Author Topic: hammer spring mod  (Read 2991 times)

  • Guest
hammer spring mod
« on: October 08, 2006, 08:02:09 PM »
ive been reading through all the tuning information available here most of it is straight forward and similar to gas flowing engines one question i have is where the washer is placed to increase the hammer tension,and what size this washer can be from what ive read it appears the washer thickness is about a quarter of a inch

Offline Gene_SC

  • Hero Member
  • *****
  • Posts: 11378
    • http://www.airguntoys.com
Re: hammer spring mod
« Reply #1 on: October 08, 2006, 11:39:10 PM »
Did you look in the Library Ian? CDT has some info there that may help.

Gene
THE ONES I SLEEP WITH: BSA Lightning XL, AA TX-200, AA ProSport, BSA Ultra, HW-97K, Crosman NPSS .177, FX Cyclone, HW-30 Nicle Plated, AA-S200, Crosman Marauder, CZ-634, R-9 DG, Webley/Scott UK Tomahawk, Benji Kantana, Benji Marauder, Benji Discovery.....
....

Gene\'s Tunz n Toyz
Springer Tunin

Offline mikeiniowa

  • Hero Member
  • *****
  • Posts: 1110
    • http://airgunartisans.com/flyingdragon
RE: hammer spring mod
« Reply #2 on: October 09, 2006, 09:52:44 AM »
A small OD 1/4 inch washer will fit or a #10 machine screw washer, keep stacking until it won't cock then back off one......it's hard on the end of the valve stem, I perfer to go with a lighter spring in the valve.

Offline IJL

  • Full Member
  • ***
  • Posts: 197
    • http://www.qbtune.zoomshare.com
RE: hammer spring mod
« Reply #3 on: October 10, 2006, 01:02:40 AM »
Ian, MikeinIowa is absolutely right and the shim goes straight under the hammer spring, but I doubt you will need to shim it or mod the valve. Some of these QBs will go well over the uk limit with just a good porting and polish so take care!(Make sure you know what weight pellet carries the most energy, they vary!) This is the guide from CDT that I started with. It got my PCP converted QB to almost 40 fpe till I worked out how to slow it down again!

http://www.gatewaytoairguns.com/library/Charlie’s%20QB-78%20Tune.htm

Ian