6 replies to this topic

[Split]

Hey. I find it interesting that as I write this, someone else is writing a removable something or other for the at3k. Cool with me, I still beat Bob to the punch.

Anyway, Objectives:
Drop Clip
Add a working pressure gauge

Not too much, but on such a complex gun, I appreciated the challenge in the drop clip.
There are 30 odd pictures, so that means 2-3 posts worth. Just wait until they're up if you could.

First, here's the stock gun, opened up. Lots of screws, nothing too difficult though.


Unscrew this small thing and we begin.


Here's the basic breakdown:

The pump hits that white arm, which pivots a white piece, turning a one way mechanism that holds the turret, i.e. advancing to the next barrel. It's locked in place until you fire and the white arm is reset.
The lever piece on top has a little nub in there that stops the one way mechanism turning in the other direction (the one that it normally can) when it's engaged, i.e. locking the turret in place once the barrel is selected.
To the right is a spring loaded piece that seals the tank to the turret.

Here's the one way mechanism. The metal rod is what connects it to the white arm. The white ring there can be and should be removed for this mod.


Internals removed, arm in locked position.


Here are those removed internals, and the little nub that the spring loaded lever I talked about before actuates. I left it out.


This little spring loaded arm is on the other side of the tank, and is what makes that nice clicking noise when you spin the turret. It stops the turret from going in the way that the one way mechanism does, just as a redundancy effect so you don't damage the rotation. Nifty.


Go ahead and take all of that junk off of your turret. Grab your pliers. This is the best way to remove the stock barrels.

Jam them down into the stock barrels, and use leverage to pop them off. The air restrictors just fall out, real nice like.

Remove these four screws:


Lightly pry off the blue piece. One of my 3k blues was only glued in one spot, but the other was in like three. You can try boiling it off, but a bit of leverage worked for me just fine.



These keyring things (as seen in a drop clip rf20, if I remember correctly) are what we're going to be using primarily.


Jumping right into it, take the base piece (the one with the sliding parts and retaining balls) and drill a 1/8" hole into it. Tap it for whatever screws you're using. I used a #6-32 (from the +bow getup).

Route your white cap onto the screw and into the base as such.

Take a sanding wheel on your Dremel, and sand off the bottom lip.


Here, you can double up your springs for this. The added one is just an air restrictor spring from the same gun.

Important: The white piece that is on there had the inside bored out to 3/8" diameter.
I also added 3 counter sunk metal washers to this, and you should too, for spacing, and making the springs push harder.

Edited by Splitlip, 13 January 2009 - 04:00 PM.

[Split]

You need to cut back this white ring to make space for our base. You can see the before back in the first post when looking at the gun internals.


Go ahead and minimize the shell like so:

Don't take off the second lip on the inside, just the first. That's the one that keeps the turret from sliding in and out.

At this point, I plugged the pump, and set this up so that it would be dry by the time I was done:

It's that little sealing piece. I sanded out a little bit from the front, added some goop, and a perfectly sized, beefy o-ring.

Next, we go back to that base piece.
Dremel out a groove right where I did.


Run a bit of craft wire around, tied to itself on one end, and running all the way back to the handle, through the washer sinks and white cap.


I'm going to jump to the Pressure gauge for a second.
Here's the parts list for it (and this works on virtually any air gun):
T connector: 5116K504
Brass Coupler: 4429K119
Mini Pressure Gauge: 38105K31

You'll need one of each. Drill a 3/8" hole in the shell and assemble the three parts together with teflon tape/paste on the male fittings as tightly as you can. Cut the tubing in the 3k with a pair of dikes. You may need to remove some amount of tubing as you install this. Connect the ends of the tubing to the T, and you're done. Avoid pressurizing it for about 24 hours if you used the paste, to allow it to set.

Finished:



Back to the drop clip, sand out a small part for your base piece's wire:

Go ahead and attach a keyring to the end of the wire ran through there.

At this point, we get to work on the actual turrets again. Mark where the end cap needs to end on the turret. Now cut back the end up to the part with two nubs, and drill it out to 3/8" diameter.
Hold the end cap up to the side of the shaft of the turret, to where you marked it, and mark where the hole is. Drill an 1/8" hole directly through where you marked through the entire shaft.

Run an 1/8" nail through.

Mark it, remove it, dremel it down, and put it back:


One minor thing:
Put on a stronger spring to the sealing piece that we modified, glue the piece to the spring, and the spring to the tank.


So now you should be all done. You may need some minor tweaking, but assembly should be well understood by now. The base piece goes between the white arm and the ring we cut off, just like before, linked to the pivoting part.


To put the turret in, just push the turret in and spin until the nubs on the turret line up with the nubs in the one way mech. This works because the end cap on the base piece rests against the post that the white arm is on, and when you push it in, the sliding part moves, retracting the locking balls and sliding the end cap on. Very nice.

To take out the turret, pull the keyring attached to the sliding part of the base, the balls retract, and the turret can come off.

I haven't barreled this, and I apparently won't have to. Some things happened:

So here's the pressure at 4 pumps - 55 psi!, but a tiny leak beat me to the picture.


The link to the pump from the handle doesn't last very long under those kinds of forces.


And finally, the turrets got eaten up.


Was a fun, successful exercise, that just didn't last. Shame. Makes a scary sound at 55 psi though. I'll single it and see what ranges I can get out of it.

Thanks for not posting; feel free to now. Enjoy.

Edited by Splitlip, 13 January 2009 - 04:12 PM.

[imaseoulman]

Every SM3K I've tried to take up to higher pressures (like, above 40-45psi) develops a leak that gets worse over time. Nice job though.

[Split]

I've been screwing around with it more. Second clip seems to be holding up alright. I would recomend that anyone who does this installs some sort of spacer to hold the one way mech in place. Mine keeps shifting. Other then that, it has been working well.

Thanks for the comment seoulman; oddly enough it doesn't leak when I only take it to 45 psi. It seems to be leaking from the connection of tubing to the pump, so I'll get that fixed up.

[nerfer34]

Very interesting, good work. ALthough it seemed like you did too much work the for the results that you got, but hey that happens sometimes.

Also, I think yyou have sold me on that pressure gauge. I do have a question involvong the gauge, Do you need those 2 other parts for it to function properly? Or could you just just feed the tubing in/out of the gauge?

[Ner Commando]

This is a pretty cool mod. I guess I need to get me one of these things.

[Split]

It looks like a lot, but it was really about 3 hours total. I work pretty quickly, I just detailed a lot of what I did really thouroghly.

And yeah, you need the T to take the tubing connection to a NPT threaded connection, then the brass coupler to connect the two. Unless you were drilling straight into a tank or something, you need them.