Need some help with sch 40 mast

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I found a design for a 21ft tip up mast that I like and I would like to copy but make it 42ft instead. The problems I have seen with the basic setup is a weak hinge point and the base should be stronger but I'm not the expert here. What I would like to do with this mast is place a small wifi plate antenna (or a yagi) at the top and weld a sleeve into the middle. Now my problem is, what size is the pipe required for sliding into the 2in sch 40 and what would be the best way to make a better pivot point?Yes I understand this can and will kill me if I let it which is why I am trying to strengthen the weak points of the design.http://wiki.radioreference.com/index.php/Tilt-Over_MastLast edited by black_doggy; 06-05-2014 at 07:46 PM.
Reply:1 1/2 sch 40,80,or 120 etc all fit slighty loose inside 2 sch40, the only difference is their ID gets thicker. 2 1/2" sch 40 fits nicely over 2" sch 40. 42' is geting pretty long depending on whats going on top.  I would think your almost in triangular,stackable truss territory there.
Reply:I have not done anything like this . It looks ok but there is a lot of difference betwine 21 feet and 42 feet . I personally do not think  2" schedule 40 will make a free standing tower I would want at least 3 sets of guy wires.   I have some 2" schedule 40 it seems pretty limber in the horizontal position.  Have you thought about wind on the tower? To answer your question I do not know. Just my opinion. Good luck on your project .
Reply:Be really flimsy at 42 ft with just a single pole last last I made that tall was out of 12inch sc40 and it still moved a lot at that hight. I'd think you'd want to go with what blackbart said you'd have to use a triangle frame structure to reach that height you could still do the same idea of have it fold down just have to come up with a def approach to it.
Reply:I looked at the pictorial presentation in the link black doggy posted.That person's style of tilting mast was a little similar to a birdhouse mast I built for my mother in law a few years ago.The concrete  base slab for my birdhouse project  was not so deep as the hole featured in the radio mast project, but it was 3' X 3' and 9" thick at a depth of 8" below the yard surface (bottom of that section of pour was approx. 17" below the lawn surface).  The center section of the base slab was a formed rectangle 15" X 18" and rose to a height of 3" above the yard surface.  The reason I did it like that (small top, wide bottom) was so there would be a wide footprint for lateral stability, but with a small appearing base showing above ground.  And the weight of 8" of soil backfilled on top of the underground portion of concrete is just as effective as "ballast" as if the area comprised within that perimeter had been entirely concrete.One thing I think the man who built the radio mast could have done to make his installation a little neater would have been if he had driven his grounding electrode into the center of the 5' deep hole, to the prescribed 8' depth, BEFORE he poured the concrete.  Had he done that, his grounding electrode would be situated inside the circle perimeter of the pour, instead of over in the yard some inches away.  Maybe he learned of the requirement for the dedicated grounding electrode "after the fact".Kinda cute how he used the mini weatherhead right next to the lawn surface for the radio cables to emerge from the conduit.A few shots of my bird project below. Attached Images
Reply:BD, I have been looking at that same design.  example I saw used 2 1/2 sch 40 and 2 sch 40 20' sticks and got about 38 feet out of it.  I'm looking at holding up a horizontal delta loop HF wire antenna so very little weight.  Was thinking about using a clamp and 10' stick of chain link top rail pipe to get another 8 feet or so with minimal stress or weight. I'll be building two of these in the far corners of my back lot. Issue I'm running into here in the Pacific Northwest is sourcing the pipe.  I'm planning to improve the hinge/mount with a plate bracket instead of 3/8 bolt.
Reply:I was happened to get lucky and find two pieces of brand new schedule 40. The only thing going on top of this mast will be one small WiFi antenna about 2 pounds at the most. I have some  rings that I can attach in the middle. I should not need to worry too terribly much about wind since this is a round tube with a small square plate on topSent from my XT1080 using Tapatalk
Reply:I'm thinking of Flag Poles.......Seems though some are 3", then 2" while others are 2" and a few 2", then 1-1/2", maybe only 30'?Most good ones have the channel legs(like Bird Feeder project) to tip up on and not over center!2" at 40' is a long ways, it will sag a little(verticla bow) with guys wires, lean a little without wires.Keep it 42 feet from anything you don't want damaged and put it up!