Author Topic: Hi Rate Compression Spring for PCP  (Read 2585 times)

jpigg55

Hi Rate Compression Spring for PCP
« on: October 12, 2021, 09:00:20 AM »
I found this video that describes how a PCP regulator works: https://www.youtube.com/watch?v=h9CRxVw_vVs
What I'd like to know, or find out, is how to match the spring to the desired pressure. Anyone know where this info could be sourced ?
SB 9A, Clausing 8520, Sanford MG 612

RayH

Re: Hi Rate Compression Spring for PCP
« Reply #1 on: October 12, 2021, 10:40:25 AM »
The pressure desired in the valve chamber divided by the area of the piston head equals the spring load.
That does not include a friction factor but it will get you in the ballpark.

Checkout one or more of the linked catalogs to see if a stock spring will fit your requirements.


https://www.asraymond.com/catalogs.html
« Last Edit: October 12, 2021, 10:43:02 AM by RayH »
Ray

jpigg55

Re: Hi Rate Compression Spring for PCP
« Reply #2 on: October 12, 2021, 06:19:51 PM »
Thanks Ray, but I'm not sure how springs are rated.
The info I'd need is the compression force range over distance for the spring itself.
SB 9A, Clausing 8520, Sanford MG 612

RayH

Re: Hi Rate Compression Spring for PCP
« Reply #3 on: October 12, 2021, 09:36:23 PM »
Thanks Ray, but I'm not sure how springs are rated.
The info I'd need is the compression force range over distance for the spring itself.

That info is in tables in the catalogs you'll find in the linked site.
Ray

PJB

Re: Hi Rate Compression Spring for PCP
« Reply #4 on: October 13, 2021, 08:19:12 PM »
Force is the spring constant x deflection.    The catalog should specify eg lbs/in etc.   


Sent from my iPhone using Tapatalk
1991 Bridgeport Series I 2J-VS  9"x48"
1979 Clausing Colchester Bantam Mk2 11"x30"
1972 Harig Super 612
2015 Tormach PCNC-1100 Mill

"They wants what you gots!"

RayH

Re: Hi Rate Compression Spring for PCP
« Reply #5 on: October 13, 2021, 08:53:05 PM »
In the Die Spring Catalog they give you at least FOUR data points of LOAD (same as FORCE) vs DEFLECTION. Plot those four points on a graph and connect the dots. That line (curve?) represents the recommended useful range of that particular spring. What is the difference in deflection? What is the difference in load? Divide the load difference by the deflection difference. That is the spring rate (spring constant).

In the Compression Spring Catalog they specify SPRING RATE (lb/in) in the far right hand column.

It's all right there.
Ray

jpigg55

Re: Hi Rate Compression Spring for PCP
« Reply #6 on: October 13, 2021, 09:10:12 PM »
Thanks, I goofed initially trying to open with IE. Didn't work so well.
Tried again with FireFox and it worked.
SB 9A, Clausing 8520, Sanford MG 612