46 replies to this topic

[ItalionStallion]

I finished my X-bow project last week. I've been very busy and it took me a while.

Anyway, heres what i did:

I replaced the original spring with a Defender DT3 spring. I re-inforced the cocking handle. I also put on a nested PETG pipe.I also had 1 bungee cord on it.

I hoped id get pretty decent ranges out of this gun but man was i disapointed. I got a maximum of 15ft. And when i ramrodded it i had to shoot atleast 3 times just to get it out of the barell.

So what i did was duct tape the end of the air chamber in effort to hold some of the air in. I also removed a double trigger spring i added for some reason..

I really dont know whats wrong, i took my time and i feel the job was VERY clean. And nothing popped out in my head as something i did wrong.

2 things i did not do that might help are that i could have added a few more rubber bands and lubbed up the plunger. But does it help THAT much?

Help would be nice..

[NinjZ]

Your first problem is you used PETG, not really the best barrel for an X-bow. How long is the barrel? Could you show us some pics of your exact modding?

If you darts are really tight in the PETG that might be part of the reason. If darts are too loose this can happen too, but ive never heard of that happening in PETG.
If this isnt the problem then its probably just a matter of air leaking out someplace other than your barrel.

[ItalionStallion]

I forgot to post my pics, here they are:

http://tman89544.tripod.com/id67.html

I dont really think PETG would be a problem for an X-bow.

My darts fit snug, but not too snug.

EDIT: My barell is about 9 inches.

Edited by ItalionStallion, 25 July 2004 - 08:46 PM.

[NinjZ]

Hmm, well I guess its not your barrel/darts. You can take the tape off the back end on your plunger tube because thats defenatly not it. Mabey try pushing out the rubber on the plunger a bit to get it to seal better. Also mabey re-glue and tape your barrel to the plunger tube again, could be leaking. What glue did you use?

When you shoot it, does the air like go out quikly and without much resistance?

[okto]

sounds like a combination of leak and too much friction. what did you seal the barrel onto the cylinder with?

[ItalionStallion]

I just sealed it with Hot glue. Im gonna add a layer of epoxy and hot glue tommor, i think that may be a problem.One more thing i was skeptical about, see the plunger at the end of the cocking barell. When i originally took teh gun apart i couldnt remember if it went in or out.

Im gonna add some silicone to the plunger so hopefully that loosens it up a bit.

Im going to do that probably tommorow so ill give evevryone an update then.


BTW when i shoot the gun it sounds very week. In a way it sounds muffled.

[NinjZ]

When you go to re-glue heres what I do to get a good seal. First put a nice bead of glue around the end of the pvc ( on the exact rim of it where it will contact the plunger tube ). Then put it on and hold it untill its totally dry. Then put a bead around the edge and let dry. Then put another nice helping all around that with a nice wrapping of duct and E-tape. I do it to all my guns, has never failed me.

[Vintage]

Don't use hotglue or epoxy to attach a barrel. Both break off too easily. Use Plumber's Goop.

I only use hotglue as a temporary setup for testing layouts before I make the connections permanent.

~Vintage

[Talio]

OK, first off, petg was a lowsy choice. You say it fits snug but not to snug. Thats bad. This gun is so powerful, but delivers a real quick burst of air.

Here's what I would do.

while hot glue is great for keeping the barrel on, a little pg around the stub that comes out of the plunger tube would be better. Tape is key here, it will keep everything in place.

The barrel situation, what I would do is first take a peice of 17/32 brass, cut it long enough to stick a dart in, and glue it directly over the plunger nub. Then take your coupler/pvc and put it over it. Then it would basically work like CX's nested M shot mod, just load the dart into the brass. Not to mention this seems like an easier way to load the gun.

Those are my suggestions, I think it's your barrel, I've never had luck with petg in spring guns.

Talio.

Edited by Talio, 26 July 2004 - 12:26 AM.

[ItalionStallion]

^^^^

That would work, but they dont sell brass around here. Only copper.

My stefans actually fit good downt he barell, i really dont think thats a problem.

