Regarding the C-130 firewall issue, I had similar reservations about attaching the firewall to the fiberglass nacelle, without further support.

With my first attempt, I tried a plywood "profile" approach, using a single 7/16" thick profile, with the engine mounted on its side. I epoxied the profile to the wing and fiberglass nacelle. The result was a tremendous amount of engine vibration.

I attempted to solve this by balancing the props and spinners, but still could not get the vibration to an acceptable level. After some research and a lot of head-scratching, I determined that "profile" engine mounts are inherently flawed in that they are simply reacting to this little oscillating "mass" called a piston! With the piston at a "right-angle" to the plywood profile, it can't help, but vibrate - a great deal. In fact, if you were to observe any profile type airplane, you will note that they all vibrate excessively. All this to say, this was not a good idea for the C-130.

My second attempt is now underway and will incorporate a traditional plywood firewall epoxied to the fiberglass nacelle, with the addition of two plywood supports behind the firewall. These two plywood supports will connect the firewall to the wing, augmenting the support from the fiberglass nacelle.

Yeah, tell me about profiles vibrating! My GP P-38 is a pain. I was thinking with going something along the lines of what Jimcork has done. Just run a couple hard wood rails down the side attached to a 1/4" firewall and then bolt those onto the nacelle farther down closer to the wing. As for the front of the nacelle I would just glue some hard wood blocks on the front of the firewall and mount it like a cowl. I just finished cutting out the firewalls I just have to go buy some rails but I dont want to go jumping the gun until I get the airplane and plans. (If I ever do!)[:@]

I noticed rryman that you just bolt the fire wall right on to the front of the rear nacelle half. Any problems with the screws tearing out or is the fiberglass in that area strong enough??..................................
========================
Hawkpilot,
I have had no trouble so far with the arrangement I made. I did have two screws loosen up on one nacelle some time back, but I believe that was due to an out of balance prop. I guess I just "assumed" that they were in balance when I put them on, because I don't believe they just got out of balance from flying. Anyway, here's a pic of how I did it so you won't have to rummage back through all the threads. I basically made two 1/4" firewalls. the rear one is bolted to the nacelle with DuBro #2 button head screws. (a lot of them!) The engine mount is bolted to the front firewall, which is in turn bolted to the rear firewall. the cowling is bolted to the front firewall also. I did this so that if I had to change the thrust on any engine, I could shim between the firewalls to make any corrections, and the spinner would stay centered on the cowling, since the cowling would follow the adjustments. (I hope that made some sense!) Anyway, as it turned out, I didn't have to change a thing, the bird flew off the ground perfectly and I haven't changed anything since. So, if I take out the screws in the back firewall, the entire engine pod, fuel tank, servo and all slides right out of the nacelle, without taking off the spinner, prop, cowling, etc. Like you said, everyone has their own way of doing it, and they all probably work equally well. I'm just a nut about having to get to things I guess. Some of Murphys Laws:
1. Access holes are always 1/2" too small
2. If they are the right size, they are in the wrong place.
3. The least accessible part will be the first one to fail.

I have lots more pics if you need a shot of anything. This B-24 I'm building now makes the Herk seem like an ARF, but I'm enjoying the build. It's a well thought out kit.
Happy holidays to all,
Randy

Man, I love that Herk pic with Santa downloading it!

Thanks for the info! I've pretty much saved every pic from this thread so I could just pull it up quick if I had a question. I am really wanting to get started on this beast but again QF has screwed me. He agreed yesterday that he would send the rest of the kit out today 3 day air so I could get it by friday (UPS delivers on christmas eve) and he even gave me a tracking #. Well of course he didnt send it out and god knows when he will..I'm sure I'll get some off the wall excuse again. Good luck to anyone else that orders from QF!

Happy Holidays to all,

Enrique

Yes, the rails seem like a good idea. As for Bob Sealy's slow response, I'm not sure what's going on there. I've always had good service from Bob, he must be overwhelmed with orders - perhaps?

I've got some photos of my 130 if you would like to see them, please let me know.

