"Tune to the knee" --- Taipan Vet Long .25 --- HOW?

[JohnnyPDX]

I've heard "tune to the knee" many times and now I want to know how. Not looking for more power just reduced ES and long range accuracy.

I have:
Taipan Vet Long .25
factory reg setting as it came from Talon Tunes
chrony

I am reading the rsterne thread and TRYING to digest and arrive at a summary of steps.
https://www.gatewaytoairguns.org/GTA/index.php?topic=74919.0

[JohnnyPDX]

On further reading it seems a PITA if having to adjust the regulator.

"I personally ALWAYS tune my regulated PCPs to the knee of the curve, ie I back off the hammer spring preload until the velocity just starts to drop (3-5% below the plateau is about right).... Generally that extends my shot string 100-200 psi below the setpoint, giving me additional shots on top of the already efficient setup.... If the gun is shooting harder than I want, then I reduce the regulator setpoint a bit, reduce the hammer preload to get back to the (now lower) knee of the curve.... and end up with even more shots.... Yes, I could just back off the preload, but then I have to worry about that bump in the velocity curve below the setpoint, so instead I drop the regulator setpoint and retune to the new knee..."
Source:
https://www.gatewaytoairguns.org/GTA/index.php?topic=74919.0

[Hobbyman2007]

Here’s the coles notes version.
1 -adjust the hammer spring to get more velocity until there is no gain in speed.
If the speed keeps climbing until you are at coil bind . Your regulator is set too high for the spring. Reduce regulator pressure or get a bigger spring
2-reduce hammer spring tension until you are between 3-5% below max velocity. Call it done.


Now if your velocity is too low or too high. Refer to step one.

[JohnnyPDX]

Here’s the coles notes version.
1 -adjust the hammer spring to get more velocity until there is no gain in speed.
If the speed keeps climbing until you are at coil bind . Your regulator is set too high for the spring. Reduce regulator pressure or get a bigger spring
2-reduce hammer spring tension until you are between 3-5% below max velocity. Call it done.


Now if your velocity is too low or too high. Refer to step one.

I am actually laughing right now. I really needed this summary, send me an invoice.

THANK YOU

*This is doable!!!!!!!!!!!!!!

[JohnnyPDX]

In my case the velocity keeps climbing until the coil binds so I need to adjust the regulator down but I may not do that I may just back off the hst and see what I get.

Not sure what to do at this point because I'm all I'm really trying to do is adjust for 100 yard shooting and find the best pellet for that and get the lowest extreme spread that I can

[rsterne]

You only need to adjust the regulator pressure if the velocity you get when on the knee is not what you want....

Bob

[JohnnyPDX]

I think it doesn't have a knee.

I'm going to do some more strings

[nervoustrigger]

That's an indication the regulator pressure is too high...too high relative to the maximum amount of hammer strike available.  You either need to reduce the regulator's setpoint or use a heavier hammer spring. 

[JohnnyPDX]

That's an indication the regulator pressure is too high...too high relative to the maximum amount of hammer strike available.  You either need to reduce the regulator's setpoint or use a heavier hammer spring.

That's what I understand from Hobbyman's  simple instructions. Thank God some people know how to condense!

Not sure if I will do that thought it seems pretty straightforward adjusting the reg.

[Pelletjunkie]

Sounds like someone is reluctant to tear their gun down to adjust the reg. In the quest for long range accuracy, you must. No shortcuts.

[Pelletjunkie]

Or buy a gun with an externally adjustable reg. Now you might understand why they are so appealing.

[JohnnyPDX]

Before I take it apart I need to verify that there is even a need to do that.

My verification process is to do cronnie Strings then go shoot and see how it looks on paper

[Pelletjunkie]

One chronograph string will tell you all you need to know. If your gun is still increasing speed as you turn the HS adjuster until you can’t cock it, it’s time to degas and get out the tools. Do you know how to degas your Taipan?

[Pelletjunkie]

You will need to make one of these.

[JohnnyPDX]

One chronograph string will tell you all you need to know. If your gun is still increasing speed as you turn the HS adjuster until you can’t cock it, it’s time to degas and get out the tools. Do you know how to degas your Taipan?

Howdy. I just did a 30 shot string.

low, 922
high, 941
avg, 931
es / range, 20

Yes to this "If your gun is still increasing speed as you turn the HS adjuster until you can’t cock it,"

The Earnest vid showed him degassing by cranking in the hammer spring adjustment screw. Is there a better way?

[Pelletjunkie]

In that pic I posted. That little post I built is used to degas. It goes in the back of the hammer. Then you slowly turn the HS adjuster until the gun starts to hiss.

[Pelletjunkie]

Then you will have to make something like this to pull your reg out of the tube. Or you can make a reg cannon and blow it out by using your fill probe and some air.

[miksatx]

Or if you have a hand pump you can blow it out. I put a sock over the end then place one foot on the sock and end of the tube couple pumps and bonk right in the sock!

[Pelletjunkie]

If this is a project that concerns you, I know jumping online and waiting for answers not worthy. If you feel more comfortable with having instant answers to your questions, send me a PM. I will give you my phone # and you can just text me. I have no major plans today.

[Pelletjunkie]

When did s u c k s become a non PC word and have to be replaced with “not worthy”?