HW/Weihrauch Broken Spring

[Croxton63]

The short questions: When springs break is it subtle or dramatic? Do they often look like the one below? If not and you have some examples please post them to satiate my curiosity, and perhaps help educate newbies like me.

The background: I bought a HW50s .177 in the late fall and fitted a Hawke air max 2-7 x 32. Then a fellow member, Ugly John, suggested I get a chrono which I did. The gun chrono’d at 9.5-10 ft lbs. It seemed to shoot fairly well, but every now and then I’d hear a metallic click which made me wonder if I was imagining something. The new gun “twang” went away and i thought it had settled down. Nonetheless, after watching a bunch of videos and seeing a few posts i thought I’d set myself up with winter projects which may seem like a morning’s work to you experienced folks. I didn’t want to start breaking it apart until I’d got all the tools for the job.
Last week I started at it. When I opened the gun I found the spring broken, which surprised me because it was shooting quite well. It seemed that after it broke the longer piece wrapped itself around the shorter piece. The inside of the tube looked pretty clean with no gouging, just a few light scratches.
I’ll post a few photos of the broken spring and the new TBT spring kit side by side - it was buying the new kit which prompted me to open the gun up.

Followed by a photo of the 10 shot chrony string showing its performance with a broken spring.

 

[.20calguy]

I've jokenly said when my HW shoots it's best it's fixing to ether break the spring or it already broken ..lol

I most times can catch a slight snap or click when cocking and clue in broke or just broke it . Then a slight pot drop then chrony a 100fps loss +/-.. lol.. still just a small sight adjustment up and it's still shooting spot on target .

Like you said if you just did not know you'd just keep on shooting it it can't ..lol

Thats what they say about an old tube amp. They sound best just before they let the smoke out. Lol

 

[Bedrock Bob]

For what gun ?.. you may have to do some fine tuning the cocking shoe to not gall. But once done they shoot well.

Yup. Cocking shoe against the Vortek guide. It's just a little scuff at the end of the stroke. I think it's just touching the very edge of the cocking shoe casting.

I was going to work on dressing up the edge of the cocking shoe like a trigger sear. Rounding the corner a little to push grease under rather than scrape it away and finishing the surface halfway back.

Am I on the right track?

 

[Bedrock Bob]

I've jokenly said when my HW shoots it's best it's fixing to ether break the spring or it already broken ..lol

I most times can catch a slight snap or click when cocking and clue in broke or just broke it . Then a slight pot drop then chrony a 100fps loss +/-.. lol.. still just a small sight adjustment up and it's still shooting spot on target .

Like you said if you just did not know you'd just keep on shooting it it can't ..lol

Spot on as always Mr. McNasty.

Mine shoots buttonholes at 575 fps. Sometimes I wonder why I worry about velocity. Actually I don't until I run out of front sight at 50 yards. When you start missing low at range it's frustrating to learn a new trajectory. You get used to a sight picture and suddenly it's not right anymore. That front blade gets mighty tall and the rear sight is obscured in front of that obnoxious tunnel up front.

As the broken spring winds up in itself and hunches over on the end it just keeps getting lower. Pretty soon I'm dropping them in a soup can at 75 rather than hitting it in the side. But they all land amazingly close together no matter how loopy it gets.

 

[A.G.R]

Thats what they say about an old tube amp. They sound best just before they let the smoke out. Lol

have had a few Macs and Audio Research. Got tired of waiting for failure and every time you turn them on it can be worse than before. Went SS 20 years ago haven’t looked back. Drink a and know it’s the same every time ….until CAPS GO OUT.

 

[A.G.R]

Yup. Cocking shoe against the Vortek guide. It's just a little scuff at the end of the stroke. I think it's just touching the very edge of the cocking shoe casting.

I was going to work on dressing up the edge of the cocking shoe like a trigger sear. Rounding the corner a little to push grease under rather than scrape it away and finishing the surface halfway back.

Am I on the right track?

Yes. Gun has to be apart and soften each edge as well as the inner radius with a dowel and paper

Dont hurt to do the inner wings to with jewelers file to ease edges. Leading edges for sure. Kinda hard to explain it’s a fee deal. Or 4 beer in its goot crime.

