Question about Epoxy

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ardo
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Thu Apr 04, 2013 2:14 pm

I'm trying to figure out if epoxy may be used to replicate a broken hop up unit from an airsoft blowback CO2 pistol, since there are absolutely no replacement parts to be found. The original part was made out of pot metal.

I was hoping to create a latex mold of the original, then use marine epoxy to make a replacement. The thing is, I'm not sure if epoxy would withstand repeated hits from the slide & outer barrel. This is different from compression forces working on a piston, which is often made of epoxy.

This forum had accumulated so much knowledge regarding DIY airsoft, hopefully someone has an answer. TIA.
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jrrdw
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Thu Apr 04, 2013 3:44 pm

Try it and find out. It's part of the fun...
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jackssmirkingrevenge
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Thu Apr 04, 2013 3:54 pm

Or maybe someone can machine it for you: http://www.spudfiles.com/forums/the-off ... 23135.html
hectmarr wrote:You have to make many weapons, because this field is long and short life
ardo
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Thu Apr 04, 2013 8:19 pm

jackssmirkingrevenge wrote:Or maybe someone can machine it for you: http://www.spudfiles.com/forums/the-off ... 23135.html
Thanks, JSR. The part is somewhat complex. I have a friend with a fully equipped shop, he had done some work for me in the past. He thinks that doing this part on a manual milling machine would take too much of his time, and I of course do not have the dimensional drawing for a CNC.

Jrrw, the 'try and find out' method doesn't work for me: building airsoft is not my hobby, I shoot airsoft to help me practice for IPSC competition with real steel. Trying to fabricate a part is more of a desperate measure.
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jackssmirkingrevenge
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Fri Apr 05, 2013 1:21 am

pics of the part you want to replicate?
hectmarr wrote:You have to make many weapons, because this field is long and short life
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jrrdw
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Fri Apr 05, 2013 7:00 am

jackssmirkingrevenge wrote:pics of the part you want to replicate?
Nme make/manufacture and model number would also help.
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Fri Apr 05, 2013 7:01 am

jackssmirkingrevenge wrote:pics of the part you want to replicate?
Don't have a real picture with me, but parts Z27 & Z28 on the attached diagram are the ones I'd like to replicate. Thanks!
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HopUpAssembly.jpg
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ardo
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Fri Apr 05, 2013 7:15 am

jrrdw wrote:
jackssmirkingrevenge wrote:pics of the part you want to replicate?
Nme make/manufacture and model number would also help.
The is a Cybergun/KWC Tanfoglio Limited Custom CO2 6mm.

I've had problems with it from the start, trying to get replacement parts got me nowhere. So far, I've had a cracked slide (my friend's shop managed to laser-weld it), ripped hop up rubber, broken rear sight, and now the left side of the hop up unit snapped in half. I'm trying to keep it running until I find a reputable dealer to buy the replacement gun. Here in Canada we only have two surplus stores that sell this model.

I shoot about 600 rounds of airsoft a week, and that may be too much for crappy pot metal it is made of.

I looked into buying a better-made gun - unfortunately, the Tanfoglio is the closest to what I shoot in IPSC Production class. It is also quite accurate, unlike some better made pistols like KWA KZ75 - which I also have.

Thanks for helping.
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jrrdw
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Fri Apr 05, 2013 3:52 pm

Is this what your shooting http://www.airsoftmegastore.com/4516-CB ... y-KWC.aspx and did you contact this particular store for replacement parts?

@ JSR:
parts Z27 & Z28
Valve housing loading tube? combo???

It would take several different end mills to do the finishing but it could be done. Whats that? No CNC Milling Maching??? Hows your dremal usage and engraving skills...
ardo
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Fri Apr 05, 2013 4:20 pm

jrrdw wrote:Is this what your shooting http://www.airsoftmegastore.com/4516-CB ... y-KWC.aspx and did you contact this particular store for replacement parts?

@ JSR:
parts Z27 & Z28
Valve housing loading tube? combo???

It would take several different end mills to do the finishing but it could be done. Whats that? No CNC Milling Maching??? Hows your dremal usage and engraving skills...
Close...
http://www.airsoftmegastore.com/4517-CB ... y-KWC.aspx
I contacted everyone I could find: stores, US distributors, Cybergun in France, KWC in Taiwan - you name it. I even wrote to Eric Grauffel, and got a response. No parts to be found anywhere.

The part is a hop up unit: it holds the inner barrel, hop up rubber, and an adjustment bracket. Since I already made my hop-up non-adjustable (I shoot at 5-7yards at scaled down targets, and don't need any hop-up), I'm thinking of modifying the unit by making it a solid 2-part shell that holds the barrel, hop-up rubber, and nothing else. This may simplify the design, and make it more solid.

LOL as a matter of fact, my buddy has CNC machines but I can't really ask him to spend his time to digitize the part (not sure if he even has that) into CAD then do a single part run. My dremel skills are just OK, certainly not enough to tackle this job.

I was researching some more on high impact resins, like Devcon plastic steel liquid or Flexane 94: the latter is actually a hard rubber compound, so I'm thinking it may work. It will wear more than pot metal but shouldn't break. And I can always make another one from the same mold.
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Sat Apr 06, 2013 7:01 am

the latter is actually a hard rubber compound, so I'm thinking it may work
I see that blowing to bits and you spending a good hour or two picking the bits out of you gun.

Solder is tough enough and easily workable. Have you thought about using that? You could super glue the broken parts together and make the mold out of plaster/spackling anything a long those lines.
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Mon Apr 08, 2013 8:15 am

Thanks, I never used solder for anything other than electronics, I will try to read up on this.
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cammyd32
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Mon Apr 08, 2013 12:55 pm

If your going down a casting route, it would probably be cheaper to get your hands on some pewter, pound for pound it comes out much cheaper than solder, and i've found it is by far better to cast with.
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Tue Apr 09, 2013 7:37 am

cammyd32 wrote:If your going down a casting route, it would probably be cheaper to get your hands on some pewter, pound for pound it comes out much cheaper than solder, and i've found it is by far better to cast with.
I don't think I'm ready to invest the time in learning how to cast. I also don't think my wife or my neighbors will appreciate this new hobby of mine. ;)
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jackssmirkingrevenge
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Tue Apr 09, 2013 11:55 am

have a look at these guys: http://www.smooth-on.com/

I recently visited a similar retailer and the results are really amazing, can't help you with specific products though.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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