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Walther LP3 valve & seals

Posted: Sat Jul 08, 2023 6:38 am
by JiriK
I went to a closing gunstore nearby and bought among other items two Walther airguns in "kit" format; LP3 and LGR.
Kit form meaning that they had been disassembled at some point and were waiting for new seals that never came.
Oddly LGR had extra piston and extra chamber end plug (the part where loading lever pivots)

Seals on both were obviously bad. Tips on places from where to order replacement seals are welcome.
I have 3D printer and TPU material. Have you tried if it works as valve seal material?
Also have a small lathe so I can make small parts.

Valve on LP3 confuses me. I searched for info on how to assemble the LP3 and found some forum posting that had all parts laid on table. Also note that there were at least two versions of valve.
Attached is photo of my LP3 valve body and parts I have for the valve assembly. Is there something missing?

Re: Walther LP3 valve & seals

Posted: Sat Jul 08, 2023 10:51 am
by Gwhite
Earl's Guns may have parts. They no longer service Walther air guns, but they have some parts. Here's a thread I started a while back looking for resources to get a Walther CP2 up & running again:

https://www.targettalk.org/viewtopic.ph ... 05#p322405

I had an LP3 MANY years ago (like 40...) that I bought through a friend in Switzerland. I had to get rid of it because no one in the USA at that time serviced them.

I just realized you are in Finland. I would hope the options are better in Europe than in the US. If you find a good source of repair info on Walthers, please post it. I still need to take apart & fix the trigger in the CP2.

I 3D print a lot of stuff, but I've never worked with TPU. I suspect making static seals that have to hold pressure over time won't work well due to the porous nature of most printed parts. If you pack them with silicone grease, they might work for seals that only experience brief spikes in pressure during firing.

Good Luck!

Re: Walther LP3 valve & seals

Posted: Sun Jul 09, 2023 6:59 am
by JiriK
I have a spool of TPU but I haven´t tested printing anything with it yet.
TPU doesn´t work with Bambu AMS so need to use ext spool holder. Not a big issue bit still.

My main issue with the valve was that I saw pictures of disassembled pistol and there was a part called "Spring guide"
I was unsure if my pistol was missing that part or if this version of valve didn´t come with it from factory.
Found dimensions of the guide so I turned one from brass yesterday. Valve still doesn´t hold pressure, but it is better. Trying to source proper seals.
Also missing the pin between striker and valve and small locking screw from barrel pivot screw.

Re: Walther LP3 valve & seals

Posted: Thu Jul 13, 2023 7:21 pm
by JiriK
I tested that 3D printed TPU material on Walther LGR SSP Air rifle valve seal.
First version worked for 3 discharges :)
Second didn´t work at all, think it was too thick and deformed when installed. I cut that in half to see how well shape fits valve body.
Third is ok, we´ll see how long it lasts.

I have a small lathe, trying to source suitable material to make seals.
Also have a resin 3D printer that I haven´t even tried yet. Resin materials -as far as I know- aren´t flexible but parts are more precise.
Could be used to make mould to pour PUR in...

Re: Walther LP3 valve & seals

Posted: Thu Jul 13, 2023 8:04 pm
by m1963