GTA
General Discussion To Gateway To Airguns => Gamo Gate => : August 21, 2007, 01:01:02 PM
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I just got the parts for my shadow today. And I'm eager to put it together but would like to know the best way to eliminate most of the twang/vibration. I have used spring tar but wasn't sure if you just coated the spring or goobered it on. So if some of you can help me out maybe show pics or recommend some things to try id be much appreciated.
Thanks,
Jason
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lots of info here http://www.gatewaytoairguns.com/library/Library_MainPage.htm
Charlie won't give away all his secrets, however, their are lots of links and thesearch function is very helpful, John
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So just goober it all over the spring then? Also where is a good place ot get some more tar. I dont have alot left.
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The best lube to use for the spring is either heavy tar or velocity tar. I suggest that you never use moly on a spring. In most cases the heavy tar is more than adequate and moly though a good lube in some applications and areas has little or no dampening value.
Russ Best said it best when it comes to applying heavy tar. You spread it like you are spreading butter on an ear of corn. It should be on the outside of the coils and string slightly from coil to coil. I also determine how much I'm going to apply usually by the geographical area that the owner resides in. I wouldn't worry about the tar getting slung off the spring as much as I would the amount of tar that is there as it gets colder and the lube stiffens up. Heavy tar gets very thick but there is nothing better to use on a spring.
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Now last question, where can I get heavy tar at?
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James Maccari in our Mall. You can get just the tar or get the kit for all airgun lubing need's. Ed
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^^ OH thanks much Ed, I forgot about that.
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No prob. I just got the whole kit for tuning my babies.Ed
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Well I found soem tar from when I got my rebuild kit. I used quite a bit and covered the coils pretty good. Now is there supposed to be a decent velocity drop? I mean like 50 fps? before the gun shot around 880-890's and its prolly around 820-830ish. Its not really a huge problem seeing as the gun shoots pretty smooth now, but just wondering if thats normal.
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Unless you have a chrony it's pretty hard to tell. Because of the difference in the feel of the gun, it quite often seems to be less powerful but in reality, it's not.
The heavy tar if used in excess can reduce the velocity, especially in cooler to cold weather. Also, a lot depends on what spring you used and what seal. Another factor could be the seal sizing if needed. If it is pretty tight, it can cause some excessive drag. Also, if you were not careful in the deburring process, you may have nicked the seal. Normally the .177 should be in the 850-860's to the low 900's somewhere depending on the pellet and how it is set up. I don't really like to see them upwards of 920 or so and sometimes detune them to drop them down a little.
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Charlie I have a chrony. And it was shootin 790's then each consecutive shot it was going up. And last I seen before the storms rolled in and my light got cut was about 820. I have the crosman spring fronm when I replaced it back in january.
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That's starting out pretty slow and I would think there might be a problem. The gain is common and gains as the seal wears into the compression chamber. Did you cross hatch the chamber itself? What seal did you use in it? Did you size the seal to the chamber? What spring did you use? Did you use Macarri's lubes in it? Also, the Crosman spring in my opinion is not the best spring to use and I never use them. Did you use Macarri's lubes in it? Let's see if we can pin it down.
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Ahh aite.. Well not to shure how to size a piston. So no I didnt, I used the stock one in a new tube from gamo. Seal looked fine to me (visually) just checked for cuts or anyhting else I kinda figured that would be a problem. I used moly to lube the piston (not the face just the edges made shure none got in the compression portion of it). It did seem pretty tight when I put it in.
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I didn't mean sizing the piston but rather sizing the seal to the chamber when installed on the piston. Some seals do need to be sized. The seal will develope a different wear pattern over the existing one if you used the same one over again and especially if in a different tube. That can cause blowby around the seal. You didn't say what spring that you used or what moly. The moly can make a difference and should be at least 60% and not over 70%. Also, what did you tar the spring with?
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I have the crosman spring I forgot who I got it from on here, he offered a tune kit so i grabbed one he was fairly popular on here a few months ago (offered a nice spring compressor). Not shure what amount of moly is in there.. the tar was spring tar that was included with the kit.
I guess my next question would be where to get a new good spring and seal along with a lube kit.
I seen JM's page for the lubes.. now which spring and seal :)
Thansk so much so far everyone, especially bob for helping to track this down :)
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There's your problem. You need to start from scratch. I had a feeling that was the case and it's not the first time it has come up to me. And if you added the needle bearing thrust bearing in the piston, I highly suggest you get that out also or you might find that your gun is trashed. Hopefully you didn't use his guide and if so, you should get the stock guide and replace it. Maccari's E-1500 is a drop in spring. Use the small Apex seal and get his heavy tar and the moly.
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No I dont have the needle bearing. wheew..... I figured that spring would be alot more than $17.00 Think I might just get one this friday along with the seal and some lubes.
Thanks bob :)
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Its not a bad price to fix this and make it shoot harder. But honestly as of now the gun is shooting about 830 with superdomes and its smooth. Just a nice thud and the pellet comes out. I might just leave it alone for a few weeks and see how it goes. :)
thanks everyone !!
