Help reverse engineer this select fire Hi-Capa

spazzytroy · May 20th, 2009, 17:21

While I wait for the weekend to roll around, I figured I would ask for help on another project ASR couldn't help with.

Someone has figured out how to rig a hicapa 5.1 with a select fire switch. Unfortunately I havent been able to get in contact with the author of the video, but I would really like to replicate this. I'm not sure how to embed flash on this forum, so here is the link instead.
YouTube - Tokyo Marui(Ã©Â¦Â¬Ã§â€°Å’) Full Auto/Semi Hi Capa

If I had to take a guess, I would say that the leaf springs in the back of the gun are getting manipulated with that switch, based solely on the position of the switch. However, I haven't been able to replicate this mod. The closest I've gotten is full auto by pushing the far right leaf spring up under the sear. This disables the trigger, and empties the mag, in full auto, as soon as the slide closes... useless. I also already know how to shortstroke the gun to get rid of the hammer problem, so it's just a matter of figuring out the trigger stuff.

Again I hope some of you guys have some ideas on how this could be accomplished. I'm also curious how the select fire on the Prokillers or M93Rs work, as maybe there could be some similarity.

Thanks again for your help.

EDIT: ooh! it auto embeds... spiffy

HeadlessChicken · May 20th, 2009, 17:30

Illusion would probably be best to ask, I was also in contact with safx about my Prokiller as I've heard he knows WA pistols.

BloodSport · May 20th, 2009, 17:35

Didn't TM make a Full Auto Hicappa?

Crunchmeister · May 20th, 2009, 17:44

Quote:

Originally Posted by BloodSport

Didn't TM make a Full Auto Hicappa?

They do - the Hi Capa Extreme. But it's not select fire. It's auto only.

ILLusion · May 20th, 2009, 17:51

I have a feeling the select fire switch is actually holding the disconnect lever, rather than affecting the leaf spring.

Styrak · May 20th, 2009, 17:55

Quote:

Originally Posted by ILLusion

I have a feeling the select fire switch is actually holding the disconnect lever, rather than affecting the leaf spring.

Methinks this as well.

spazzytroy · May 20th, 2009, 18:14

You mean the same disconnect lever I've been fooling with for the past week? I guess like you said earlier it would use the slide cycling as a timing mechanism for unlocking the valve knocker, as well as moves the hammer back.

But if this is the solution, why did people doing the Xtreme conversion have to mod the trigger disconnect as well? (the4thpower3 milled the whole right side of the bbu off, kinda kills the semi auto function)

Styrak · May 20th, 2009, 18:34

Because that ISN'T the solution if you want both. It's the solution if you want one or the other.

incrediboy729 · May 20th, 2009, 19:17

I know you can make a WE 1911 full auto by bending the leaf spring's middle "twig" back, but even that is not very reliable; as the one in the video seems very reliable. But i didn't experiment with it much so maybe you can make it reliable by the leaf twig method. I would be concerned whether or not that it is actually full auto or just "slamfiring" with everything sliding around. I would be scared that it is NOT real auto and just damaging parts.

MadMax · May 21st, 2009, 02:13

I'm inclined to think that the selector is attached to a slip of metal which lays on top of the trigger bar and under the sear. When the switch is pushed up, the slip of metal slides up so it lays between the sear and the trigger bar so the sear gets pulled back even though the disconnector on the right side drops out and disconnects the bar from the sear.

Sliding the switch down pulls out the metal leaf and the sear-trigger bar connection becomes dependent on the disconnector being in place which puts the gun back into semi mode.

I'm thinking that this is a selectable SINGLE sear arrangement because of the significant amount of vapor expelled in full auto mode. This makes me think that the hammer is following the slide forward bashing the mag valve open which makes for an inefficient power stroke because the mag valve opens before the nozzle returns to battery.

Proper full auto is usually done with two sears. One is the usual semi auto sear which has a selectable mode usually done by varying the total trigger pull available (a movable stop which allows or prevents additional movement). The other sear I call the full auto sear because it's only function is to hold the hammer back until the slide returns to battery. With the semi sear held back, despite what the disconnector does (f/a mode usually allows enough movement to hold the semi sear back even with the disconnector pulled), the only sear which retains the hammer is the f/a sear which releases the hammer when the slide makes the last 2.5mm of travel back to battery.

This arrangement allows the nozzle to be properly breeched before gas is released.

MadMax · May 21st, 2009, 02:21

Quote:

Originally Posted by ILLusion

I have a feeling the select fire switch is actually holding the disconnect lever, rather than affecting the leaf spring.

You can't block the disconnect lever. You have to allow it to drop down or it'll bind in the blowback block. I suspect that the mechanism provides a selectable "substitute" for the disconnect lever and puts itself between the trigger bar and the sear.

