Custom power hammer spring kit Crown II?

[Goldwing]

Is there a Custom hammer spring kit Crown II that people are using?

The one made by one of the tech at FX (Ernest Rowe) stop making his and will be introducing a new kit in a few months and wondered if there was a quick fix getting a stronger spring like the one for Huma ?

Thanks

His discontinued kit

OEM

 

[Long_Gun_Dallas]

My understanding is that the factory spring is pretty stiff as is. Though, the upper one does look a smidge thicker.

What are you trying to accomplish exactly? I mean caliber/power wise.

I have an extra guide and a weight that look pretty much the same as what's pictured above. Modest 7gm weight. You should be able to order these on ebay last I checked. Of whatever weight you want.

Mine is a mk1, and does 50fpe (25gr @950fps) in .22 with a 500mm barrel.

 

[Goldwing]

I'm shooting JSB 34.9 and want to raise the speed closer to 900 and now at only 800 with it maxed out on the power wheel at 24

I did note a raise in speed when lowering the second reg from 140 to 120

 

[Long_Gun_Dallas]

Try running 135 bar, and adjust the hammer tension on the screw under the power wheel (on hammer adjuster insert) add some tension there. Mkii should have no issue shooting those speeds. 25 cal, correct? 

 

[Goldwing]

Try running 135 bar, and adjust the hammer tension on the screw under the power wheel (on hammer adjuster insert) add some tension there. Mkii should have no issue shooting those speeds. 25 cal, correct?

I lowered the reg pressure to 130 bar and it got me up to 836.614 that's that best I ever got it, so I will slowly work the hammer

Yes 25 cal

Thanks !

 

[qball]

Question: is the HS preload maxed out? It doesn’t appear your HS preload is maxed out when you are losing speed above 130 bars. My crown reg is set at 155 bars. 

 

[Goldwing]

Sorry not familiar with the term HS preload?

 

[Long_Gun_Dallas]

Same thing I was talking about. I think on schematics the part is referred to as hammer spring adjuster?



With my factory hammer, peak power seemed to be at 130 bar, but FX gauges can be quite Inaccurate. I've used more than one gauge set on mine, so I can say that more certainly.

With added 7gm weight peak output was at 150, but you always want to be on one side of the peak, either under or over for more balanced valve operation 

 

[gendoc]

Question: is the HS preload maxed out? It doesn’t appear your HS preload is maxed out when you are losing speed above 130 bars. My crown reg is set at 155 bars.

what he said ^^^^

both my mk2 regs set @155 also..... my long range gun does 976fps with 600mm barrel 24.8gr nsa, and the compact does 960fps with 380mm barrel 20.2gr nsa

both very accurate !!

 

[Goldwing]

I found so far with the 2nd reg at 123 bar optimum (797.244) tried 155 but it dropped to 721.785, all with the power wheel at 24

Messing with the D5 screw (hammer to power wheel), in and out next, as a reminder I'm sticking with the JSB 34.9 as my overall do everything pellets

Greatly appreciate everyone's help!

https://www.youtube.com/watch?v=uvTZ4cmYDO4&ab_channel=AirGunnerBob_O

 

[Long_Gun_Dallas]

You need to adjust hammer before finding your peak output on regulator pressure. Weak hammer strike means you are going to find optimum output at a much lower reg setting.

Here's one of my spring adjusters. The one in the gun is set about identical.

At 135 bar on my 380mm .22 I get either 960fps with 16gr or on all low settings on hammer and port wheel I get around 650fps. I also get 950fps with 25gr .22 slugs as stated in the 500mm with 150bar and an added 7gm hammer weight. 

 

[Goldwing]

Thanks for the info on your picture 

Will try again with the new information 

thanks again, will report back after some experimenting with the added info

 

[Long_Gun_Dallas]

Sounds good Just keep in mind mine is a MK1 with a smaller valve and plenum. I have some very effective port work done, but from everything I've seen, the MKII's with no port work are capable of more power than mine on the same settings/hammer weight, ect. 

 

[18.13]

You should be able to get there I have my reg at 115 hammer wheel at 18 shooting the 34gr at 900

 

[Goldwing]

I went ahead and moved the D5 screw (hammer to power wheel) out to your 6.79 and now at least get a higher speed of 859.58 with it now at 150 on the second reg

Will continue tinkering this week end with degassing and re work up on the second reg again from 115 -->

Thanks so much for the help!

 

[Ex.Magnum]

Is there a Custom hammer spring kit Crown II that people are using?

The one made by one of the tech at FX (Ernest Rowe) stop making his and will be introducing a new kit in a few months and wondered if there was a quick fix getting a stronger spring like the one for Huma ?

View attachment 204711

Thanks

Just now saw this topic.
A few months ago assembled my own hammer spring kit.

I purchased the Huma "power spring" some 8 months ago. Using it in combination with a self made 6 gram brass hammer weight on a slightly milled hammer spring guide body, it performs quite ok; as Long_Gun_Dallas already indicated, the Huma spring 's power curve is but a tiny bit higher than the factory spring's curve. Milling out some of the spring guide body’s material around the hammer guide stem not only provides room for the spring to sit in, but at the same time it also assures the original hammer travel distance to remain intact.

 

[LDP]

You shouldnt have any problems getting more velocity than that completely stock unless you are running the 380mm barrel. I have a crown mk2 setup with the 380mm barrel with the reg set at 155 bar and hammer pre load set a little short of max. With the power wheel set at 23 I can get 25gr. JSB up to 883 fps and 34 gr. JSB up to 813 fps. I have another crown setup with a 700mm barrel. That one is set at 130 bar for reg and I never touched the hammer preload. I have the power wheel set to max and it pushes 34gr. JSB to 875 fps and 25gr. JSB to 975 fps. Both are completely stock and the 380mm barrel setup had no problem running the reg at 160 bar. I am pretty sure if you get the hammer preload set to max or very close it will work just fine in stock form at 160 bar or under and get the velocity you are looking for.

 

[qball]

To get to Max preload you need to increase the preload until you can’t cock the gun anymore then back off a little bit at a time till you can.

Don’t add hammer weight till you tried max preload, it is more efficient/accurate to have more HS tension than use weight to achieve the same speed/power.

 

[Goldwing]

How do you adjust the preload? video or instructions?
Thanks

 

[Kgphotos]

Check out this video from AEAC on YouTube. It’s long but you will learn a ton about tuning your Crown.

Kenny