Recent content by HauntedMines

Howdy - I'm looking for a way to approximate the anchoring strength of a partially buried concrete caisson (pier). It would be used for anchoring a guy wire coming into it at about 45-degrees from above. Most of it's in the ground, a few inches sticks above where the cable fastens to it...

Oops, correction to that last reply. I read your 3" pipe as 3" radius, you probably meant 3" diameter. So it's 1.5" radius, which means 75000 ft-lbs torque produces (12/1.5)*75000 = 600,000 lbs pull at the surface of the pipe. Double helluva lot. And to be really correct, you'll want to...

Hi MSN56 - This isn't correct: OK so if you look at my orginal drawing if i have the motor that has a 1 inch shaft and has 1000 ft lbs of torque that means it can pull at 1000 # at the shaft. If a motor is rated at 1000 ft-lbs of torque, and has a 1" shaft, it means that *if* you put a...

I think the more important issue is the efficiency of delivering power from the source (the two people driving the cart). At too slow and too fast a pumping/pedaling speed your people will be inefficient at delivering their maximum power. So the goal would be to find the optimum gear ratio...

If your can is not airtight, perhaps use a slow fuse string that holds a compressed spring or your mousetrap. Light the string (fuse) at the start, then 30 seconds later the fuse burns to where it cannot hold the spring's compression anymore, releasing the spring and it's mass. If you go the...

Thanx 256bits et al, I appreciate the design load advice and the deflections, etc. It is all sensible. I'm researching design changes along several parallel lines: Increasing from 7 posts (stanchions) at 20ft spacing to 13 posts at 10ft spacing (significant cost impact for the added...

Hi msn56, Here's how I think about torque, maybe this explanation will make it easier to understand: The first thing to note are the units: its a force at a distance, like ft-lbs. Thus a shaft that has a torque of 3000 ft-lbs means if you stuck a lever arm on it 1 ft long, it would...

Maybe it's your electric personality? :-) If you are in an area where there's a strong electric field from a local source (so the field drops sharply with distance), your body could act as a crude antenna, while the metal plate could be acting as a capacitor coupling it to ground. Then when...

Thanx all for the good ideas. I'll bring these up at the next board meeting which is this week. Using scaffolding seems like a simple and inexpensive answer, but I'm uncertain if our host site will allow it; they're picky about aesthetics. But I do know they'll allow us to leave concrete...

Hi Studiot - Thanx for the advice to move this to another forum. I don't find a "Report" button, maybe because I'm the original poster of this thread (or just tired!)? Moderator, please move this thread to a more appropriate forum (General Engineering?). Or someone report this for me if...

A lay-man's way of thinking about it: Every air compressor I've ever used, from a bicycle pump to a large shop-compressor, heats up when it runs. Considerably. I've also been around pneumatic motors, and they too get hot when in use. That tells me they're loosing energy thru heat. If I...

Sorry, that's 30psf (lb/ft^2), not psi, for my guess of the wind pressure.

Howdy - We're a small nonprofit that hosts a single annual event. For advertising this event we construct a large sign on a hilltop that's visible from the nearby highway. In years past this sign would last a few weeks before it would be destroyed by wind. Obviously our guess on how strong...