 

[Bedrock Bob]

Yes. Gun has to be apart and soften each edge as well as the inner radius with a dowel and paper

Dont hurt to do the inner wings to with jewelers file to ease edges. Leading edges for sure. Kinda hard to explain it’s a fee deal. Or 4 beer in its goot crime.

I got it covered. Thanks for the confirmation.

It's worth a couple beers! If you are ever in this neck of the woods I'll buy. We can shoot and lie and see how high we can pee up a tree too!

 

[.20calguy]

have had a few Macs and Audio Research. Got tired of waiting for failure and every time you turn them on it can be worse than before. Went SS 20 years ago haven’t looked back. Drink a and know it’s the same every time ….until CAPS GO OUT.

I'm worse I went digital. Lol
my unit, a Neural DSP Quad Cortex captures amps and pedals. Just carry it and a guitar.

 

[.20calguy]

have had a few Macs and Audio Research. Got tired of waiting for failure and every time you turn them on it can be worse than before. Went SS 20 years ago haven’t looked back. Drink a and know it’s the same every time ….until CAPS GO OUT.

Audio amps.
I was thinking guitar amps for that coment. My old hifi speakers used to have Macs running them. I still have the speakers in use, but the Macs are long gone.

 

[JamieUK]

Just some thoughts on the 7 compressed coils on the spring that failed.....

If you consider how compression springs work, a spring with evenly spaced coils will evenly share the torsion across each coil. On your spring the coil that snapped was fighting against the compressed coils.

Those compressed coils will have also increased the spring rate, so each coil will have been twisting further across the stroke length than if they were all active coils, possibly prematurely over working the spring. Bit of a recipe for disaster

 

[Tarheel]

Still very new to airguns. I have a 43 yr old Crosman American Classic and a two month old HW30s. I have very limited knowledge of the way these guns work. It is a bit scary to me that an HW airgun just a few months old can have the spring break. The squeaky wheel gets the grease, so to speak - so I hope this thread reflects info on springs breaking whereas the many, many more HW airguns that don't have a spring break are of course less inclined to contribute to this thread. I only paid $300. for my HW30s but I would be very disappointed if the spring breaks sooner rather than later - if ever. Also, most of you contributing to this thread are apparently very good at mechanical things and do you own repairs. I have no mechanical skills and would have to ship my HW30s somewhere for any repairs. Like I said, still learning on this web-site.

 

[Croxton63]

I am grateful for the input of people who take the time to contribute to threads like these. This is the most mechanical thing I’ve done in years, and I wouldn’t have had the confidence to try it without having these online resources; Volunteers would be another way to describe them!

 

[Croxton63]

We got a break in the colder weather today so went out and ran some pellets through the Chrony. I understand that the spring will probably take a bit to settle in, but for a HW50s .177 I am pretty happy with this initial string.

 

[JP806TX]

Good to see that you got your gun back together.

Here's a fun comparison. After you get the new spring broken in.

Are you able to group better when your gun was around 9.6 FPE (with a broken spring)
or
Are you able to group better with your new spring around 11.8 FPE.

For me, I was advised to detuned my TX200 to around 10-10.5 FPE and I added weight to the stock. This combination seems to make the recoil more manageable for a competition springer.

Oh and I lightened the trigger. New year...new things to try.

 

[Croxton63]

That’s a good question! I’ll have to wait until the weather warms up so I can compare my targets - I kept my best card from the summer for that reason.

 

[Bedrock Bob]

I am grateful for the input of people who take the time to contribute to threads like these. This is the most mechanical thing I’ve done in years, and I wouldn’t have had the confidence to try it without having these online resources; Volunteers would be another way to describe them!

We all learn this stuff together. It's a two way street. Your experiences and outcomes are a wealth of knowledge for anyone who offers advice or follows the conversation.

The guns are simple enough anyone could work on them. It's a big jump if you don't have a shop full of tools and a plumbers license. But once you dive into it It's not that bad. You just need the voice of someone who has made some mistakes to steer you away from them.

No matter what kind of air rifle you are working on there are a dozen guys here in love with one. They will know everything about it. They all want to tell you how they do it or how they did it or what they are going to do to it next.

They peck at each other and crane their leathery necks sometimes, but you will always get a wealth of information from the discussion. It's usually spot on. There is a whole bunch of experience represented here.