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Hi Craig,
The masthead piece is not ceramic, its stainless steel, I believe. If you look at some vintage photos where the light is just right, you can clearly see this to be the case. The ceramic piece in the antenna system was the insulator / fairlead at the top of the rudder.
Anyway, a few years ago (ok, probably a decade), a former L-5 owner named Jason Sharkey had access to a 3D scanning machine and had a batch made from an original. I imagine that all were probably sold and at least a few found their way onto some L-5 restorations. I was given one with a slight defect and have not used it yet but, alas, It’s buried in a box somewhere in my overstuffed hangar that is over 3,500 miles away from me. So, I can’t help at the moment and I won’t be back in Phoenix until next month, but it gives you a lead to follow up on.
I no longer have contact with Jason since I invited him out of the club due to his extremely mercenary price-no-object approach to scouring up highly sought after L-5 parts and RCA radio equipment and reselling at exorbitant prices, but I think you can locate him through the Indiana DeLorean Auto Club. If you’re a member of the LinkedIn network you can probably find him there too.
JG
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Hi Jim: Kinda unusual that the head is metal rather than ceramic. I know someone that has one, probably from Jason. I’ll see about borrowing it and making a cast pattern off of it. I’m not up on casting stainless, but using a 4 axis mill could replicate them reasonably quick. Will have to cogitate on it a bit.
Craig
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Hi Craig ,
The reason a metal head works is because the tube which it sits upon is made from phenolic and it is non conductive, (this is referring to the mast and head which protrudes through the top of the cabin).
If you are referring to the insulator on the rudder , it is indeed ceramic. I spoke with a local ceramics expert about making one 22 years ago. This was back when people could take a “ceramics class” through the YMCA or community colleges . Apparently , making garden gnomes and flower pots is a different classification of “ceramic”. Different clay, and firing process is used. So at the time, I was unable to get any produced. I made mine from Bass wood tuned on a small wood lathe. I painted white and coated with epoxy resin. It was not intended to be a long term solution, but it has been going 21 years:). I will help pitch in for set up costs if you are making rudder mounted units. Sam Taber
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Sam: Thanks for the info on your tail piece. Most of the mastheads on faster birds have been ceramic, so this was a little surprising. After years of searching, I did find the answer on how the radio connects to the long wire. There is a mushroom shaped fitting at the base of the mast that is steel of some sort, that the antenna lead from the radio, is jumpered to. The antenna wire simply passes thru this fitting, giving a surface contact and allowing the RF to pass to the wire. An acquaintance of mine that restores lots of old military radio gear, happened to post a photo of his RCA long wire system and there was that fitting. I’ve got the dimensions, so just need to draw it up and send him a copy for checking.
I’ve got a pretty good idea on how to slip mold the tail insulators, but need to get my hands on one for a bit and to create a pattern. Lanny has one over at the hangar, and I should be able to pull a pattern off if it.
Working on the antenna reel drawings right now, and correcting some hardware errors from the pattern unit that I am using. Drag cone drawings are next after that.
The IN-83 insulators for the antenna wire between the radio and the mast, have become very hard to find in any quantity. I think I’ve located a source for a current production bead that is extremely close in all dimensions and even color. I’ll probably drop them an order, as soon as I can verify the dimensions from the package of IN-83’s that I do have. I need about 600 for another aircraft project that takes the same ones. A package of 1000 pieces is relatively inexpensive, so we shall see.
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Craig,
If you are referring to the fairlead coming out of the top of the aircraft, I think I can help you out. Recently we made the metal fairlead piece that sits on top of the phenolic tube that exits the aircraft that the antenna wire goes through. We took an original, had it 3D scanned and cast in brass then nickel plated as the originals were. I will check to see if we have a spare, if not we can get them made.
If anyone else is interested, let me know. We could place an order. They are a bit expensive, they run about $130 a piece plus another $10 for the plating.
As for the ceramic leads on top of the rudder, we are unsure how to get those made. We don’t have one to copy anymore, but I think we can borrow one. My thoughts were to either have it 3D printed in ceramic, or milled out of ceramic. I know it may sound strange, but I looked it up and people can do that now.. it really is amazing what can be done!
If you are making the cones too, that’s great! We are trying to reproduce them too. Thanks to a good friend on here for letting us borrow one to copy a while back we were able to get the dimensions of the base and make a copy of the rubber stamp that was molded into it when it was rubberized. We are nowhere near ready to make it, but in the near future we will try.
Anyway, I hope we can help you and any other members in search of that part. I have no control over the price unfortunately.
Sean
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Sean: Count me in for one. I’ve got an acquaintance that came up with one of the fittings at the bottom of the mast and has given me the dimensions. It’s a stepped mushroom and is some sort of coated metal. Haven’t worked that out yet.
I finished making sketches this morning of all the components of the antenna reel. I’ve got to get them into CAD and start correcting them and bringing them to standard dimensions and materials. Whom ever executed this one, did so without much accuracy on some things and way too much on others.
For the ceramic cone on the rudder, I was thinking of doing them in a reverse lost wax process…3d print the mold and slip cast the part. I haven’t done any ceramic work sine I was in junior high, so been away from it for a long time.
Re: drag cones…. I have two here on the desk to copy. One is the black rudder/plastic style and the other is an acetate one. They are of different sizes, so I’ll draw up both. Neither has any kind of attachment hardware, so that would need to be sorted out as well. My thinking, is that I’ll come up with a small wire frame and sew up a nylon cone instead, like a tiny wind sock.
Craig
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Craig,
Send me an email at ayres1989@gmail.com
That goes for anyone else interested. If we get enough people we can make an order, if not I can put you in contact with the company and you can get one from them directly. I’m not sure of the current cost, but a few years ago the price I quoted was what they were when I ordered almost 20 of them.
Sean
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Regarding the ceramic insulators IN-83, I ordered from Isolantite item #1084, which is a very close replacement. I also ordered the IN-84 insulator, item #503, for my G model from them. They are the original vendor for our L-5 and was quite interested in my airplane and installation of the SCR-274 radios.
Mary Lou Hall was my contact at Isolantite.
Charles
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