10 replies to this topic

[PointBlank]

Today I bought a brand new night finder and began thinking of mods to do to it. I decided on building a bigger plunger tube out of PVC. I thought of using 3/4" PVC because it was comparable in size with the stock plunger tube. Because I don't even know were to begin on making my own plunger mechanism I plan on extending the length of the stock one and using the stock plunger head. The only problem is that the plunger head just barely doesn't fit into the PVC. What I need help on is a way to expand the inside diameter of the PVC evenly so that the plunger can move through snuggly.

Any input would be most appreciated.

Thanks,
-PointBlank

[Kabuki]

PointBlank, on Feb 6 2008, 01:24 PM, said:

Today I bought a brand new night finder and began thinking of mods to do to it. I decided on building a bigger plunger tube out of PVC. I thought of using 3/4" PVC because it was comparable in size with the stock plunger tube. Because I don't even know were to begin on making my own plunger mechanism I plan on extending the length of the stock one and using the stock plunger head. The only problem is that the plunger head just barely doesn't fit into the PVC. What I need help on is a way to expand the inside diameter of the PVC evenly so that the plunger can move through snuggly.

Any input would be most appreciated.

Thanks,
-PointBlank

What is the outside diameter of the plunger? (I haven't had one open yet). I know that you have already purchased this piece of pipe, but did you try taking the plunger to a store and trying it inside different types of pipe? As far as expanding the diameter, the only real option is to bore it out with a giant drill bit. But if you don't have exactly the right size, then buying a bit that large is going to be expensive. Certainly more costly than finding a different pipe.

[PointBlank]

Yes, I did go to the store to select which size to buy.

[CaptainSlug]

PointBlank, on Feb 6 2008, 04:24 PM, said:

What I need help on is a way to expand the inside diameter of the PVC evenly so that the plunger can move through snuggly.

You can't change the inner or outer diameter of a part cleanly without a lathe. You'll have better luck trying to modify the plunger head.

I don't have a NiteFinder to take apart and measure with a digital caliper right this second, so instead look at this thread:
http://nerfhaven.com...?showtopic=8084

KBarker did exactly what you're trying to do.

Edited by CaptainSlug, 06 February 2008 - 06:01 PM.

[Retiate]

Ditch the stock plunger head and make your own with a neoprene fender washer (I think that's what it's called...) Carbon uses them in his SNAP series, and they seem to work well. I'd get some dimensions down and check that method out. Boring out the inside of your plunger tube will leave the interior scratched up and will most likely have a poor seal with the o ring.

[xNFx 37]

You need thin wall 3/4 PVC

[CaptainSlug]

xNFx 37, on Feb 6 2008, 06:08 PM, said:

You need thin wall 3/4 PVC

That's not a terribly specific suggestion/ What Schedule or type of pipe are your recommending? If you don't know for sure what exactly it is you're recommending and that it is definitely going to work, then you probably shouldn't suggest it.
The OP didn't really way exactly what kind of pipe he tried to use anyways. All we know is the OD based on the 3/4 size designation.

[xNFx 37]

I saw a writeup on it using 3/4 thin wall. sch. 40.MOD

[PointBlank]

Since I am not fortunate enough to have a lathe I am making myself a makeshift lathe with a drill a dowel rod and sand paper it actually looks like its going to work. And thanks for all the suggestions thus far especially CaptainSlug.

[Kabuki]

PointBlank, on Feb 6 2008, 03:39 PM, said:

Since I am not fortunate enough to have a lathe I am making myself a makeshift lathe with a drill a dowel rod and sand paper it actually looks like its going to work. And thanks for all the suggestions thus far especially CaptainSlug.

make sure to use multiple passes, and probably do your final pass with at least 600 grit paper, 1000 grit if you can get it. Also, if it were me, I would probably wash the inside surface with carburetor cleaner when done. It will gloss the surface.

[PointBlank]

Ive tried everything so far and it's not accomplishing anything. I have decided to give up on the matter and try a diferent mod. Oh well.