Converting telescoping pole to fixed

[Wilson]

Like a lot of other folks, I found out too late that telescoping bird house poles aren't all that and a bag of chips. I posted a question about a suitable replacement in the main forum but didn't get any help.

Long story short, I did come up with a stopgap fix. It might (underline might) last more than the one season but I hope to replace it with something more robust (and that doesn't need a guy wire) in the coming winter. So I'm not promoting this is an ideal solution, just something that met my two primary objectives (low cost, fixed pole) and that might lead others to better ideas.

If it was going to have to be a fixed pole, it also was going to have to use a yardarm, pulleys and a rope. And I wanted to spend no more than 25¢. I busted my budget by about $60 (not including bits of hardware, glue and pieces parts I already had lying about) but I decided to use the original telescoping poles in combination with a length of PVC tubing.

I bought a 20' length of 2" ID PVC tubing (cut to ~18'), a 2' length of 1-1/2" ID PVC, one 2" tee fitting, one 2" cap, four 1-1/4" caps, two pulleys and various and sundry small bits. The end result is the old steel pole is captured inside the PVC tubing, and both are mounted on top of the original socket pole. All the caps serve as 'grommets' to keep the steel pole more or less centrally located within the PVC tubing.

The tee is glued to the top with the 1-1/2" tube running through it to form the yardarm. I mounted pulleys inside the smaller tube, suspended from the top so the rope runs through the inside of it. While I was at it, I used the same hardware that's securing the pulleys to mount small diameter steel rods to the top of the tee as perches.



It was a 2-man job to erect. Because nothing is fixing the inner steel pole lengthwise inside the PVC pipe, you can slide the pole down until a foot or so extends out the bottom of the pipe. Then one guy tries to guide the inner steel pole into the socket pole while the other guy gradually "walks up" the PVC tube, all the while supporting it enough it doesn't ride down the steel pole and "guillotine" guy #1's fingers against the mouth of the socket pole.

I wasn't sure how much lateral rigidity the PVC would add but, as it turns out, it wasn't much. I had hoped it would lean less than it does under the weight of the house (~11 lbs), but that's why the yardarm extends further out the back than it does the front. It was so I could add a counterweight, if it was needed. I also took the precaution of attaching a rope to the tee to tie the weight onto before I put up the pole.

Once I got it set up and wasn't comfortable with the amount of leaning, I also didn't have a warm fuzzy with the idea of adding even more weight to the top of the pole, which increases the chances it might get permanently bent by strong winds, so I used the rope as a guy instead. There's just enough tension on it to keep the pole near vertical. I was lucky to have a short tree close enough and in sort of the right direction from the pole to serve as an anchor for the guy that keeps the rope high enough off the ground not to be a safety hazard when I'm mowing the lawn walking across the yard in the dark of night.

But the PVC tube/pole did give me a simple way to top it with a yardarm and pulleys, which is key to a fixed pole, so it wasn't a complete waste.



Also yet to do: replace the cotton twine used to keep the house aligned to the pole with bungie cord, and use a hefty trucker's bungie cord to manage tension on the guy rope, and act as a shock absorber.

I've not yet figured how to prevent the pole turning when the house "weather vanes" in the wind but that's tops of my must-do list. The whole rig appears a bit noodly, but spring thunderstorms aren't too far off, so I should know soon whether it'll survive the season.

[Wilson]

I think I've got the problem of twisting in the wind cured.

I fitted an automotive hose clamp to the bottom socket pole, which is set in concrete. Then I cut a "keyhole" in the 2" PVC pipe so the pipe goes back into the bottom end cap but the cut-out fits around the worm drive on the hose clamp:



I cut the top of the hole with a 1" hole drill. It looks oval from this angle but the top of the keyhole actually is semicircular, which I thought was needed to prevent stresses concentrating around the cut-out and possibly causing cracks. And the end of the cut-out is captured in the end cap, so no worries there.

After the hole, I cut straight down to form the keyhole with a dremmel tool. I was lucky it fit so well around the worm drive but if it hadn't, I could have adjusted the angles of my dremmel cut-outs to keep it snug.

Extra points because the head of the adjusting screw is still accessible, so I can loosen it and adjust the position of the pole if I think it needs it without having to disassemble the whole shebang.

So now the pole can't twist in the wind unless it turns the socket pole in the concrete.

