Need a few clues here. I'm scratch building a scale model, not a jet this time, but as most jets use retracts I'm sure most of the knowledge about retracts will be here. Was given this set of Down & Locked retracts along with the box of smoke & mirrors to make it all work. No instructions at all.

All the screw jack units work fine in both directions when powered with a 4.8 volt receiver pack so that's a start. But how are they controlled at the travel limits up & down? I can understand that other electric retracts have some sort of feedback via the third wire like a servo but these have just two. These were seen as the latest & greatest at one stage but quickly disappeared.
Not much positive feed back on them after a Google search.

Options: 1/ get some instructions (where?) & try to get them working.
2/ if the screw jack units are not the problem, just the control system, I could control them by other means & chuck the control box.
3/ forget the whole idea & fit a set of Spring Air units which I also have although speed control is not so great with these & a slow retract cycle does look cool.

Any advice would be appreciated, thanks in advance!.

the controller box uses amp load to determine when to stop the cycle.

xicoy, jp, electron, and others sell good retract control box units for 2 wire systems.

Chuck that controller in the garbo is the first thing to do
Get ya one of the latest Electron controllers and be done with it
Most people had issues with D&L controllers , service was bad , lack of communication = D&L went belly up & down the drain

Were the screw jack units durable & properly engineered and all the issues were just with the control unit?

I don't want to build myself into a corner & carry out lots of chopping & modifying to try to fit something later on.
Mount them on carbon adapter plates so I can swap them out later on?

D&L? Got a round file? Best way to address D&L problems to come.......

Are the basic mechanisms & screw jacks ok or are they a disaster waiting to happen as well as the box of smoke & mirrors?
I can deal with basic mechanical problems & will have to do some mods anyway.

If it's a lost cause I will simply take them fishing & use the Spring Air's.

swap meet em, at a bargain basement price, after ya bin the control box.

using em as fishing weights might release things ya don't want released into the water...