Bissa · May 21st, 2009, 02:56

I dont know that much, but is it possible that the person used the TM Hi Capa Extreme and modded it to work in semi auto. It may be easier since that means that full auto problem has been solved.

ILLusion · May 21st, 2009, 15:04

Quote:

Originally Posted by MadMax

You can't block the disconnect lever. You have to allow it to drop down or it'll bind in the blowback block. I suspect that the mechanism provides a selectable "substitute" for the disconnect lever and puts itself between the trigger bar and the sear.

As we discussed last night, I was referring to what you call the "knocker disconnector."

Difference of terminology. :P

You are correct, though. The sear disconnector can't be blocked.

spazzytroy · May 21st, 2009, 15:06

Quote:

Originally Posted by bissa

I dont know that much, but is it possible that the person used the TM Hi Capa Extreme and modded it to work in semi auto. It may be easier since that means that full auto problem has been solved.

I think it would be harder to do the other way. The Xtreme blowback unit has the trigger disconnect completely removed, so I'm unsure what mechanism you could use to disconnect the trigger.

@MadMax: Do you know if the actual Xtreme employs a 2 sear system? While I was doing research for this project I found some good video slow motion of the Xtreme firing. It looks like the nozzle is home before the hammer falls. I do however agree that the gas flow in that video is excessive.

Xtreme Slow-Mo (starts at 1:18ish)
YouTube - Ã¦ÂÂ±Ã¤ÂºÂ¬Ã£Æ’Å¾Ã£Æ’Â«Ã£â€šÂ¤Ã£â‚¬â‚¬Hi-CAPA XTREME.45Ã¯Â¼Ë†Ã£Æ’â€¢Ã£Æ’Â«Ã£â€šÂªÃ£Æ’Â¼Ã£Æ’Ë†Ã£â €šÂªÃ£Æ’Â³Ã£Æ’ÂªÃ£Æ’Â¼Ã¯Â¼â€°

the4thpower3's conversion
YouTube - FulloAuto

Since the4thpower3's conversion is using the same trigger as the orginal hicapa (and theres no major cloud), is it safe to assume that the select fire mod is causing the hammer to fall early? Or is the excess gas a function of whatever temperature or type of gas they were using to shoot the video?

spazzytroy · May 21st, 2009, 19:42

@MadMax: Finally found a pic that I could use. You're talking about inserting a slip where I drew the red line? I could see that working if the slip is made out of something bendable like spring steel. Fixed to the switch and just bending naturally as the trigger bar pushes it.

With the mechanism engaged, the trigger bar would push the slip, the disconnector, and the sear all at once. The gun would cycle, the disconnector would drop low (as in the position pictured), but the sear would still be held down by the slip. Ingenious!

The only thing I'd be worried about is discharging the gun while engaging the slip. I guess the trick is finding something strong enough and thin enough. I've got some spring steel that was actually a strap to hold bricks together in a pallet while they're being moved around. Might do just the trick.

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May 20th, 2009, 17:21	#1
spazzytroy Trader rating Join Date: May 2009	Help reverse engineer this select fire Hi-Capa While I wait for the weekend to roll around, I figured I would ask for help on another project ASR couldn't help with. Someone has figured out how to rig a hicapa 5.1 with a select fire switch. Unfortunately I havent been able to get in contact with the author of the video, but I would really like to replicate this. I'm not sure how to embed flash on this forum, so here is the link instead. YouTube - Tokyo Marui(Ã©Â¦Â¬Ã§â€°Å’) Full Auto/Semi Hi Capa If I had to take a guess, I would say that the leaf springs in the back of the gun are getting manipulated with that switch, based solely on the position of the switch. However, I haven't been able to replicate this mod. The closest I've gotten is full auto by pushing the far right leaf spring up under the sear. This disables the trigger, and empties the mag, in full auto, as soon as the slide closes... useless. I also already know how to shortstroke the gun to get rid of the hammer problem, so it's just a matter of figuring out the trigger stuff. Again I hope some of you guys have some ideas on how this could be accomplished. I'm also curious how the select fire on the Prokillers or M93Rs work, as maybe there could be some similarity. Thanks again for your help. EDIT: ooh! it auto embeds... spiffy Last edited by spazzytroy; May 20th, 2009 at 17:33..