[Wilson]

I suppose last night the new pole got the acid test, and it didn't end well. We had a big thunderstorm pass through with 40 mph winds. This morning the pole has a distinct but not catastrophic lean. The pole looks to be bent but it could just appear bent because it's no longer vertical and it bows under the weight of the house. I grabbed the pole at the base and attempted to rock it and it did move, so the storm appears to have loosened my concrete base. The original pole was only 14 feet long but I lengthened it to 18 feet. I dug the hole to the dimensions prescribed in the instructions that came with the pole, but the longer pole amounts to a longer lever acting against the base, so this might not have happened with just a 14 foot pole. Not really the fault of the "conversion," but my failure to anticipate the added strain against the base.

In any case, I have one nesting pair and five chicks that hatched three days ago. The storm pushed the temperature down to the high 50s and I'm not comfortable driving off the sitting mother martin to check on their welfare when it's so cool, so I'll wait until it warms at least to 70.

[Wilson]

I think I've finally got it done right.

The logical answer to my problem was a steel pole. But finding a suitable steel pole was proving to be a problem on a couple accounts. First, all the poles I could find being sold either as a flagpole or as a bird house pole had a pretty steep "brand name markup," like north of $200 in a 20-foot length. And they all were round poles, which aren't as flex-resistant as square tubing. And round tubing was going to severely complicate my plans for constructing a "yardarm," the horizontal structural member at the top of the pole, from which the house was to be suspended.

And I wanted to start with a 20-foot pole, which also proved to be a problem. Home Depot and the like don't stock metal poles longer than 10 feet, and I wasn't about to try to bond two shorter poles together. But steel yards that sold 20-foot stock didn't want to sell to me except by the ton.

Out of desperation, I E-mailed every steel yard and pipe and tubing wholesaler within a hundred miles, asking for a quote on a single 20-foot tube. Low and behold, I found one about 25 miles away. So I got a 20-foot 2"x2" cold rolled steel pole, 1/16th" wall thickness, for a whopping $70.

I wasn't sure a sixteenth-inch 2x2 would be rigid enough so when I got it home I tested it by mounting it as rigidly as I was able (non-permanently), attached a temporary stand-in for the yardarm made from a 24" Irwin QuickGrip clamp, then I applied a 30-lb load (measured with a fisherman's scale) perpendicular to the clamp, 12 inches from the pole (which pretty closely replicated the final configuration).

The pole deflected about two inches under load, more because all my jury rigging was shifting than because my the pole was flexing. Nonetheless, since my house (clean and empty) only weighs 11 lbs, I fixed two inches of flex as my worst case scenario, and I decided to erect my pole with two inches of backwards lean. I figured that way the weight of the house could do no worse than to pull the pole perfectly vertical.

A buddy did the cutting and welding. We started by cutting 16 1/4" off one end to be used for the yardarm. Then we cut a "baloney cut" or bevel on both ends of the yardarm to provide 1 1/2" of overhang for the mounting of the pulleys. That way the pulleys would be somewhat sheltered and I could run the halyard inside the yardarm.

Then we welded the yardarm onto the end of the rest of the pole so that there was 11 1/4" of the bottom side of the yardarm extending from the pole. My bird house is 22" wide, and that 11 1/4" would give the house near ideal clearance from the pole. Then I mounted pulleys on either end of the yardarm via U-bolts bolted from the bottom into the top of the yardarm.

I decided that standing up an 18' birdhouse pole with the house and all the hardware was going to be too involved, so I cooked up a way to cement the pole into the ground so it could be removed. That way I could stand up the pole with nothing more than the guy lines I needed to hold it straight, let the concrete set, then take the pole down, remove the guys, attach all the hardware and ropes and the house, then stick it back into the socket in the concrete (this also would be handy for finishing painting the steel pole, which was interrupted by last week's cold weather).

To mount the pole in the ground, I bought a $10 roll of "flashing," which is really thin, easy to bend sheet aluminum, used for joining air conditioning ducts and the like. The flashing was 10" wide, so I cut off a 2-foot length of it and bent it four times around the 2"x2" tube (with an inch +/- of overlap). That way the bottom two feet of my pole -- the portion that was going to be in the ground -- was wrapped in some pretty flexible aluminum. I secured the flashing to what would be the bottom of the pole with zip-ties, then dropped that end of the pole into the 2-foot deep hole in the ground. The idea was that the flashing would bond to the concrete but not the pole itself. And once the concrete had set, I should be able to slide the pole out of the aluminum sleeve, leaving a reusable but snug-fitting concrete socket.

