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All Springer/NP/PCP Air Gun Discussion General => European/Asian Air Gun Gates => German AirGun Gate => Topic started by: choughton on March 27, 2023, 11:29:32 PM

Title: HW95 DIY twang n buzz fix
Post by: choughton on March 27, 2023, 11:29:32 PM
Hi. I am new to springer air rifles but have decent mechanical skills and understanding. How can I remove the twang and buzz from the HW95? I have read lots of stuff but leaves out the all important details. I am wanting to learn and understand all I can about the spring system and how to improve it. Anyone interested in tutoring a newbie? Thanks.
Title: Re: HW95 DIY twang n buzz fix
Post by: Roadworthy on March 28, 2023, 12:30:27 AM
To do it right you'll need to disassemble the gun.  To do it quick and dirty try spreading some grease on the spring through the cocking slot.  The proper fix is a properly fitted spring guide.  The easy way to do this is a tune kit which will include a spring and fitted spring guide.  I like to use Air Rifle Headquarters though others prefer Vortek.  Or you could have a guide made to fit your existing spring.
Title: Re: HW95 DIY twang n buzz fix
Post by: Deerstalker on March 28, 2023, 12:38:24 AM
My 2018 year HW95 had the piston seal damaged by dieseling due to overoiling/greasing at the Weihrauch factory.  It also had twang/buzz during the shot cycle.  Per recommendations on this forum I installed an ARH kit and Vortek seal after a through clean/polish and re-lubed with Krytox GPL-205.  The cocking cycle is soundless and the shot cycle is a dull thud and the twang/buzz is now gone.  Here is a video of the shot cycle and if you have questions about your rifle the folks here will be happy to help.  Be sure and chrono your rifle so that you have something to compare to after your tune/upgrade.
https://youtu.be/bywPFmB2_ZM    (https://youtu.be/bywPFmB2_ZM)
Title: Re: HW95 DIY twang n buzz fix
Post by: choughton on March 28, 2023, 01:19:16 AM
 I plan to disassemble the rifle, just trying to have a plan once I get it apart. I could buy a kit so I could examine what properly fitted parts means exactly. I can build/make anything. I just don't know what to build, what tolerances, what lube, how polished etc... I am very confident I can do the work, I just don't have solid direction. Thanks.
Title: Re: HW95 DIY twang n buzz fix
Post by: choughton on March 28, 2023, 01:26:11 AM
Lube? Krytox gpl-205 keyboard switch lube?
Title: Re: HW95 DIY twang n buzz fix
Post by: Roadworthy on March 28, 2023, 01:37:13 AM
I have found the best price on Krytox in the past at  Zoro.  If using it you must remove all petroleum based lubes.  They don't play well together.  You should have some sort of spring compressor when you dismantle the gun.  I don't know whose Weihrauch seals are the best.  I generally get Diana seals from Air Rifle Headquarters.  It's a personal preference thing.  I get my tune kits from ARH as well.  If using Krytox you may also use molybdenum disulfide powder.  You may not use "moly lube"
Title: Re: HW95 DIY twang n buzz fix
Post by: Yogi on March 28, 2023, 07:32:02 AM
Chad,

There are tones of U-tube videos explaining the disassemby process of your gun.  Congratulations, you bought a good one! :D

For years and years, people have used a Molybdenum disulfide grease to lubricated moving parts.  Under extreme pressure, and if placed in the wrong places, it will detonate when fired.  Because of this, some people now prefer synthetic lubrication which will not detonate under pressure.

A proper fitting guide will be in direct and strong contact with the inside of the spring when not cocked.  When cocked the spring compresses and the ID get slightly larger.  When the spring is released, the spring guide and top hat should "grab" the spring tight enough to stop the spring vibrating on its own.  That is spring twang.

GTA has lots of knowledgable and helpful posters.  Most home tuners have a lathe, the ability to work with high end plastics and other tools.
I would suggest that you consider buying a small torque wrench, a set of hollow ground gunsmithing tools(our screws are not normal), and build a spring compressor.

