Vulcan mods to make the hammer/spring assembly consistent.
This mods were performed on Zonk .22 Vulcan. his issue was sudden change in pellet speed.
in my testing —–> it was consistent for 5-12 shots or so around 900fps then drop down to 840fps for about 2 to 6 shots then back up to 900fps keeps doing this for 4 fill and can’t complete a string without the speed dropping to 840fps.
So the 1st thing I did was tuned the reg down to 120b with some polishing and better orings, didn’t see anything wrong with the reg during dissemble.
When testing the tuned reg I still see the speed drop in every fill. So I know now it’s in the hammer assembly so heres the mods I done in the photo:
1. In the middle of the hammer spring there is no spring guide so the spring flex where less resistant (rainbow) so the spring end at the HSTA rub on the threads in the action for the HSTA. to prevent the spring drag I sanded and polish the coils that’s making contact with the action threads and that also was sanded and polish.
2.The hammer was given a high polish for less friction.
3. The brass bushing for the hammer spring has an edge that side in the hammer chamber—- sense the hammer has a loose clearance that edge hits the action 1st at times that prevent the full travel of the hammer spring—the fix I reduce the OD.
4. after the hammer open the fire valve it will slam back at the brass bushing guide so to prevent metallic noise and still have a clearance for a de bouncing device (hammer is free floating so the hammer isn’t pressing on the VS when uncock) i installed a nylon slim.
here is a photo of a delrine spring retainer with a longer spring guied to replace the brass spring retainer and hopefully will keep the hammer spring from binding out ward so the back end of the spring from rubbing on the threads and reduce the impact noise.
if you want one contact John.
After all this mods I got her shooting consistently after 200+ rounds here are 3 shot string with the reg set a 120b. with 18.1g pellet.
pressure 205b to 105b
String #1 string #2 string #3
#shots 65 65 62
high: 900fps 907fps 902fps
low: 892fps 895fps 895fps
ES: 8fps 12fps 7fps
Not every Vulcan will have this issue but some useful info for others.
All Replies
If no grease the ping/music wire noise will travel, Vulcan has the loudest ping, hammer slap/impact vibration of all the BP I ever tuned, there’s one more ping I have to find and thing it’s the cocking rod—-lube that too!!
have you ever put heavy grease on a guitar string====wont sound the same!
If you really Liston close when fired—-there are two impact noise on the vulcan—the full force of the hammer spring and brass retainer will slam on the action body—-then the hammer will travel about 1/8″ and smack on the valve stem—–its noisy telling you!
Yes, in addition to what you told me when we spoke on the phone when we spoke of the Vulcan several weeks ago about the loud sounds it makes on its firing cycle, I’ve read quite a bit about it too. So it makes sense to grease those parts to dampen those noises.
I think its a bad designed to have that brass retainer carry the full load of the hammer spring and slam on the action body not directly on the valve stem, I mean edgun, cricket, mutant, Jager, ataman just to name a few that doesn’t.
I think I will remove that brass retainer and see how quiet it get and see how bad the shout count is—-I can do away with 50 shots just to make it as quiet as the mutant
don’t think so, its time consuming and just to busy but willing to help others find the right size orings!
If no grease the ping/music wire noise will travel, Vulcan has the loudest ping, hammer slap/impact vibration of all the BP I ever tuned, there’s one more ping I have to find and thing it’s the cocking rod—-lube that too!!
have you ever put heavy grease on a guitar string====wont sound the same!
If you really Liston close when fired—-there are two impact noise on the vulcan—the full force of the hammer spring and brass retainer will slam on the action body—-then the hammer will travel about 1/8″ and smack on the valve stem—–its noisy telling you!
Yes, in addition to what you told me when we spoke on the phone when we spoke of the Vulcan several weeks ago about the loud sounds it makes on its firing cycle, I’ve read quite a bit about it too. So it makes sense to grease those parts to dampen those noises.
Ernest can or will you put a oring kit together like you did for cricket?
If no grease the ping/music wire noise will travel, Vulcan has the loudest ping, hammer slap/impact vibration of all the BP I ever tuned, there’s one more ping I have to find and thing it’s the cocking rod—-lube that too!!
have you ever put heavy grease on a guitar string====wont sound the same!
If you really Liston close when fired—-there are two impact noise on the vulcan—the full force of the hammer spring and brass retainer will slam on the action body—-then the free floating hammer will travel about 1/8″ and smack on the valve stem—–its noisy telling you!
Where exactly did the nylon shim go??? I missed that…
Hoot:
between the brass retainer and main body of the hammer. VS<——- Hammer—–nylon shim—–brass spring retainer —–Nylon shim—–spring—-HSTA
If you don’t want to wear out the brass retainer and have brass dust use nylon front and back as seen on photo:
Is that the factory lube job on the parts in the second photo? That looks like a heck of a lot of grease!
:hoot:
Where exactly did the nylon shim go??? I missed that… Wait…is that the nylon shim on the delrin end? I enlarged the picture and it seems to have a raised circle in middle…
Hoot:
Dman your tester works great–thanks
I see thAt reg tester is getting some use!!!!
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:hoot:
here is a photo of a delrine spring retainer with a longer spring guide to replace the brass spring retainer and hopefully will keep the hammer spring from binding out ward so the back end of the spring from rubbing on the threads and reduce the impact noise.
if you want one contact John.
Does the delrin spring retainer replace the brass spring retainer?
This pic seems to show both of them in use…
Hoot: