GTA
General Discussion To Gateway To Airguns => Airgun Gate => : daved November 15, 2006, 02:05:39 PM
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Didn't notice this at first, maybe I overlooked it in the new gun excitement. Whatever the case, I'm now getting quite a bit of spring torque. Has anyone done a tune on one of these guns? From what I can see from the exploded view diagram I have, it doesn't have a "top hat" like the Gamo's, but there is a spacer or washer of some kind at both ends of the spring. If so, I'm wondering if a thrust bearing of some kind, like Rich has in his Gamo kits, would be workable. Anyone know? Or would a lube tune be sufficient? Any suggestions would be much appreciated here, this thing is kind of hard to handle right now. If I try a light hold, it almost jumps out of my hands, and it's almost impossible to follow through properly. Even at low magnification, there's so much rifle movement that I can't keep sight of the target through the scope. It definitely seems worse than when I first got it. Thanks, guys.
Dave
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Daved,
If the torqueing continues to worsen, I think I would call the manufacturer and see what they say. The number is 1 - 479 - 646 - 4210 . They have a lifetime warranty. Best of luck...
Rabbit :) :)
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The Needle thrust bearings Timken makes they have them in all sorts of sizes I bet you can find one that would fit the rifle spring, they are only a little more than 1/8 inch thick depending on what thickness washers you get, the washers come in every size from .030 thickness to .125 thickness.
This would put a end to spring torgue.
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I wonder if I can put that into my gamo....
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Sure I have them as an option in my tune kits.
Look here on my website
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Oh duh, lol i should have seen that. Now to figure out how to make a spring compresser ill be all set :)
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Did anyone see the new price list from Midsouth......... RWS 350 .22 $299.00 plus free shipping
Gene
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(http://www.airgunsmith.com/bearing.jpg)
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Ratite
It would seem to me that those thrust bearings are made for a lite amout of pressure forward and aft. In my 20 years in the truck component remanufacturing I was able to work with some of the big boys such as Rockwell, Eaton, Spicer, Borg Warner Manufactureing and testing.
Spicer and Eaton corp used those thrust bearings for a few years but found out that any sudden shock to the component would break the bearings apart. Then those small pieces would run through the other moving parts and start a rapid deterioration of the component.
The thrust bearings were ment for very light thrust and not shock or impact. So I would think by using them in a springer that they would eventually break down and?
Just my 2 cents..:)
Gene
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I thought about that and have been checking my b21 and L egacy for over a year with no sign of impact.
When I first started using them I used malleable buffer on the front bearing then realized there is no impact as the spring is not throwing the piston or bearing it it is pushing and if the pushing is done correctly there is an air buffer between the piston slamming into the receiver so there is no violent effect on the bearing
(If the gun is working correctly)
(http://www.airgunsmith.com/eb/bearbump.jpg)
So I thought,,, what if the gun was not working as it was designed and do I really need the bearing in the front and the rear?
Hmmmm.
I removed the bearing from the front and ran the bearing in the rear of the spring the part of the spring that stays put with no banging it just kind of sits there twisting and grinding away with only lateral forces being applied,
This is when I realized!! That’s what the bearing was intended for even though I still use the bearings for the front of my Legacy spring and over a year its still smooth as silk with no signs on impact damage or ware.
So for the most part I would use the bearings on the rear of the spring only! As springs really only need one side of the spring to not stick, grind and to stop the twang from the sudden release of steel under torque.
But to get back the 350 it has 2 bearing races one on the top and one on the bottom of the spring if the gun is properly lubed the spring will not twist.
One thing to remember the RWS 350 is what the industry has determined is a true airgun magnum and no matter what field you’re in when the term magnum is used there will be a slight increase in difficulty of control give that bad boy some time let it break in and give your self some time as well to learn to control the beast.
I have 2 RWS 350M 177 & 22 I like them very much and it took some time and effort to learn to shoot them its big its bad and it like to kick but dead on accurate and powerful in the springer world.
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I hava had Timken needle bearing in my rifles for over a year and not a problem with them. They are not under a real big load or shock in the end of a air rifle piston, after all the piston stop is not a harsh as you think because of the air cushion at the end of the stroke.
I have also used them I my R.C. racing boats in the belt overdrive system, (which I.M.P.B.A. outlawed on me) at RPM's ove 28.000 without fairure, lubed olnly with the oil in there exhaust of the engines.
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I am only aware of Timken Bearings being of the cone style only. In the 70's through the 90's Timken only made tappered bearins. Things may have changed by now.
As far as the thrust bearings are concerned they were originally designe for light thrust and not to be used for a very high RPM of motion. As far as putting them in the front of the cylinder on a springer, with my past knowledge, I would never do it..:) Just my opinion.
