Hatsan Air fill probe mod?

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Johnnys_Worx

Johnnys_Worx

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Dec 3, 2024
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Belchertown, Ma, USA
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So im looking to get some thoughts on the idea of adding a foster fitting to my Hatsan Neutron Star. Im on my 3rd probe because they get chaffed and worn after filling alot. and the port on the probe gets crap stuck in it easily. not to mention the constant oring replacements.
The idea was to tap the port hole on both sides. Add a plug on the left side and add a foster fitting to the left side. It would make it more of a standard way to fill and would eliminate leaks and the need for a probe.
thoughts?
 
Gerry52 said:
Instead of altering air reservoir itself, why not leave probe with male foster on end inserted in reservoir? Might be safer. Ymmv. I'm just not a fan of altering structural integrity of air reservoirs.
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I thought about that too, but the probe will fall out...the only thing that holds it in is 2 orings...
 
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Johnnys_Worx said:
I thought about that too, but the probe will fall out...the only thing that holds it in is 2 orings...
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If it's "falling out" something ain't right. I've never had or seen one able to just fall out in any probe gun that I've used. What gun? Have you tried different durometer of o-rings?
 
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Put a little bevel on the point of entry for the probe to stop it from chewing up the orings. You can use an oversize drill bit or a Dremel. Just go slow and easy.
Here is another neat little tip. If you chose to leave the probe in the gun, any tire valve stem cap will fit right on the foster end of the probe with just a little snap. This will keep dirt out of the probe.
I really dislike probes and leave them in guns whenever I can. Most probes go into the guns from a right or left 90 degrees to the bore. You can use a bread twist tie to put one wrap around the probe and one wrap around the tube to secure them. Just be sure it don't obstruct the foster connection.
 
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Johnnys_Worx said:
I thought about that too, but the probe will fall out...the only thing that holds it in is 2 orings...
Click to expand...
I leave the probes in all of my guns.....I solved the problem of losing the probe(s) by cutting a "rubber band" (about a 1 1/4" or so wide section) out of a bicycle inner tube. I put it over the air tube, and then over the probe. Keeps stuff out and the probe is always there when fill time comes.
 
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Avator said:
Put a little bevel on the point of entry for the probe to stop it from chewing up the orings. You can use an oversize drill bit or a Dremel. Just go slow and easy.
Here is another neat little tip. If you chose to leave the probe in the gun, any tire valve stem cap will fit right on the foster end of the probe with just a little snap. This will keep dirt out of the probe.
I really dislike probes and leave them in guns whenever I can. Most probes go into the guns from a right or left 90 degrees to the bore. You can use a bread twist tie to put one wrap around the probe and one wrap around the tube to secure them. Just be sure it don't obstruct the foster connection.
Click to expand...
It already has a bevel on the hole, but i think its because the hole has to be so tight that the orings roll in their perspective groove and it peels them? idk. but its super annoying. i have to replace them every 4-5 fills.
EdCaffreyMS said:
I leave the probes in all of my guns.....I solved the problem of losing the probe(s) by cutting a "rubber band" (about a 1 1/4" or so wide section) out of a bicycle inner tube. I put it over the air tube, and then over the probe. Keeps stuff out and the probe is always there when fill time comes.
Click to expand...
thats not a bad idea actually... I may try that...
 
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Johnnys_Worx said:
So im looking to get some thoughts on the idea of adding a foster fitting to my Hatsan Neutron Star. Im on my 3rd probe because they get chaffed and worn after filling alot. and the port on the probe gets crap stuck in it easily. not to mention the constant oring replacements.
The idea was to tap the port hole on both sides. Add a plug on the left side and add a foster fitting to the left side. It would make it more of a standard way to fill and would eliminate leaks and the need for a probe.
thoughts?
Click to expand...
I wish manufacturers would stop using fill probe, they are a pain. Let us know how your modification goes. I would like to get rid of all my probes.
 
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Update:
So i sent my regulator out to a local machinist. He drilled and tapped the two fill ports to fit two different foster fittings. On one side is the standard foster fitting. On the other is a 1/8 BSPP check valve fitting. Why? Well it was a mistake actually! I didn't realize I gave him the wrong fitting (check valve). But in Hindsight, not an issue as it will work as a backup check valve for the regulator itself. I may be removing the standard foster fitting and plugging the hole. Ill be fully reassembling it all soon and testing it. Just no time. I work 3 Jobs. Makes it hard to have time to just chill and play with my guns.
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Update:
So I pressure tested it. Yea lets just say I had to change my pants when the pressure got to 100 Bar... The check valve foster fitting threads did not hold at all. Im assuming either bad thread job or the aluminum was somehow softened when it was threaded, because the fitting exploded out of the hole!! scared the crap outa me and my dogs and my wife. She thought I accidentally fired my 9mm in my office. WAS NOT on my radar of things to think about when filling the tank. But man was it a bang....Then to make matters worse, it ripped the thread up a bit and it wasnt going to be salvageable. So on to the next update.
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Update:

After the last update, I had a buddy tig weld the hole shut. I Thought "that should do it". AGAIN i was wrong. I dont know what kind of metal this is, it must be some sort of vibrainium from wakanda or something cuz it didn't want to weld up for nothin. But I tried anyway. Well, It to exploded. The weld came out like a bullet. Blew a hole in my couch 8ft behind me when it got to 150bar. That again scared the pants off me. Wasnt ready for it. I figured id get at to at least 200 bar before i had to worry...BUT NO!!!
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Update:

Well I hope this works this time! I called Hatsan, needed new O-rings from assembly and tearing it down to much for testing. It began to leak. They asked if I modified it and i told them what i was going. They seemed interested to help, so they sent me a full O-ring kit and nylon seal for the gauge. I asked for a new regulator block in case this fails, HOWEVER, they tell me they dont have it in production anymore!! Like SERIOUSLY!!!! So if this fails, Ill have to re-machine a new one. A local shop said $250-$300 to make it. Like, CMON Hatsan! How you gonna be like that.?. But, moving on....
I cleaned up the block, removed the junk that the weld created, then 3d printed a bolt that matched the threads on the good side, screwed it in till it just passed the air hole in the block, then stuffed JB weld in the hole on the bad side, smoothed it all out and sanded clean, removed the 3d part, then painted it satin black. So far, It takes 100Bar and holds. No leaks. No explosions, lol...
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