GTA
General Discussion To Gateway To Airguns => The Shop => : kiwi October 13, 2008, 06:00:42 PM
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Hi..It's happened again...To much time on my hands & to meany ideas.
While making new guide for the first B11 I had the idea of useing a one
peice spring guide to control the spring though it full length. With two short
guides at each end of the spring it dosen't matter how well they fit you are
never going to have total control of the vibration/twang etc while there is a
3rd of the spring hanging around with no surport in the uncompressed postion.
So I have made a one peice guide, when cocked the guide will potrude out the
back of the chamber so there will be a alloy exstention with a nylon bush that
the guide will travel into when cocked. The guide is made from a 1/2" od Stainless
steel tube with top hat welded on then machined true. The tube was such a good
fit in the spring I would have been hard pressed to turn something a better fit and
then bore it to keep the weight down "It will still be heaveyer than the standard
top hat / front guide "just have to see how it goes"
"fingers crossed that the weld can with stand the shock"
Dosen't it hold that spring straight and true?
And the only component the spring will come in contact with should be the guide
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Peter, how much does that SS Spring guide weigh?
Gene
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I feel sorry for your shoulder!
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Its heaver than I would like, if it works great.. if not it ends
up in the rubbish bin simple as that ..only cost me time.
SDale...If its on a par with putting 20 + shots though a 12g
in 30 mins there no brob with my shoulder.
8 years back we had a rabbit plage till the relessed RCV
to control them. 4 of us could drop 70 plus in a afternoon shoot.
Ah those were the days
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A bit heavy...maybe machine from 25mm Dia carbon fiber rod.
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that sucker does look a little long i was wondering just how that was gonna work.
i was thinking of a two piece guide where the top half is tubing so it would fit over the lower half.
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Hi..Craig I did think of a 2 peice guide that one half slid in side the other
But the peice that slid inside would be to small in Dia for the spring.
This one is one peice and when in the cocked position will stick out the back
of the chamber by going though a nylon bush in the end plug with a alloy
shrould to cover it. The end plug will have to have 2 short bolts threaded in
to it instead or the cross pin to let the guide slide though.
Weight was a prob but when I started to look at both
the new guide and the piston as a unit it was easy.
I put the piston on a diet to compasate for the extra weight of the guide.
Standrad piston is 215 grams
Standrad tophat is 66 grams
combined weight of 281 grams
Lightened piston & new guide have a
combined weight of 300 grams
still 19 grams to heavy but the new guide
has to be shortened 40mm yet so will easy
make the 281 grams or below.
I can't think of any better way to control the spring
than a snug fitting one peice guide.
So if anyones got any ideas let me know have the guns & time
to play with other ideas.
Ps..... it is posable to make the swept volume larger by 4.7cc ...thoughts???
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sounds good Peter, keep us posted on the goings on.
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Quiver..When yer pull the trigger it won't have time do do anyting but move str8 forward..nano seconds.
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LOL...I think we are just going to have to agree to disagree on this one.
There are 3 factors required,
Speed
strength
unsurported length
or strength verses unsurported length
I only have one of these factors "speed"
and the other two are well with in the materals limits
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Hi...275mm total guide length with around 110mm tail when cocked.
Lose figgers but will only very a few mm when completed.
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Peter, this is a nice idea for controlling the spring, but I think your still too heavy. Basicly what you have is a long top hat, at more than 4times the weight. I think that with that much weight the cushion of air, will not be able to slow it down and your going to to have a hard piston slam. I could be wrong, but I think thats too much weight, for the top hat.
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with the heavy tophat would you be able to shoot heavier pellets to get a cushion of air working again?
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Hi..Craig useing heaver pellet may well work.
But i have got the new tophat/guide & piston
down to 2.7 grams heaver than the standard
tophat/piston.
As long as I can keep the total traveling mass is
the same or lighter than standard it won't matter
were the weight is carried.
lighter would be good as they kick hard
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cool Peter,
when can we expect a review?
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Got all the parts completed, The new one peice guide & lightened piston
are now 5 grams lighter than the standard units.
Have used a nylon bush at the rear of the guide and it also lets the spring
end cap rotate on its face very little fricton
A bit more polishing and its ready to go togeather.
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Very interesting Peter. You have to let us know how it works out for you. You may have re-invented the mouse trap there.
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How it all fits in
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that's lookin good Peter,
when are we gonna see how it shoots?
that piston is lookin thin is it goin to stay together?
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Hi..got it back togeather today no stock on it yet needs a mod to let it fit now.
I put 2 pellets through it...The first thing I noticed was the sound
just a sharp crisp crack then nothing. Have not heard that from any springer before.
The 2nd thing was almost no recoil, the reduction of the moveing mass by 5 grams
most lightly had something to do with that.
3rd, cant/twist I did not notice any "it will have some"
Standard B11s cant/twist really badly to the right.
Power wise ??? will be very surprised if it has lost any.
It is light years better than a standard B11
The B11 has a lot of power but is very bad mannered "twange/recoil/vibration.
So is very easy to make a big improvement to.
Don't think this will be the last one peice guide I will be making
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This has been a great project. I have been reading this thread with great interest. Please post a photo when you get it stocked so we can see how it all goes together. Some chrono numbers would be great as well.
Thanks for sharing!
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how's she comin along Peter?
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craigfperry - 10/27/2008 6:10 AM
how's she comin along Peter?
Some time this week she will be finished.
had to take it apart went to put the trigger in
D******** NO hole for the trigger spring to seat in.
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Hello Peter,
I have been trying to ignore the springers so as not to be tempted for another gun:) but I must say well done sir!
Dave