HTH's,

-Yogi
Title: Re: HW95 DIY twang n buzz fix
Post by: avator on March 28, 2023, 09:19:15 AM
One of the best things you can do to a spring gun is to make the spring spin smoothly and freely on the spring guide and top hat. If no top hat than it need to spin freely in the piston. Do this by polishing and deburring the ends of the springs. In some cases, a thrust washer on the spring guide and a penny up in the piston can be very effective. A good coating of heavy tar on the spring helps as well.
Title: Re: HW95 DIY twang n buzz fix
Post by: Toxylon on March 28, 2023, 09:31:47 AM
What I did at the newbie phase was to read the GTA forum for hours on end, using the search function with my specific questions. There's probably a thousand pages worth of quality discussion here on what to do to a HW95 to make it shoot better. The work of explaining it all has basically been done already, is what I'm sayin'.
Title: Re: HW95 DIY twang n buzz fix
Post by: nced on March 28, 2023, 11:56:11 AM
Hi. I am new to springer air rifles but have decent mechanical skills and understanding. How can I remove the twang and buzz from the HW95? I have read lots of stuff but leaves out the all important details. I am wanting to learn and understand all I can about the spring system and how to improve it. Anyone interested in tutoring a newbie? Thanks.

A few thoughts on "HW springer twang".
LOL...I'm glad that my HW95 and Beeman R9 didn't twang/vibrate nearly as much as the Gamo440 I bought and later "land filled".

1. I didn't find that the annoying twang affected my .177 HW springers accuracy very much (if at all) because I've bought, tuned, sold about a dozen over a couple decades and still have two (a HW95 and a Beeman R9)
and ALL would put five 7.9 Boxed Crosman Premiers (have become "unobtanium") into a twangy half inch group at 30 yards while sitting on a bicket resting the gun on cross sticks after an initial bore clean and a few dozen "seasoning shots".

2. Twang does reduce a bit with use as the factory spring takes a cant ant starts rubbing the spring guide. Initially I dampened the spring twang using a thick molly lube called "spring tar" and that was a mistake. While slathering a bunch of the stuff on the guide and spring coils did moderate twang but that didn't last very long with use and it made my .177 R9 (bought after the R10) "temperature sensitive" because the pellet point of impact would change with a cold morning to a warm afternoon. Basically, I nixed all "smear on twang reducing goops" and started fitting my springs with tight fitting spring guides. IMHO the only way to "disable" twang is to use a properly fitting snug spring guide,

3. IMHO, simply continue shooting your HW springer till the spring NEEDS to be replaced and replace the factory spring with a good aftermarket kit (I like the ARH offerings). I have bought bare springs from a different vendor (I make all my spring kits using bare springs) and where the ARH springs last for many thousands of shots and don't significantly sag with use I had different results using springs from "another vendor". The "other vendor" spring kit and springs I tried did work well initially but started "sagging" after about 2500 shots and the R9 lost about 80fps in less than two boxes of 7.9 grain boxed Crosman Premiers.

4. Accuracy before and after tuning is VERY dependent on the pellets used as well as the tune level. Here are a couple target shot years ago sitting on a bucket resting the gun on cross sticks when my comparing accuracy of different pellets ...........
(https://i.imgur.com/L8mI96e.jpg) (https://i.imgur.com/IzGChR5.jpg)(https://i.imgur.com/cTkKs8L.jpg)

(https://i.imgur.com/8SZm6IE.jpg) (https://i.imgur.com/dDepUwX.jpg)
 