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CharlieDaTuna - 8/22/2007 8:16 PM
There's your problem. You need to start from scratch. I had a feeling that was the case and it's not the first time it has come up to me. And if you added the needle bearing thrust bearing in the piston, I highly suggest you get that out also or you might find that your gun is trashed. Hopefully you didn't use his guide and if so, you should get the stock guide and replace it. Maccari's E-1500 is a drop in spring. Use the small Apex seal and get his heavy tar and the moly.
Woops did I screw up ordering E-2000 springs for the 440?
Cheers
Mark
Sometimes too stupid to ask before ordering....
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Maybe..maybe not. It depends on your ability. The tophat may be a problem. Let me give you some specs to relate to:
Spring         Coils          wire dia.               coil bound                   tophat thickness
Gamo Stk    34-35           .119                      4.165                         .380
E-1500Â Â Â Â Â Â Â Â Â Â Â Â Â 35Â Â Â Â Â Â Â Â Â Â .120Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 4.200
E-2000Â Â Â Â Â Â Â Â Â Â Â Â Â 36Â Â Â Â Â Â Â Â Â Â .125Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 4.500
The maximun coil bind allowable is 4.650.
As you can see, the maximum tophat thickness that you can use with the E-2000 is about .150. Unless your gun has the light tophat (and most likely doesn't as most 440's have the large tophat) which has a thickness of 2.5mm or approximatly .100, you will need to modify the tophat and/or the spring block (not the best approach but necessary). You really should also allow about .125 or an additioal .075 for cocking and spring error.
Hope this helps
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Thats good to hear, making a top hat is no problem. It shoots so well out of the box with just your trigger though I'm in no hurry to tear into it.
Cheers
Mark
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Hey Bob, out of curosity whats the strongest spring I can install into the shadow? Was that JM spring about as strong as it gets or is there something else that can fit with some minor work?
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Looks like somethins wrong, I was just reading this thread and I got a feeling of dread. I have a Shadow1000 .177. I wanted to give it a little more power so I could shoot Tomahawks and CPHeavies at the theoretical stability limit which I figure is about 1000~1090fps. Back in the middle of July, dummy me, I was reading a thread over on the Yellow forum, and ended up emailin a guy named Rich from Mich. Now, I found out that the kit that he offered for the S1K contained the JM E2000, but it also contained a needlebearing thrust washer(s). The needlebearing thrust washer, while a novel idea, just didn't sit well with me. So I ordered up some springs, seals, and lubes from old JM himself. I ordered 2 E2000 springs so that I could use one in my S1K and maybe use the other in my Hammerli or something else, or at least have a spare layin' around to "experiment with". Ok, so that was the background info to cover up my stupidity for listening to some guys over on the yellow forum, :-) and that was before I know what I know now, and that is to take any advice from the yellow forum with a grain of salt...because so far, none of the advice that I picked up over there turned out to be good advice.
So...now I've got this E2000 spring, and from what I understand reading through this thread is that the tophat will need to be modified or a new one made, which I can do, but it still bugs me.The E2000 spring is not just a drop in for the S1K. It's the E1500 that you could drop right in, *but* you losepower in a tradeoff for shot smoothness and consistency. Did I get all that right?
And believe it or not...I'm not worried about twang or vibration. I just want my S1K to shoot a little faster, and I've got the GRT3 trigger coming.
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Dave... the difference in power is very little and the velocity change will only be about 20 fps or so. The E-1500 in my opinion is a bit smoother shooting but the ID is a bit bigger and keep in mind that I make fitted guides for the TurboTunes and that includes about 95% of the Gamo's that I do. The E-2000 does fit the factory guide a little better as it has a .518 ID where the E-2000 has an ID of .530. It's a bit of a trade off but not enough to be concerned about and worth it. I would take performance over velocity any day within reason.
The Tarantula also has a .530 as well as a .128 wire diameter and why it is not recommended for use in the Gamo as a rule unless you have the capability to machine fitted spring guides and top hats. That being said, many do use the Tarantula when it's available anyhow but give up performance and they can fatigue a little early and also cant.. If you do have the capabilities and can do it, the Tarantula is an excellent spring to use.
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I'm not real sure if there is a stronger well performing JM spring than the Tarantula (see the response above) or the E-2000 with the E-1500 a close second. I've never been one that tunes for power (nor do most any other pro springer tuners) and usually decline tune requests from those that want power tunes. Usually the customer is not happy when he gets it back because the loss of performance. I just don't do them and is why you for the most part hear nothing but good about my tunes. To me consistency and accuracy are far more important than power.
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CharlieDaTuna - 8/26/2007 6:34 AM Dave... the difference in power .......... The E-2000 does fit the factory guide a little better as it has a .518 ID where the E-2000 has an ID of .530. It's a bit of a trade off but not enough to be concerned about and worth it.
Bob, I'm confused, thanks for your reply, but your'e referring to the E2000 twice with different numbers. Which one is which? I'm hopin that what you are sayin here is that the E2000 does fit the factory guide ok, and can be dropped in with no mods?
I also bought a universal firewire spring, to see what that would fit in...what do you think of those(not for a S1K).