OK Stu , my profound apologies for being one of the reprobates ragging you about multiple posts.
Your project looks like a very creative job.

My curious mind forces me ask:

A: I don't recall seeing you mention why you built this rig Stu. Is there a handicapped person
living there who can't do stairs?

B: What are the alternate means for this person (if they are disabled) to safely get down and out if
there's a fire and the electric power is lost?

C: The offset position of that lifting pipe on the lift platform makes for quite a lot of bending
load on the joint in question. And maybe a bit of "bounce" when it stops at the top or when someone
steps on at that location. How is that pipe flange under the platform fastened to it so that it
won't tear loose.

D: I didn't "get" the safety brake concept from the photo, but it sounds interesting. Does it work
something like the jam washer on a screen door closer? Can you amplify the description for me? I
realize there's very little chance of it ever being needed, but did you actually test its
performance with a dummy load by snipping a temporary link in the winch cable while the elevator was
in motion?

Finally, I myself wouldn't trust the 3/4" black iron pipe threads for this job; not with a person's
safety depending on them. Assuming you can accomode assembling things in place with the platform
fastened to the pipe, I'd go with something better than hardware store pipe there and spend the
bucks to have it welded into a 1/4" thick steel plate (about one half the area of your platform) by
a certified welder, with a collar or sleeve welded to it and the plate as well.

Just my .02.

Jeff

Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can keep smiling when things go wrong, you've thought of someone to place the blame on."




Stu wrote:

Group,

First let me apologize for posting my question more than one time.
The problem was the Google was 'hiding' my posts and I repeated them
because I believed that they were not posted. I asked Google to
'splain.

Why did I ask this questiion?

See my homebuilt elevator that 'hangs' on the threads of a single 3/4"
black iron pipe.

http://www.imagestation.com/album/?id=4288894713 Homebuilt Elevator

Thanks again,

BoyntonStu

Jeff Wisnia wrote in message ...
Ed Huntress wrote:

"Stu" wrote in message
om...
Strength of 3/4" iron pipe threads.

Thanks,

Boyntonstu

Here ya' go, Stu:

3/4" iron pipe threads produce 32,450 ksi inverted shear strength. That is,
assuming you've torqued the joint to a value between 86.5 and 86.6 ft-lb,
backed off a half-turn, and re-tightened by 11/16 of a turn.

Enjoy!

Ed Huntress

You can get at least 23.76% more than that if you use unobtanium pipe.

Jeff




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