tube and sleeve. But then again, my fuse is just about done, so whatever is decided is okay with me.

Fuselage it will be. The speed of your build is almost mindboggling. Looks like you will have Simla #4, (the first prototype was #2)
Duane

Keep your eyes on the prize!! These pictures were taken during the third test flight of Simla #2

Bill,

Yes, you have to contact Tony directly - 800-962-7802. I ordered mine yesterday and told him there might be more orders coming.

I, too, have been giving thought to the internal elevator mechanism. I was thinking in terms of using some excess 1/4-inch CF rod in place of the hardwood dowel elevator joiner and possibly making a control horn from a few laminations of CF cloth I have. Your arrangement does have a number of pluses, however.

Cheers,
Richard

I have a friend who makes CF pushrods. He has told me you need to wrap and crimp the ends with small sections of aluminum tubing to keep the tubes from splitting, or otherwise breaking. He made a couple for me, and I'll post a picture later. You drill the ends for 2/56 or 4/40 fittings depending on the plane size. He personally uses these short external pushrods with the servos mounted on the outside of the plane, (on the fuse wall), for better pattern performance.

These short pushrods reduce the possibility of "play" in the linkages for competition purposes. I'm doing this for my King Altair #4 which had the old nyrod plastic pushrods...(I've learned a few things in the last 5 years), they were braced, but there was still heat expansion "play" within the tubing itself, which eventually introduced rudder "flutter".

The internal elevator pushrod is "elegant". It's neat to see the surfaces moving up and down without an ugly linkage. It is also interesting that Ed kept an OPEN HOLE at the rear fuselage bottom (as described earlier), rather than use a hatch. Even the Taurus kit shows a small hatch held in place with a screw.

Duane

Duane, when I built the fuselage I set it up with nyrod push rods for the elevator and rudder, however, since I am going to use the internal method for the elevator I had an extra push rod exiting the fuse aft. Fortunately I set them up as mirror images so they exited at the same point on opposite sides of the fuselage so that I can use them as a push/pull set up for the rudder. Interally the rods are supported every six inches and since I am not likely to compete in any contest, I'm hoping this will serve adequately.

Okay, here's some photos of the elevator control set up. The 5/32" rod just looked too big and heavy so I went down one size. I'm not really sure where the steering armcame from since I've been carrying it around for 36 years, but I suspect something off a smaller tricycled landing geared aircraft will do. I started by bending a 90 degree bend in one end of the rod,measured how much bearing I needed and cut two out of red nyrod sleeve. Then slide one bearing on the rod, followed by the steering arm attached so that when the elevators are in their neutral position the control horn roughly parallels the angle on the trailing edge of the fin. That will give it enough clearence to give at least1" deflection in both up and down directions. I had to notch the trailing edge of the stab for the control horn to fit and have enough clearence. Next, I will notch the elevators to fit around the bearings, drill the holes for the rod to be inserted in the elevators( before I finished sheeting the elevators I added blocks for the rod to slip into). I hope this is clear enough for anyone interested in trying it this way. Oh, I almost forgot, be sure to file a flat spot in the rod for the steering arm set screw and use some sort of locktite on the threads of the set screw. Once all that is accomplished, bend the other end of the rod accordingly, making sure it isin the same plane as the first bend. That should do it.

Brodak Manufacturing has about 20 different styles of C/L elevator and flap horns just like that available. They cost about 4 dollars.
I always sandwich those horns into a ply box.
First I figure where the horn wires are going into the wood surface, mark and cut them off. I then make 1/32nd ply faces on the cut off surfaces. Then I make a ply piece to accept the wire, so it has to be slightly wider than the wire diameter. Epoxy together, trim and fit, sand it all level, and you have what we call in C/L Stunt, and horn "clip" for the surface. Probably overkill on an R/C ship because of the slight deflections and enormous airspace available, but that's how I do it.
Chris...