HW95 + Titan No.8 = pain in the arris

[DCL_dave]

Thanks for all the replies, guys. It should be obvious to you all that I am not experienced with these modern guns re. tuning and such, so I am going to see where this experiment takes me just for the experience, I need to see it for myself...but I will be ordering a more suitable spring and will probably be asking more questions as and when.

Just a footnote, what if I reduced the stroke with say one of Tinbums short stroke kits and kept this spring as is?...wouldn't this add preload and reduce the potential energy within the set up?

ATB,
Dave

[robs5230]

Just a footnote, what if I reduced the stroke with say one of Tinbums short stroke kits and kept this spring as is?...wouldn't this add preload and reduce the potential energy within the set up?

ATB,
Dave

Adding an 8 or 10mm SS extension, won't add firing preload as such, but it will limit the amount of swept volume, and the piston forward travel, in essence leaving the spring unable to reach full expansion so the spring will still be under some compression at the end of the cycle. This may prevent the bounce you think you're experiencing to some degree.

The downside of reducing piston travel / swept volume, is that it will likely reduce power. In your situation, it may not be a bad thing.

I'd also recommend chronoing with JSB Express 7.9 as well as the 8.44
With the SS extension fitted, you will notice the barrel drop further on breaking. The extension leaves the piston further away from the cocking shoe.

[eyebull]

Once or twice in the past I have done Google searches for spring suppliers and there are plenty to go at. Some suitable for our uses may be available off the shelf, although I guess we'd be very lucky if that were to be the case.

Jim Tyler mentioned on a recent-ish thread that Dr Mike Wright and he once had a batch made up to their specification. I seem to remember that the minimum order number may have been 20 springs or so to make it a cost effective exercise.

I wonder if anyone with industry insight could say if airgun manufacturers buy their springs off the shelf or have them made to spec?
Could imagine there might be a mix of both, with the budget manufacturers shaving costs by buying off the shelf.

Incidentally found a website yesterday - 'springmasters dot com' that sell a huge array of springs individually, albeit with a minimum order value of £18 (not far off the price of a super dooper airgun spring anyway). Might be worth a look?

[BTDT]

I wonder if anyone with industry insight could say if airgun manufacturers buy their springs off the shelf or have them made to spec?
Could imagine there might be a mix of both, with the budget manufacturers shaving costs by buying off the shelf.

Incidentally found a website yesterday - 'springmasters dot com' that sell a huge array of springs individually, albeit with a minimum order value of £18 (not far off the price of a super dooper airgun spring anyway). Might be worth a look?

Mike ordered six springs, which he did not ask to be pre-set, or scragged, so the first shot reduced the free length to the point at which we had negative preload. An order for six scragged springs followed, with the then fashionable 3.25mm wire. At this point, I had started to record recoil, and saw the stiff spring with little preload losing efficiency in massive piston bounce. A third order went in for a dozen springs, scragged and from 2.9mm wire. Perfect.

The unit price was around £9 IIRC. The more springs in the order, the lower the unit price, because a good portion of the price of a single spring is in the setting up.

[Shed tuner]

Yes, an SS extension may enable you to salvage something from this spring that you clearly have an emotional attachment to

[tinbum]

Yes, an SS extension may enable you to salvage something from this spring that you clearly have an emotional attachment to

I didn't want to mention that, but 10mm with a couple of dead coils would probably improve matters.
As a bonus, it will still work when the OP gets a better spring

I hear there are forum offers somewhere......?

[TonyL]

Mike ordered six springs, which he did not ask to be pre-set, or scragged, so the first shot reduced the free length to the point at which we had negative preload. An order for six scragged springs followed, with the then fashionable 3.25mm wire. At this point, I had started to record recoil, and saw the stiff spring with little preload losing efficiency in massive piston bounce. A third order went in for a dozen springs, scragged and from 2.9mm wire. Perfect.

The unit price was around £9 IIRC. The more springs in the order, the lower the unit price, because a good portion of the price of a single spring is in the setting up.

Excellent information; thank you for sharing, JIm.

Any idea on what "type" of wire was used, ie valve spring wire, music wire, composition etc., or does the supplier decide that based on the buyer's description of intended use?

[BTDT]

Excellent information; thank you for sharing, JIm.

Any idea on what "type" of wire was used, ie valve spring wire, music wire, composition etc., or does the supplier decide that based on the buyer's description of intended use?

The type of wire available will depend on whatever the spring manufacturer happens to have in stock in the specified diameter, Tony. They buy it on huge drums, and won't lay out that sort of money for someone who wants just a few springs.

[evert]

Some time back I cut down a Chinese xs B20 (HW95 clone) spring and fit it to a Meteor.
If I remember correctly, the spring was close to 3mm wire diameter, and about 13mm inside coil diameter.
And the B20 I had some years back shot quite well...

Could the B20 spring be a good alternative for HW95 tuning?

[Shed tuner]

Could the B20 spring be a good alternative for HW95 tuning?

Looking here: https://www.airgunbbs.com/showthread...ng-data-thread

looks similar to the SMK B2 spring, so yes, possibly, although it may be a fraction short ?
the same thread has the 95 spring at 245 mm long (and also 3.0 mm wire)...

[BTDT]

Looking here: https://www.airgunbbs.com/showthread...ng-data-thread

looks similar to the SMK B2 spring, so yes, possibly, although it may be a fraction short ?
the same thread has the 95 spring at 245 mm long (and also 3.0 mm wire)...

It would need a fairly thin-wall spring guide but, if it gives, or you can pack to, an inch of preload, it should give in the 10.5 - 11 ft. lb. range. depending on calibre and pellet, Jon.

[DCL_dave]

Adding an 8 or 10mm SS extension, won't add firing preload as such, but it will limit the amount of swept volume, and the piston forward travel, in essence leaving the spring unable to reach full expansion so the spring will still be under some compression at the end of the cycle. This may prevent the bounce you think you're experiencing to some degree.

The downside of reducing piston travel / swept volume, is that it will likely reduce power. In your situation, it may not be a bad thing.

I'd also recommend chronoing with JSB Express 7.9 as well as the 8.44
With the SS extension fitted, you will notice the barrel drop further on breaking. The extension leaves the piston further away from the cocking shoe.

Thank you for the advice, I will bear it in mind.

[TonyL]

The type of wire available will depend on whatever the spring manufacturer happens to have in stock in the specified diameter, Tony. They buy it on huge drums, and won't lay out that sort of money for someone who wants just a few springs.

Thanking you further for this insight, Jim..

I wonder if most spring makers will declare the composition at the time? And, if a buyer was then placing an order for a subsequent batch, it might raise the question of consistency of quality, characteristics and longevity? Or am I overthinking that?