Author Topic: Thursday June 29 (Read 7208 times)

DanB · « **on:** June 30, 2006, 01:36:35 AM »

So this 'Thursday' posting kind of covers everything from last Wed through today. Last Wed I went down to Daves Caboose and helped him a bit working on his cord wood sauna/bath house. Should be pretty neat when its done!

This was the gear/magnet rotor for the old Wood Axe wind turbine I made a few years ago. It was the only hub I had on hand that fit my winch so I cut the center out of it with a hole saw so I could weld a bit of an extension on it, turn it - and fit the sprocket for my winch (that will hopefully pull my tower up)

There's the winch pretty much finished up. It's got a 1hp 1725 rpm motor on it with a reversing switch that I mounted to the box on the motor. The sprocket on the motor has 10 teeth, on the winch we have 60. It's #40 chain. The winch has a 36:1 worm gear reduction. It's rated 6000 pounds, I think I'll only need about 1600 pounds of force to pull the tower up. The cable will be attached to the pad, then it'll go over a pulley on the jin pole, then to the winch.

We put legs on the tower base/pivot and setup the jin pole exactly where we need it. This makes it easy to position the winch. Once everything is where we want it will dump concrete over it.

We setup the winch on boards over that large 10KW Okeef Merit generator that we dropped in the hole. We got the winch square with the jin pole and level and then welded it to the generator with large angle iron and lots of other bits of scrap steel.

There's the winch mounted to the generator with lots of other scrap welded on in different places - ready for concrete.

The west most hole is about 5 feet deep and contains the better part of a model A Ford running gear.

The North hole has a model A rear end, a cracked model A cylinder head and a bunch of 'Volvo brake disk windmills' that never got built.

The East hole was tough. We hit solid rock at about 2' in part of it and 3' in the other. I drilled lots of holes in teh rock and epoxied in re-bar and then welded stuff to that. It's surprisingly rigid - there's room here for about 1.5 - 2 yards of concrete, then we'll mound up lots of dirt on that. Hopefully it'll be OK - this is the one that worries me a little bit but not much.

This is one of the 10' long blade blanks for the wind turbine. Heavy!! - Im a bit worried about that but I think it'll be OK. I expect the finished blades will be around 30 pounds each. These are 8" wide at the tips and 15" wide at the widest part. The root will be about 3.25" thick.

This fellow surprised me this morning! I came out the back door of my shop and he was about 20' away - we both jumped! He just came by to inspect my anchors before the concrete truck showed up.

They showed up around 10AM this morning with 7 yards in the truck (thats the most they can bring up the hill).

There goes the O'Keef Merit generator!

At least 3 yards went here - I don't think its going anywhere, this rock, with generator and all should weigh well over 10,000 pounds.

Tim came down to help - it was a pretty easy 7 yards of concrete, not much work really. It went a bit further than I thought - I was worried Id run low before the last hole got done but as it was I got more in each hole than I expected. I can't say all this is going to work as planned, but the anchors should be solid and its all been good fun so far. Perhaps Monday we'll raise the jin pole and start rigging up the tower.

willib · « **Reply #1 on:** June 29, 2006, 07:49:05 PM »

Dan is there anything to hold everything up if the chain breaks?

just want to make sure...

awesome blades !!

DanB · « **Reply #2 on:** June 29, 2006, 07:52:35 PM »

hmm... what chain? not sure what you mean.

willib · « **Reply #3 on:** June 29, 2006, 07:55:53 PM »

The chain from the motor to the winch

wdyasq · « **Reply #4 on:** June 29, 2006, 08:48:48 PM »

Only the design of the winch.....

Ron

RP · « **Reply #5 on:** June 29, 2006, 09:31:16 PM »

Beings it's a worm gear drive it'll hold but it might be a good idea to weld on stub of 1/2" hex shaft so a drill could be used as a backup.

Dan, can you give more detail about the rock anchor set up? I'd like to know what size holes, how deep and more about the epoxy you used on the rebar.

DanB · « **Reply #6 on:** June 29, 2006, 09:37:06 PM »

The worm gear winch should hold the load if the chain breaks. This worries me a little bit too - but it's one reason I insisted on a worm gear winch. The winch also has an adjustable brake on it that helps hold the load. As it's setup now - with no load, the motor works harder in the 'down' position than it does in 'up'.

All the anchor holes are about 3 - 4' wide and 5' or so long. The shallow one - I just drilled about 10 holes 8" deep into the bed rock and hammered/epoxied re-bar into bedrock to help tie the concrete to it. It should be fine - that anchor weighs about 5000 pounds not counting bedrock and the soil in front of it is undesturbed.

