Karl Townsend wrote:
On Fri, 25 Feb 2011 00:05:28 -0500, Bob Engelhardt
wrote:

Karl Townsend wrote:
...
Anyway, a #35 roller chain would make for a far easier and less
expensive installation. Given that the knee will only move slowly at
tool changes and always have downward force; is this causing another
problem that I don't see?
Would the plane of the chain be horizontal? If so, chain doesn't like
to run like that - it's weight tends to run it off the sprocket unless
it's tensioned just right or has guides.

Bob

Good point. An issue I hadn't considered.

I really worked this little design problem with Autocad last night.
I'm not coming up with a good idea. Not finding a decent way to do the
pulley is only one issue. Putting two lbs. of **** in a one lb. box is
the real problem.

if someone out there would like to spend time with this, I'd actually
*pay* money. Hard for me, I know. But cheaper than building it wrong.
The person would need something like Alebre or other 3D modeling
software.

On another note, I found a Pro to come out and scrape in the ways. And
a company to send the ball screws out for rebuild.

Karl


How about a shaft drive to a worm gearbox with the ball nut driven off
the driven gear?

--
Steve W.