[okto]

One more thing i was skeptical about, see the plunger at the end of the cocking barell. When i originally took teh gun apart i couldnt remember if it went in or out.

i think you put your plunger head on backwards. the gasket on a lot of spring guns is flared, so it forms a two-way valve. so it only works (well) one way. try flipping it around.
PETG is a bad choice. 9/16 brass, maybe 19/32. the three shots thing sounds like a too-tight barrel.
hotglue is a bad idea. i only use it to secure things in place in the gun, ie hoses, parts that are designed to be held tight by the two halves of the case but are loose, that bit.

[Talio]

Okto, what the fuck. The plunger head isn't backwards, don't touch it.

[okto]

gear down, turbo.
how, do you know the plunger head isnt on backwards? i mean, he said he wasnt sure which way it went...im not stealing your amazing guru advice. calm.

[leftnut]

gear down, turbo.
how, do you know the plunger head isnt on backwards?  i mean, he said he wasnt sure which way it went...im not stealing your amazing guru advice.  calm.

He looked at the pictures shit head. Don't give him bad advice if you waren't even sure if your right.

Edited by leftnut, 26 July 2004 - 10:27 AM.

[Groove]

Yeah, sounds like a classic sealant problem + dart snuginess (is that even a word? I like it.) to me. And as Talio already mentioned, PETG was a very poor choice for a Crossbow. I myself used to use PETG when I went to Armageddon, brass is just far superior. If you can't get brass, then get CPVC.

Solution: New barrel + Plumber's Goop + darts that actually fit SNUG in your barrel.

I just Gooped the internals of my Xbow. "When in doubt, goop that sonuvabish." Thats what I did. Ran goop over EVERYTHING with a seal. Helps out a lot because epoxy shatters fairly easily given the right amount of force. Try again, and try these things out.

[NinjZ]

Vintage, hotglue works really well when supported with a layer of ductape and a layer or two of E-tape.

[okto]

again, kids, it was put forward as a suggestion. if your tolerance for stupid moves is that low...*laughs* you guys must be a blast IRL.

Edited by okto, 26 July 2004 - 02:15 PM.

[Jangadance]

It's just that you gotta be careful with an item that, when in perfect condition, could instead earn you $100+ on eBay.

[ompa]

Maybe the plunger head is morphed a bit- it looks fine in the pictures, but it may be a different case otherwise. Try increasing the efficiency of the plunger head, either by using Ninjz's method of masking tape, or try using a DT3 plunger head instead of the normal x-bow head. It worked for me. Just make sure you band/bungee the x-bow if you try it with the DT3 head, it's kinda tight; but it will work.

~ompa

[Viper]

I've had that prob w/ my crossbow in the past. With arrows the air can be forced out too fast if you mod it too much. The seal might very well be folded incorrectly or there may have been a leak forced by the additional force involved.

[ItalionStallion]

I re-epoxied it this morning and im going to add some bands.

Like Janga said i wanted to be VERY careful with this gun because its worth a ton.

Ill post more pics tommorow after the Epoxy is done drying.

[ItalionStallion]

I just got the gun and put it back together. Heres what it looks like now:



The guns sounds ALOT better, no muffled sound. I think thats because i lined it with silicone. The ranges are slightly increased but are still only at about 30 ft. The darts just seem so lob out of there with almost no speed. When i remarodded it it still takes me a few shots.

Im thinking that i should just switch to a PVC barell instead. Would that be the right thing to do?

[ShortShit]

Well then it seems to me its the PETG, sorry to tell you buddy but I think that is really hindering it. Also, the bungees dont look like they are situated the best, I always thought you wanted them to have only forward pull, apposed to forward+up or forward+down pull.

EDIT: to answer your question: 1/2" PVC and MEGA 5/8" darts work fabulously in the Xbow. Always have.

Edited by ShortShit, 27 July 2004 - 01:23 PM.

[cxwq]

The problem has got to be your dart fit. What exactly do you mean by a nested PETG barrel? Just that you put it inside a piece of PVC?

You want a couple inches of fairly tight fit at the base, then a relatively loose sliding fit for the rest of the barrel. You should be able to easily blow the dart down the main barrel section, but have to twist it or ram it into the restriction at the base. If it's taking a few shots to get them out when you're ramrodding them, the PETG is probably too restrictive with your darts to serve as the main barrel section.

Megas suck ass for aerodynamics, you're better off ordering some brass and doing it right.

[Suave]

Yeah, I think it's the long PETG barrel.

Try megas, they're lovely.