Shoebox compressor tricks mods for big bore /other gun guys

OK as some of you know on here , i have now well over 200 hours on my shoebox compressor , i wanted you guys to get some inside scoop tricks ,mods that i have learned/come up with so far on running this compressor , i have a ton of hours wrenching on this compressor , also talking to Tom K on the phone a lot , I am a part of his R&D testing /running of the shoebox since i have a ton of cylinders ,and shooting big bore airguns using a ton of air , he has been helping out with things/parts to try out, and test,

OK I think the most important thing you can do is elign the piston rods ,to the cylinder bore holes , and reshape the end of the pistons and polish them , VERY CRITICAL MODS !

Start off by taking the pistons ,and cylinders off, take all the parts out of them / orings check valve , then bore sight the alignment on the pistons to the cylinder bore , you can do this by moving the pistons all the way back on the stroke out , then putting the cylinders back into the main block with all the orings and check valves out so you can see all the way through the cylinder , look through the check valve side of the cylinder use a light behind the other side so you can see how the piston rod alignment to the cylinder hole that it goes back in forth in , now if the alignment is off , you can loosen up the billet block and move it a little until the piston rods are lined up/centered with the cylinder holes, then tighten up the block turn the pistons by hand to make sure everything looks straight , then tighten the block back up

OK now a very VERY CRITICAL mod to do to the pistons , you want to make the front edge of the piston rods look like a round nosed flat point bullet ! here is the deal …..the front of the piston from what i have seen so far is cut flush squared on the end …..this part front of the piston goes in and out of the 1st oring , the second oring the piston shaft stays in it the whole time it runs , so if you have a tapered front piston shaped like a round nose bullet it will go in and out of the oring WAY SMOOTHER ! instead of having a sharp edged bashing it’s way in and out causing failure a lot sooner of the critical 1st oring ,

OK let’s mod the piston , i have come up with a very easy way to do this , before you take out the piston use a long caliper to measure how far it is sticking out of the billet block that it is mounted on { very important to measure this -before you remove them, so you can put them back in at the same length }

after you take them out , put the side that was mounted in the aluminum block in a hand held electric drill , now take a flat file, lay it flat on a bench , then take ,and spin the piston rod with the drill at a slight angel and start grinding shaping the end of the piston rod on the file to make the front of it look like a round nose with a small center flat point ,change the angle as you grind to make a nice rounded smooth bullet shape to it .
you can hold the piston with a rag on it while it is spinning to put pressure on it against the file while shaping it.

once you have a decent rounded shape using the file , then use some 400-500 grit sand on that area you just shaped by spinning the rod in the paper in your hand to smooth it out , then switch over to 1000-1500 grit paper now spin the piston rod again this time not only smooth the bullet shaped end out but also smooth the whole piston rod out by spinning the piston and moving the ultra fine sand paper back , and forth polishing the piston rod up real good , this ultra smooth finish with tapered bullet shaped end , with correct piston rod alignment, will make the o’rings last way WAY LONGER ! ! 😉 😆