Full auto blow back mod?

NoobWithAnAttitude · 10-24-2012, 06:24 AM

Ive been wondering lately if its possible to modify a blowback marker to work in full auto without electronics. Anybody know?

Jedihippie · 10-24-2012, 08:37 AM

yes... make the trigger sear not reset itself

cpt_crunch · 10-24-2012, 09:37 AM

Quote:

Originally Posted by Jedihippie

yes... make the trigger sear not reset itself

Most people call that the blender mod. technically full auto, not necessarily desirable.

there was a long discussion on this somewhere in this forum but i can't remember where. I don't remember anyone coming up with anything really practical way of modifying an existing gun.

as far as complete guns check into the automag RT

Jedihippie · 10-24-2012, 09:52 AM

Quote:

Originally Posted by cpt_crunch

Most people call that the blender mod. technically full auto, not necessarily desirable.

there was a long discussion on this somewhere in this forum but i can't remember where. I don't remember anyone coming up with anything really practical way of modifying an existing gun.

as far as complete guns check into the automag RT

or the tippmann rt mod

EvilAuthorityX · 10-24-2012, 12:29 PM

Tippmann factory F/A

Box · 10-24-2012, 02:47 PM

Might be possible to make something like the Lightning Link for an AR-15, but only for a paintball gun.

It's worth noting Lightning Links are not legal to make, or have in the US.

JT Pimp · 10-24-2012, 09:20 PM

*Warning, modification of this type is not recommended and may be dangerous, read at your own risk. I am not responsible for what you decide to do*
Most mechanical sears reset because the sear has a slot where the connector bar goes threw. So when pressure is on the sear the trigger will trip it, but once the hammer goes forward the sear slips past the trigger and needs to be reset. You can simply fix the sear to be engaged all the time with the trigger by shimming the sear to stay in a fixed position. Please note that most blow backs if let full auto in this fashion will cycle around 50cps or more and may cause damage to the marker and or yourself and others.

masterofTHUMBS · 10-25-2012, 12:52 AM

You really just need some sort of dampening system to slow down the bolt on its way back. You know when you have a tippmann running out of air and it is just farting? That would be full auto without any sort of dampening system. The tippmann factory f/a uses two dampeners along with multiple sears to catch the bolt and hold it momentarily before it is released again. I'm not too sure exactly how it works internally though. You basically want a system to allow for a ball to slide into the breech before the bolt comes forward but you also want to make sure that the bolt is not hindered in its blowback speed. If you slow down the hammer/bolt on its way back, the bolt will not compress the main spring enough because it has less kinetic energy. Response triggers are really the only easy way of doing full auto on a tippmann. Get it tuned right and all you have to do is hit that sweetspot for some bouncy trigger action.

You could possibly do full auto on an autococker. You would need a mech trigger frame that would be able to take a cam for an autotrigger. But you would also need a way to actuate the 3-way. Perhaps somehow link the timing rod to the 3-way so when the gun is uncocked, the ram goes to cock the gun and then when the gun is cocked back fully, the ram goes the opposite direction forward. The only issue is that the 3-way would have to allow for a lot of linear motion unless you used a lever similar to how the trigger works, meaning the timing rod would pull a longer distance but would push the 3-way in with a higher force. You would have to turn down the LPR to the lowest pressure possible to cock the gun to make sure the whole contraption doesn't go out of control.

So, in all, you would need a linkage on the timing rod, some sort of lever attached to the side of the gun, possibly another linkage for the 3-way, and some sort of trigger plate that would allow for 3-way actuation and a cam for an AT, and an AT pump rod cut down and tapped for the ram.

Tempted (Banned) · 10-25-2012, 01:08 AM

Quote:

Originally Posted by masterofTHUMBS

You really just need some sort of dampening system to slow down the bolt on its way back. You know when you have a tippmann running out of air and it is just farting? That would be full auto without any sort of dampening system. The tippmann factory f/a uses two dampeners along with multiple sears to catch the bolt and hold it momentarily before it is released again. I'm not too sure exactly how it works internally though. You basically want a system to allow for a ball to slide into the breech before the bolt comes forward but you also want to make sure that the bolt is not hindered in its blowback speed. If you slow down the hammer/bolt on its way back, the bolt will not compress the main spring enough because it has less kinetic energy. Response triggers are really the only easy way of doing full auto on a tippmann. Get it tuned right and all you have to do is hit that sweetspot for some bouncy trigger action.

You could possibly do full auto on an autococker. You would need a mech trigger frame that would be able to take a cam for an autotrigger. But you would also need a way to actuate the 3-way. Perhaps somehow link the timing rod to the 3-way so when the gun is uncocked, the ram goes to cock the gun and then when the gun is cocked back fully, the ram goes the opposite direction forward. The only issue is that the 3-way would have to allow for a lot of linear motion unless you used a lever similar to how the trigger works, meaning the timing rod would pull a longer distance but would push the 3-way in with a higher force.

So, in all, you would need a linkage on the timing rod, some sort of lever attached to the side of the gun, possibly another linkage for the 3-way, and some sort of trigger plate that would allow for 3-way actuation and a cam for an AT, and an AT pump rod cut down and tapped for the ram.

Infinitely adjustable, extremely cheap, I have about 300 of them.

Bigjoe11 · 10-25-2012, 07:56 PM

If you really want to do this, you could just attach some weight to the bolt system. more weight= longer cycle time. The biggest danger with this mod is that the fps will increase as you continue shooting. Since the sear doesn't catch it every time, the cycle will begin when the bolt/striker are all the way back. Also, it may bounce off the back, causing it to come forward faster as well. I wouldn't reccomend dampers bacause they may stop the gun from fully recocking.

mexi ca40k · 10-25-2012, 09:47 PM

I am not entirely sure about this, but would just removing the sear for `full auto` wear out the gun a lot faster? and by faster I mean needing new internals every 2-3 cases or so. Probably better off buying a rt automag.

masterofTHUMBS · 10-25-2012, 10:31 PM

Well, I wasn't really talking about hooking a damper up to the bolt but using it along with a second sear to catch the bolt when it fully compresses the main spring. When the bolt moves back, it catches a spring loaded sear (holds it slightly against the bolt, sear is above bolt) that moves along the gun. As the bolt begins to move forward, the damper (or just a spring, haven't thought it through all the way) would compress slightly while there would be a ramp above that would push down on the opposite side of the sear. After the sear moves past the ramp at a certain point, the sear rotates and it releases the bolt. When the bolt comes back, it catches the sear which again is being pushed against the bolt by the tiny amount of spring force above it. All together, it is a second sear that moves with the bolt (not much, just enough to slow it down at the start of it's travel) that is actuated by a ramp above the sear that pushes down on the front half while the back half is pushed down by either a second spring or by just having the main travel spring be slightly offset on the sear. The main travel spring is parallel to the bolt. The sear would have a pin through it that would ride along two slots that run parallel to the bolt. If you used a second spring to hold the back half of the sear down, you would need something to have the spring push against that would be static rather than having the spring push against the ramp. There could be a piece that would have fins that would ride on the rails. There would be a pin going through the rails (that would also go through the sear). There would also be somesort of piece to hold the spring down while the upper face of this piece would run against the top ramp. Attached is a pic of the piece.

Sear:

Bracket (?):

Assembly:

masterofTHUMBS · 10-25-2012, 10:41 PM

I would love some feedback, didn't have any good paper nearby or a straight edge but hopefully you get the point. Imagine the whole thing like grabbing the bolt as it comes back and releasing it as soon as you feel it come forward. It would eliminate the bolt from flying out of control (chopping anything in the breach). It could be adjusted by maybe a set screw that could push in second sear spring (compress the spring for slower ROF, loosen for higher ROF). The whole thing would need to be made out of extremely low friction metal or plastic (although that would wear down pretty quickly).

Tempted (Banned) · 10-26-2012, 02:50 AM

What you are getting as is adding what can only be described as a friction brake. You are adding something that will need servicing. If you are familiar with how the Cyclone feed system works, think of that except instead of attaching a a connecting rod to it, attach is an oil dampened one way shock to it.

Jaccen · 11-05-2012, 09:01 AM

Some have had success using VM's or other old mechs. Heavier parts so they cycle slower.

Or do something like this:

Quote:

Hellbore's Full-Auto Stingray

This is my full-auto Stingray. No electronics are used.
The rate of fire is adjustable, and if you turn the adjuster all the way down, you get semi-auto.

http://cleedo.com/fastingray.html

Bigjoe11 · 11-12-2012, 12:16 AM

Quote:

Originally Posted by masterofTHUMBS

I would love some feedback, didn't have any good paper nearby or a straight edge but hopefully you get the point. Imagine the whole thing like grabbing the bolt as it comes back and releasing it as soon as you feel it come forward. It would eliminate the bolt from flying out of control (chopping anything in the breach). It could be adjusted by maybe a set screw that could push in second sear spring (compress the spring for slower ROF, loosen for higher ROF). The whole thing would need to be made out of extremely low friction metal or plastic (although that would wear down pretty quickly).

I like the idea, like stated above it is more a brake than a sear. That seems like the best delay system idea I've seen so far.