Hämmerli Master reseal

[jirushi]

Hi,
I recently bought this Hämmerli Master from eGun in Germany.



I am resealing it, with help from exploded diagrams of the valve that Mark D kindly sent to me a while ago.
And a tool that a Dutch friend made for me.



Probably only Mark knows, but perhaps interesting to ask this in a thread, for future reference:
is there a seal in this brass bit, that goes in the tube cap?





Also, when I try to put the retaining nut back into the valve, I cannot get the piercing pin to lign up into the hole. Any tips?
This is a photo of before I took it apart; how it should be.

[draitzer]

Louis, the little brass piece does need a seal - that's what keeps gas in until the opposing pressure drops. Looks like yours has crumbled away and somewhat disappeared.
As to installing the pierce pin, it's been a long time but I'm sure I did not remove that retaining nut at all, instead with it already in place assembling all the valve & pin components from the front end. It was still fiddly because the spring around the pin is long; I recall starting the front valve assembly thread, then using a tool to center the pin before tightening the nut. As the problem is really the length of the return spring (pin doesn't protrude to get centered) one time I shortened the spring a tad to help and saw no bad effect on performance although in theory the velocity should increase.

Don R.

[jirushi]

Thank you Don, that's great info.

Good to know that you know how to work on Hämmerli's.

I bought a spare valve from Mark a while ago, so I will install that one whilst I try to sort the Master valve LOL.

The spring around the pin is indeed very long and strong. Turning the retaining nut makes the pin go off center. Quite frustrating. Perhaps I should try to guide it with a dental pick.

Then there will be the question of how far to screw the retaining nut back in. In other words: some tinkering fun to come.

[draitzer]

From my diagram it looks like the rear nut is installed just to the end of its threads inside the body:
https://imgur.com/bMaLUAF

To center the pin, an elegant work-intensive solution could be to make up a driver tool with a spring-loaded centralizing probe protruding from its front (center-drill the probe to locate on the pierce needle) - but a jeweler screwdriver is what I used to nudge it.

Best of luck!
Don R.

[Lawrie Amatruda]

Thank you Don, that's great info.

Good to know that you know how to work on Hämmerli's.

I bought a spare valve from Mark a while ago, so I will install that one whilst I try to sort the Master valve LOL.

The spring around the pin is indeed very long and strong. Turning the retaining nut makes the pin go off center. Quite frustrating. Perhaps I should try to guide it with a dental pick.

Then there will be the question of how far to screw the retaining nut back in. In other words: some tinkering fun to come.

Louis,

I use a small diameter piece of metal tubing to jiggle the pin into the right position, if you don't have any tubing, you can use the back end an old metal ball pen refill, or you may need to cut the ball point end off, the nut needs to be tightened all the way until it stops.

Cheers, Lawrie.

[Mark D]

Thank you Don, that's great info.

Good to know that you know how to work on Hämmerli's.

I bought a spare valve from Mark a while ago, so I will install that one whilst I try to sort the Master valve LOL.

The spring around the pin is indeed very long and strong. Turning the retaining nut makes the pin go off center. Quite frustrating. Perhaps I should try to guide it with a dental pick.

Then there will be the question of how far to screw the retaining nut back in. In other words: some tinkering fun to come.

See how additive this dismantling has come Lawrie & Don have covered off the centring of the piercer pin. If you put that brass top hat valve in a drill - pin end held by the chuck and set the drill to spin clockwise ( I think) and then grip the top section with a cloth and slowly increase pressure the top will come off in your hand. That way you can clean out the old cheese seal and install a nice red one that will last until the next millennium. There is a lip on one side that face the seat of the valve.

[IMG]DSC01985 by Mark Davis, on Flickr[/IMG]

[Mark D]

Very fine thread in that top hat valve - new seals need to be tight fit on the shaft and a tool like the one in the photo allows you to push it over the shoulder of the stem using a bit of synthetic oil.

[IMG]DSC00731 by Mark Davis, on Flickr[/IMG]

[IMG]DSC00733 by Mark Davis, on Flickr[/IMG]

[jirushi]

Thank you very much Lawrie and Mark for your great advice.

I managed to align the piercing pin with the ballpen trick Lawrie, great stuff.

