"David Lesher" wrote in message
...
"Jim Wilkins" writes:

My platform stacker uses cam followers rolling on rectangular tubing.
http://baileynet.com/index.php?page=...m=cam+follower

[Not sure what your stacker does/looks like...]

https://picasaweb.google.com/KB1DAL/...44343827153698
This is a similar model standing up.
http://www.veshai.com/image/ms01.jpg


So how many followers do you have? One per side [4] or 2 per side [8]?
How do you have them mounted so as to adjust the spacing against
the tubing? I was thinking a wearable plastic surface on the
traveler part.

There are four cam rollers on mine, two per side. The lower ones roll on the
platform side of the vertical rails, the upper ones on the handle side. They
prevent the platform from tipping down but not up, which isn't necessary as
its weight holds it in place. They mount in holes in the tapered 1/2" steel
plates welded to the platform's back. One of the plates is visible above the
pump pedal

The stacker's rollers aren't adjustable. Three bear on the rails anyway and
the fourth makes contact if the load is heavy enough to twist the platform
back to straight. $10 was a fair price for its condition.

The guide rollers on the sawmill adjust the same way as a motorcycle rear
axle, with yokes and screws.

The rollers apply a considerable compressive pressure to the track unless
they are widely separated, which costs track length. You might get away with
4x4 PT posts if the rollers were stacks of rubber caster wheels that bore on
their full width.

That's why I suggested a removeable jib crane made from fairly
cheap ready-made commercial components.

I suspect the spouse may object to same. Plus the idea it swings
over makes it an "ooops" as you hit the house.

So you remove it and leave only the less offensive post, with a bird feeder
or wooden Ma Deuce on top. The bed crane has holes for a locking pin to keep
it from ooopsing the pickup truck.

I still like the lead screw idea, even if not built from garage
door openers. A belt/pulley drive to slow the rotation down
would be one approach. One problem is I know I'd need to splice
several threaded rods together, while maintaining the thread
integrity. Plus, I'd like larger diameter, finer threads.

You can buy 10' threaded rod as conduit hanger at the Borg. Lifting the ~150
Lb head on my sawmill doesn't overstress a 12V Makita drill driving the
leadscrew directly.

Personally I would build a simple and acceptably artsy or easily removed jib
crane or hangman's gallows if I didn't already have the truck crane to
borrow. It's far less initial work and maintenance than a vertical track and
platform with rollers.

I'd replace the winch cable with hand-friendly polyester braided rope and
attach plywood to the house at the bottom to absorb the damage if the canvas
sling of firewood fell. If you have to move to the top to raise and unload
it you won't be underneath.

The swiveling crane above my chimney that supports the ground-operated
cleaning brush is built like a sailboat mast and boom, and painted to blend
in with the tree branches behind it. Having a taller stayed mast lets the
boom be much thinner and less visible since it needs to withstand only
lengthwise compression, no bending. If you need an excuse for the mast, put
a flag or antenna on it.

You guys want to overengineer a very simple project in a way that invites
riders and accidents.

jsw