Title: Re: HW95 DIY twang n buzz fix
Post by: choughton on March 28, 2023, 01:09:40 PM
Thanks for the responses. The problem with the common "do a search" suggestion is threefold, #1 you may read 1000 pages to find one sentence that mostly/partly answers a question and if the information lacks a bit, there is nobody to ask for clarity #2 you will find contradicting information, again with no discussion for clarity  #3 and most importantly, hanging around searching leaves a newbie out of active conversation with more knowlegeable fellas.(IMO the best way to learn) I have a machine shop with all manner of tools needed to build whatever I need. I expect to have to duplicate the factory spring guide with proper tolerances. I am a pretty fair gunsmith, machinist, welder and mechanic. I received mixed opnins on guide fitment, lube quantity and one suggestion for "a penny in the piston" ? Thanks again for the responses. Please lets discuss the matter further. Maybe focus on lube type/quantity and spring guide fitment. I use TW25b routinely and always have it on hand. How would TW25b work compared to "tar"? Really just trying to learn and sperate the wheat from the chaf so to say. Thanks again.
Title: Re: HW95 DIY twang n buzz fix
Post by: Artie on March 28, 2023, 03:12:04 PM
Personally I think "lube" tuning or "tarring" springs to kill twang is antiquated.
Furthermore, a new guide and spring is not necessary to eliminate the twang.  The easiest, cheapest method to silence the spring is with a thin strip of plastic captured between the last couple of coils and the spring guide.
Refer to the attachment for an example of what I am talking about. Incidentally, the spring & guide in the photo are oem HW95.
You want as tight a fit as possible, i.e.. "twist on" tight, so shop around for some scrap donor plastic sheeting of different thicknesses before undertaking the project. I have also used brass shim since I have a large selection in thousandths.
Otoh, if you have a lathe and delrin stock on hand, spin out a guide and be done with it.
Title: Re: HW95 DIY twang n buzz fix
Post by: choughton on March 28, 2023, 05:38:30 PM
Thanks Artie. I do have some delrin on hand and a bunch of copper shim stock. I suspect coming up with some plastic would not be too difficult either. If I make a new guide rod how should it fit the spring? What do you think about TW25b for a lube? Thanks.
Title: Re: HW95 DIY twang n buzz fix
Post by: Artie on March 28, 2023, 05:59:33 PM
On receiver lubes: I keep all my springers fairly dry except for Honda M77 moly paste. I don't do the Krytox or GPL thing in the receiver even though I have both. Removing the stuff later is nearly impossible. That's me, and you will hear others who disagree...

Some people like their guides "screw on" tight with friction on every coil. This should keep the spring straight if the tophat nearly kisses the end of the guide, no place for the spring to bend to. The friction will also cost fps to a degree.

Some folks prefer a tapered guide, tight at the end where I showed the shim , and looser toward the end.

Start tight I say, and see how it shoots. You know the addage... you can remove material but you can't put it back. An HW95 can afford to loose some speed so I wouldn't be overly concerned about a tight guide robbing fps as long as the guide can screw on and off without too much trouble. If it was an HW30 otoh, I would opt for a tapered guide to keep speeds up.
Title: Re: HW95 DIY twang n buzz fix
Post by: nced on March 28, 2023, 07:04:56 PM
Thanks for the responses. The problem with the common "do a search" suggestion is threefold, #1 you may read 1000 pages to find one sentence that mostly/partly answers a question and if the information lacks a bit, there is nobody to ask for clarity #2 you will find contradicting information, again with no discussion for clarity  #3 and most importantly, hanging around searching leaves a newbie out of active conversation with more knowlegeable fellas.(IMO the best way to learn) I have a machine shop with all manner of tools needed to build whatever I need. I expect to have to duplicate the factory spring guide with proper tolerances. I am a pretty fair gunsmith, machinist, welder and mechanic. I received mixed opnins on guide fitment, lube quantity and one suggestion for "a penny in the piston" ? Thanks again for the responses. Please lets discuss the matter further. Maybe focus on lube type/quantity and spring guide fitment. I use TW25b routinely and always have it on hand. How would TW25b work compared to "tar"? Really just trying to learn and sperate the wheat from the chaf so to say. Thanks again.

<b<"I expect to have to duplicate the factory spring guide with proper tolerances."
There is the SOURCE of spring twang if you find twang annoying. HW spring guides are a sloppy fit in the springs which allows the coils to oscillate back and forth after the piston and last coils stop while the rear coils are still surging forward after the piston stops. A twang killing "properly tight" guide needs to be tight fitting in the spring coils to the point that the guide needs to be twisted counter the spring wind while pulling to be removed. A loose fitting guide will easily pull out of a spring but with a "properly tight" fit the spring will act as a "Chinese finger cuff" when pulled without twisting counter to the spring wind.

