A4hawkpilot,, your rudder servo is very much like mine. I used a 1/4 scale 120 oz servo in the vertical stab, but low enough for the servo arms to extend through the stab and used a pull pull w/ 4x40 linkage. I will give you yours looks better with the hidden linkage.

did you fly the A4 bird? I saw one land at Danang on fire do a realllllllllllllly hot landing. He was flamed, but flamed out also.

Nerves of steel that guy, but then I was on the end of the runway in my bird waiting for take off with him head straight for me.. Good thing for tail hooks and cables.

Fire truck put the fire out. all was ok. Time............................1971

John I used the dremel cut off wheel to make mine it worked well.

Gunny thanks for the info,, have credit card will shop. Jim

John, I used a dremel cut-off wheel for the straight aways and a small dia. router for the curves to cut out the fiberglass. I cleaned it up with a nail file and a large dia. dremel sanding drum around the curves.

Hey Jim. I just picked up a $20.00 aluminum tripod at Sears Hardware today for my laser trac and I can use my digital camera on it too.

Gunny

Ahh..where would we be without dremel tools. I also did mine and just about everything else with a dremel.

Jim,
If I was in a jet equipped with an ejection seat I would have punched out way before trying to put it on a runway while on fire. Pretty ballsy. I had my radio stack catch on fire at night in IMC about 2 months ago and that was about as much as I can take.
I wish I could have flown a real A-4 but in 1971 I still had 7yrs to go before I was even born.
I'm just a low time flight instructor/pt 135 cargo pilot at a school here in Idaho.

Anybody got any suggestions on how to get the lead edge of the wing just right? The contour sander I ordered did not come in, so I am not wanting to wait anymore. Is the lead edge on the plans pretty close to what we need? What methods do you use to guage correctness? - besides guessing?

Billy I just use a long sanding bar 18in with 80 grit sandpaper glued to it . Then just by feel and eyeball.

........... I just use a long sanding bar 18in with 80 grit sandpaper glued to it . Then just by feel and eyeball..........

Pretty much the same way I do it. I have a small finger plane that I use to do the rough shaping, bringing the upper and lower surfaces close, then try to draw a centerline on the L.E. with a felt marker and work to that. I make up sanding blocks out of pine and contact sandpaper to them. they work well. For final sanding I usually curve a piece and use my palm across the front.
Randy

Ok, guys,, I was different. My leading edge is built up 1/8 balsa. I cut each strip 3/16" narrower than the preceding one. The first layer was glued to the cores and sheeting. Then each layer was 3/16" narrower and glued on to the preceding layer. The ends were 45 degree cut and no joints overlaped anyother joint. I did this until I had the contour I wanted.

Then,,, I used the straight edge sander to feather the edges and round off the leading edge. This edge is important in how the bird stalls. Too pointed and it could have a sharp stall. Mind is blunt and stalls very nicely. But,,,,,,,,,,,,,,,,,,,, I have done NO spins to date, even though the guys still taunt me to do one. Jim

Well guy's, my engines came in today. They were very light, but they were larger in appearence than I expected. They resembled .40 size. I'll probably run the first one in a few days. I've got $ 220 in all of them. By the way, what tool do most of you use to cut the firewall line on the nacelles?

I'm starting on the landing gear bracing this weekend. I've got the axles, but waiting on the main wire.

Do most of you have a cut-out in the bottom of each nacelle to allow for clean airflow from the front and out the bottom?

Tommy

Tommy I used a band saw.. Jim

Well I've got 7 flights on the first engine. It dead sticked the first two until I richened it up a bunch. The rest have been flawless. Now I'm gonna make an enclosed cowl and see what happens.

How do you guy's plan on getting air to the engines?

Tommy

I installed my 4 strokes horizontal with the cylinder in the breeze and have had no problems.
Granted it would have looked better inverted fully cowled, But I wanted reliability first. Jim

................................But I wanted reliability first.

