15 replies to this topic

[2iko]

Okay, I just randomly came up with this and drew it out as best I could in paint:


Basically it has a reverse-spring powered pump attached directly to the tank so it compresses the spring, pushing air out the other end using the plunger, pushing the sealed (o-ring or some similar method) PVC down holding the copper breech cover, covering the breech.

Now that was quite a wasteful design as it used air I was supposed to have to shoot the dart out. Now it's just a breech design which uses a spring to open automatically once the trigger resets, then you close it with your first stroke on the pump or cocking mechanism. This would then stay closed while you pump more if needed, the only thing that will open it now is if you pull the catch mechanism for it. I'm going to rig it up to open that catch after the trigger comes back to the armed position.

The breech would look something like this:



Here's my tank designs:


Credit for the basic tank design would go to NerfCrazy: Homemade 2k Tank.

What do you all think? I can't wait to get parts for this... I'll make the tank first then see what I can do after that.
I'm thinking of an awesome trigger design but I'll have to draw it later.

Edited by 2iko, 08 August 2009 - 08:27 PM.

[TantumBull]

What is actuating the breech?

[louiec3]

I think this is how it works, but how will the breech cover return to the open position?
Also with my experience with my Semi-auto the less friction there is the easier it is to work with.

[rbtying]

If it works in the way that louiec3 described, then you will likely lose a lot of air to the actuation of the breach. Perhaps you should try reducing the long pathway?

[CrazyIvan VI]

Or you could just build it instead of posting a useless speculation thread.

Build it, and THEN post a topic on it.

[analogkid]

Or you could just build it instead of posting a useless speculation thread.

Build it, and THEN post a topic on it.

Nah, this is a WIP thread if you ask me. He just wants to double check that everything looks good before he goes ahead. This is definitely a doable project and he sounds as though he will go through with it. Way better than the standard "OMG 5PaRtaN LAZAH how i BULID it????CAN haz 5Inper 54otguN ROFL??!?"

To return the breech to the open position, why not use the pump? You have to pump it anyway, and a cleverly placed bar that goes from the breech to the pump would address this problem. It couldn't really be attached, but if there was somewhere on the breech that it could push on, then it could work. Let me make a picture.


The only downside here is that the pump would have to be fully extended when firing.

Edited by analogkid, 08 August 2009 - 06:43 PM.

[2iko]

Yeah, the problem would mostly be that I would not be able to pump more than once with the clip in, unless shotgun loading.

So for those wondering, the breech is actuated by the fact that air is being pumped in front of the 1/2" PVC in the breech, pushing it back, also pushing the brass nested inside back against the air tank (a seal will be made when I come up with one, probably going to pull the clip forward a tiny bit to add more smaller brass at the tank.) This would seal the breech.



Alright I cut the design down a bit, realized that whole extra pump mechanism wasn't really needed there if I threw a spring in behind the 1/2" PVC sliding piece. Hopefully it can save more air in the tank. I was also thinking of a locking mechanism for the breech system so it doesn't spring back open immediately after the shot is fired, resulting in a loss of air. I'd then have the trigger set up to release it when it resets the trigger forward.

I'm not worried about the air loss involved, it might take 1 extra pump just to fill that empty space to push the 1/2" PVC back but that would be the most it would take.

I'm assuming this design works on the same principle the Blastfire does to re-arm all the air tanks when you pump it. When you pump a Blastfire it pushes a plunger in the top airtank backwards, closing off all the air tanks, allowing it to be moved forwards to open each individual tank. This is simpler, only closing the breech instead.

Edited by 2iko, 08 August 2009 - 01:07 PM.

[analogkid]

Yeah, the problem would mostly be that I would not be able to pump more than once with the clip in, unless shotgun loading.

Thats why its not attached to the breech. after the first pump, the arm would still slide but wouldn't move the breech, it woukd stay in the open position

[louiec3]

Actually with your breech design you can't shotgun load because the breech just covers the dart it doesn't push it in the barrel.

Another thing with your design if the gun isn't pumped up fully the breech won't close, and it won't shoot. The pipe connected to the pump would be a better design because you can eliminate the extra air needed to push the breech cover closed.



I drew my pretty picture in paint to show a concept of what it could be like on an at3k.

If you did AssassinNF's one pump AT3K mod you could have a nice primary.

Yes I do know this is starting to become a Modification with a Homemade breech.

[2iko]

Wow, thanks for all the help guys, I see now that the pump attached to it would work, even if it was attached permanently. I was thinking the dart fit would be tight enough to pull the dart forwards again, but that is an assumption and shouldn't necessarily be true.

I thought I had something here but the benefit does not outweigh the negatives. The design still works, it's just that it's using extra air when it doesn't have to, I see that now.

[CaptainSlug]

Nah, this is a WIP thread if you ask me.

How exactly can something be a WORK IN PROGRES if no actual work has been done yet?

[2iko]

Nah, this is a WIP thread if you ask me.

How exactly can something be a WORK IN PROGRES if no actual work has been done yet?

Wouldn't that only depend on your definition of "work"? I did plenty of work on this. I'm still not done.

Okay, so we can ignore the air tank part of this and it's an interesting breech idea. Like I said before, if I could rig it up to close with the first pump and it stay closed by latch which lets go when the trigger resets. This would be a great breech for pump guns and it would still work well in springers.

The breech would look something like this:

Edited by 2iko, 08 August 2009 - 08:21 PM.

[ricochet rebels]

If I understand correctly (correct me if i`m wrong) a magstrike is similar to what your trying to achieve, If you notice in the picture below,the part circled in red moves forward then fires, being pressed back into the starting position by a spring highlighted in blue.

You could then take it and attach a copper or brass breech, this would give you your desired action would it not?

Edited by ricochet rebels, 08 August 2009 - 09:04 PM.

[2iko]

I'm not sure, what's pushing the part in red forward?

Also I don't have a Magstrike, never have.

I'm thinking my design would be quite cheap but I've got to go look for the parts on the other side of town.

[ricochet rebels]

I'm not sure, what's pushing the part in red forward?

Compressed air, if you`v not noticed it is a pump-up gun.

[CaptainSlug]

this would give you your desired action would it not?

No, the magstrike piston moves all of an inch.

BTW, this thread sucks. Do you have any idea how hard it is to get that many moving parts to seal properly? I have no faith in your ability to machine parts to the tolerances required for that. Also, those rubber washers at the front will simply get pushed out by the pressure.

Edited by CaptainSlug, 09 August 2009 - 09:17 AM.