F-100D Build Log Col. Art Johnson Plans - RC Groups
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May 07, 2015, 01:32 PM
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Build Log

F-100D Build Log Col. Art Johnson Plans


Hi All,

Originally this started off as a question about foam core wings.. Since I got the question answered and already seem to have a thread going on my project, I just decided to convert this to a build thread.

I have a lot of experience scratch building all kinds of things, however, this is my first scratch of an Airplane/jet. I am using the plans from Col. Art Johnson. I plan on using a 120mm or somewhere there abouts EDF unit...

I guess it's still a scratch even though I am using plans and I paid someone else to cut the wood for me... saves me that much anyway. Everything else is up to me.


Hi All,


I have a question about foam core wings...I am in the process of building out a wing however, it calls for foam. What kind of foam do others use to make foam core wings? I've got plenty of that lowes foam I used for plugs, but I am not certain how suitable it would be for a foam core wing. I guess one concern is how heavy that foam might end up being.
Last edited by erospawn; May 12, 2015 at 09:46 AM.
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May 07, 2015, 01:59 PM
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turbonut's Avatar
Depends on many things.. what is the project? most use standard eps white foam..like the home depot stuff..I have used the same for a lot of wings but it is very soft. gliders tend to use blue foam or pink. weight of the foam will be up to the user opinion a lot.
May 07, 2015, 02:05 PM
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It's for an F-100 short kit...
May 07, 2015, 05:54 PM
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turbonut's Avatar
I would use white styro...EPS home depot stuff..then balsa skin and glass
May 08, 2015, 08:22 AM
Registered User
Thanks..sounds like a plan. I wonder..,. I guess I'd have to do a straight up plug if I wanted to do strictly glass. May as well do that too...then I'll have an old fashioned one and a glassed one.
May 08, 2015, 09:27 AM
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CoolerByTheLake's Avatar
Quote:
Originally Posted by turbonut
I would use white styro...EPS home depot stuff..then balsa skin and glass
Good advise on the wings--I've done some that way

Don't bite off more than you can chew!! Just get the wings done first. And build your kit. You have no idea how much time , work and money it is to pull a fuse off a plug- I know first hand --I did this one. 1/7th scale F-86F . And I don't think I'll ever finish it
Cooler
May 08, 2015, 11:14 AM
Registered User
Quote:
Originally Posted by CoolerByTheLake
Good advise on the wings--I've done some that way

Don't bite off more than you can chew!! Just get the wings done first. And build your kit. You have no idea how much time , work and money it is to pull a fuse off a plug- I know first hand --I did this one. 1/7th scale F-86F . And I don't think I'll ever finish it
Cooler
I do have some idea 1/8th scale Sikorsky S-76D
May 08, 2015, 01:23 PM
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turbonut's Avatar
Thats cool!
May 10, 2015, 09:10 PM
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So, I worked this week and got one wing built and almost covered. I'm not sure where I'm going with the wings just yet. I need to see how they mount into the fuselage because I would like to be able to assemble/disassemble them for transport. I went ahead and used the formers the plans called for and I if I can, I might make the wings just one piece that bolts into the fuselage.. I'll have to see how that works out once the wings are built and I can see how the wings mount to the fuse... It's look like a one piece wing is going to be the way to go as it stands.

I skinned the wing on the top...along with flaps and ailerons. But, again, I'm looking to the more experienced guys for help along the way...

Currently, the wings, flaps and ailerons on one wing are skinned on the top... I am leaving the bottom unskinned so I can add the foam to the wings, plus servo mounts and retracts .. and get an idea of how to settle all that...

As for the flaps and Ailerons.. Question: I am unclear if the plans call rounding off the the flaps and Ailerons where they mate to the wing itself. Should I round off the edges on the Aileron since they will be moving up and down? Also, about the hinges... I'm not sure I like plastic Robard hinges... What do the larger scale planes use for hinges? The plans call for an Aluminum tube with bearings etc...


Total weight on one wing so far is ~11oz..
Last edited by erospawn; May 10, 2015 at 09:24 PM.
May 11, 2015, 10:33 AM
Registered User
After a bit of research, I think I'm going with the large Robart Pinned hinges. They are for 1/4 to 1/2 scale anyway and I think they'll fit.

I've also been looking over the Wing connection points. I think making the wings separate and being able to bolt them together and to the fuse should not be a big deal. Although the model calls for laminating and carbon fiber tape on the leading and trailing edges of the wings, shouldn't covering the model with a layer of fiberglass and epoxy thinned with denatured alcohol provide a similar strength?
May 11, 2015, 11:38 AM
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turbonut's Avatar
Looks like you are moving fast. What plans are you working from(size) I would not use thinned epoxy. I use west system mixed as designed. Thinning changes it properties
May 11, 2015, 12:57 PM
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Im using the plans developed by Col. Art Johnson that were in RC magazine some years back, 1983 I think. I am "modernizing" them so to speak. http://www.outerzone.co.uk/plan_details.asp?ID=5940

56" Wingspan
~67" Length
Weight ~12-15 pounds ...Im hoping it comes out a little lighter than this.

I picked those plans mainly because I found a company online that was using the same plans and providing the formers already laser cut. I figured it was worth the money to already have everything pre-cut.

I got the idea for thinning epoxy from the video link below. I thought by thinning, it would allow the Balsa to absorb the resin better and thereby improve strength.. I've got plenty of Epoxy resin and glass from USComposites that I've used on other projects. I was thinking of using 1/4 Oz Fiber glass clothe.

Fiberglassing Tutorial (17 min 20 sec)
Last edited by erospawn; May 11, 2015 at 01:08 PM.
May 11, 2015, 09:03 PM
deltas are cool
AIR SALLY's Avatar
on a plane that method might add a lot of weight. I guess one could try a test piece then weigh it and see which way is heavier. most epoxy company's will tell you not to thin with alc.
May 12, 2015, 12:47 AM
Anything that gives me a High
super kupfer's Avatar
https://www.rcgroups.com/forums/show....php?t=1982818

Been following this thread, very nice work.
May 12, 2015, 08:30 AM
Registered User
I tried searching for other F-100 builds that were using the same plans. I only searched for Art Johnson, the maker of the plans. Either way, looking through that thread, that was what I originally was going to do.. I still might though.. making a plug seems a bit easier than stick building, at least I think so. This is my first Airplane from scratch and on a large scale at that. I went big'er, but I can't go too big because it won't fit in the back of my truck lol.
Last edited by erospawn; May 12, 2015 at 09:46 AM.


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