What makes a short stroke spring piston rifle different from a long stroke spring piston rifle?I don't understand what makes one rifle / 430L a short stroke and a HW77 a long stroke.What is the mechanical difference in the power plant?
Quote from: truck driver on August 29, 2019, 10:09:18 AMWhat makes a short stroke spring piston rifle different from a long stroke spring piston rifle?I don't understand what makes one rifle / 430L a short stroke and a HW77 a long stroke.What is the mechanical difference in the power plant?Stroke is how far the piston comes out of the compression chamber when cocked. Short stroke, faster shot cycle, less air volume limited power, more spring input and stiffer cocking to make up for loss of volume to get Max power out if it.Long stroke, slower cycle, more volume easier to make power. Less spring input to make power.
Quote from: Kerndtc on August 29, 2019, 11:19:07 AMQuote from: truck driver on August 29, 2019, 10:09:18 AMWhat makes a short stroke spring piston rifle different from a long stroke spring piston rifle?I don't understand what makes one rifle / 430L a short stroke and a HW77 a long stroke.What is the mechanical difference in the power plant?Stroke is how far the piston comes out of the compression chamber when cocked. Short stroke, faster shot cycle, less air volume limited power, more spring input and stiffer cocking to make up for loss of volume to get Max power out if it.Long stroke, slower cycle, more volume easier to make power. Less spring input to make power.So if you shorten the latching rod in the piston you lengthen the stroke and a skirtless piston would be needed or one with a shortened skirt to accommodate the shorter rod?
Quote from: truck driver on August 29, 2019, 11:55:58 AMQuote from: Kerndtc on August 29, 2019, 11:19:07 AMQuote from: truck driver on August 29, 2019, 10:09:18 AMWhat makes a short stroke spring piston rifle different from a long stroke spring piston rifle?I don't understand what makes one rifle / 430L a short stroke and a HW77 a long stroke.What is the mechanical difference in the power plant?Stroke is how far the piston comes out of the compression chamber when cocked. Short stroke, faster shot cycle, less air volume limited power, more spring input and stiffer cocking to make up for loss of volume to get Max power out if it.Long stroke, slower cycle, more volume easier to make power. Less spring input to make power.So if you shorten the latching rod in the piston you lengthen the stroke and a skirtless piston would be needed or one with a shortened skirt to accommodate the shorter rod? In theory YES ... but other MECHANICAL issues must also allow it. Such as the mechanics and travel afforded by the system that cocks the rifle. If the travel is not there to create a longer cocking stroke it simply won't cock if a shorter latch rod was in place. Some barrel cocking gun when cocked has the piston seal just forward of the cocking rod slot and you could NOT pull it back further with a stroke change.
Any changes made in the leverage will adversely effect force required. Generally longer stroke guns require longer cocking arms because the pivot point of the latch rod is further away from the primary arm pivot. Becase the pivot points are spaced apart further to gain more "Stroke" the effort required is more. ALSO be aware the SIDE LOADING of the piston increases substantially on single link / arm cocking system. Compound cocking systems like HW 50 / 35 guns reduces this side loading and suffer from less wear and potential scuffing / galling issues of the air tube / piston interface. * Tho CAN NOT be stroke changed ... NO FREE LUNCH Sadly.
short stroking a piston gun USED to refer to making it longer so it didnt travel as far ("Short stroke") and it wouldnt produce as much energy given the saem size compression tubeNever heard the term "long stroke" till now
Compound cocking systems like HW 50 / 35 guns reduces this side loading and suffer from less wear and potential scuffing / galling issues of the air tube / piston interface. * Tho CAN NOT be stroke changed
Quote from: Motorhead on August 29, 2019, 12:39:37 PMCompound cocking systems like HW 50 / 35 guns reduces this side loading and suffer from less wear and potential scuffing / galling issues of the air tube / piston interface. * Tho CAN NOT be stroke changedWhat about short stroking achieved by adding a spacer between piston front, and seal? latching position with the sear remains the same, as does the cocking linkage geometry. The piston front face just does not go "home" all the way to the front of the compression cylinder when fired, due to the spacer.
Thanks for the replies.If you would put a spacer on the piston between the piston head and seal would that increase the fpe out put by adding preload ?