Gene
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I am not an engineer but I would think that if thrust washer was used in front of cylinder on springer the constant impact would break the bearing down. What I mean is the bearing cage would fall apart and the rollers would come out. But putting the thrust bearing in the rear of the cylinder then you would not have the impact. That would be safe I would think.
I have always had a rule of thumb about mechanics. The less moving parts the better.. :) So unless the thrust bearing made a significant difference in performance, I would not use them. But I am not an Air Gun Smith and can only logically determine certain factors from my past experience with bearings etc.
By the way Ratite, about the RWS 350. I have read allot of experienced post regarding this modle. Most comply with what you say about learning how to shoot it..:)
I do not know if my Gamo 1250 would be classified as a true magnum but it is one powerful springer. One that I would never want to be in front of if fired... hehe Same would probably go for the RWS 350.
Gene
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I have shot a few 1000 pellets through a Leagcy with one of these top hats in it and still smooth as silk
Here I use a washer then a bearing and then another washer in this custom Legacy tophat
(http://www.airgunsmith.com/neededgifs/brasstophar.JPG)
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Direct from SKF bearing website.
Needle roller thrust bearings
Needle roller thrust bearings can support heavy axial loads, are insensitive to shock loads and provide stiff bearing arrangements which require a minimum of axial space. They are single direction bearings and can only accommodate axial loads acting in one direction. Particularly compact bearing arrangements can be made, taking up no more space than a conventional thrust washer, if the faces of adjacent machine components can serve as raceways for a needle roller and cage thrust assembly. For applications where adjacent components cannot serve as raceways, the assemblies can also be combined with washers of various designs.
Because of all the possible combinations, all bearing components must be ordered separately.
Need to do a little research on bearings Gene.
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Hi Guys,......I have a little experience to share on the benefits of these thrust bearings.
As I need to keep my staff and mowers going all day every day I found that installing these in replacement ofthe greased steel washers atop and bottom of the shafts retaining the castor wheels on mowing decks, reduced the need to grease, reduced the instance of failure of the retaining "C" clip and reduced wear of the washers completely. Needless to say these mowing decks take a hammering all day every day. The directional shock from the wheel up the shaft, combined with the lateral movement of the castor wheels is a very violent as you bounce across the ground. These thrust bearings are just the bees knees and have virtually eliminated downtime due to this area of the mowing deck failing.
I would agree that installing a thrust washer system behind the spring makes sense, as that spring untwists it has to go somewhere. I recently pulled a packing washer out of a gun that had big "bite" marks from the roughly finished spring termination, and accounted for the "twitch" when fired. I had followed conventional thought and dressed and polished it to mirror finish and reinstalled it with good results. However if I had to repeat the job again I would install the thrust bearings now.
Good discussion guys,.........I enjoyed it very much.
regards Adam
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I really don't need to reasearch bearings Rich. I was applying an my experiences with thrust bearing on truck drive train components. I have worked very close with Eaton, Rockwell and Spicer corp on bearing and metal failure for many of my years. Maybe the relative difference in the mechanics are no where near air guns.. :)
Like I said my opinion was based on that industry. Fatigue and hardness failures through applications. And I do think these posts and replies are great stuff for our members. We all can gain experience and knowledge from one another. Thats what it is all about...:)
Gene
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I agree, definitely makes for good reading and information. Like Gene, I had origianlly thought about the shock factor before getting one of Rich's needle bearing top hats but decided to give it a whirl anyway. I am really pleased with the results overall.
Someone brought up another point about adding the bearing behind the spring. With the bearing factor in mind, Do you guys think that there would be any apprecialble benefit to having a bearing at both ends of the spring? or maybe just overkill.
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The whole concept I think here is to keep spring from twisting. I would think if Rich is correct about the impact factor that one end would be sufficient. Myself would not use bearings. A well polished end with a grade eight polished washer would probably do the trick, if proper lubricant is use between them.
Guess we would not have SUV's instead of station wagons, if someone had not of thought of the concept either..:)
Gene
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I really don't like getting into controversial subjects but.... the idea of using needle thrust bearings has been around for many years and the topic comes and goes every once in awhile and don't last long. I have tried them in different combonations a number of years ago and came to the same conclusion that most of the pro's did in the past. Very few if any of the pro tuners ever use them except in special applications.
Regardless of what some might say, there is a tremendous amount of impact when the piston slams home (and it's steel against steel) and if you think about it, and what it does, and the relationship it has to the double recoil of the springer and scopes then I think you would agree. Of course there will be some that will disagree also.
Years ago prior to his passing away, and when James Kitching and I were working together, I had discussed the idea of thrust bearings with him. It was one of the few times that he had said to me "get that out of your head. It's a waste of time and your customers money and can cost you in the long run". He would always say to me "get it out of your head" if I would start on a no-no. Later I would see for myself the damage that a thrust bearing can cause when it lets go, and personally I would never put one in any of my customers gun. And definitely not in my own guns.
