The (new) Crosman Forum, your first and last stop for all things Crosman

Jim Gillilan's Custom 1322 Carbine

Jim Gillilan's Custom 1322 Carbine w/Custom Stock

Here's one I'm especially proud of and is modded all over, doing 12fpe at 15 pumps.
Stock is Teak from Thailand and super light weight 1322 Carbine!

 Return to Index  

LOL! Okay, then. Consider this significant difference between your test and actual...

April 19 2017 at 4:28 PM

Steve in NC  (Login pneuguy)
Crosman Forum Member
from IP address

Response to Now, Steve! Just say B.S.! Call me out when in error!

...pumps. In your rig there's a large angle between the link and the axis of the "tube" and direction of the 500# load. This angle is (much) worse in the case of the short link than the long link, which in the former case is placing a side load on the "piston" that's (much) larger than the load itself. Consequently a large part of the resistance you felt at the lever in the short-link case was probably caused by friction between piston and tube.

But in an actual pumper, by contrast, pressure and force don't become significant until late in the stroke when the lever is far past vertical and the link, no matter what the B/A ratio, is nearly parallel to the tube, making the contribution to total effort that comes from side loading and friction relatively minor even for short links.

To cut to the chase, and unless I'm still failing to visualize it (very possible), I guess I'm saying your whole test was B.S. happy.gif

This message has been edited by pneuguy from IP address on Apr 19, 2017 4:30 PM

 Respond to this message   

Crosman Corporation 1-800-724-7486

This forum is not affiliated with the Crosman Corporation in any way// Information presented in this forum is intended for informational purposes only; use at your own risk//Posts made to this forum are solely the opinion of the individual member