Thanks,
Joe

Check a previous post and you will see the pics of my engine mount. The rails have not loosened and the vibration in minimal. The engines are very smooth when all 4 are running. The advantage of the rail is that it moves the stress point away from the engine and the rails provide a dampening effect to the sides of the nacell's which also helps to reduce vibration. I also used the black plastic type mount,, kraft I think. Only once have I found 2 screws loose on the rails. Consider there are 28 total screws for all 4 engines and only 2 were found loose. I did use blind (T nuts to some) on the back side. They are 4x40 socket head screws with a flat and a lock washer. I painted over the screws which makes it easy to tell when one is loose. The paint also acts as a lock tite. Jim

....The reason I'm starting on the nacelles is because after placing the order Nov. 8th all I've gotten from QF so far (20th of Dec) is 4 nacelles and the 2 center section foam wing cores.
===========
The wing cores were all I got to begin with, and I worked on those till I got the fuse. I believe Bob makes a lot of fiberglass stuff for other manufacturers in addition to his own stuff. As I recall, it took me about a month and a half to get all the stuff.
Randy

Hello to every one on this thread and merry christmas.I have read all this thread and wrote to a couple of you guys(thanks Joe(Grinder)for your reply)What I am looking for is some feedback on Dan Palmers plan for the C-130.I have read conflicting reports,some say they are rubbish and nothing fits and they are over engineered.Other people say they are the bees knee's.So if anyone has built or is building one can you let me know what you think.
[email protected]

Hey there, Ive been wanting to build a c-130, but I don't know where to buy any kits. Do you have any suggestions?
Thanks, Tommy D

Tommy,
Jet Hanger hobbies has a 133" one, and Quality Fiberglass has a 102" one. Far as I know, that's the only two kits available. I don't know a thing about the JHH model.
http://www.qualityfiberglass.net/ located in Cookville, Tenn.

Thanks for the info, Cookeville is about an hours drive from me.
Do you have any info about different props? Has anyone ever used 3 & 4 blade props?
I've had a little experience with functional 4 blades from Zinger on some P-51s and they flew the planes, but with substantial reduced speed and thrust.

Thanks again, Tommy

I should just pay you to go pick up my C-130 and ship it out to me since QF can't seem to do it.[]

Ok.... on the Quality Fiberglass Kits... realize that this is a home run business... not exactly a huge factory. I have had a small delay on my C-130, and all it took was a phone call. It may be because of other work, or just Christmas. The owner is a really nice guy and does good work. I would suggest giving him another call... he is a really nice guy and has a good product. Everyone gets tied up and runs behind this time of year.
Bill R.

PS Jim Corkern... I got my aluminum railing the other day and drilled out my engine holes.... I might be calling you soon.

Merry Christmas all!!

I don't know if this is the same manufacture but I saw a C-130 fiberglass kit at american eagle
www.flyrcmodels.com
Wyldman

I ordered this thing Nov. 8th, not recently.
Give him a call? Try a few calls. One of the FIRST questions I had when I ordered was how long will it take to get it. His awnser? He would have it shipped by the end of the week because at that time it wasnt busy around the shop. After 2 weeks of waiting I called only to find out he had not even started and got the end of the week excuse again. One week after that guess what, still not done. After that I called yet again and he says EVERYTHING was ready to go and hewas going to ship it the next day. Seven days later I only get 4 nacelles and a piece of foam. Then he waits until I call him, after getting this tiny little box, to tell me he still needs to ship the rest off and the box is sitting right there. Its a joke. I run my own buisness as well and would never get away with pulling this crap. I'll admit he is nice and was very helpful with any questions but delivery is terrible.

ANyway, sitting here trying to explain is not going to get it here any faster so I am done. If it hever does get here I look forward to building it when I get back from my small christmas vacation. Happy holidays guys.[8D]

Do you have any info about different props? Has anyone ever used 3 & 4 blade props?
I've had a little experience with functional 4 blades from Zinger on some P-51s and they flew the planes, but with substantial reduced speed and thrust.

Thanks again, Tommy
[/quote]

I'm having these made up for mine Palmer plans C-130 132"ws. Testing should begin in March. I'm using the RCV 90's

http://www.propellers.us/prop.jpg
http://www.propellers.us/prop1.jpg
http://www.propellers.us/prop1a.jpg

Grinder.

