Author Topic: VAWT and Genny Repeatable Low Cost Design (Read 11797 times)

kitno455 · « **Reply #33 on:** November 25, 2005, 03:22:25 PM »

looks good. make really sure to use very good quality bolts to hold the flanges. they will be under significant tension and shear load. in fact, if you can move the bearing up, so that it is in the vertical center of the mill, that will reduce the load to almost pure shear.

allan

willib · « **Reply #34 on:** November 25, 2005, 03:35:44 PM »

Hi Mtn Man ,

how much was it ?

what was it off of ?

does the clerk have a sister?

MountainMan · « **Reply #35 on:** November 25, 2005, 03:50:45 PM »

"how much was it ? " US$114 plus tax

"what was it off of ?" Still don't know. Maybe kitno or somebody else will recognize it?

"does the clerk have a sister?" No clue. Good chance I look like a creepy old bald guy to her anyway.

jp

MountainMan · « **Reply #36 on:** November 25, 2005, 06:17:35 PM »

Once again, having never taken a shop class is biting me in the backside.

Where can one go to buy bolts of different quality? Home Repot only sells one quality of bolt, probably low quality. What kind of a store can you go to where you get a choice of paying more for a better bolt? I can't ever remember seeing that kind of selection at any other kind of hardware store either.

thanks,

jp

ghurd · « **Reply #37 on:** November 26, 2005, 06:08:39 AM »

Bolts.

Try a real hardware store, where they wear blue jeans and T-shirts, and the only way you know they work there is when they say "Need help?"

"Got Grade 8 bolts?" should be your answer.

G-

DanB · « **Reply #38 on:** November 26, 2005, 08:41:57 AM »

Yes, thats the same part number I'm working with. I like that one because it's machined on both sides so we have two true surfaces to work with (not all hubs are). It also seems to be one of the most common/easy to find parts there is. Dexter 81-9A

nanotech · « **Reply #39 on:** November 26, 2005, 09:21:48 PM »

My father worked (when he was still alive) at a company called Tacoma Screw Products. They had every kind of nut, bolt, washer, and screw ever made. You can contact them at 1-800-562-8192 or you can browse thier site at http://www.tacomascrew.com/

maker of toys · « **Reply #40 on:** November 27, 2005, 01:40:55 AM »

Mountain Man- Since you are in california, look to see if there's an OSH within striking distance- they stock Grade 8 as open stock. it's the gold-colored stuff. Often it's fine thread, too. . . . which may or may not be a problem for you.

generally speaking, the larger the number of lines on the head of the bolt, the higher the grade. (for the 'ordinary' sort of SAE thread zinc plated steel bolt; the sort of bolt we're concerned with here will have its lines in a star pattern. metric hardware will often have an actual numeral stamped on the head. when you start talking bolts from specific alloys, head markings (when present) get arcane in a hurry.)

common examples:

no lines: grade 2. really soft; may be acceptable for fishing weights or stationary sheetmetal work. Sometimes used as 'shear bolts' for farm machinery. Easy to overtorque. this is the typical grade of all-thread, wood screws, lag screws and carriage bolts. unmarked metric fall in this catagory.

two lines, usually forming a right angle: Stainless, usually 18-8, 303 or other free machining alloy, and useful for many of the same things grade 2 steel is used for. (though the bolts are probably stronger than that, I wouldn't trust a hardware store stainless bolt for anything with a cyclical load. I'd rather order something specific and have it come from a traceable source.) 303 is too tough to use as a shear bolt, but still easy to overtorque.

three lines: grade 5. general purpose, used for bolting vices to benches, motors to mounts, etc. Metric 8.8 is roughly equivilent. sometimes you will find lag screws of this grade; good quality machine screws may be in this grade range.

six lines: Grade 8. often has a golden zinc-chromate or cadmium plating instead of the silvery-blue zinc of other grades. Used for bolting down pickup beds, mounting engines and accessories, trailer hardware, etc. Metric 10.9 is roughly equivilent.

there are higher grades, but they are usually specified for specific purposes and might be brittle or otherwise unsuitable for RE purposes. an example is metric 12.9, which may be used for low-stress engine internals (holding the oil pump in place, etc.)

be sure and get the grade of nut that goes with the bolt; hardware stores typically stock grade 5 bolts and nuts; those that stock grade 8 will typically have nuts to go with.

MountainMan · « **Reply #41 on:** November 27, 2005, 09:06:31 AM »

Thanks nano and maker,

I've saved both or your info on bolts for frequent reference.

I remember an episode of CSI where the suspension of a bus came apart because the bus company was using cheap bolts. They used this same terminology "grade 8" in that show. Who knew you could actually learn something useful on Thursdays?

thanks,

jp

electrondady1 · « **Reply #42 on:** November 27, 2005, 09:35:38 AM »

with the machined flat on the back side of the spindle it will be possible to attach the back rotor lower.if nothing else that should shorten the stator support rods /reduceing stator movement.

nanotech · « **Reply #43 on:** November 27, 2005, 06:54:22 PM »

Just one more reason to wish my father were still alive. I could have phoned him up with all the specifics of what the bolts would be used for (diameter of bolt circle, number of bolts, shear force expected, tensile force expected) and he would have told me in a matter of seconds what diameter, length, and strength of bolt you would need!!!

A bonus would have been that I could have gotten you said bolts for cost. Delivered!!

But alas, now al I can do is refer you.....