With a "properly fitted" guide the grip of the spring is released when cocking the gun as the spring ID increases with compression. When the sear is released and the spring extends it also becomes a bit smaller in diameter and the coils again grip the guide which kills the oscillation of coils, thus killing twang and vibration..........

Anywhoo, some folks measure the spring ID then machine the guide based on the measurement plus a few thou. This never worked well for me because the spring ID increases simply due to preload depending on the amount of preload. Each spring varies is slightly in dimensions due to the spring wire temper and heat treating, even the two ends of the same spring can be different by a few thou. I prefer to simply cut a Delrin guide (I prefer plastic over metal) so it's a bit excessive in diameter, then shave the guide in the lathe till it fits "properly tight" by feel. Here is a pic of the spring kit in my .177 HW95 based on a "light wire" Maccari E3650 spring (354 coils of .120 wire)............
(https://i.imgur.com/nh5lB1b.jpg)
(https://i.imgur.com/GXZl4Hh.jpg)
Title: Re: HW95 DIY twang n buzz fix
Post by: choughton on March 28, 2023, 08:34:59 PM
Again Thanks all for input. I am feeling like I have a pretty good grip on the spring guide. I will try the TW25b for lube. It is very good stuff and tends to stay where you put it. What is the "top hat"? What is its function? Is it necessary? I don't think the HW95 has a "top hat" in stock form but I could be wrong.
Title: Re: HW95 DIY twang n buzz fix
Post by: avator on March 28, 2023, 08:38:07 PM
The top hat is the spring guide at the top of the piston. It's purpose is to keep the spring centered, among other things. If you look at the picture in Ed's post just ahead of yours, you can see a top hat in the right end of the spring.
Title: Re: HW95 DIY twang n buzz fix
Post by: choughton on March 28, 2023, 09:23:43 PM
Thank you. Does the top hat help much for my purposes? (reducing twang/buzz) I would guess a top hat should be tight in the spring? When the rifle is cocked, should the spring guide and top hat be nearly touching? Is there a concern of coil bind if a top hat is installed in a factory spring? Can the top hat and spring guide relationship/clearance be seen with stock off and rifle cocked? (to determine top hat length) Thanks again.
Title: Re: HW95 DIY twang n buzz fix
Post by: avator on March 28, 2023, 09:31:30 PM
Thank you. Does the top hat help much for my purposes? (reducing twang/buzz) I would guess a top hat should be tight in the spring? When the rifle is cocked, should the spring guide and top hat be nearly touching? Is there a concern of coil bind if a top hat is installed in a factory spring? Can the top hat and spring guide relationship/clearance be seen with stock off and rifle cocked? (to determine top hat length) Thanks again.
Yes, all the above can be factors. Again, you want your spring to spin freely... if not you may experience torque.
Title: Re: HW95 DIY twang n buzz fix
Post by: Bayman on March 29, 2023, 08:24:54 AM
Cliff notes.
Vortek piston seal.
Maccari FAC spring kit.
Parts Done
Very simple

Completely degrease compression tube with brake cleaner. Only apply a very little grease on the piston seal shoulder and the last half inch of piston skirt. Absolutely don't get ANY grease in front of the piston seal. For grease I use either krytox or Almagard 3752. Save the moly paste for the pivot and chisel.
Title: Re: HW95 DIY twang n buzz fix
Post by: choughton on April 02, 2023, 11:12:27 AM
Thanks for all the rresponses. Any preference for spring guide material? I have delrin, uhmw and nylon. Thanks.
Title: Re: HW95 DIY twang n buzz fix
Post by: sicumj on April 02, 2023, 12:03:12 PM
I used white Delrin on my guide and top hat.  I made mine about a thousandth over so I had to screw it into the spring. I tried it a couple of times before being satisfied on size. Top hat thickness was around 1/4 inch and I did not trim spring.  I used Krytox 205 a Maccari spring and a Vortek seal.  I did not size the Vortek seal.