So my team had constructed a simple 6-bar forklift system for an early Starstruck competition, but we now want to revamp it to a slip gear catapault. Is it possible to use a 6-bar lift as the basis for a slip gear launcher? Or do we need to completely start over our launcher design?
It’s completely possible 
Here is a slip gear design I have posted: https://www.youtube.com/watch?v=vRnOAls6UBQ
Also this one is 4 bar with pneumatics catapult, which should function somewhat the same: https://www.youtube.com/watch?v=qKkRtKkx2j4
Also suppose the catapult is strong enough, you can do it without lifting.
Okay thank you! The design that we were considering was slightly different than the videos you had posted, as the part of the launch that was powered with rubber bands (or other form of tension) was always a simple linear attachment. We would have the entire 6-bar powered by the slipgear/tension system and. I am yet to find a video that matches our scenario. So I am concerned with proceeding as planned.
The main issue here is that the length of the lever arm changes by nature of the 6-bar, which screws with our calculations for torque needed
What about a reverse 6-Bar slip gear? Maybe that could be a possible thing if built correctly. 
While I personally have not seen a 6-bar catapult in a competition I know that it is feasible and that could give you more clearance. It becomes tricky to calculate, like you said, but a 1:5 or a 1:7 with rubber bands should be enough torque. If you can find an optimal point while keeping in mind the change in length then you should be fine.
What do you mean by reverse?
a.k.a. danny’s lift, a.k.a. 169’s lift in skyrise
I feel like for early season, dr6b is difficult to build. It’s also kind of chunky. What will be the advantage of that?
It reaches really high. A double reverse 4 bar might be tall enough.
Oops… I meant to say inverted 6 bar. My bad :L
Here’s a concept you can work out of
Maybe you can add a stopper where the inverted 6 bar would reach its height limit when the bar is vertical.
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hashtag SR xD
ahh gotcha 
ok, so we built a mechanism like this, 6 bars, goes up, then we had a dual action cam that punched the object, quite powerful, but we found that it was hard to hit the correctly to make it go far enough, i mean if you got hit at full tension, it could break your fingers, but it wasn’t hitting the star hard enough to get it over the net. so we scrapped it and built a dump on the same chassis, feel free to ask any questions.
@ANON_00111001 have you guys decided to hang? Have you guys thought of different intake designs like the standoff intake like the RI3D or the claw intake?
we were planning on attaching a hook on to the 6 bar and lift ourselves that way, we had more than enough torque. as for the intake, our motor usage and, the clearance required for the launch mechanism forced us to use a spatula or standoff design, and we found that a plastic piece really helps with distance.