@Mark, that looks like Lawrie's excellent seals? A few Hämmerli parts will go to England in the next resealing batch
I put two o-rings in that brass part. Probably not a durable solution, but it seems to work for now.

The gun holds pressure and fires 7.87 gr JSB's at 380 ft/s.

2.5 ft/lbs, I think this is quite low?
Not sure what a 10 meter pistol should do.

[Mark D]

Hi Louis

Yes, Lawrie made the seals. 380 is about average for a 10m of this age, Walther LP2,3 are about the same. Try some 7.4grn match pellets.H&N and Crosman both make them.

A couple of tips to get the best fps:

1.Clean the barrel with a bronze cleaning brush, I doubt it's been cleaned for years, lead was purer in old pellets and with the oxidisation that can build up in front of the loading probe a good clean will help.
2. Take out the hammer and spring and give them a good clean, polish and lube.

[jirushi]

Hi Louis

Yes, Lawrie made the seals. 380 is about average for a 10m of this age, Walther LP2,3 are about the same. Try some 7.4grn match pellets.H&N and Crosman both make them.

A couple of tips to get the best fps:

1.Clean the barrel with a bronze cleaning brush, I doubt it's been cleaned for years, lead was purer in old pellets and with the oxidisation that can build up in front of the loading probe a good clean will help.
2. Take out the hammer and spring and give them a good clean, polish and lube.

Thank you for the tips Mark!

I left the hammer in place as I couldn't unscrew the cocking knobs, but I might have to try again.

The gun has held pressure, but I will send the brass part in the tube cap to Lawrie as my o-ring solution probably won't last very long.

Could someone advise me on how to set the blow off valve screw? It will empty the CO2 when it drops to a certain pressure.
I should test and try, but perhaps there is a guideline for the length of threads that protrudes from the cap

[Mark D]

The threads on the hammer cocking buttons are a standard thread. If you hold them in a vice suitably protected with leather and turn the body they will come undone.

The blow off end cap is set by how early or late you want it to release the balance of the gas.

1.If you turn the inner screw down then it will release the gas early.
2. If you turn it out so a lot of thread is seen it will release late.
3. Make sure to tighten the locking disc.
4. The valve should not be set until at least 3-4 shots have been made following the fitment of a new CO2 bulb.

[jirushi]

Thank you Mark, great advice once again.

I think I have got the Hämmerli bug. The quality is fabulous. It is dangerous to look for other models. Unfortunately, importing airguns from the UK is not possible anymore, but I have seen this beauty for sale in Germany. Who knows!

Do you know if the Junior, Match, Master and Single (amongst others) were made in Switzerland, or is it hard to tell (were they also made in Germany after the big fire in the Swiss factory?).

[Mark D]

Hi Louis

Have a read here:http://www.airgunbbs.com/showthread....ammerli-Single

No more CO2 pistols were made after the fire.

I have seen some 'Rapid' models that were marked up 'Made in West Germany' The Swiss built Rapids had a heavier frame, on the ones I have seen.

That Single is the 'kurz' model and 1st variant as it has a fixed front sight. All 'kurz' models use a 8grm Sparklet bulb like the 'Sparkler' and 'Rapid' models. The 'Lange' models have the same barrel length as a 'Master' and use a 12grm CO2 bulb or with an adapter they can use a 8grm bulb. Both Kurz and Lange models use the same valve as the Master. There are some early Single models that had a different style aluminium valve, but we are heading into nerd territory now

[jirushi]

@ Mark, sorry for my very late reply, I forgot. Thank you for the information. It is great that you know so much about Hämmerli.
I "won" the Single from Germany on Egun, at quite a good price. It has arrived in Amsterdam. Some enjoyable resealing is planned for tonight

[jirushi]

This Single has another valve type than my Master and Junior. Those have the ball type valve, which I think is much more durable than this seal type valve?

I shall have to ask Lawrie for his resealing services again

In the meantime, the spare valve that Mark kindly supplied to me a few months ago, is in the Single and works great. I think that is the ball type.

@Mark, do you know if the alu valve in the Single is an earlier version of the steel one?

And do you perhaps also know the size of the o-ring at the thin end of the valve assy?

Many thanks, Louis