I recently built a powered moving target. Using an old dewalt 20volt drill , steel cable from harbor freight,DC electric motor from amazon and Pulleys from lowes. Was pretty easy. Pm me if you have any questions.
My only improvement would be to have it on a foot pedal for one person use.
Not sure if this is what your looking for . . . but check out the videos by Greg Richards on You Tube. This is one of them: https://www.youtube.com/watch?v=-Zqrq3Pk91A&t=6s He made several videos for 3-D Archery.
I followed his example and made my own foam target on a "return hinge". It works just fine, but your traditional bow needs to have enough shooting poundage to get the foam target to fall over and then it returns to its upright position.
The best return hinges are the ones whose tension you can crank up or crank down depending on the size of your foam target.
I've seen & shot a few on zip lines from 6-7 feet up on 1 tree to the bottom of another tree 20 or so yards apart. 1 person pulls the pin & the others take their shot & then roll it back to the high tree spot.
The gravity zip lines I have saw didn’t work to well. I am sure they could though. Youtube has a lot of videos on moving targets.
Lord willing thinking about building another that you attach 5or 6 ballon’s too. It will use a motor to spin bringing a ballon just above the top of a bale of hay or some other type of target. Shots will be moving and time limited making it fairly challenging.
We use to go to shotgun matches and they had a bicycle turned upside down using the rear rim as a pulley, as you paddled it took targets out and In pretty fast. You could rig up an archery target in the same fashion.
I rigged a hi/lo target behind our place many years ago. Rope and two wood pulleys I made from scrap. One pulley had a crank handle, and was mounted just below chest height on the end of the wood pile end framing. That pulley was fixed. The other pulley was mounted to the top end of a sawhorse. The sawhorse could be moved.
I could get an above ground, or dragging on ground rabbit target by moving the sawhorse and adding or subtracting slack to the haul line. Worked great. And a ton of fun. Beats static targets by a long shot.
I built one at our archery club. There is a video on our facebook page at Blue Ridge Bowmen. It is a zip line cable and laundry line rollers which we mounted in a housing. It works really well and the shooters enjoy it.
Not a moving target, but a timed shot that puts pressure to shoot: The shooter has to put the golf ball into the pipe then nock his arrow and shoot before the ball rolls down the pipe and drops into a bucket. You’d be surprised at the number of folks who fumble with their equipment as they hear the ball gain speed rolling the metal tube. Lots of hoots and hollers from this one!
Get a piece of pipe 10-15 feet long that a golf ball fits inside. Fasten one end of the pipe at the shooters position about shoulder height. Now experiment with the angle and fasten the lower end of the pipe so the ball takes 10-15 seconds before clanging into the bucket.
One thing to be aware of with the targets on the zip lines… They need to be heavy enough to get moving. One of our guys set some up for a big shoot, and they simply didn’t weigh enough. Nothing that couldn’t be solved by adding weight to the back side, but that posed some pretty obvious complications for anyone who got a little too much penetration. But hey, that keeps the compound guys away from “our” targets, right? ;)
And if you have room for it, there’s the old used tire trick. Just fill the center with something which will stop an arrow and roll it down a hill or across a level area. It would appear that we have a couple of electric motorized, target bases, but I have never seen them in use. Not sure exactly how those are operated or how well they work. Seems like you could have things get expensive pretty quickly if too many shots came in low.
It doesn't get any better than the Forksville running deer target! I spend most of my time there. Rips on a small straight track. They frequently stop it and make it buck too.
If you are going to use a gravity line, then you have two ways of doing it, a tether line, which causes its own problems and needs a nice clear area so the rope won't get caught or a release.
We use both. Here is the tethered line. Oh, and it is recommended to have a can of WD40 Handy too.