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It will hit the valve harder opening a regulator set higher. Both the spring setting and the weight of the hammer affect how much of a blow the valve gets.
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it should not damage your gun if you shorten the spring but you would have to source a new spring if you want to go back to where you are today.
I could not get the hammer spring turned down far enough in my P35-177 to match the regulator setting. I wanted to be a little under the peak speed with 10 grain pellets. The adjustment screw was about to fall out of the housing. So I clipped a coil off the spring. I stuck that end into the hammer so it won't scratch up the action. It works well. Cocking is easier and I have the pellet speed I wanted. I could still go up a lot on hammer spring tension if I ever want to.
I'm not suggesting this is as elegant of a solution as a new spring that will apply less force to the hammer but it is a viable option.
I could not get the hammer spring turned down far enough in my P35-177 to match the regulator setting. I wanted to be a little under the peak speed with 10 grain pellets. The adjustment screw was about to fall out of the housing. So I clipped a coil off the spring. I stuck that end into the hammer so it won't scratch up the action. It works well. Cocking is easier and I have the pellet speed I wanted. I could still go up a lot on hammer spring tension if I ever want to.
I'm not suggesting this is as elegant of a solution as a new spring that will apply less force to the hammer but it is a viable option.
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I thought you wanted less speed, not more. I heavier hammer would help you open the valve against a higher regulator setting to give more speed. Have you tried a higher regulator setting to verify the existing hammer and spring will not open the valve at the regulator setting you need? The hammer by itself will not change the speed much if at all. But if the current hammer and spring will not open the valve (the indication you will see is the velocity will be real low for the increased regulator setting I got less than 600 fps recently when I should have gotten over 800 fps, for instance) then I would try a heavier hammer. I cannot tell from what you've shared if you've only varied the hammer spring setting or if you've also changed the regulator. It sounds like your hammer spring is pretty flexible with how much force it can apply so just increasing the regulator a little may give you what you want. When I say to increase the regulator I am also assuming you will also increase the hammer spring force. I keep increasing the hammer spring to where the velocity stops increasing and then decrease the velocity about 5% by decreasing the hammer spring force.
Safest way to change a regulator is to degas first but some are supposed to be OK with increases without degassing. Turning the regulator down seems to always require degassing. On mine, clockwise turns the regulator down, counter clockwise turns it up.
Safest way to change a regulator is to degas first but some are supposed to be OK with increases without degassing. Turning the regulator down seems to always require degassing. On mine, clockwise turns the regulator down, counter clockwise turns it up.
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Heavier hammers allow one to run less spring (pre-load or rating in lb/in) due to increased momentum, or with the same or more spring, allows you to open the valve more to produce more power provided it is not already over-dwelling to the point of only wasting air or hitting the back of the valve
Heavier hammers generally don't help hammer bounce, they do the opposite, because of this momentum which is what is detrimental to hammer bounce, versus raw fpe/ke which decays much faster after the initial hammer strike, momentum is harder to decay. Akin to comparing to stopping a train, versus a race car via mechanical brakes.
The optimal setup runs the least amount of hammer weight needed with the most amount of spring that is reasonable to cock to obtain the desired blend of lift and dwell. Primarily due to momentum being hammer bounces worse enemy, and unpleasant as the inertia is felt during the shot cycle. Large shifts in weight will have some effect on dwell, and huge shifts in spring rating will effect lift. However within the nominal limits of a pcp, the effects are hardly measurable unless taken to quite the extreme.
-Matt
Heavier hammers generally don't help hammer bounce, they do the opposite, because of this momentum which is what is detrimental to hammer bounce, versus raw fpe/ke which decays much faster after the initial hammer strike, momentum is harder to decay. Akin to comparing to stopping a train, versus a race car via mechanical brakes.
The optimal setup runs the least amount of hammer weight needed with the most amount of spring that is reasonable to cock to obtain the desired blend of lift and dwell. Primarily due to momentum being hammer bounces worse enemy, and unpleasant as the inertia is felt during the shot cycle. Large shifts in weight will have some effect on dwell, and huge shifts in spring rating will effect lift. However within the nominal limits of a pcp, the effects are hardly measurable unless taken to quite the extreme.
-Matt
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Look.
There´s a WAY more elegant, efficient and usable solution to that but it DOES take that either you or someone you know or if so a local machine shop does...
Have access to a lathe.
It works like this.
Hammer momentum in its own rights but this of course also means that there´s something to counter act that momentum. Pressure at the poppet, and in turn how mallable (read - soft) the actual seal is.
One of the main factors for closing force on the poppet is the poppet stem diameter. In turn, a smaller stem/spindle of course also = better flow beneath the valve seat.
