Guy wires «in hand»??

[Waterfront]

Hi everybody.

I was looking for guy wires for a 60' tilt-up tower (with a 12' prop sitting on top of it), and looking around my local stores, they don't sell really big (diameter) steel ropes to use as guy wires. The best I've seen is Canadian tire, selling 1/8 and 3/16 aircraft cable. The 3/16 cable has a working load of 840 lbs, and only costs 0.40$ per feet. So, I was thinking, would using 2 of these cables «in hand» give me a working load of approximately 1700 lbs? I'm gonna be using guys at the top, and 2 more levels at 20' and 40' above ground, so, I still need to figure how the weight will be distributed between those 3 levels, and what's the maximum the top one needs to be able to withstand, to make sure that 2X is enough... but besides that, would the concept be allright? Or should I keep looking for a wholesaler or some other retailer that actually sells «real» 1/4 - 3/8 cable?

Thanks,

Waterfront

[kell]

You'd need to keep the pair under equal tension.

It is an interesting engineering challenge.

[harrie]

Hi waterfront. I have a 12' dia.duel rotor on a 60 foot tower made of 4 inch pipe, and use  1/8 cable running 4 ways at the mid point, and 3/16 four ways at the top of the tower, with turnbuckles on all. I think this is enough to do just fine. at least I have had no problems yet, its been up for two years now. The prop balance should of course be as perfect as possible, so as to avoid continuous shaking of the tower. It probley wouldnt hurt to have another set at the 3/4 height of the tower, which I may do.

great fun, harrie

[Waterfront]

Allright, thanks harrie!

It's always nice to hear from someone whose actually done something similar! Since I'm waterfront, the wind speeds can reach quite high, and we always have one or two «big storms» during the year, and I wouldn't want my tower crashing down, so I'll use 3 levels of 3/16. What kind of wind speeds do you see at your site??

I hope Canadian tire's loaded up for the season, because I'm going to rape there stock, hehe... I might actually shop around, to see if someone can beat the 40 cents + tax per feet price on that... Depending on who I find, I might go to 1/4 instead, I'm quite a bit worried about it crashing down, hehe...

If you don't mind my asking, what did you do for your tower base and guy wire anchors?? Concrete? How much/How deep? That's another thing I was debating...

Thanks,

[kenputer]

If you have a princess auto in your area then that is the place to get your cable at a good price that is where I got mine. I live in N.S. and we have lots of granite rock here so I drilled the rock ,put 3/4" anchors and eye bolts for my guys. where there was no rock I filled 5 gallon buckets of cement and buried a few feet and that does the job also.

havin fun

kenputer

[picmacmillan]

i have seen on ebay a guy who sells whole rolls of heavy gauge guy wire cable for real cheap..like 50 bucks for a whole roll..mmm,maybe do a search on there for rolls of cable?..he sells it sort of regularly so i think he has alot of it..his biggest thing is it weighs 2000 pounds a roll, so it is a challenge to move it i think...pickster

[TomW]

Not sure if anyone mentioned this but why not just use 2 lighter ones where you have to side by side at slight angles to one another? connected to same tower  point but anchored just a bit apart?

No idea if it is sane, sensible, or will even work but sure seems doable.

Cheers.

TomW

[Waterfront]

Yes, but then you'd need twice the anchors... so, alot more concrete, hehe...

I remember seeing some around the board once, but can't seem to find that post again, does anybody have any formulas for the force that the wind will put against the tower (well, the prop really)? I'm trying to figure out just how much thrust my guys need to be able to withstand, but I'm not having much luck converting windspeed and prop surface into lbs or kg of force...

Keep on posting!

[wooferhound]

These pages should be a great help in designing and building your tower

http://www.otherpower.com/otherpower_wind_towers.html

http://www.fieldlines.com/story/2005/12/1/142635/398

http://www.fieldlines.com/story/2004/7/10/1401/02390

http://www.fieldlines.com/story/2005/1/24/132025/954

[Waterfront]

Thanks for the tip kenputer, went to Princess Auto, wow, do they have some nice stuff! Nice prices too! All kinds of diameters for steel wiring, Clips, Thimbles... even some turnbuckles (although no safe working load indicated on them, will need to research that one...)

Thanks again,