If it were that advantageous, then the manufactures would use them , especially in the mid to upper class guns if it were that beneficial. But they don't and for good reason, and it would be very inexpensive for them to do it at the time of manufacture.
When the gun is cocked, the spring itself does not twist much anyhow and how much depends on the construction of the spring. And if you use a Stainless Steel washer as a thrust washer, you will accomplish the same results and possibly even better especially if you are using a tophat as you have three points for rotation at the bottom and at least one at the top. What is important of course is eliminating as mush resistance as possible, especially when it "unwinds". By smoothing the spring ends and removing the grinding marks (and they don't necessarily need to be polished if the proper lube is used) and even more importantly removing the sharp edges both on the inside as well as the outside edges at the cut off you will remove a great deal of resistance. And one more thing that is important. When thrust bearings are used in an application, the outer surfaces of the races "or washers" that the needle bearing sets on in most cases sets on machined flat surface. The surface in the bottom of the piston in springers is not a machined surface for the bottom race to be seated on nor is the spring end if it sets on the opposite race.
Bottom line....in my opinion.... use a thrust bearing if you like, but myself, having tuned literally hundreds and hundreds of guns through out the years, I see little or no real advantage to using them and I've never had a customer complaint about torque. If everything is done correctly, there is no reason too. I don't use them and as I said previously and I don't know of any tuner that has a few years experience behind them uses them or any other pro-tuner that uses them as part of a normal tune.
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Well that was pretty definitive Bob............
I must say I would still like to try it,...........just for an experiment. And with the added benefit of not being a tuner for anyone else's Airguns but myself I can afford to take the loss.
Thanks for your attempt to make me see the error of my ways, You have, but I suppose I am recalcitrant. And yes I am working on a special aplication project.
Regards
Adam.
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I will have to admit I dont tune the chinese airgun well not many
I would say 200 or so, 90% of my of my work is with American made or the upper end imports (not Chinese) compared to European the Chinese quality is just not there and to take a 100$ gun then tune it for 150$ never did make any since, Except for the most extreme hobbyist, and it seems that’s what’s been going on in the Chinese airgun world
(Taking the Chinese airgun to the extreme) not just stopping at 99% but going all the way. And some times exceeding 100 percent !!!! WOW
Because of this over the top commitment by the Chinese airgun hobbyist I have seen many many awesome over the top springers.
You don’t need special applications to try something new a bearing will always be better then a washer to reduce friction. If you have an idea run with it.
Here is the tophat I built for my sons Legacy it shoots just under 500 FPS we detuned this gun for local competition it is sweet and smooth.
This gun has over 2 years on it with 1000s of 177 pellets through it,
with the bearing the cocking is much smoother and the shots are quieter and smoother as well
(http://www.airgunsmith.com/eb/legtophat.JPG)
I have always been amazed at what airgun hobbyists have come up with and more then not extremely impressed with the creative ingenuity most have shown.
It seems there is a lot of knock downs and it wont work say-ers on the forums theses days where there used to be a bunch of pusher uppers with complements and encouragement in the hobby forum world.
I guess for some there is just too much at stake and the hobby has become a high stakes financial endeavor and that for the most part that will take the fun out of it.
I say
Gentlemen start your engines and put your ideas forth take this hobby to the extremes bust through the outermost boundaries ignore the naysayer but remember this is your hobby so relax and enjoy
Be Safe show safe teach safe and allow others to have fun
Ratite
The Airgunsmith
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Like I said, if you are inclined to use a needle bearing thrust, go for it. I’m certainly not condemning it, just saying I myself wouldn't use it as I don't see any real improvement over it in the way that I do things. And I've also seen the damage it “can†cause if a cage lets go. And I’m certainly not saying that it is going to happen if you use it. Just that it’s possible.
As everyone knows, or anyone that has been around for the last 5-7 years, I started with the Chinese guns and eventually would up doing just about all the springer’s from the bottom to the top of the line out there. However, the Chinese guns I see very little of any longer. Where in the very early years the Chinese market made up about 95% of my business, it is now probably less than 15% of it. I get few of them in any longer and those are the B-26’s, the B-30’s and the B-40’s. They were terrible and a real challenge to work on and make into something that was good. But as Kitching and Collins told me a long time ago… if you have the patience and the ability and can successfully learn how to make and convert these Chinese guns into winners, then you'll be good with any springer. Well I think I did that as do several hundreds of customers over the years.
And Ratite is right when he says that there are a lot of Nay-Sayers out there and many people that discourage or knock others for their ideas. I hate to see that and at the same time, I don't like to see people discouraged to a point that they don't post their opinions or voice/present their logic regarding their ideas. I’m certainly one to voice my opinion and the logic behind it and always will, but when I voice my opinion, it is based on not only my many years of past experience but also of others with experiences and logic that are much wiser and with more experience than I. After all, I find that you can be in this business for ten years and still not know it all.