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Thread: Top hat choices for a TX and that huge factory piston weight

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    Top hat choices for a TX and that huge factory piston weight

    Does anyone know why AA fit that huge piston weight to new TX's ?

    I have a fair few to choose from, I'm using a v-mach that is sized for a AA spring right now and I guess most of you use something similar.

    Are any of you using something different?



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    That is the tallest top hat I've ever seen. Seems like they used to be about 10-15 mm past the end of the spring. I use a plastic (Delrin) top hat and it's very light. I also had an old Delrin spring guide laying around that was a press fit in a spring I have. I cut it down to about 10 mm of the tube length and the back tip, that goes into the recess of the end plug was filed off. I shoved the little 10 mm into the top of my spring and the base of the guide, which is about 5 mm thick, is now my top hat for one of my guns. Any extra spacing that may be needed is always put on the rear guide to keep piston weight down. I don't really know the reason to do this, but everyone says to lighten the piston for best feel. This is on a short stroke gun and may be not the way to go on a MarkIII stroke gun.

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    Quote Originally Posted by Barryg View Post
    Does anyone know why AA fit that huge piston weight to new TX's ?

    I have a fair few to choose from, I'm using a v-mach that is sized for a AA spring right now and I guess most of you use something similar.

    Are any of you using something different?


    The large piston weight is there to compensate for the overloaded spring and tight seal.
    Bin it, add a delrin top hat, size the seal and cut the spring to suit.
    Mahoosive difference in shot cycle. Turns the "lazy" mk3 into a mk2 beater.
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    Quote Originally Posted by FPoole View Post
    That is the tallest top hat I've ever seen. Seems like they used to be about 10-15 mm past the end of the spring. I use a plastic (Delrin) top hat and it's very light. I also had an old Delrin spring guide laying around that was a press fit in a spring I have. I cut it down to about 10 mm of the tube length and the back tip, that goes into the recess of the end plug was filed off. I shoved the little 10 mm into the top of my spring and the base of the guide, which is about 5 mm thick, is now my top hat for one of my guns. Any extra spacing that may be needed is always put on the rear guide to keep piston weight down. I don't really know the reason to do this, but everyone says to lighten the piston for best feel. This is on a short stroke gun and may be not the way to go on a MarkIII stroke gun.
    I'm not sure if they still fit the huge TH but that is the size that was in my bought new HC about eight years ago

    I wonder if AA still fit them and if so why.

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    Quote Originally Posted by robs5230 View Post
    The large piston weight is there to compensate for the overloaded spring and tight seal.
    Bin it, add a delrin top hat, size the seal and cut the spring to suit.
    Mahoosive difference in shot cycle. Turns the "lazy" mk3 into a mk2 beater.
    Interesting you should say tha Rob, Steve P after a long chat sent me a kit that I have been so satisfied with, it has the plastic top hat and a one piece metal guide to fit a AA factory spring and a choice of two seals blue and green.
    I did have the usual trouble with when cocking the safety and trigger not cocking sometimes but the metal guide seemed to solve this problem, I assume that perhaps because it's a precision fit in the block with no flex the stem all lines up (just a theory but it works for me)


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    I seem to recall reading that that big heavy top hat was a factory fit to get the power in.177 up to comparable levels with .22"
    As with all received wisdom this should be treated with caution.
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    Quote Originally Posted by averageplinker View Post
    I seem to recall reading that that big heavy top hat was a factory fit to get the power in.177 up to comparable levels with .22"
    As with all received wisdom this should be treated with caution.
    Yes thats correct. The weights are the factory way to manage power
    A well set up TX does better without these weights in any calibre.
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    Quote Originally Posted by Barryg View Post
    Interesting you should say tha Rob, Steve P after a long chat sent me a kit that I have been so satisfied with, it has the plastic top hat and a one piece metal guide to fit a AA factory spring and a choice of two seals blue and green.
    I did have the usual trouble with when cocking the safety and trigger not cocking sometimes but the metal guide seemed to solve this problem, I assume that perhaps because it's a precision fit in the block with no flex the stem all lines up (just a theory but it works for me)

    Looks well made Barry and yes a sloppy fitting rear guide can cause all manner if issues.
    Steel is a bit OTT though. A well made delrin guide does the job.
    The advantage with steel guides (apart from longevity) is that they seem to make power easier where delrin ones do restrict power somewhat. I have a complete hatred of delrin guides that are over tight.
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    I don't have LOTS of experience with the TX, but........

    Mine's a .177 HC (Mark 3) and the original top hat was the large heavy one, as pictured. I think .22s will have a different size top hat as standard? Maybe also the full length ones? Replacing this with the Delrin item and less shoulder height reduced preload and, of course, all-up piston weight. Then increasing preload at the back restored the power and gave a much nicer and quicker perceived feel.
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    Got mine(used)before Christmas & it appears to be a mk2 in a mk3 stock, i got a TBT kit for it, but when i took it apart there was no top hat, but it did have 2 plastic washers inside the piston, & the plastic spring guide.
    Can i cut down the old spring guide & use that as the top hat, just so i can get the power down slightly more,currently 11.6.

    Rob

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    Quote Originally Posted by robthedog View Post
    Got mine(used)before Christmas & it appears to be a mk2 in a mk3 stock, i got a TBT kit for it, but when i took it apart there was no top hat, but it did have 2 plastic washers inside the piston, & the plastic spring guide.
    Can i cut down the old spring guide & use that as the top hat, just so i can get the power down slightly more,currently 11.6.

    Rob
    Good question.
    If the washer (flange) will inside the piston - it could work, but it would be awfully sloppy on the latch rod and may cockle over - unless the spring pressure on the washer at the front of the piston would hold it correctly.
    If the flange does not fit inside the piston - it's a non starter and I cannot for the life of me remember if it would.
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    Thanks for replying, i decided in the end to remove another 3/4 of a coil from the spring, now down to 11.1 & i'm happy with that

    Rob

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    what people are calling a "top hat" is really a piston weight and can be used to tune your shot cycle , if you just bin it you might end up with a gun that bounces, test with 8.4 gr and 7.9 gr , you are looking for the power to be almost the same , with the lighter pellets making slightly more power .

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    Quote Originally Posted by robthedog View Post
    Got mine(used)before Christmas & it appears to be a mk2 in a mk3 stock, i got a TBT kit for it, but when i took it apart there was no top hat, but it did have 2 plastic washers inside the piston, & the plastic spring guide.
    Can i cut down the old spring guide & use that as the top hat, just so i can get the power down slightly more,currently 11.6.

    Rob
    I think I forgot to mention that the guide I turned into a top hat only had a small flange and it fit perfectly inside the piston. It was a 1 piece job as well. It also had no play on the piston stem so it was just begging to be converted.

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    Quote Originally Posted by FPoole View Post
    I think I forgot to mention that the guide I turned into a top hat only had a small flange and it fit perfectly inside the piston. It was a 1 piece job as well. It also had no play on the piston stem so it was just begging to be converted.
    Thanks for the information.

    Rob

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