DanB · « **Reply #7 on:** June 29, 2006, 09:43:12 PM »

to answer other questions...

the holes are 1/2" dia and I just covered the re-bar with west system epoxy before I hammered it into the holes. I think it'll work OK. My old tower is anchored this way with lots less re-bar in somewhat less deep and it's still standing - though I wouldn't do it again that way and my old tower scares me now. (I think all towers scare me at least a little bit)

richhagen · « **Reply #8 on:** June 29, 2006, 09:49:07 PM »

Wow, even the gin pole is impressive laid out like that. That thing is huge, make sure all animals and people are clear of there when that tower goes up just in case something gives. That is a huge amount of weight way up high. Not that your last tower wasn't also, but this is a multiple of that. The blades don't look so huge in the photo until you consider that those are reasonably close to 2 by 4's laminated together to make the blank. Scott is going to need a special jig for those. Rich

stevesteve · « **Reply #9 on:** June 29, 2006, 10:51:04 PM »

Looking awesome and I thought that I over-engineered things ;-)

I'd be in trouble with my neighbours if I tried to build something as large as the jin pole on it's own.

Is the tube used in the jin/tower new or is it reclaimed material?

I am looking forward to seeing the next set of pics!

nothing to lose · « **Reply #10 on:** June 30, 2006, 04:23:14 AM »

I'll trade you 2 deer for a moose.

You guys are doing great with everything it seems. Cordwood sauna/bath house looks great so far and sounds interesting.

Glad things are working out so well with this big gennie for you so far. Looks like it's getting close to done.

Gary D · « **Reply #11 on:** June 30, 2006, 06:15:40 AM »

Dan, looks good so far! Do you feel a need for a long steel gusset for an extra bit of strength between the jin pole and the tower? Looked at your tower page (older thoughts) and that might take a bit of strain from the 90 degree jin angle? Will be learning from your thoughts and actions. Keep cool up there, and if it's still tinder dry, keep Dan F. handy... ;-) Gary D.

BigBreaker · « **Reply #12 on:** June 30, 2006, 07:48:43 AM »

The gin pole carries only a compressive force and almost no torque (as measured between the tower and the pole. I'll make the structure "look" better because most people expect two orthogonal structural members to carry a torque between them.

DanB · « **Reply #13 on:** June 30, 2006, 08:32:41 AM »

Yes, I've pondered this too and lots of folks have suggested it. As it is now, I don't think it's the weak link - there should be very little force between the two... so - I don't think I'll put one in there. Maybe if it looks scary when we first try to raise the tower we'll change things.

DanB · « **Reply #14 on:** June 30, 2006, 08:39:00 AM »

It's all new stuff and overall this is a fairly expensive project (About twice the cost of the turbine itself). The tubing is almost $12/foot (I bought 120' of it). The concrete was right at $1000 (its expensive to get a truck to come up here). The cable and hardware is right at $500. The winch, motor and other misc costs probably add up to $300 so overall the experiment costs around $3000. If it works out (which I think it will eventually but I won't be surprised if problems come up along the way) then I think we're getting off pretty cheap. The 20' turbine is probably going to cost about $1500 overall (mostly the cost of magnets and water jet work) so the whole system should be aroulnd $4500 which is cheap... (if it works!). If the whole thing fails I figure I got $4500 worth of entertainment in building it anyhow.

kitno455 · « **Reply #15 on:** June 30, 2006, 08:47:45 AM »

how many wires are you going to use between the gin pole and the tower, and what is their placement? i think localized compression buckling of the gin pole somewhere in the middle is your most likely point of failure. from looking at the pics, it seems to have a slenderness ratio of a soda straw. not exactly the kind of thing you want to compress without support.

allan

WXYZCIENCE · « **Reply #16 on:** June 30, 2006, 09:10:04 AM »

O Yes , but its blown up and I need to build another.

Dan, I looked at your Wood-Axe. Must have been one of your first. Recycle it's parts for the new one aha.:-) I like the new poll, this must be the another your are building. It will go up without any glitches. Lots of wind that day. Joe.

RP · « **Reply #17 on:** June 30, 2006, 12:59:57 PM »

Thanks Dan

BigBreaker · « **Reply #18 on:** June 30, 2006, 01:54:37 PM »

(Note: In my post above, the "I'll" shoulda been "It'll")

I think it will look a bit scary at first, precisely because your mechanical intuition will see the weakness of the gin pole to any torque.

Now that I think about it, there is a big torque. Picture the tower at a 45 degree angle. The gin pole will have the same angle in the other direction, making a "V". There will be a lot of force to "flatten" that V shape and lower the tower. Think about it... a shorter gin pole would lower the tower (compression) but a wider angle between the pole and the tower would also (torque).

