Soft spring for a HW35

[gtfreight]

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.

[Shed tuner]

if the guides are snug, try adding a piston sleave with a dollop of grease

[gtfreight]

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.

[evert]

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 )

[gtfreight]

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.

[Garvin]

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.

[gtfreight]

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.

[maximus]

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.

[Shed tuner]

yeah, rather than chopping a stiff spring, it'll be nicer with a softer, longer spring.

[evert]

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.

[gtfreight]

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.

[Shed tuner]

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.

[TonyL]

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.

[gtfreight]

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?

[TonyL]

I've never sleeved one personally, Gary. But I think JB & Co who have have often used things like old radio aerials and suchlike.