Reply With Quotehi rod
the ptfe is the seal itself you have pm coming
rgds scirroco
Banned
Hi,I have just tagged this question on to another thread, then realised no-one will spot it
So, can anyone please give a little more spec on the PTFE pistons? Do they run an "O" ring seal as well as the piston, or, is the piston itself machined to a seal finish. I've got "all the gear but no idea" (again)
Any assistance would be great as I would like to bring at least one Airsporter up to the standard it would have been if designed today (internally).
T.I.A.
Rod
Registered User
hi rod
the ptfe is the seal itself you have pm coming
rgds scirroco
Donor Fixer
The Airsporter heads I've seen have been made only of PTFE with a slight wedge profile rather than a sealing lip. You size them with abrasive paper and then firing the rifle makes the final fit as the soft material forms to the cylinder bore.
Rich
Wanted - Venom Mach 1/2 Trigger
Donor Fixer
Personally if I was intending to bring an Airsporter up to more modern standards I'd be looking to fit a parachute type seal in place of the alloy head.
Wanted - Venom Mach 1/2 Trigger
Banned
At the moment they all have Nylon heads but please enlighten me about parachute heads. Can you give me any details / specOriginally Posted by lightning22
I stopped shootng when early Airsporters were current so have a lot to catch up on now I have a rekindled interest.
Rod
Thanks for the PM Steve, appreciated and will ring
Hi Mate......I am not up on all the modern gear, but these might be what he is on about!
http://www.shootingandscuba.co.uk/ac...ce_Spares.html
Click on the weihrauch link to see piccys of piston seals.......I fitted one of these for a guy a while back, and thought to myself what a well designed bit of kit .......compared to the slices of dead cow I use in my old bangers!
Banned
Thanks Ed, I'll check it out.
Rod
Administrator
T R Robb used to sell a ptfe piston head for the Airsporter and Mercury, find him here http://www.trobb.f9.co.uk/
All the best Mick
Donor Fixer
Ah, later Airsporters have an alloy head in place of the earlier nylon unit.
The parachute seals are what you would find in most modern rifles, fitting one to an Airsporter would take some engineering of the lathe variety, I'm not aware of a drop in conversion unfortunately.
Rich
Wanted - Venom Mach 1/2 Trigger
Banned
Ah, well, I've got the lathe, all I need is the spec (having never seen one).
Rod
Donor Fixer
The seals pictured >>here<< are parachute seals, first step would be finding the internal diameter of the compression tube, then a seal that matches it before working out how to join the seal to the piston.
If anyone out there knows the internal diameter of a Mk6 Airsporter 'S' I'd be interested.
Rich
Wanted - Venom Mach 1/2 Trigger
Administrator
Hi Rod
Internal diameter of an Airsporter cylinder is 1.125"
As you have your own lathe why not try machining a new O ring head for your Airsporter?
The standard head loses a lot of compression as its front face is not the same shape as the end of the cylinder.
The buffer washer can be removed from behind the piston head so that the piston head can be moved backwards to sit on the piston so gaining a small increase in stroke.
All the best Mick
Banned
Hi, thanks for all the info so far, it's a great help. Any other little snippets more than welcome.
What I would like to do is replicate the best so far then improve on that, the theory being, that if I can get the piston / seal assembly perfect, I can then reduce spring length / tension thereby retaining performance but making a smoother rifle.
I think a chrono really should be the next purchase, firing into a piece of 3/4 ply isn't really good engineering practise, or very accurate
Thanks
Rod
Posting Permissions