I think you are right about the multi blade props. If you look at the airfoil on the props in your pic and compare to MAS or APC you can see how you lose efficiency. This means more power to get the same thrust. Sorry I don't have the airfoil curves to show you. However if you get the air foil to match the better prop you can improve your multi blade results but won't match the same amount of thrust / power input, at least in the model category. The real herk used them due to high power turbines and limited space for a 2 blade prop due to engine spacing. (engine spacing,, sound familiar in relation to prop size).

You must consider on a model the time for blade 2 to enter the same airspace that blade 1 just left is very small due to the diameter and circular speeds. On the full size herk ( at least the E model as I remember ) THe 4 blade prop turns 1021 rpm,, much slower than a model engine and when blade 1 of the full size space is occupied by blade 2 a far greater time has elapsed and the blade has moved through the air stream much furthere. This allows for cleaner air and improves efficiency.

Hope this helps you with your work. Merry Christmas.. Jim

I agree with your analysis on the props, Jimcork. While I'm neither a scientist or engineer, I have done some testing of 3 blade props, and have found that they will not even come close to the efficiency of two blades. If you have a plane that is overpowered, such as my TF AC-47 with .40 engines, then running 3 blades will work fine. The reduced efficiency of the props makes it fly very scale. The down side, of course, is keeping a close eye on your take offs. You can't just horse it off the ground with engine power. The RCV engines however may work with the multi-blade stuff, since they are running lower rpm. In any event, they are some fine looking props you're getting made, Grinder.
Randy

Well guys, I bit the bullet this holiday season and decided I MUST get some work done on the C-130. I cut my elevators out of the hor. stab... of course... I cut them too long. I am having some trouble with the stab seating in the saddle. I cannot seem to get the front aligned right. I am going to cut my nacelles today and try to make my firewalls tonight.... maybe even try to get the engines mounted in the nacelles by the end of the week.

Have any of you looked closely at the alignment of the actual core edges when in the saddles? On the first wing I built and the second as well, I found them to not be aligned at some points. they would be as much as a 1/16 twist between cores. I think I am going to glue the cores together first (1 piece wing), then sheet them in the saddles once the cores are bonded together.

Any pointers on the hor. stab?

Hope everyone had a great holiday

Bill Richardson

The stab is where I had the biggest problem and it affected flying seriously.

I would use the flat portion of the wing saddle on the fuse. as a reference point.

NOTE: I used the Robart indicent meter for this work.

1) Use the flat saddle and level it using a graduated level.

2) Take the horizontal stab and attach it to the stab saddle.

(I had drilled my 2 nylon mounting bolt plates and use the nylon bolts)

3) Shim the leading edge of the stab for a MINUS 2 Degrees.

(I know you are asking Minus? but consider if the stab is Minus 2,, when the stab is ZERO the wing is at +2 Degrees,
The +2 Degrees has worked well on mine and I experimented from - 2 in 1 degree increments until I reached +2)

4) Mark the leading edge of the stab on the fuse and this will give you a reference to mount the stab.

The Leading edge bottom of the stab was just about flush with the bottom of the fuselage where they touched.

Hope this helps. I would consider this a critical step.

Jim

Now for the wings.

I made a 1/8" ply rib former for the join points at the removable wing tips. Then I drilled a 1/4" hole in the leading and trailing edge of the rib for a short dowel. I white glued the ribs to the cores with the dowels in place but not glued. I also used the foam wing saddle to hold alignment until the white glue set.

I would suspect my wing also has a very "small" amount of twist on the right wing tip but not enough to affect flying. The only reason I think this is true is during power off stalls the plane will always drop the left wing tip first. I can not see or measure any twist in my wing.

The wing setup was a real thought process but when I spent about a month looking at the cores,, I finally figured out how to build a straight wing.

Good luck.. Jim

Great Pic in AMA Magazine this month.. Jim

haven't gotten mine yet.... what is in it?
Bill R.

BillR:

Mine came yesterday.

It's a picture of Randy Ryman with his C-130.

Bill.