========I concur with Jim. I mounted mine just enough above horizontal that putting a glow ignitor wouldn't interfere witht the next engine. Since I'm flying off grass, I'm running mine at a high enough idle that I don't worry much about a flame out at low speed. Still has a real good decent rate like that. They will definitely look good cowled in though.
Randy.

Randy and Jim, do you think I will be able to get away with keeping them cowled, or is there just not enough air that can come through the small opening in the cowl and out the bottom to keep them cool enough?


Tommy

Update: Main landing gears. (My own design)

Pic. - 1. Upper railing (1/4" x 3/8" hard wood) glued to fues. at the top edge of the "hump" in wheel well.

Pic. - 2 & 3. Main landing gear plate. (1/8" birch ply).

Pic. - 4. Three wheel well former assemblies constructed from (1/8" ply, 1/4" x 3/8" hardwood and 1/4" balsa tri. stock.)

Continued from above.

Pic. - 1 & 2 show mounting of the Robart strut mounting blocks and mounting clamp rings.

Pic. - 3 Robo Struts and wheels installed.

Pic. - 4 Former assy's. screwed to landing gear plate with a temporary alignment guide rail.

To be continued:

Gunny

And where did those come from?

From Robart.

I really like the shock system on the robarts and will considering updating mine. Do you have part #'s ,, Thanks Jim

I bought The following for my c-130 "Robo stuts all around":

(5) #650 straight robostruts 3/8" --4 for the mains and one for the nose---------------------------$44.95 ea. total--$224.75
(5) #654001M mountings blocks----to hold the robo struts to the ply side plate---------------------$11.50 ea. total--$ 57.50
(10) #654003M steering arm yoke-8 clamped to the mains & locked to the side ply plate.
2 for the nose strut not clamped to anything so it may steer--$ 1.65 ea. total--$ 16.50
plus their shipping and handling charges-------$ 8.00

So the total gear strut assy. cost me just over $300

===================
Well Tommy, I just looked at mine again. For what it's worth, I believe that if you cut open the intake area on the front of the cowl where it is supposed to be, and the cylinder head is sitting directly in front of it, you will probably get enough cooling if you open up the back of the cowling enough. Some years back, I read a really good article about engine cooling. Don't remember everything, but I do remember the article saying that the only part of the engine you needed to worry about was about the top 1/3rd of the cylinder head, because that (obviously) is where most of the heat of combustion is generated. There was also some stuff about the opening to let the hot air out had to be at least twice the size of the inlet. I guess the reasoning there was that the cool air would be coming in, picking up heat and expanding, and need more room to exit. I guess you could give it a try on the ground. If it works on the ground it certainly should work in the air.
I have just never been a fan of inverted engines. Tried a couple, didn't like the trouble they caused, and at my age I'm not looking to add trouble. I considered inverting mine for a little, and putting on glow drivers and the works, then abandoned the idea for simplicity. If I don't want to see the engines, I just look at the left side of the plane!!
Maybe Bill Robison can give you some insight to this. He seems to be on top of stuff like that. I've sure used a lot of his advice.
Good luck,
Randy

>>EDIT for HTML coding. wr.

Randy:

I can't add anything to what you said. Very wll done.

Bill.

Yea Randy, I totally agree with everything you mentioned. I've found an old Tilex bottle that is very similar in shape and size to a nacelle, so were going to cut it and mount it on and see what happens. The only thing is, the engine is not inverted on the Duraplane. I'm sure there will be some difference.

Thanks again, Tommy

Pictures showing the "truck" wheel assy. being glued to the fues. / wheel well sides. The top row of 4 screws clamp the assy. in (to the top cross rail) while the bottom is tack CA'd to "clamp" the bott. end of the truck. In a nut shell. The 3 former assy's. are being glued to the fiberglass and to the top rail. The plate is removable.

Stay tuned.

Gunny

Wow Gunny, nice job on the gear set up. Looking really good.
Here's a shot of my current winter project. After some lettering, nose art and a few decals it will be ready for final assembly-just in time for spring.
Randy