GeoLane at PTD dot NET wrote in message
...

You might be better off making a wooden gantry crane. Some call them
a "lifting horse" like a giant saw horse. There are several ideas on
lifting things in this post at Practical Machinist:
http://www.practicalmachinist.com/vb...5-post1553677/

The one that Forest Addy describes has 4x4 legs and a 4x8 cross member
around 10' long. Unfortunately no pictures of the ones he made. I
wondered about the bracing from the legs to the cross piece.

I assembled a temporary one like that with laminated 2x4 legs in an A with
center post, and channel irons for the track, bolted together with the end
attachment plates and diagonal braces sandwiched between them.

The casters were trailer tongue jacks. They wouldn't roll with the load
suspended so I lowered the ends to move the load with the trolley, then
raised them to reposition the gantry. New England glacial till is firm
enough that we don't need to pave all our trails and work areas, but small
wheels still don't roll well on it.

This is the channel and the end support geometry, minus a diagonal brace
that isn't needed he
https://picasaweb.google.com/KB1DAL/...88504883032706

Two legs in an A require less material; with three like that you don't have
to cut up the ends and can leave them full length and reuse them elsewhere.
The post is a carefully selected 3"x5" landscaping timber and the braces are
two 2" pipe legs of a neighbor's engine pulling tripod that he gave me after
a truck ran over and bent the third one, and I told him I had the shop
crane.

One long shoulder bolt holds everything together at the top. The track hangs
on a turnbuckle that levels it. That photo was taken before I drilled the
extra holes in the web for the diagonal braces that the free-standing gantry
version needs.

Erecting that much weight overhead is tricky, one hand holds the steel while
the other slides in the bolt, which I taper to help alignment. I slide
boards across the next-to-top rungs of a z-folding ladder and balance the
two channels on them, then raise and attach the end support(s). When it's
secure I pull out the planks and lift the ladder off over the channels.
Reverse to disassemble. This limits the height of the gantry beam to the
size of my ladder, but I probably couldn't slide the channels into place on
a much taller ladder anyway.

That is 3" channel iron (surplus pallet rack) I bought for sawmill track.
It's adequate for logs but heavier stock would be better for machinery.

jsw