shenlonco

My Feedback: (2)

You are crazy!
You can probably do it ..run a flexable metal braided rubber hose into the gun unit so you can still rotate and move barrel up and down.... I am happy with my marui guns in the HL tanks it's good enough for me.... and with the new paint balls they break at plenty long enough distance not like the 13ft with the old ones...don't think you need all that power trying to hit a tank from 30ft away is plenty hard enough and the new paintballs will break from that far.

besides no one here to do battle with anyhow...just me all alone cruizing around shooting up things!

shenlonco

My Feedback: (2)

O i have the G23F also!
mine don't shoot as accurate as my other guns though...trying to find a upgrade barrel mine might have been buggered from the factory,,it always shoots to the left side a lot..

swathdiver

I see MadBulls on ebay for them often. Mine shoots right on from 10 yards with .20gram bbs. My 6 year old shoots it more then I do. She almost always in the 10-Ring now, especially since she got glasses! FYI, they never shoot without me around, it's locked up when not in use.

I don't think you'll need steel braid, Perry didn't use it, I don't think the pressure will be higher then 100psi.

shenlonco

My Feedback: (2)

Thanks James...now looking for the barrel!
[&o]Searched E-bay ...can't find anything

Perry S.

Swath, coming to the dark side huh? I have been thinking about revisiting the original gun design to regain the 6 mm shot. If I understand your description the gun will not function. Others have tried it. What I have learned since this whol shebang started is that you need a good supply of air place close to the breach in order to get any velocity. THe pressure drops across feed tubes are prohibitive. THat is why there must be an accumlator close to the breach. It needs to hold a large gulp of air at firing pressure and the activating valve has to have a very low pressure drop.
To answer another question I use the CO2 cartridges because they are the only way (at least I've found) of storing the energy needed for multiple powerful shots. They are charged to 800 psi. I don't believe the R134A system will get there. I don't believe that they store the mass of gas the CO2's will and I have never seen tanks that are small enough for 1/16 tank use. I think they are standard fair in 1/6.
It was quite an ordeal to miniaturize the gun system and make it reliable. I hope yourself and others can improve upon it.
Perry

swathdiver

Yes!

In your initial design you had a servo actuated valve in the back of the airsoft unit. In that position it was about 3" from the breech right? My idea is to mount the Mouse close to the back of the airsoft unit so the stock barrel elevation unit will still work and distance from breech to valve about 4 to 5 inches. I did see some very small electric valves that could fit inside the gun but don't know if they'll flow enough air. The volume of air from valve to muzzle would be about 2 cubic inches for a King Tiger sized barrel. An accumulator of 3 cubic inches should be plenty right?

I understand now what you're saying about the gas supply and CO2. Have you worked with Propane or Green Gas?

Perry S.

I would say no to propane because it is combustsble and I dont think enough green gas can be packed in at high enough pressure to supply multiple shots. If you look through the thread you will see a parts list. I would go with that valve and instead actuate it with the pneumatic solenoid instead of the servo. It would be easier to configure in there. This will run directly off the HL elec's.
A good size for an accumulator would be 2-3 cu in. I find provides good airflow and sustainable firing. Remember the accum must fill and pressurize for each shot. I usually pressurize to 100-125 psi although I once set it up to 250 psi, the .3g aluminum 6mm bb's were brutal.
Perry

kotori

I was talking with one of my boating buddies, and he said he once ran an experiment on cannon efficiency. He used the Clippard MJV-2 valve with MPA-3 pilot actuator and experimented with various barrel length and accumulator sizes. He found that at least 1.5 cubic inches of volume and a barrel that is about 5 inches long from the bend is optimum. Any less than 1.5 cubes and you need to kick up the pressure, any more and you don't gain much benefit, though I'd rather have more volume than not enough. Any less than 5 inches length and you don't have enough length to accelerate, any more and the friction will slow the ball down. I don't recall that anyone else has validated these numbers, but I consider him to be an expert designer for model warship cannons.

