Even better looking than a HW35
And if you decide to keep it an O ring head then use a Meteor O ring, instead of the Airsporter one.
Far too many rifles to list now, all mainly British but the odd pesky foreigner has snuck in
Registered User
Originally Posted by look no hands
Yes, I had heard that is the better fit. I ordered parts from Chambers. Do you know if the O ring that they supply is usually too tight? I have a Mk.1 Meteor, and am fairly sure that there is an O ring in my spares box.
Steve.
Even better looking than a HW35
I think they may be, the Airsporter ones are OK but they just take longer to bed in , the Meteor O ring is like a bedded in Airsporter one but from the start.
Far too many rifles to list now, all mainly British but the odd pesky foreigner has snuck in
Registered User
With a bit of luck, and no postal strikes, i should receive the parts this week, so we shall see. With the price of pellets now, the less bedding-in, the better.
Steve.
Registered User
The tap on the mk4 is tapered the same as mk1,2,3 but not self indexing and mk5 and on have the parallel two piece tap.
I warm the tap body and coat it in candle wax and then work it in to form a seal.
I was WRONG the tap ts PARALLEL with a outside diameter of half an inch.
Last edited by crowbar; 16-11-2022 at 01:25 AM. Reason: waffle
Administrator
You may want to double check on that as I've just pulled the tap out of a MK4 and it's perfectly parallel at 1/2" OD.
All the best Mick
Go ahead,,, String that bow
Steve I had two taps machined .177 and .22 with a groove at either end then tried two sizes of o rings. one did not fit the other fitted but I thought I would try a goldilocks size. After fitting the seals on my 177 the other three went AWOL, but my .177 the bane of my life ended up worse and I have clearly done something else wrong. The .22 responded to treatment well and just tested now at 586,575,586 fps with super domes = 10.8 ish fpe.I have read of the leaky loading taps, but mine seems fine at the moment. No doubt that means it will leak in the future.
Did you get grooves machined, or is it a work in progress? I would be interested in the test results.
Steve.
In spite of the o rings if I cock it open the tap and release the cocking lever air still comes hissing out of the top of the loading port. WIP.
When I find or buy more of the o rings I shall do an update.
Registered User
O rings will not take care of all leakage around the tap, so the only proper solution it to make up an ovesized tap.
Too many airguns!
Go ahead,,, String that bow
I've been wondering about that and read of people electroplating the tap I'm unsure by how much and of which metal given that it might have to be sized to fit. You are right I may have cured leakage from the ends but it still escapes from the top.
Last edited by Dornfelderliebe; 16-11-2022 at 02:51 PM.
Registered User
My order from Chambers arrived today. Their supadoopa tuning kit, https://twchambers.co.uk/airgun-spar...4-to-mk7-and-s, an alloy piston head, and a spare piston O ring (just in case).
The buffer washer fitted in mine was white plastic. Hard as a rock, with zero buffering ability whatsoever. It was not even a tight fit between the head and piston. I was surprised just how much I had to compress the new one to get the pin holes lined up. But I did manage it, using a small sash cramp, two half inch drive sockets, and two repair washers. Needs must.
The new piston O rings were too big, IMO. A very , very, tight fit in the cylinder. I fitted a slightly smaller one,(probably for a Meteor), that seems OK. The piston will not drop under its own weight, but needs a fairly light push. The loading tap seems to hold air OK - for now.
The spring that came with the kit is sized as per Cobham, and is 0.5" longer than the one that was fitted. It has a Delrin guide, and a steel Top Hat with a Delrin washer. Maybe the steel TH is to add a wee bit of weight when fitting the alloy piston head? I will see how it performs, and maybe make a delrin TH to see if there is any noticeable difference.
I may also try a piston liner. The spring is quite a good fit in the piston, but I have some 0.2mm PTFE sheet on the boat from China. A liner from 0.5mm PTFE was too tight.
I am keen to get this back up and running again. Then I can continue throwing more money at it.
Steve.
Registered User
I have just pulled the tap out my MK4 and you are quite right I even put the micrometer across it and it measures up at
.498" and I'm sat kooking at it thinking "wot a nob" it's old age and that MK2 tap I was playing with a while back.
Thankyou for pointing out my mistake and I will remember (Ithink) it's PARALLEL!!
Cheers Crowbar
Administrator
No need to apologise, we all make mistakes --- as long as the correct information is eventually stored on here we're good to go.
All the best Mick
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