The fact that the Pole Version II wrenched its concrete socket base in a storm told me I wasn't using enough concrete, so I enlarged the hole. I calculated the new hole size to accommodate 150-lbs of concrete mix, twice as much as I had used previously.

When I put the pole into the empty hole in the ground, I had a makeshift plumb bob tied to the backside of the yardarm. Once I stood up the pole, I could tell at a glance from the position of the plumb bob whether the pole was perfectly vertical. That also made it a cinch to dial in the two inches of lean I wanted. So I rigged three guy lines tied to tent stakes driven into the ground at roughly 120° intervals, stood up the pole, got my vertical, got my lean, and then poured the concrete.

I gave the concrete two (cold, wet) days to set before I tried to remove the pole. It scared me at first because it didn't want to budge, but I rocked the pole a bit and it came right out, leaving a perfect and reusable socket.

I attached all the hardware, and routed the ropes, then put the pole back in its hole (much easier to get it out than to put it back). My ultimate goal is to set this up so my aging mother can lower and raise the house by herself, so I hung the house via a simple block and tackle with a 2:1 mechanical advantage. The halyard runs through a pulley attached to the house itself, which mean the house rises one foot for every two feet of rope you pull (hence the 2:1 MA), so it should only take seven or eight pounds of force to raise.

If it still proves too much for my mother to manage, the next (and final) modification will be to attach a hand winch, the kind used on boat trailers, to raise and lower the house by. They're only about $23 at Harbor Freight.




According to my carpenter's level, the pole had EXACTLY half a bubble of lean when under no load (the legendary half bubble off plumb ). With the house hoisted and secured, it was EXACTLY half a bubble off plumb. Still. Turns out the pole is rigid enough that it exhibits no perceptible bowing under the load of the clean and empty house. Which means all my fretting over measuring the flex and leaning the pole by two inches was for naught. But you can't look at it and tell it isn't perfectly vertical. At least I can't.

So here's how it's looking now:



Still needs a bit more paint, I haven't yet attached the cleat for tying off the halyard, and I'm still engineering the "harness" to keep the house properly oriented to the pole but with an elastic component to absorb some of the battering the house would take in the wind if it were connected rigidly. But otherwise, I am well pleased with how it's turned out. We had wind gusts today of up to 20 knots, so I got a good idea of how durable it will be. The house got slapped around pretty good, but the pole was only moving an inch or so at the top, a dramatic improvement compared to Pole Version II. Especially after all the money and labor I've wasted getting to this point, I couldn't be much happier.

Here's the detail of how the house hangs from the yardarm:



The third pulley is out of sight slightly inside the "chimney" , inside the pipe that clamps the house together. That gives the hardware a little shelter and also lets me pull the house right snug up against the yardarm.


If I had it to do over, I wouldn't have "cheaped out" and bought the Heath house that's supposed to mount on the four telescoping poles. The telescoping poles aren't as easy to operate as I'd have hoped, and my aging mother could never have managed it. The PUMAs are so entertaining, and Mom's gotten so invested in their upkeep, in the end it would have been worth it to me to buy a more upscale house from the outset, one made for mounting by a pole that runs through its center (with its weight balanced all around the pole), and that's handier for a frail old woman to manage.

But once I was committed to the Heath house (which I figure I am, on account of that whole "nest fidelity" thing), I should have done a more thorough job of searching for a source for the steel pole. The house now must be at least 10x more secure than it was on the hybrid PVC and telescoping steel contraption I referred to as Pole Version II, even with the guy wire, which it couldn't have survived even the one season without.

But with the new steel pole, I say ...BRING IT ONE, HOMES!!


EDIT:
Over the weekend (written 3.25.2013) we had wind gusts as high as 43 mph, and neither the house nor the pole visibly is any worse for it. I will lower the house in the next day or two to clean out the HOSP and starling nesting material and will check the rope at that time to make sure it isn't damaged. I actually was watching it during a 40-mph gust and the house was dancing a jig but the pole hardly moved at all.