OliverLove

Just a side note, Green Gas used by airsofters is propane. The only difference is a slightly different scent is added, and silicone oil to help lube all the O-rings in the guns.

swathdiver

Thanks for the info Kotori. This plan is to use 6mm airsoft so there won't be any 90 degree bends. Also, the King Tiger's barrel from muzzle brake to back of airsoft unit is about 12 inches. Using a tightbore 6.04mm barrel that worked out to about 2 cubic inches. So the accumulator must be at least that big, right?

Perry, I'm ready to buy some parts. I think the Clippard Mouse actuated by the switch that gets hit by the piston/nozzle assembly will work great! Is the parts list you're referring to the one with the T-34 picture?

swathdiver

My plan is to use propane, readily available and cheap! Just gotta keep that gas away from the electric motors or...

I have a gas blowback bb gun that uses propane. The magazine cannot be more then 3-4 cubic inches at most and that is usually good for about 30-40 shots depending on the outside temp and if we're using the gun with stock valve or hi-flo. Velocity is about 280fps.

I'm trying to figure out and understand how the main storage tank fills the accumulator, it's not clicking other then some sort of valve is used that works by pressure. Is it adjustable?

Also, how do you regulate the pressure in the accumulator to the firing valve?

How do you adjust the amount of gas the valve lets out?

I should be sleeping but I have to figure this out!!

shenlonco

My Feedback: (2)

My guess is it probably works like how you ajust the presser on a air compresser even though the tank fills all the way up you can make the air come out any pressure you need from the ajuster on them.

Perry S.

Swath,
Yes the parts list from t-34 gun is the same for all my tanks. To anser your questions here is the theory of operation for the gun. Starts with the CO2 cartridge. These come pre-charged at about 800 psi. The black item you see screwed to it is a regulator. It is adjustable and can drop the pressure to anywhere from 0-300 psi. Theres a hex head socket you turn to do that. I usually run at about 100-125 psi. Then a 1/16 hose connects to the accumulator and tees of to the firing valve (EC-3-6). This charges the accumulator. So now it is at 125 or so psi. To fire you actuate the firing solenoid (I use my HL electronics). This pressurizes the firing actuator (MPA-3). there is a piston in there that will actuate your main firing valve (MJV-2). Now all the air in the accumulator rushes out through the breach and barrel, firing the bb. I know this may sound complicated but it's not really all that bad.
Let me know if you need more and make sure to post your pics
Perry

swathdiver

Thanks Perry!

Forgive my ignorance, I have a question. Why not run a line from the black regulator directly the accumulator on one end and the other go straight to the Yellow cap Clippard Mouse? The HL electronics will activate that and the air will be released from the accumulator, through the Mouse and directly into the gun?

The more I think about my gas blowback pistol the more I think we won't need the main storage and regulator. Just the accumulator with a fill fitting on top for the propane. Placed on the right side of the gun, you could access it through the loaders hatch to fill it. I think the Coleman Propane tanks store the gas at 300psi. Hmmm...

Perry S.

THe mouse doesn't have nearly the flow rate you need. This was tried early on in the thread. It will not work.

Word of safety. Not sure if your going to do this with parts from your AS gun but you need to be careful with hooking up to pressure tanks without knowing the pressures and what have you. You need to make sure your fittings, valves, tubes, etc are rated for the pressures you have. Especially if you have made your own accumulator.
Perry

swathdiver

Ok, think I got it now. The Yellow Mouse actuates the other valve with air also. So would the Mouse be 2 or 3 way?

Perry S.