I'd weld some tubing between the pole and the tower at some modest distance from the pivot point to brace that angle. A temporary guy wire from a lower tower attachment point to the end of the gin pole would be good too.

ghurd · « **Reply #19 on:** June 30, 2006, 03:08:43 PM »

I am very sad the 'Wood-Axe' is gone.

ivandenisovich · « **Reply #20 on:** June 30, 2006, 03:27:13 PM »

I think the part that everyone is missing is the guy wires between the end of the gin pole and the tower. You are correct, at 45 degrees the forces between the tower and the gin pole will be at there maximum. However, as long as the guy wires and guy wire connections points on the tower and gin pole hold, everything should be ok. At near about the 45 degree point, the weight on the hinge will also be at its maximum. All in all, it looks very nice.

hvirtane · « **Reply #21 on:** June 30, 2006, 04:11:54 PM »

It looks a bit strange that many kinds of parts made of steel have got so little value there that you are

burying them underground inside concrete. What is the price of scrap steel/iron per kg there?

Otherwise it all looks very good.

- Hannu

richhagen · « **Reply #22 on:** June 30, 2006, 04:18:36 PM »

I was a little sad about that too. But at least part of it has move on to something new. I'm not sure what will become of the magnet doughnut with teeth.

TomW · « **Reply #23 on:** June 30, 2006, 04:43:02 PM »

Hannu;

I do not pretend to speak for Dan. But, you do realize that this "stuff" is at 8,000 feet of altitude and a fairly long drive to civilization? It would likely cost more to haul it to the recyclers than the scrap prices would bring. Not to mention time and effort loading and unloading.

Just an observation from someone who has been up there.

Cheers.

TomW

willib · « **Reply #24 on:** June 30, 2006, 05:57:49 PM »

I think i saw jimmy hoffa in one of those holes

DanB · « **Reply #25 on:** July 01, 2006, 07:44:42 AM »

Hi Allan - My plan is for 3 cables from the end of the jin pole, one to each coupler on the tower (except the bottom one). I am a bit worried about couplers without cables on them (both on the tower and on the jin pole) - but I prefer to avoid cables near teh ground if possible so Im first going to try it that way. If it looks like it might need more Ill add them (if it survives the test).

kitno455 · « **Reply #26 on:** July 01, 2006, 12:10:01 PM »

i once worked for a company that installed free-standing stadium-type lighting. usually used a crane, but on occasion, we used a rig with a jin pole that had two winches.

i guess who ever made it was worried about the jin-pole buckling, so this unit had one cable from the tip of tower to tip of jin pole, and one from middle of tower to middle of jin, and the two winches were both attached to the nose of a backhoe. the operator used the tip cable to do most of the work (if memory serves it was a bigger cable and winch) and the middle cable was just kept tight, to keep the jin from bowing.

i dont know that this applies in your situation, but just watch for the jin having any bow in it.

allan

hvirtane · « **Reply #27 on:** July 01, 2006, 12:31:29 PM »

the middle cable was just kept tight, to keep the gin from bowing.

How can you prevent it from bowing the other

direction, toward the tower?

- Hannu

sahlein · « **Reply #28 on:** July 01, 2006, 12:49:26 PM »

about $20USD for 1000 kilos.

sahlein

sahlein · « **Reply #29 on:** July 01, 2006, 12:51:38 PM »

I didn't know he was a scrap dealer!!

sahlein

jmk · « **Reply #30 on:** July 01, 2006, 04:54:40 PM »

Hi Dan, The tower looks like it is coming along great! I thought it was neat to see some youg fawns and a red fox at my site, but you toped it off with that moose. He looks mighty tasty! I think your gin pole will be fine. If not just weld some of your old tower to it. What ever it takes I' sure you will figure it out. Keep us posted on the sona. That looks like it is going to be pretty neat. What is he planing to heat it with?

kitno455 · « **Reply #31 on:** July 01, 2006, 05:22:40 PM »

there were two wires from the tower to the pole, one at their tips, and one at their mid-points. the jin pole could still buckle to the side, it would need guys to ground anchors to stop that.

if you think about it, a jin pole in use is not much different from the raised tower. they are both under significant compressive force and they both have a stupid slenderness ratio.

given that the tower is heavier and has such a mechanical advantage over the jin pole due to the difference in length, i am surprised that we dont see more jin-pole failures. i guess the slightly better slenderness ratio of the jin pole makes all the difference?

allan

picmacmillan · « **Reply #32 on:** July 03, 2006, 07:19:43 AM »

hi dan..looks great

..its easy for us couch potatoes to say whats needed

but we will all have to raise one of these big towers some time, and it will be nerve wracking for all of us, no matter how much engineering has gone into it...i am confident your tower will work ..on the cord wood sauna i have a comment or two, as it was hard to see from the picture...is the bark still on the wood? cuz if it is? it will cause you grief later when it falls off, and when the wood itself shrinks there will be gaps in the sauna walls......if possible, all the bark has to be gone......also, if the wood you used was green(or wet), it will shrink about 3/4 of an inch per 1 foot of wall height so for instance above the door which is usally about 7'?, the wall will shrink 5" or more...just a couple things to look out for from a proffesional log butcher

...just a suggestion....it is a great idea you have there to build a 1 man, 9 women sauna like that

...pickster

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Author Topic: Thursday June 29 (Read 7208 times)