So what i do these days, almost as sorts of a standard operational procedure, is to convert the valve housing to take a 2mm stem out of hardened steel.
In this case the stock poppet with a modified seal for an Aselkon, and next to it a 2mm jobbie on a PEEK seal. In the case of the Aselkons the diameter for the stock thing is on 3mm, and one might think "what difference does a mill do"... but it does.
In turn using PEEK for a seal can reduce opening force on the poppet by as much as 15%.
Many a pcp use a stem of even greater diameter, for even bigger winnings. A good source for 2mm material is what we call "silver steel" or.. drill rod.
Decent source.. regular bicycle spokes.
What i do is turn the "top hat" for the setup (the seal in other words) and then drill a 10mm deep on on 1.5mm diameter. Then i to the letter use brute force setting the stem on 2mm into that hole for an absolute MASSIVE press fit and indeed to this day i have to see one come apart.
I normally make the seal on a 15-16mm total as in that manner there´s enough material in there to hinder the 2mm rod from digging into the seal by any appreciable amount.
The new stem "bearing" part i just make out of brass, or actually bearing bronze in my case. Set the diameter i need for the outside vs what the valve body hands and then either thread or press fit using Loctite cylindrical.
Then the whole thing on the lathe setting it using a dial indicator for minimum runout.. and drill a 1.9mm dia hole. Then run a 2.000mm reamer through there and done deal..
PEEK however is a rather stiff material why i mainly use it for guns to see from say 140 bar up. Haven´t tried it, but i bet for lower reg pressure applications POM would be a better material choice as it´s softer.
Difference in power SPAN is not to be taken lightly! Let me tell you that much!
For higher "horsepower" applications this stunt can hand a good 30J, and that no laughing matter exactly. The beauty of it is that there´s no real downsides to this.
It basically just widens the span of the gun, and rather profoundly so.
Point in case (and many more like it) this 22cal Aselkon MX-10. Now sporting a 145cc plenum it slings 40 grain slugs just up against the speed of sound at will, for an easy cool 135J on the stock approx 550mm barrel.
Here a by me heavily modified 25cal Kral Puncher Breaker. Same deal. Can reach well beyond 140 at will.
..and so the story goes...
There´s a WAY more elegant, efficient and usable solution to that but it DOES take that either you or someone you know or if so a local machine shop does...
Have access to a lathe.
It works like this.
Hammer momentum in its own rights but this of course also means that there´s something to counter act that momentum. Pressure at the poppet, and in turn how mallable (read - soft) the actual seal is.
One of the main factors for closing force on the poppet is the poppet stem diameter. In turn, a smaller stem/spindle of course also = better flow beneath the valve seat.
So what i do these days, almost as sorts of a standard operational procedure, is to convert the valve housing to take a 2mm stem out of hardened steel.
In this case the stock poppet with a modified seal for an Aselkon, and next to it a 2mm jobbie on a PEEK seal. In the case of the Aselkons the diameter for the stock thing is on 3mm, and one might think "what difference does a mill do"... but it does.
In turn using PEEK for a seal can reduce opening force on the poppet by as much as 15%.
Many a pcp use a stem of even greater diameter, for even bigger winnings. A good source for 2mm material is what we call "silver steel" or.. drill rod.
Decent source.. regular bicycle spokes.
What i do is turn the "top hat" for the setup (the seal in other words) and then drill a 10mm deep on on 1.5mm diameter. Then i to the letter use brute force setting the stem on 2mm into that hole for an absolute MASSIVE press fit and indeed to this day i have to see one come apart.
I normally make the seal on a 15-16mm total as in that manner there´s enough material in there to hinder the 2mm rod from digging into the seal by any appreciable amount.
The new stem "bearing" part i just make out of brass, or actually bearing bronze in my case. Set the diameter i need for the outside vs what the valve body hands and then either thread or press fit using Loctite cylindrical.
Then the whole thing on the lathe setting it using a dial indicator for minimum runout.. and drill a 1.9mm dia hole. Then run a 2.000mm reamer through there and done deal..
PEEK however is a rather stiff material why i mainly use it for guns to see from say 140 bar up. Haven´t tried it, but i bet for lower reg pressure applications POM would be a better material choice as it´s softer.
Difference in power SPAN is not to be taken lightly! Let me tell you that much!
For higher "horsepower" applications this stunt can hand a good 30J, and that no laughing matter exactly. The beauty of it is that there´s no real downsides to this.
It basically just widens the span of the gun, and rather profoundly so.