3 way

zippy0036

Hi,
I've been reading this thread with great interest. I'm currently resurecting an old tamiya king tiger using hl parts as I had a hl panther that I thought was complete pants .more like a cross between a tiger1 and a panther (a Panger, tinther?), so I gutted it and used the innards on the kt with a few mods. however the kt gun barrel is a nice ally one but has a muzzle id of only 5mm or so, so as i'm going to use it instead of the hl panther barrel i'm restricted to .177 or 4.5 mm. On examining the gun I found a simple barel change to 4.5mm brass wasnt going to work, as the 177 bb would a) jam between the breech face and the back of the barrel and b) probably not reach the muzzle due to a lack ftlbs if it didnt do "a" first. So like you guys I started to look into alternatives.
The simplest, cheapest and most promising seems to be to install a gas blowback walther ppk, all the hard work is already done.It's cheap, it's small, it runs on a 12g co2 bulb, has a 15 shot mag,being blowback it doesnt need an extra channel for a battery draining loading mechanism , the original hl motor and gears can be adapted to pull the trigger, which being light, will not put undue strain on the motor/gear unit.using the gears will keep the cycle slow, making the gun less likely to "double tap"
I have made a QD turret so reloading wont be a hassle. The whole turret lifts off complete with the traversing ring, exposing the bulb and mag base, if I were to do this on another hl tank with a standard turret, then I suppose it might be better to put a small hatch in a "sweet spot" in the floor so I can change at least the mag without having to split the hull.
Has anyone else considered or tried this mod?

Perry S.

Haven't tried that particular mod. You'll probably be the first. I was able to install a CO2 system in the turret of my KT using the design laid out in this thread.
Here's the build
http://www.rcuniverse.com/forum/m_61..._tamiya/tm.htm

Perry

zippy0036

Thanks Perry,
Looks quite impressive, maybe I wont hack the ppk after all. I still like the Idea of blowback loading though, esp if I can link the sliding part to my alloy barrel so it recoils on firing. The rest is coming on nicely, the electronics are in and tested and I've managed to make 2 LED MGs (old radio antenna sections and 11 fibres from a fibre optic lamp )
next job is to make an adjustable cradle for the laser sight I've just gutted, - and come up with a cunning plan for turning it on and off [sm=confused.gif]

zippy0036

Perry.
You mentioned you used a laser for targeting, how have you wired it in? self powered and always on? was thinking of using 2 tiny solenoids and 2 micro switches and installing the switches in parallel into the lasers own button cell circuit. then the solenoids can then be wired into the traverse and elevation circuits operating the switches when either or both are on. do you think the micro electronic reciever switches you mentioned earlier in the thread could be wired to do the same thing as my solenoid /switch arrangement?

Squad1b

Ok so first off i am new at this hole RC tank thing. But, i like the power that you can put out with BB`s. I have no idea how to build any of these. I need someone to point me in the right direction. I know i want the T-34 and i really want the CO2 upgrade. How do i do it. Website would be a plus!!!!

Brandon

Perry S.

Zippy,
In my Tiger build I used HL electronics and I use the stock fire button to actuate the firing solenoid. As far as the laser goes I run it of the main 7.2 volt battery (make sure to use a resistor to get the voltage down). Didn't want to fuss with extra batteries. Here's a how-to
http://www.rcuniverse.com/forum/m_58...tm.htm#5842138

Squad1b
Welcome aboard. If you read this thread from the beginning you will see everything that you need is in there. Along with some of our failuresI guess 'this' is the website for it.
Perry

darthelmer

Hi Guys,

Excuse me but canI ask Just one Question... How will the Co2 activate ? I mean is there a button to which it is pressed quickly to shoot a single pellet? or the description of the working valve mechanism or whatever to make the sudden gush of air work...

Im Kinda thinking.
please include a pics too

thanks sir...[&:][]

thomasjohnmurphy

Lol, I'm the other tank who James had given his madbull barrel to. I like the madbull barrel for a number of reasons (it had a inner diameter of 6.03 - one of the tightest of all airsoft barrels. Its aluminium so its easy to work with. They are cheap - a 650mm barrel can be had on ebay for less than $30 and can be cut into 4 barrels (I've probably made over 2 dozen barrels so far for various tanks.) Combining the madbull barrel with one of my modified guns I've been able to get as high as 250fps ( most guns will shoot over 200 fps) One thing you have to remember, because of the tightness of the barrels you want to keep them clean (I use a paint thinner to clean/ dry silicone to lubricate - using a pipe cleaner) I am using a systema 6.04 barrel for my Matorro KT and am very happy with it. So either barrel is a good bet for increasing the power of you tanks shooting abilities.