Quigley hollow

[NickG]

Had a great day yesterday at the AA owners bash at micks , many thanks Mick, It was nice to catch up with the tuning clan, I have to say John Budds, and Charlies 22mm tunes are fabulous, and I am now trying to source tubing to make one for myself with maybe a couple of differences , , so we can compare at a later date.Its also inspired me to return to my 21mm and am now getting somewhere with it. Thanks to the Air Arms boys for getting the event organised,

And by the way did Charlie make it home , or is he still there trying to hit the bucket once before he sets off

[Shed tuner]

you reminded me... I got the tube from the bay, vendor: neropipelineconnections

So happy to have converted you away from o-rings - still working on Tony though

[prosport.177]

Thanks nick,
It was good to catch up and have a compare of the tunes.They are really very similar, but reached in a slightly different way.

Ha ha, i must have been the only one that did not hit it ,) And to put salt in the wound purl shot it standing! and you knocked it over countless times, and mr budd on his second shot!!!!!
Hummmm ha ha nxt time.
Thanks to mick for a great event and all the hard work put in.

[NickG]

you reminded me... I got the tube from the bay, vendor: neropipelineconnections

So happy to have converted you away from o-rings - still working on Tony though

Not quite, trying to source some 21/22mm quad rings, and going to have a go at making my own polyurethane labrynth seal, Got the 21mm making 10 ftlb with tighter o ring, but it diesels when I go any further, and its slamming, so going down on trans port to 3.4, and see if I can squeeze a little more power from it , almost zero recoil and silly easy cocking in the hc. so its worth working on If I can get it to 10.8 it will be awesome, May make a copy of an hw seal at 21mm to try also. Thanks for the link

[TonyL]

Glad you had a good time, chaps, and that you gurus have been getting your heads together yet again.

All brilliant stuff!

It'll be very intriguing to see how the next stages of tinkering goes and what developments occur before the September Bash!

Well done you all.

[Shed tuner]

Glad you had a good time, chaps, and that you gurus have been getting your heads together yet again.

All brilliant stuff!

It'll be very intriguing to see how the next stages of tinkering goes and what developments occur before the September Bash!

Well done you all.

Running out of idea in terms of the basic geometry... 22mm is good, and easy (seals readily available), 21 is also OK if you use o-rings. One you get down to 20 or less you hit two problems:

i) Stroke starts getting too long to accommodate; 100mm is a practical max for TXs and many other guns are less; we are already at ~90 with 22mm
ii) fitting a mainspring starts getting tricky - anything less than a 18mm OD spring is just not going to fit, whilst allowing a rear guide of a reasonable wall thickness to take the 10mm piston rod. Say a 1mm wall guide thickness = 12mm OD, spring 12mm ID, gauge 2.8, OD17.6 (about 18 when cocked), so with 19mm you only have 0.5mm clearance around the spring for it not to vibrate / touch the comp tube walls

So for me the next area is anti bounce / recoil absorption... gets thinking cap on....

[TonyL]

Running out of idea in terms of the basic geometry... 22mm is good, and easy (seals readily available), 21 is also OK if you use o-rings. One you get down to 20 or less you hit two problems:

i) Stroke starts getting too long to accommodate; 100mm is a practical max for TXs and many other guns are less; we are already at ~90 with 22mm
ii) fitting a mainspring starts getting tricky - anything less than a 18mm OD spring is just not going to fit, whilst allowing a rear guide of a reasonable wall thickness to take the 10mm piston rod. Say a 1mm wall guide thickness = 12mm OD, spring 12mm ID, gauge 2.8, OD17.6 (about 18 when cocked), so with 19mm you only have 0.5mm clearance around the spring for it not to vibrate / touch the comp tube walls

So for me the next area is anti bounce / recoil absorption... gets thinking cap on....

Yep, as you say, Jon, 21mm was always going to be the practical limit to sensibly accommodate the spring and guide.

To my way of thinking, the 22mm sounds far more practical as the minimum bore size as, like you say, seal availability; maybe not that much to be gained in piston weight saving comparing 22 to 21, and that the slightly higher swept volume will be a little more forgiving to accommodate different "preferences of tune" and not running into an area where swept volume becomes too critical and the gun running a higher state of tune, relying on more spring, higher temperatures or maybe even combustion to make the power??

