GTA
All Springer/NP/PCP Air Gun Discussion General => Machine Shop Talk & AG Parts Machining => Topic started by: dkwflight on July 11, 2011, 09:27:06 PM
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Hi
How about a sticky with seal dimensions and interchangeability for as many suppliers as possible.
Spring dimensions and coil count for the different guns would be nice too.
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Try the Library.
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Hi
The library does have part numbers but no sizes.
http://www.gatewaytoairguns.org/GTA/library/Seal%20Fabrication.htm (http://www.gatewaytoairguns.org/GTA/library/Seal%20Fabrication.htm)
This is where I got the idea for fabing a seal from teflon. I think my version works a little better.
I still would like sizes and dimensions and interchange in a sticky or in the library.
My crosman titan gp seal looks like some of the seals listed by some of the aftermarket suppliers. Dimensions of the seals would alow me to compare and maybe try a different version.
I can measure my spare seal and list it if any are interested.
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This is a great idea!Part numbers will do nothing when someone is trying to upgrade or just plain o' try to make it work better.A full list if started should be pinned.
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That's not a bad idea but if someone does put it together, it would go into the library. Also, spring wire size and coil count can change in guns, especially in the Chinese mfg. so in many cases it would not be dependable. The same can apply to seals. An excellent example of that is the B-26.
CDT
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Crosman Titan GP .177 part number B18-04-1A
for model number C1K77NP
Also Benjamin trail NP .22s and .177s
interior dovetail hole .493
outside 1.0"
outside taper about 2 degrees
interior taper about 2 degrees.
Thickness .207"
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Trail NP BT9M22WNP p seal item 1 B18-04-1A
Quest 500 C5M77/C5M77X p seal item 1 B18-04-1A
Quest 800 C8M77,77X,22,22X p seal item 1 B18-04-1A
Quest 1000 C1K77,77X,773932 p seal item 1 B18-04-1A
Phantom 1000 CS1K77/CS1K77X p seal item 1 B18-04-1A
The Crosman piston seal B18-04-1A for Benj Trail NP BT9M22WNP measures OD~1inch, ID~1/2inch(13mm), Height ~7/32inch(~5.5mm). Sides sloped at ~15º(or ~75º depending on how you want to think of it). I have the Maccari aftermarket version ordered from
www airrifleheadquarters com/catalog/item/251485/43077.htm
…will post dimensions when it gets here.
If we’re going to do this, might as well do it right, part no.s, OD, ID, Height…all in both inches & mm. Easy for me to say and I’d be happy to help…e.g. spreadsheet. Not sure side slope is really necessary though. Links to aftermarket suppliers would be user friendly for us AND cashflow positive for suppliers.
I have on hand the aftermarket Maccari piston seal referred to on his website
www airrifleheadquarters com/catalog/item/251486/42975.htm
as WaltherTalon-Hunter-Mag-Turkish Guns-(Piston Seal) $14 1.15"OD WTPS-T
which I’m told fits not my gun but the following:
NP XL Series
BT1500WNP 177 piston item 1 BT22-04-1
BT1122WNP 22 seal item 1 BT22-04-1
BT725WNP item 1 BT22-04-1
My particular one is green and measures OD ~1.150inch(!29mm), ID~0.570inch(~14.5mm), Height~1/4inch(~6.5mm). The sides are sloped at ~9º (or ~81º).
The old timers will be in much better position than a noobee like me to vet the data.
Reference material like this will make GTA, to paraphrase ezman604, an even greater place to be.
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If we’re going to do this, might as well do it right,
+1
But I would ask for a bit more precision in the measurements if possible. Like "0.987 inches" or "25.0 mm" - something like that. Just a thought...
Tom
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If these were not soft parts, I would totally agree. But even Maccari posts a range of OD dimensions. Because they are soft, not sure more precision is practical or warranted...see what I mean?
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If these were not soft parts, I would totally agree. But even Maccari posts a range of OD dimensions. Because they are soft, not sure more precision is practical or warranted...see what I mean?
actualy as anyone who has fitted a seal will tell you a few thousanths one way or another will make a BIG difference in fit... and JM DOES measure his seals down to a couple thousandths or so..... so ayerstg DOES have a point :)
honestly for a list like this to be usefull it does need to be measured with calipers....
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There are basically about a half dozen or so standard seal sizes that gun manufactures use when it comes to a synthetic parachute type seal and most manufactures use only a couple different seals (especially Chinese made guns or the Gamo/Crosman clones).
If you are going to "try" to do this, you need to do it right and you will have a lot of variables as well as contradictory measurements. Most people do not have any idea how to measure seals, fit seals or even have the tools to measure them accurately. Seals do need to be pretty precise. A couple of thousandths tolerance can be an awful lot of variance. Also, the outside taper is usually not significant as long as it is there.
Because most tubes by many manufacturers are not concentric and can also have a lot of taper, how are you going to measure them to be accurate and what are you going to measure them with???? How do you intend to measure the bore at the beginning of the compression area of the compression tube???
Another point... unless you are actually making seals from scratch, you do not need all of the other measurements as they are pretty much standard across the board to that manufacturer as well as most others. Just creating more confusion because all you are going to have is a bunch of conflicting numbers, especially when most seal measurements for a given mfg. are pretty much basically the same to begin with.
It just seems to me to be an exercise in futility and confusion...Just my opinion
CDT
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I guess a list would help some and annoy others just like anything else in life.People in general will always try to find ways of improving on something or replacing something and thats just a part of human nature.For one I think that a list should be made and let people themselves figure out how the info can help them.We are all different and for the most part we have no idea who does what for a living so assuming is not a good thing.Lets take me for an example: I get a rifle from a member here that I was told was in good working order and had be serviced by a very well know company that is a big player in air guns.I get the rifle in and it works just fine until I try to shot into a wood target and I then see it had zero power.Now keep in mind that just weeks back I did not even know that high powered air guns even existed.I then began reading up on the internet and got as much info as I can find.I've now taken the rifle apart,I've seen some mistakes and fixed them and I've even made a conversion kit to make this unit into a nitro piston something which has not been done yet.
I say for those that have the ability to get the measurements together do so and lets start a list and let people use that list as they see fit.