May 20th, 2009, 17:30	#2
HeadlessChicken Trader rating Join Date: Oct 2008 Location: Toronto, Ontario, Canada	Illusion would probably be best to ask, I was also in contact with safx about my Prokiller as I've heard he knows WA pistols. __________________ "Hey I'm the first one to say its a great country but its a straaaaange culture. This is a place where gun store owners are given a list of stolen credit cards but not a list of CRIMINALS and MANIACS. And now they're thinking of banning toy guns...AND THEY'RE GONNA KEEP THE F**KING REAL ONES!" -George Carlin 1937 - 2008 (RIP buddy)

May 20th, 2009, 17:35	#3
BloodSport Traveling Man Trader rating Join Date: Aug 2001 Location: Moose Jaw, Saskatchewan	Didn't TM make a Full Auto Hicappa? __________________ Saskatchewan Age Verifier! Contact for more Info.

May 20th, 2009, 17:51	#5
ILLusion GBB Whisperer Trader rating Join Date: Jun 2002 Location: Toronto	I have a feeling the select fire switch is actually holding the disconnect lever, rather than affecting the leaf spring. __________________ *Advanced Airsoft Armaments and Enhancements* Quick to the gun, sure of your grip. Quick to the threat, sure of your shot. Diligentia, Vis, Celeritas Accuracy, Power, Speed

May 20th, 2009, 18:14	#7
spazzytroy Trader rating Join Date: May 2009	You mean the same disconnect lever I've been fooling with for the past week? I guess like you said earlier it would use the slide cycling as a timing mechanism for unlocking the valve knocker, as well as moves the hammer back. But if this is the solution, why did people doing the Xtreme conversion have to mod the trigger disconnect as well? (the4thpower3 milled the whole right side of the bbu off, kinda kills the semi auto function) Last edited by spazzytroy; May 20th, 2009 at 18:20..

May 20th, 2009, 18:34	#8
Styrak Trader rating Join Date: Jan 2007 Location: Saskatoon, SK	Because that ISN'T the solution if you want both. It's the solution if you want one or the other. __________________ Airsoft Sales and Repair/Upgrade Services Last edited by Styrak; May 20th, 2009 at 19:49..

May 20th, 2009, 19:17	#9
incrediboy729 Trader rating Join Date: Dec 2006 Location: California, USA	I know you can make a WE 1911 full auto by bending the leaf spring's middle "twig" back, but even that is not very reliable; as the one in the video seems very reliable. But i didn't experiment with it much so maybe you can make it reliable by the leaf twig method. I would be concerned whether or not that it is actually full auto or just "slamfiring" with everything sliding around. I would be scared that it is NOT real auto and just damaging parts. __________________

May 21st, 2009, 02:13	#10
MadMax Delierious Designer of Dastardly Detonations Trader rating Join Date: Dec 2001 Location: in the dark recesses of some metal chip filled machine shop	I'm inclined to think that the selector is attached to a slip of metal which lays on top of the trigger bar and under the sear. When the switch is pushed up, the slip of metal slides up so it lays between the sear and the trigger bar so the sear gets pulled back even though the disconnector on the right side drops out and disconnects the bar from the sear. Sliding the switch down pulls out the metal leaf and the sear-trigger bar connection becomes dependent on the disconnector being in place which puts the gun back into semi mode. I'm thinking that this is a selectable SINGLE sear arrangement because of the significant amount of vapor expelled in full auto mode. This makes me think that the hammer is following the slide forward bashing the mag valve open which makes for an inefficient power stroke because the mag valve opens before the nozzle returns to battery. Proper full auto is usually done with two sears. One is the usual semi auto sear which has a selectable mode usually done by varying the total trigger pull available (a movable stop which allows or prevents additional movement). The other sear I call the full auto sear because it's only function is to hold the hammer back until the slide returns to battery. With the semi sear held back, despite what the disconnector does (f/a mode usually allows enough movement to hold the semi sear back even with the disconnector pulled), the only sear which retains the hammer is the f/a sear which releases the hammer when the slide makes the last 2.5mm of travel back to battery. This arrangement allows the nozzle to be properly breeched before gas is released. __________________ Want nearly free GBB gas?

May 21st, 2009, 19:42	#15
spazzytroy Trader rating Join Date: May 2009	@MadMax: Finally found a pic that I could use. You're talking about inserting a slip where I drew the red line? I could see that working if the slip is made out of something bendable like spring steel. Fixed to the switch and just bending naturally as the trigger bar pushes it. With the mechanism engaged, the trigger bar would push the slip, the disconnector, and the sear all at once. The gun would cycle, the disconnector would drop low (as in the position pictured), but the sear would still be held down by the slip. Ingenious! The only thing I'd be worried about is discharging the gun while engaging the slip. I guess the trick is finding something strong enough and thin enough. I've got some spring steel that was actually a strap to hold bricks together in a pallet while they're being moved around. Might do just the trick.

Help reverse engineer this select fire Hi-Capa

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