schrieb:

Chip, since you've seen one with this design, how did they drive them
simultaneously?

Todd, can't recall how they drove both vertical screw jacks
simultaneously. Obviously there had to be some kind of shaft extending
to the opposite-side jack but not sure whether it was driven by the
screw in the first jack or what. I suspect you've already checked the
Anschau and Entec sites like I have and discovered there's no photo. I
recall seeing one somewhere a while ago, though, so maybe someone can
point to it.

I was intrigued because it seemed like the best of all worlds: like
having two hydraulic bottle jacks without the leaks. I can't recall the
details but it was a spare and I could have bought it from Entec on the
spot saving freight, etc. And knew for sure it would bolt/weld right up
to my fuselage track. But the price for the jack assembly was pretty
steep ($500?) and I decided to pass.

Not sure why more of them aren't done that way. The biggest
disadvantage I can see apart from possible cost is that, like the
twin-hydraulic-jack approach, the jack towers have to be far enough
apart to avoid scraping the sides of the fuselage/cradle (with some
room to spare for misalignment coming in). But it looked like it would
have worked fine for my ship.

Chip Bearden
ASW 24 "JB"

For a lifting unit with vertical spindles there are spindles with a
90° drive gear and a strong, but very little axial ball bearing
needed. The axles from the gear have to be long enough to weld a
spindle between the two units to connect them. The distance must be
outside the rails to make space for the fuselage. With some gliders
this will give difficulties with the space to the wings and this will
make it impossible to use this system on certain gliders.
One spindle needs a left hand drive, the other a right hand drive (
They are working mirror-like because one is left of the rail, the other
is right of the ramps rail ). And this spindles should not exceed 300
mm in height because of the danger of scratching your wings leading
edge.
Where to buy?
We make them.( In little numbers)
Only 4 and a half manhours each, you need two spindles.
And than you need to connect them and to weld them on a base.
This may explain the price.......
AS
cobratrailers