bruno22rf Posted January 30, 2019 Report Share Posted January 30, 2019 So about 7 months back I bought an Original mod5 pistol from a dealer - good price but the gun was clearly below par power wise I have finally got round to stripping the thing only to find that the washer, that should be held on by an integral taper on the piston crown , has been bodged by machining the taper off and drilling a hole (off centre I might add) then Riveting a rubber washer on before chopping it roughly into shape and refitting it. Pistons are no longer available and expensive if they were (£50) so I'm looking for suggestions as to a viable, and cost effective, way of replacing the washer - even getting a 24mm washer seems difficult and the original item (still available) has a large hole in the centre so drilling/tapping and using a countersunk bolt is not an option. Quote Link to comment Share on other sites More sharing options...
moor man Posted January 30, 2019 Report Share Posted January 30, 2019 Pic required really, the answer is out there. Quote Link to comment Share on other sites More sharing options...
Mice! Posted January 30, 2019 Report Share Posted January 30, 2019 can't see why a 24mm washer is a problem? Put up a sketch of what you need, and what material. Quote Link to comment Share on other sites More sharing options...
bruno22rf Posted January 30, 2019 Author Report Share Posted January 30, 2019 Easiest way to explain is - if you look at chambers gun spares and find the Diana/original mod 5 piston washer you can enlarge it and see the size of the hole in the middle - the previous owner of my pistol has left me with an approx. 3mm hole drilled off centre on the piston "face" . Quote Link to comment Share on other sites More sharing options...
Mice! Posted January 30, 2019 Report Share Posted January 30, 2019 stick a link up, if you can get some sizes I'm sure i can knock something up, hopefully Quote Link to comment Share on other sites More sharing options...
bruno22rf Posted January 30, 2019 Author Report Share Posted January 30, 2019 Will get my daughter to put a picture up of the piston tomorrow - don't have a washer yet as not worked out how I'm going to attach the thing when I get it. Can get a new piston with seal from Italy for just under £50 but with a service kit on top it's going to make the project uneconomical. If I was still a precision Engineer (20 years) this would be a doddle. Quote Link to comment Share on other sites More sharing options...
Kev1gun Posted January 31, 2019 Report Share Posted January 31, 2019 Tell me what you need making and what material, I might be able to help, Lathe and mill here ready to go. kev1gun Quote Link to comment Share on other sites More sharing options...
bruno22rf Posted January 31, 2019 Author Report Share Posted January 31, 2019 Kev1gun - you are a life (and pistol!) saver Sir - if I order the washer would it be possible to post the 2 parts to you along with a sketch of what I think should work? Quote Link to comment Share on other sites More sharing options...
Walker570 Posted January 31, 2019 Report Share Posted January 31, 2019 Without a picture it is difficult to make a comment but I would not have thought rebuilding the end of the piston is a big deal, even using good olde J&B to put a new holder in place. Quote Link to comment Share on other sites More sharing options...
bruno22rf Posted February 6, 2019 Author Report Share Posted February 6, 2019 Bit bored today so I rang a few Airgun service/repair specialists regarding this matter - very little interest from the first 3 but then Halleluiah - Dean from John Knibbs picked up the phone and, at last, not only interest but sensible, intelligent suggestions from the guy who is obviously an experienced Engineer. It's so nice to be able to discuss thread diameters, pitch and head sizes with someone that clearly knows their stuff. Sending the piston to him in the next few days so we may finally be getting somewhere . Quote Link to comment Share on other sites More sharing options...
Mice! Posted February 6, 2019 Report Share Posted February 6, 2019 5 hours ago, bruno22rf said: It's so nice to be able to discuss thread diameters, pitch and head sizes with someone that clearly knows their stuff. Think you need to get out more🤣🤣 I'll send you some pics out of my Zeus book if you like? Quote Link to comment Share on other sites More sharing options...
bruno22rf Posted February 6, 2019 Author Report Share Posted February 6, 2019 Ah - the old Zeus book, my one time bible. Used to know the tangents etc of most angles off by heart in my yonder programming days. Never thought I would miss Engineering but producing precision components for the Aircraft Industry (and the Airship that was going to fly regular trips to America) and F1 cars was always interesting . We used to make parts for detecting vibration on Railway lines and I would "invent" a pitch so nobody could produce spares for them! Quote Link to comment Share on other sites More sharing options...
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