Point in case (and many more like it) this 22cal Aselkon MX-10. Now sporting a 145cc plenum it slings 40 grain slugs just up against the speed of sound at will, for an easy cool 135J on the stock approx 550mm barrel.
Here a by me heavily modified 25cal Kral Puncher Breaker. Same deal. Can reach well beyond 140 at will.
..and so the story goes...
Upvote 0
Look.
There´s a WAY more elegant, efficient and usable solution to that but it DOES take that either you or someone you know or if so a local machine shop does...
Have access to a lathe.
It works like this.
Hammer momentum in its own rights but this of course also means that there´s something to counter act that momentum. Pressure at the poppet, and in turn how mallable (read - soft) the actual seal is.
One of the main factors for closing force on the poppet is the poppet stem diameter. In turn, a smaller stem/spindle of course also = better flow beneath the valve seat.
So what i do these days, almost as sorts of a standard operational procedure, is to convert the valve housing to take a 2mm stem out of hardened steel.
In this case the stock poppet with a modified seal for an Aselkon, and next to it a 2mm jobbie on a PEEK seal. In the case of the Aselkons the diameter for the stock thing is on 3mm, and one might think "what difference does a mill do"... but it does.
In turn using PEEK for a seal can reduce opening force on the poppet by as much as 15%.
Many a pcp use a stem of even greater diameter, for even bigger winnings. A good source for 2mm material is what we call "silver steel" or.. drill rod.
Decent source.. regular bicycle spokes.
What i do is turn the "top hat" for the setup (the seal in other words) and then drill a 10mm deep on on 1.5mm diameter. Then i to the letter use brute force setting the stem on 2mm into that hole for an absolute MASSIVE press fit and indeed to this day i have to see one come apart.
I normally make the seal on a 15-16mm total as in that manner there´s enough material in there to hinder the 2mm rod from digging into the seal by any appreciable amount.
The new stem "bearing" part i just make out of brass, or actually bearing bronze in my case. Set the diameter i need for the outside vs what the valve body hands and then either thread or press fit using Loctite cylindrical.
Then the whole thing on the lathe setting it using a dial indicator for minimum runout.. and drill a 1.9mm dia hole. Then run a 2.000mm reamer through there and done deal..
PEEK however is a rather stiff material why i mainly use it for guns to see from say 140 bar up. Haven´t tried it, but i bet for lower reg pressure applications POM would be a better material choice as it´s softer.
Difference in power SPAN is not to be taken lightly! Let me tell you that much!
For higher "horsepower" applications this stunt can hand a good 30J, and that no laughing matter exactly. The beauty of it is that there´s no real downsides to this.
It basically just widens the span of the gun, and rather profoundly so.
Point in case (and many more like it) this 22cal Aselkon MX-10. Now sporting a 145cc plenum it slings 40 grain slugs just up against the speed of sound at will, for an easy cool 135J on the stock approx 550mm barrel.
Here a by me heavily modified 25cal Kral Puncher Breaker. Same deal. Can reach well beyond 140 at will.
..and so the story goes...
Fwiw I use peek on poppets that see as little as 25 lbs holding force personally, and in other applications as low as 100 lbs. It boils down to surface quality and sealing margins more than holding force on the poppet, in my experience.
I am not a fan of 2mm stem bores personally, it loosens the 'tuning window' which means its more sensitive to variation in hammer strike...I have all the math to support this if you would like me to go deeper, just ask.
I personally wouldn't go less than 2.5mm on a stem bore for most pcp's, for the average user... while the stem diameter that sits within the throat can go down to 2mm no issue, imo to improve flow and reduce the required throat diameter to support porting forward of it.
~3mm stems are fairly standard in pcp's for a reason, to provide more consistent closing force that is less sensitive to hammer strike variability, and for end-user tunability. Meaning, smaller stems within the bore take a lot less shift in hammer spring pre-load to shift fps, this is not always a good thing....Sure they take less hammer strike, but there are better ways to skin this cat...
Such as a pilot valve or balance valve, both of which will have their own caveats, but by far and large, out perform the simple reduction of stem bore and consequent stem diameter when it comes to reduced hammer strike requirements...because they reduce the holding force, not the closing force (the latter, greatly effects tunability, the former, does not).
This..coming from a user who currently has 1mm stem diameter present in my throat, that still relies on a 3mm stem within the bore for consistent closing force.
2mm stem bores absolutely work and are one approach, heck, you can go down to 1.5mm and with HSS drill rod you'll likely never snap the sucker unless your holding force on the valve approaches and exceeds 180 lbs. Which, touching on that, you should be weary reducing stem diameters without knowing their limitations based on the force acting on it, from holding force in a closed state, to closing force in an open state. But again, it's not the best approach or manufacturers would all be doing this long, long ago...
