Increasing crown hammer weight

Jump to latest Follow Reply
Long_Gun_Dallas

Long_Gun_Dallas

Member
Jul 6, 2019
3,880
2,127
NC, United States
For some reason I can't understand, or no one wants to divulge entirely. (FX themselves have no comment) No one is selling fx crown hammer weights. 



So, it's up to me to make one for myself. Right now I have 3 concerns

#1. Material. I'm wanting to use tool brass (c360). But l I'm wondering if it will deform over time, though I feel it would have to undergo a truly expreme amount of use for this to occur.

#2 Actual weight. I know this was being used for larger calibers and has a weight of roughly 8.25gm. I'll primarily be shooting 22 slugs, so I'm not sure that much weight is needed. But I'm likely going tomake 2 weights. One that I'll modify (for testing), and a final version.

#3 There appears to be a hex shaped recess on the face that butts against the hammer, but I'm not sure what it's for? Mass calculations (for brass and steel) come out close to 8.5gm without the recess, so it can't be very deep....

1564860087_11982415545d45deb73b1027.24814962_PSX_20190803_151930.jpg
1564860087_4292271225d45deb75822f3.07417218_271525.PNG
1564860087_12874245335d45deb78de056.33410927_271525-1.PNG

 
I've seen this before. My concern is that by increasing the mass of the spring/weight system, the lock time will be increased which is counterproductive to accuracy.
Click to expand...

I had considered this. But if the valve has too much pressure behind it (I cant really run past 130 bar effectively) Whats the alternative? Reducing the size of the valve is out of the question.... That would be counter-productive. I've got duplicate factory parts on hand in case tuning proves futile. 

And WHY is it you want more weight ?
Click to expand...

The valve doesn't open effectively much beyond 130 bar. 
 
Upvote 0
I've seen this before. My concern is that by increasing the mass of the spring/weight system, the lock time will be increased which is counterproductive to accuracy.
Click to expand...

I had considered this. But if the valve has too much pressure behind it (I cant really run past 130 bar effectively) Whats the alternative? Reducing the size of the valve is out of the question.... That would be counter-productive. I've got duplicate factory parts on hand in case tuning proves futile. 

And WHY is it you want more weight ?
Click to expand...

The valve doesn't open effectively much beyond 130 bar.
Click to expand...


Just increase hammer energy by going with a tad bigger gauge wire spring ?
 
Upvote 0
A hammer weight will allow you to use less hammer spring tension while also hitting the hammer harder so you can take advantage of higher reg pressure.

Just going to a heavier spring will make the trigger pull heavier, which is worse for accuracy than a slower lock time.

With the hammer weight I used on the Crown, accuracy never suffered.
Click to expand...

Indeed.

Also good to know (that it didn't affect your shooting). The part is relatively small. And it's not much of a weight increase. 

Also, for a hammer to have little or no affect on POA during lock time, it need to be positioned well within the reciever. Part of the reason the Crown is so accurate. 

When i had a friend spin one out for my wildcat, i had him make the face of the weight thicker for more mass 0.1 on your drawing. The spring rests against it i wasn't worried about losing spring adjustment. Also used copper as its heavier than brass. No deformation at all. Sorry if the setup is a little different than the crown.
Click to expand...

Thanks for the input on that. I almost ordered copper, but I couldn't find the hardness I wanted. So, I went ahead and ordered a 8" length of 1/2" width cs360 bar. The copper is slightly heavier, but I got enough material to make 4 at least 🙂. I have a feeling I won't need the full 8-8.5 gm anyhow. 


 
Upvote 0
Have you considered working the other end of the problem, as in making the valve easier to open via harder material such as peek and/or reducing diameter of the poppet? If the Crown has a tapered seat you can likely spin up a smaller diameter peek poppet and dramatically reduce the required valve opening force.

I use this method on my p15's and end up needing lighter than OEM hammer springs to produce easy 40-45fpe in .22 and .25.
 
Upvote 0
Valve design and associated triggering mechanism should be the next step in the evolution of PCPs. This will take time and money to develop, so I expect the process will be slow in coming, but you tinkerers will contribute a lot to this, I'm sure. Daystate seems to be well on the way with their electronic trigger, although I'm not fond of electonic stuff.
 
Upvote 0
Have you considered working the other end of the problem, as in making the valve easier to open via harder material such as peek and/or reducing diameter of the poppet? If the Crown has a tapered seat you can likely spin up a smaller diameter peek poppet and dramatically reduce the required valve opening force.

I use this method on my p15's and end up needing lighter than OEM hammer springs to produce easy 40-45fpe in .22 and .25.
Click to expand...

That actually did cross my mind. But I imagined if I was making a smaller poppet, I would be making a smaller seat as well. But there is almost certainly room for improvement without reducing the size of the seat opening. I'll look into that further. Thanks 🙂

Valve design and associated triggering mechanism should be the next step in the evolution of PCPs. This will take time and money to develop, so I expect the process will be slow in coming, but you tinkerers will contribute a lot to this, I'm sure. Daystate seems to be well on the way with their electronic trigger, although I'm not fond of electonic stuff.
Click to expand...

I share that sentiment. If it's not broke, don't fix it, haha. I'm always a bit out off by overly complex things. I was REALLY tempted to get a huben. But as I said.... 


 
Upvote 0
Can anyone point me in the right direction or have a hammer weight they would sell for the Crown. I am at a loss here, I have tried contacting FX ya nothing so can't even order parts to make up something of my own. I bought the Crown exactly 1 year ago and got it came with a slight leak of course. So bought a HUMA reg to put in a fresh set of O-rings. Then I see that if I want to push my reg higher I need to work on the hammer weight and he is the issue!! Someone please help, grown man about to cry over here.... 
 
Upvote 0
1566599995_20230623645d606b3b4f2e21.98184416_271525.PNG
Importaint dimensions are the two widths. This weight should come out to about 8.4gm? At these dimensions in brass. I made mine shorter, so it is 7gm. 

1566600244_1373890275d606c348e4356.55639311_20190818_112849.jpg


Got a 1/2"x8" piece of stock, threw it in a chuck and spun it. Used a few grinding tools and dial caliper to get it to the right size. Do t have a lathe yet, nor do I have a place to put one. Or felt like getting one just to make something I didn't need it to make. 

1566600314_6104231035d606c7aa9cc25.01405435_20190808_162226.jpg

 
Upvote 0
I'm pretty sure that one of these hammer weigh would fit your Crown 

 
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu