Page 1 of 2 12 LastLast
Results 1 to 15 of 24

Thread: Soft spring for a HW35

  1. #1
    Join Date
    Mar 2008
    Location
    Rochdale
    Posts
    2,304

    Soft spring for a HW35

    I have had to cut and compress the spring on my 35 so that the preload doesn't start until the trigger block meets the thread and it's resonating when shot. The guides are fitted snugly and it didn't do it before I shortened the spring so I'm thinking that it's bouncing back and forth through the shot cycle.
    Is there a softer spring that will cure this or is there another option?
    Thanks,
    Gary.

  2. #2
    Join Date
    Apr 2002
    Location
    Near Wimbledon, SW London, or Lusaka, Zambia
    Posts
    26,987
    if the guides are snug, try adding a piston sleave with a dollop of grease
    Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.

  3. #3
    Join Date
    Mar 2008
    Location
    Rochdale
    Posts
    2,304
    Quote Originally Posted by Shed tuner View Post
    if the guides are snug, try adding a piston sleave with a dollop of grease
    Thanks Jon, there's already a sleeve in it but I'll add some grease at the weekend.

  4. #4
    Join Date
    Jun 2012
    Location
    Oslo, Norway
    Posts
    2,876
    Quote Originally Posted by gtfreight View Post
    I have had to cut and compress the spring on my 35 so that the preload doesn't start until the trigger block meets the thread and it's resonating when shot. The guides are fitted snugly and it didn't do it before I shortened the spring so I'm thinking that it's bouncing back and forth through the shot cycle.
    Is there a softer spring that will cure this or is there another option?
    Thanks,
    Gary.
    Maccaris spring softened my .177 HW35:
    https://www.airrifleheadquarters.com...88/9689749.htm

    This spring has a smaller diameter, which keeps the piston away from the piston ID.
    The spring it is longer than the original, and has more preload, so it requires a well fit tight guide to remove all vibration.
    ( I dont like large amounts of grease for vibration dampening )

  5. #5
    Join Date
    Mar 2008
    Location
    Rochdale
    Posts
    2,304
    Quote Originally Posted by evert View Post
    Maccaris spring softened my .177 HW35:
    https://www.airrifleheadquarters.com...88/9689749.htm

    This spring has a smaller diameter, which keeps the piston away from the piston ID.
    The spring it is longer than the original, and has more preload, so it requires a well fit tight guide to remove all vibration.
    ( I dont like large amounts of grease for vibration dampening )
    Thank you. Food for thought.

  6. #6
    Join Date
    Mar 2006
    Location
    City of London
    Posts
    9,896
    Quote Originally Posted by evert View Post
    Maccaris spring softened my .177 HW35:
    https://www.airrifleheadquarters.com...88/9689749.htm

    This spring has a smaller diameter, which keeps the piston away from the piston ID.
    The spring it is longer than the original, and has more preload, so it requires a well fit tight guide to remove all vibration.
    ( I dont like large amounts of grease for vibration dampening )
    Have you tried Maccari's heavy tar? You can dampen a spring by using only a small amount, in my experience, although I've not tried it on an HW35.
    Vintage Airguns Gallery
    ..Above link posted with permission from Gareth W-B
    In British slang an anorak is a person who has a very strong interest in niche subjects.

  7. #7
    Join Date
    Mar 2008
    Location
    Rochdale
    Posts
    2,304
    Quote Originally Posted by Garvin View Post
    Have you tried Maccari's heavy tar? You can dampen a spring by using only a small amount, in my experience, although I've not tried it on an HW35.
    Thanks Garvin, you've given me an idea. I have some "Tygris open gear lube". I'll give that a go.

  8. #8
    Join Date
    Nov 2008
    Location
    Preston
    Posts
    3,278
    Quote Originally Posted by gtfreight View Post
    I have had to cut and compress the spring on my 35 so that the preload doesn't start until the trigger block meets the thread and it's resonating when shot. The guides are fitted snugly and it didn't do it before I shortened the spring so I'm thinking that it's bouncing back and forth through the shot cycle.
    Is there a softer spring that will cure this or is there another option?
    Thanks,
    Gary.

    Does it still twang with hobbies? Sometimes the lighter pellet reduces piston bounce and kills the twang.
    Plinkerer and Tinkerer

  9. #9
    Join Date
    Apr 2002
    Location
    Near Wimbledon, SW London, or Lusaka, Zambia
    Posts
    26,987
    yeah, rather than chopping a stiff spring, it'll be nicer with a softer, longer spring.
    Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.

  10. #10
    Join Date
    Jun 2012
    Location
    Oslo, Norway
    Posts
    2,876
    Quote Originally Posted by Garvin View Post
    Have you tried Maccari's heavy tar? You can dampen a spring by using only a small amount, in my experience, although I've not tried it on an HW35.
    Yes, I've used it quite a bit, but still think that depending on tacky grease for vibration dampening is an emergency fix. But it has its use in some guns, especially in powerful FAC guns where the tar does not rob the gun of much power.
    After trying several different spring lubes in a variety of guns, I've come to the conclusion that my favorite is a not too sticky PTFE grease on tight fitting delrin guides.

  11. #11
    Join Date
    Mar 2008
    Location
    Rochdale
    Posts
    2,304
    I don't know if this would make any difference but it's a 55 year old gun that originally had a leather piston seal and a 4mm tp. The leather seal was quite a tight fit and I'm not confident in resizing it so a modern piston was tried which improved it no end, the shot cycle was surprisingly good but it needed the spring shortening and when I did this was when it started to resonate.
    Last edited by gtfreight; 04-12-2020 at 03:52 AM.

  12. #12
    Join Date
    Apr 2002
    Location
    Near Wimbledon, SW London, or Lusaka, Zambia
    Posts
    26,987
    you really need to sleeve the TP down to 3.2mm mate.. just glue some tubing in; it's a long port, so lots of surface area fo the glue.

    the longer stroke synth piston is a great upgrade for these guns - but the TP needs reducing.
    Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.

  13. #13
    Join Date
    Apr 2012
    Location
    Retford, Notts
    Posts
    37,287
    Jon makes a very good point re the TP. However, my old "cronk" has the later piston fitted whilst retaining the original TP size ('cos I'm lazy) and is fine - V-Mach spring and guide set fitted.
    As an "easier" fix, keeping an eye on the power, of course, how about increasing the preload slightly with a washer under the top hat? Some tacky grease, as suggested. And, as maximus, mentioned, try some different pellets. If you haven't already done so, be sure to try some (low start pressure) JSBs.
    THE BOINGER BASH AT QUIGLEY HOLLOW. MAKING GREAT MEMORIES SINCE 15th JUNE, 2013.
    NEXT EVENT :- May 17/18, 2025.........BOING!!

  14. #14
    Join Date
    Mar 2008
    Location
    Rochdale
    Posts
    2,304
    Thanks for all your help. With my very limited skills I wouldn't know how to make a sleeve for the transfer port, I'm thinking I need some 4mm tubing and somehow make a 3.2mm hole in it and then glue it inside the port?

  15. #15
    Join Date
    Apr 2012
    Location
    Retford, Notts
    Posts
    37,287
    I've never sleeved one personally, Gary. But I think JB & Co who have have often used things like old radio aerials and suchlike.
    THE BOINGER BASH AT QUIGLEY HOLLOW. MAKING GREAT MEMORIES SINCE 15th JUNE, 2013.
    NEXT EVENT :- May 17/18, 2025.........BOING!!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •