Tuning Thrust bearing
- Thread starter beerthief
- Start date
Issue by design is this ...
Because these are designed for light thrust loads and "DUE TOO" the rolling pins being a constant diameter end to end, as they are rolled they would roll straight ahead, but are housed in a retainer to hold a position forced to roll ahead on a radius.
The pins as retained held see different rolling radius's on the inside and outside of pins and as a result ALWAYS are in a skid !!! with lubrication and constant rotation round & round they work as intended, shuffle the plates back & forth under high loading the plate would rather skid on the pins ... as stated post #18
Because these are designed for light thrust loads and "DUE TOO" the rolling pins being a constant diameter end to end, as they are rolled they would roll straight ahead, but are housed in a retainer to hold a position forced to roll ahead on a radius.
The pins as retained held see different rolling radius's on the inside and outside of pins and as a result ALWAYS are in a skid !!! with lubrication and constant rotation round & round they work as intended, shuffle the plates back & forth under high loading the plate would rather skid on the pins ... as stated post #18
Upvote 0
As has been said, they've been tried over here....and failed, causing damage.
In my opinion (well, not just mine actually) you should be running a polished/hardened/greased steel slip washer against either end of the spring too. This will all but eliminate torque twist.
The TX has a free rotating piston, so will probably be fine with Delrin. HW's of course don't, so can be more susceptible to it. As a side note, a HW seal will rotate through 360 in roughly 10-12 shots, so even with the fixed piston, there is some corkscrewing that 'wants' to happen during the compression stroke (maybe why their seals often feel slack on the nose?). Correct lube and seal fit to cylinder wall is key.....
In my opinion (well, not just mine actually) you should be running a polished/hardened/greased steel slip washer against either end of the spring too. This will all but eliminate torque twist.
The TX has a free rotating piston, so will probably be fine with Delrin. HW's of course don't, so can be more susceptible to it. As a side note, a HW seal will rotate through 360 in roughly 10-12 shots, so even with the fixed piston, there is some corkscrewing that 'wants' to happen during the compression stroke (maybe why their seals often feel slack on the nose?). Correct lube and seal fit to cylinder wall is key.....
Upvote 0
Loose seals will eventually fail.. they will allow piston can’t during cocking. If it easily rotates on the nipple it’s gonna fail or gall the edge of the front piston.
The piston is under a bit ALOT , OF TOURQUE AT FIRST BREAK AND WANTS TO DIG DOWNWARD , ALOOSE NIPPLE WILL ALOW MICRO MOVEMENT and eventually galling ..up in the cylinder. The worst part.
The piston is under a bit ALOT , OF TOURQUE AT FIRST BREAK AND WANTS TO DIG DOWNWARD , ALOOSE NIPPLE WILL ALOW MICRO MOVEMENT and eventually galling ..up in the cylinder. The worst part.
Upvote 0
There's actually very little rotation when compressing/ expanding a coil spring. If there was significant torque in most cases it would still be distributed in opposite directions into the same compression tube. Which would negate the ability to feel the torque.
When a springer rolls when fired it's because of the way it sits in your shoulder. The whole torque thing is greatly exaggerated.
Heres a brand new Hw95 spring act the installed length.
Here's the same spring compressed to the cocked length.
You can see maybe an eighth turn of rotation. How much torque are you getting out of that? Sometimes old beliefs have merit. Sometimes they don't. In this case it's easily debunked with a simple experiment and some logic.
Polishing the spring ends or better yet delrin guides and top hats are more than enough. Engineering roller bearings and the like it's entirely unnecessary. Do it if it makes you feel good but I wouldn't expect alot from it.
Be well
All.
When a springer rolls when fired it's because of the way it sits in your shoulder. The whole torque thing is greatly exaggerated.
Heres a brand new Hw95 spring act the installed length.
Here's the same spring compressed to the cocked length.
You can see maybe an eighth turn of rotation. How much torque are you getting out of that? Sometimes old beliefs have merit. Sometimes they don't. In this case it's easily debunked with a simple experiment and some logic.
Polishing the spring ends or better yet delrin guides and top hats are more than enough. Engineering roller bearings and the like it's entirely unnecessary. Do it if it makes you feel good but I wouldn't expect alot from it.
Be well
All.
Upvote 0
Don't agree in fashion shown ... If friction at spring ends is so high spring can't twist when compressed very little will be noted.
Now flat surface lapp all the washers at each end, apply a heavy moly lube to allow easier high torque rotation and try it again ?
As a note of HISTORY past ... if spring torque is not an issue then why was it not only FWB but Diana among others in there most advanced competition spring piston match rifles utilized opposing counter wound springs in these rifles ... Huh ?
Last edited:
Upvote 0
Had a condor branded Diana 75 that used the GISS system and opposing springs like Scott mentioned. There’s torque in there, anytime a wire is spun around a mandrel to form a spring . Once compressed , it tries to straighten itself out. The only way to get rid of the rotational force is to go with a gas ram.
Upvote 0
My R1 with stock internals definitely had spring torque. The slip washer was bent (due to the splines/feet on the spring guide)
which I am sure contributed to this
which I am sure contributed to this
Upvote 0
Yup ... and why we professional tuners after grind flattening foot accurately, also place a small bevel on the coil end so it DOES NOT dig in and gouge surface it rotates against
Upvote 0
i asked that question over 10 years ago on the Yellow and was told it would be destroyed
so, i have when in a gun added 2 thin stainless washer on both end
polish the spring 1 slip point
2 washer best side together another slip point back washer may slip but doubt it
and with that no coil bind at cocking and release
now i have done mostly pistols and i can feel it working when cocking
i use very thin washers so there is no preload
just did it to a Tempest i have been working
https://www.ebay.com/itm/164573184907?var=464175123565
so, i have when in a gun added 2 thin stainless washer on both end
polish the spring 1 slip point
2 washer best side together another slip point back washer may slip but doubt it
and with that no coil bind at cocking and release
now i have done mostly pistols and i can feel it working when cocking
i use very thin washers so there is no preload
just did it to a Tempest i have been working
https://www.ebay.com/itm/164573184907?var=464175123565
Upvote 0
The washers were stacked and lubed the. The washers were rolled back and forth until there was no twisting pressure in either direction. What you see is a valid representation of how much the spring wants to twist with that much compression.
As far as opposing counter wound spring guns goes they were successful because they neutralized directional reoil. Not because they eliminated torque.
Upvote 0
The rifles Torque motion comes from the springs rotational mass being in motion having nothing to do with some mechanical force in play.
We need to agree to disagree here as we both seem to know or think they know something the other is not realizing
Upvote 0
WOW three cups of coffee in the morning sure get a lot of replies , Thankyou
Yes i thought about the "slamming upon firing" would destroy the bearings but just had to ask the question .
Thanks again for all the answers .
Yes i thought about the "slamming upon firing" would destroy the bearings but just had to ask the question .
Thanks again for all the answers .
Upvote 0
I've never had a problem with twisting after installing the Vortek or the Tinbum kit. There was definitely twist before.
From my limited experience a greased delrin surface against the piston is all that is needed.
I couldn't imagine a needle bearing under that kind of thrust load holding up. A tapered roller bearing is used for that kind of application. The spring dosent need a bearing there. Just a slippery durable surface to allow it to move a little as it winds/unwinds.
Sidestep the entire (mostly perceived) problem and install a gas ram. Best darn propulsion system since gunpowder. I love them. I would convert every spring gun I own to a gas ram if they offered the option.
The twist is an accuracy killer from a rest. I've decided that is why my springers don't shoot well from a bag. The effect is negligible when you hold the rifle and control the twist/recoil. Lay it across a bag and groups definitely open up.
It makes sense that even if the spring is rotating in the piston that the mass of the spring itself will impart a little twist. A delrin thrust washer keeps that twist from being transmitted to the piston by reducing friction. But it can't reduce the twist caused by the rotation of the spring itself. So no matter what type of bearing you put in there, there will always be a bit of twist. It just seems a lot more controllable when the spring torque is isolated to the spring.
From my limited experience a greased delrin surface against the piston is all that is needed.
I couldn't imagine a needle bearing under that kind of thrust load holding up. A tapered roller bearing is used for that kind of application. The spring dosent need a bearing there. Just a slippery durable surface to allow it to move a little as it winds/unwinds.
Sidestep the entire (mostly perceived) problem and install a gas ram. Best darn propulsion system since gunpowder. I love them. I would convert every spring gun I own to a gas ram if they offered the option.
The twist is an accuracy killer from a rest. I've decided that is why my springers don't shoot well from a bag. The effect is negligible when you hold the rifle and control the twist/recoil. Lay it across a bag and groups definitely open up.
It makes sense that even if the spring is rotating in the piston that the mass of the spring itself will impart a little twist. A delrin thrust washer keeps that twist from being transmitted to the piston by reducing friction. But it can't reduce the twist caused by the rotation of the spring itself. So no matter what type of bearing you put in there, there will always be a bit of twist. It just seems a lot more controllable when the spring torque is isolated to the spring.
Upvote 0
To take this a bit deeper ....
It is not the rotation of spring when it can do so freely threw out its stroke travel, it just winds up and unwinds freely .... IT IS WHEN the friction at either end of spring allows rotational tension to build up due to a LACK OF rotation that at some point breaks free and violently corrects this stored torque energy to release the tension that it effects accuracy. Newtons 3rd law of physics once more being of equal & opposing reaction. Spring releases energy in rotation one direction, it imposes reaction forces the other direction.
Now mass of the containment vessel ( The gun itself ) absorbs a very large part of this ... but it there none the less if / when a spring is bound up held from free rotation and breaks free suddenly.
Physics 101 ...
Upvote 0
As I STATED. SPRING CONTROL IS MORE IMPORTANT than how fast it rotates.
Try a fast twist spring on a 30 ft lb springer and see your dentist
soon.Upvote 0
Ah,Now I can picture how that comes about;it would seem that you would want the spring to rotate the same way every time.I am going to install a JM tune kit in my English Longbow today,I am just going to polished and put a slight bevel on the end of the new spring .
Intersting conversations,I learned form from them.
Intersting conversations,I learned form from them.
Upvote 0
When teaching mechanics around spring tech a simple question asked is WHAT IS A COIL SPRING ? .... in 4 words or less
Answer ... "Radially Wound Torsion Bar"
How do torsion bars work ? ... They rotate down there length storing and compressing motion energy wanting to return to a relaxed position.
How does a coil spring work ? ... They rotate the wire there wound from down there entire free coil length when either in compression or expansion wanting to return to a relaxed position.
Sadly Steel springs fatigue and ultimately fail as the motion at the molecular binding level of the steel breaks down just as if taking a piece of metal working it back-n-forth it work hardens and finally fractures.
Spring steels while designed for the task, fail is a similar fashion due to fatigue caused by motion over over and over again.
* VIBRATION after the shot cycle is still working the steel !!!! and why twangy vibrating spring piston air guns are harder on springs than tuned ones on fitted guides and spring thrust washers that allow free motion. As a springs violent torque rotation if present is a secondary vibration same as post shot spring twang .... Both add additional wear & tear to the spring steel.
Just sharing on this rainy day ...
Answer ... "Radially Wound Torsion Bar"
How do torsion bars work ? ... They rotate down there length storing and compressing motion energy wanting to return to a relaxed position.
How does a coil spring work ? ... They rotate the wire there wound from down there entire free coil length when either in compression or expansion wanting to return to a relaxed position.
Sadly Steel springs fatigue and ultimately fail as the motion at the molecular binding level of the steel breaks down just as if taking a piece of metal working it back-n-forth it work hardens and finally fractures.
Spring steels while designed for the task, fail is a similar fashion due to fatigue caused by motion over over and over again.
* VIBRATION after the shot cycle is still working the steel !!!! and why twangy vibrating spring piston air guns are harder on springs than tuned ones on fitted guides and spring thrust washers that allow free motion. As a springs violent torque rotation if present is a secondary vibration same as post shot spring twang .... Both add additional wear & tear to the spring steel.
Just sharing on this rainy day ...
Upvote 0
oh The Lonngbow.Ah,Now I can picture how that comes about;it would seem that you would want the spring to rotate the same way every time.I am going to install a JM tune kit in my English Longbow today,I am just going to polished and put a slight bevel on the end of the new spring .
Intersting conversations,I learned form from them.
what caliber ? Do not use a soft seal. Big parachutes will kill that gun. Macarri seals are WAY TIGHT AND TO SOFT.
Not that I know , Ive got three on hand and have owned several.
They can be magic at 12 ft lbs with a piston adjustment that was implemented by V-Mach.
They are a bastard stroke to tube size ratio until adjusted. My UK brethren all Agree with stroke it and not for power but smoothness.
.177 is tough in that gun. .22 benefits from a lot less coils and port work.
Im Doing a 23.5mm x78 mm stroked and sleeved Longbow now. .177 now and initial testing is sublime.
Upvote 0