Not to deter anyone from doing such mods, heck, have at it, but be warned of all the above.
-Matt
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Hitting 950-980 fps with 34 gr slug is asking a lot...
You'd need 2500 psi / 170 bar on a 500mm barrel with healthy plenum and ports, or 2300 psi / 160 bar on a 600mm barrel, and these would be tuned at plateau and be very inefficient, so ideally add another 150 psi / 10 bar to each configuration for a healthy tune shooting 34 gr's at 970~ fps...assuming 25 cal, .22 cal would need more.
-Matt
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It allows you to run a much higher reg pressure as the heavier hammer will open the higher pressure. Thus you can shoot higher velocities and heavier projectiles. I would say please use your gun stock and see what its capable of first. Diving head first into heavier hammers and slug power kits can really cause headaches if you don’t know what you are doing.
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Yeah Matt, i hear you.
As far as balanced valves, have played around with that as well but truth be told i at that state believe we´re way out of sight for the general enthusiast and/or tinkerer.
I´ve opted to dive deep as far as reduced stem poppets and can´t say more than that it works, rather well at that, but of course this entails picking the correct materials to play with.
No argument on that one, but i´ll also state that as long as we´re talking some sort of alloy steel basically it will within reason take the pounding.
Have by now helped a whole bunch of fellow enthusiast on the subject and they´ve all, to my knowledge at least, been real happy with the outcome.
Absolutely agreed on harder seal materials and sealing. Issue i see with that is that many won´t take to heart what that takes, linear behavior and seat n seal lining up.
Fact is, on a 2mm stem out of hardened steel it is often such that the actual stem both can and will bend if ever so slightly out of whack (as in elastic deformation). At least that´s my findings. Of course then to the cost of a higher wear on the bearing surface, which however is rather simple to replace after all - need be.
But no matter if smaller stem or balanced valve, what it comes down to in both cases is to first up of course hand a wider span (albeit balanced valves are often limited in themselves as far as) and at that still keep cocking effort and loads inherent on hammer setup within reason.
At least as i regard it.
As a lesser diameter stem is as simple as it is, all considered, to pull off it´s also something the average Joe can and will get away with.
That said though, of course to each his own. I by NO means claim this to be the solution to all ills. Just to be ONE way to get higher power numbers at a min of effort that i swear by that most fellow enthusiast are unaware of.
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One flipside to extremely heavy hammers is first up that the internals are rarely dimensioned to take that sort of pounding.
Next up it is more the norm than anything that heavy hammers will grant a rather sluggish action.
Third up there´s a very good practical example of both, and that´s the Hatsan BT series rifles. If memory serves the stock hammer comes in at something as insane as 140 grams.
Getting it to half that weight makes for a rather dramatic change in behavior, and as noted power is to be found "in other ways". Albeit that the BT series has always been considered to carry "a lot of motor", and it indeed does.
What i´m saying is that i for one at least find this whole concept to be a matter of balance. For most pcp´s i´d like for hammer weight to at least stay beneath 50 grams.
Or more to the point, they really should as in my opinion no matter design or brand really if more is needed then i´d say a redesign, partly or on a whole, is called for.
But hey..
That´s just me.
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@ Matt.
Btw. FWIW manufacturers actually ARE going to 2mm stems now. Just look at Snowpeaks new T-Rex series.
Uhu. On 2mm out of the hole alright.
Actually that carbine is something i´m working on right now and have to go on record and state that for a budget proposition piece of kit.. color me impressed. WAY higher grade build vs Snowpeaks old PR-900/Stormrider.
Not even on the same map.
One thing that got binned though was the stock moderator and shroud setup. FOR a waste of space... Rest of it is rather traditional to the build, just on way higher tolerance vs previous and in turn better materials used as well.
This particular one then the 25cal jobbie. Right now getting a somewhat larger plenum (that speaking of traditional of course resides within the tube)
Btw. FWIW manufacturers actually ARE going to 2mm stems now. Just look at Snowpeaks new T-Rex series.
Uhu. On 2mm out of the hole alright.
Actually that carbine is something i´m working on right now and have to go on record and state that for a budget proposition piece of kit.. color me impressed. WAY higher grade build vs Snowpeaks old PR-900/Stormrider.
Not even on the same map.
One thing that got binned though was the stock moderator and shroud setup. FOR a waste of space... Rest of it is rather traditional to the build, just on way higher tolerance vs previous and in turn better materials used as well.
This particular one then the 25cal jobbie. Right now getting a somewhat larger plenum (that speaking of traditional of course resides within the tube)
Upvote 0