Here’s a servo controlled valve I designed for 1015 a few years ago. It was made for isolating a pneumatics subsystem, but it would work well with low pressures or vacuum.
It was made from a kit servo, a chunk of 2" x 3" x 1/8" box from that year’s kit (chopped at one end), a hacked down slice of 8020 X-extrusion (tweaked slightly via Dremel for a snug, slip-on fit), a the kit’s vent valve, and a pair of kit SMC swivel connectors. NO modification of servo, valve, or connectors occured. The “valve twister” is simply slid onto the knob.
This valve was used by my old team 1015 in Stack Attack, to solve a deployment problem. Our fork-lift couldn’t be fully down, NOR up, because either violated “Initial Dimensions”. It had to be held at an ANGLE.
That year’s rules also said you could ONLY used what was IN the pneumatics kit. We had three cylinders, which already tied up the three supplied valves in basic control. We couldn’t buy another to plug the vent, nor substitute a valve (like we can now) for one that simplifies multi-positioning pneumatics design.
Well, that meant we needed ONE more valve than was supplied, just to hold and isolate the forklift deployment cylinder from the system at startup at “half mast”. (Hmmm…)
The idea came to me when I noticed the vent valve was 1.75" between ports, which meant it fit exactly within the 2" (OD) x 1/8" thick box or U-channel extrusion. I also noticed they didn’t REQUIRE the vent valve to BE a vent valve that year (unlike now)…
So, this valve was born…
Construction note: With appropriately placed holes, the valve is retained by the two SMC fittings. There are holes along the long side on the left for mounting the assembly to the robot.
The only problem with THIS particular copy is that it was SLOW to actuate. The kit’s vent valve is tough to turn, and is almost at the limit of the servo’s capacity. (It took over a second to toggle, but it DID work.) A ball bearing valve, or a stronger servo would be highly advised in a newer copy. (…Besides, this year’s rules REQUIRES a vent valve to be present, so you’ll need a second manual valve anyway to make this.)
Anyway - We built this one and connected it to the vent output of thr forklift deployment valve. We prepositioned the forklift deployment cylinder with slow motion pre-round, then manually shut THIS valve off. THAT held our fork-lift at the appropriate angle to make dimensions.
The program then simply commanded it to ON when the robot was enabled. Instant “transformer” to Operating Configuration! It worked like a charm, every time…
The reason I post this now is that I mentioned in a Pneumatics thread that this “class” of valve is Non-Piloted. THEREFORE, a faster variant of it made with either a stronger servo or a ball bearing manual valve MAY have application to someone here for this year’s contest, to control vacuum.
It may also be used like we used it, to shift your robot (in this case via one or more additional cylinders) from your initial dimension configuration to "operating configuration, without requiring you to tie up a valuable kit valve.