Hatsan tank valve hole/transfer port do not line up. Solution?

[colorider]

I want to do the tank valve mod (plug 5 holes and open up the one that lines up with the transfer port) on my spare tank. Unlike my other tank, the new tank top valve hole does not line up with the transfer port.  The transfer port is dang near in between 2 of the valve holes.  I can snug the tank into the gun a bit tighter and get it closer, but still not lined up. about 2/3 of the valve hole are showing when looking through the transfer port.   My other tank was spot on dead center.  What are my options at this point?. 
I don't have access to a lathe or a mill.  I do have  good work bench and a plethora of power tools. 

[rsterne]

Sometimes you can loosen the brass sleeve in the tube that the valve screws into, and slide it in or out a few thou so that the reservoir hits the end of the tube and stops in a different orientation.... However, if you have another reservoir and want them interchangeable, that is not an option.... I would suggest you plug only 4 holes, and do a little grinding on the web between the two that almost line up so ease the flow to the transfer port.... Altenately, maybe you can make or find a thin shim to place on the valve on the end of the reservoir....

Bob

[colorider]

Thanks Bob,

I want both tanks to be as close as possible to each other for consistency reasons.  I took your advice and made a shim out of an old Iphone screen protector.  Turns out it is the exact thickness I need!!!!  When snug, the top port lines up perfectly.  One thing that came to mind is that the  hammer may strike this valve lighter than the other one because the valve pin will be a fraction less inserted into the gun.  It is such a small amount of difference so I'm not  sure.  Will have to get it over the chrono to get some actual numbers. 

[redlined_b16a]

I only have one tank but I wound up machining a couple thousandths of an inch off the part that valve screws into.
This allowed the valve to screw in deeper making the hole line up.However I have a lathe.
But As stated before ypu can grind out the webbing inbetween two holes.

[Ribbonstone]

Thin shim on the brass shoulder of the tank...stops rotation a little sooner?

[colorider]

Yep.  A very thin shim so when the whole tank assembly is screwed into the gun, it tightens earlier and the hole lines up.  I'm assuming a leak won't happen as the 0 rings do the sealing.  We shall see. 

[redlined_b16a]

A thin shim would do the job.A sheet of paper is about .004"
Try a paper shim see if that gap will work,perhaps two papers or enough to get whole lined up,count papers and add the numbers to find a perfect shim thickness rather than machining or lapping.

[Ribbonstone]

Won't hurt....can line it up.  Managed to get an old Pneuma air tube and a new one to line up by that method....if the .002-.003" difference in stroke made a difference I couldn't detect it, chronograph or by target.

I just used indrustial type packing tape, which is thinner than normal...something like  .002".

[colorider]

Glad the shim is going to work and others have had success.  While putting my tools back I saw a package of epoxy.  The plastic packaging looked perfect to make a better and more durable shim.  Turns out it is going to be perfect.!  The screen protector one was a bit flimsy and I didn't like how I fit it.  The new epoxy package one looks and sits perfect. 

[Rallyshark]

I have used both methods successfully.  Just as Bob mentioned, you can give yourself a couple thousandths of play just by loosening and tightening the cylinder carrier to get it to line up.  I also have a .004 brass washer/shim on one of my other tubes.  I have also done a valve that lined up dead center between two of the holes.  I simply cleaned up those holes and brought them together in the center with good results.  There's more than one way to skin a cat

[GoneShootn]

I had the same problem and used shims made out of different things, like a plastic file folder and refrigerator magnet material. You might also be able to use thin auto gasket material. You can cut the outside circumference with scissors, but the inside hole will need to be punched, so it needs to be material that will punch out easily. I made a punch out of a piece of, I think, 1/2" emt tubing, but I also ordered one from china via ebay. Two, actually - one for the outside dimension, as well. They haven't come yet, though, so I can't say how good they are. I think the sizes I ordered were 16.5mm and 30.5mm.

Naturally, you would use shims if the valve hole goes a bit "past" the TP when screwed all the way in. The shims would make it pull up a bit short.

[Ribbonstone]

I'd really rather have the air cylinder screw up firm/hard just from a vibration standpoint....having  soft fit there, introducing a possible "flex" or "wiggle" doesn't seem like a great idea....might not make any difference, but give a choice I'll take a brass shim.