[hmangphilly]

Had a great day yesterday at the AA owners bash at micks , many thanks Mick, It was nice to catch up with the tuning clan, I have to say John Budds, and Charlies 22mm tunes are fabulous, and I am now trying to source tubing to make one for myself with maybe a couple of differences , , so we can compare at a later date.Its also inspired me to return to my 21mm and am now getting somewhere with it. Thanks to the Air Arms boys for getting the event organised,

And by the way did Charlie make it home , or is he still there trying to hit the bucket once before he sets off

nick what size do you need , i might have a bit of something .... if i dont come back on here , send a pm ...itll flag up on my email

hoy, wots all this about lab seals ?

jon , how accurate is that tube ? have you measured it ?
I'm on a bit of a comp tube trip ... that's where it's all at in my opinion .
to start with , going the easy route with seamless tube , that precision tube off the bay measures up pretty good...... round ish and straight ish . but only certain sizes available sleeving is messy

spoke to a chap last week about honing and he reckons out of solid bar will be better ....off to see him later

[Shed tuner]

Well, I went with the precision seamless tube, and whilst I haven't measured it precisely, running the sealed piston down the bore feels very smooth and consistent. I gave it the barest polish with 1200 wet n dry on a dowell, but not really needed, more to tidy up my own machining marks. It did need a few thou off the outside to fit nicely into the TX tube. Readily available size is another reason I chose 22mm ID / 25mm OD

[NickG]

nick what size do you need , i might have a bit of something .... if i dont come back on here , send a pm ...itll flag up on my email

hoy, wots all this about lab seals ?

jon , how accurate is that tube ? have you measured it ?
I'm on a bit of a comp tube trip ... that's where it's all at in my opinion .
to start with , going the easy route with seamless tube , that precision tube off the bay measures up pretty good...... round ish and straight ish . but only certain sizes available sleeving is messy

spoke to a chap last week about honing and he reckons out of solid bar will be better ....off to see him later

I am after a piece of 22mm bore by 1.5mm wall to give 25mm od, Charlie gave me a link but they are on holiday, but no rush I am working on the 21mm at the moment.

The first comp tube I sleeved, was a 26mm hw, I sleeved reamed and then honed to 25mm, it was a right faff, and difficult to size properly as my bore comparator does not go down to 25mm.
The precision tube is very good to start with as its drawn.

My elder brother, ( a retired engineer), put me on to labrynth sealing its used on gas compressors where lube and friction are important, just experimenting at the moment.

[NickG]

Running out of idea in terms of the basic geometry... 22mm is good, and easy (seals readily available), 21 is also OK if you use o-rings. One you get down to 20 or less you hit two problems:

i) Stroke starts getting too long to accommodate; 100mm is a practical max for TXs and many other guns are less; we are already at ~90 with 22mm
ii) fitting a mainspring starts getting tricky - anything less than a 18mm OD spring is just not going to fit, whilst allowing a rear guide of a reasonable wall thickness to take the 10mm piston rod. Say a 1mm wall guide thickness = 12mm OD, spring 12mm ID, gauge 2.8, OD17.6 (about 18 when cocked), so with 19mm you only have 0.5mm clearance around the spring for it not to vibrate / touch the comp tube walls

So for me the next area is anti bounce / recoil absorption... gets thinking cap on....

You don't need 10mm diameter latch rod, the waisted part is strong enough, and thsts only about 6mm diameter, maybe reduce the diameter , and alter the latch sear, may be more work than the benefits are worth though

[Blackbaronfish]

I would just like to thank you guys for supporting the AIR ARMS charity bash at the weekend. It was a great meet and to be in the company of so many die hard springer boffins was the icing on the cake. I dont normally do spring guns but im now after a mint EX88

Many,many thanks

BBF

[Shed tuner]

You don't need 10mm diameter latch rod, the waisted part is strong enough, and thsts only about 6mm diameter, maybe reduce the diameter , and alter the latch sear, may be more work than the benefits are worth though

that's true, maybe 8mm rod the the bulk of it.. but then can you actually get springs in the sizes we'd be talking ? 17mm OD ?
And it;s going to have to be thinner gauge / lots of coils to avoid being too stiff with that tiny circumference for each coil..

[prosport.177]

Jon take a look at the webley value max.
From memory it does not have a piston rod..
.)

[TonyL]

Jon take a look at the webley value max.
From memory it does not have a piston rod..
.)

Was thinking of rodless designs, too.

Are the Hatsan 55/60 rodless? I'm thinking, they're longer stroke? Which'd be what's needed for the "small bores" to work?