Catman Posted March 17, 2007 Report Share Posted March 17, 2007 Day 4 - Saturday 17th, March Some more progress, we're waiting on a shipment of some bits before we can full conquer the internals Drilling out the front end for the outer-inner barrel: Drilling the screw holes for the bottom plate The bottom plate will hold the piston so it needs to be removable, heres what it looks like with the screws in. We mess about with the internal design and despite a leaky test rig get a reasonable ~300fps from compressed air. Holding the piston while it recoils is an experience (^^ over £600's worth of stuff in that photo ) MadDog welds the outer-inner barrel on: Link to post Share on other sites
creepingfear Posted March 18, 2007 Report Share Posted March 18, 2007 This probably isn't any use as it relates to an M2's real operation but I thought you'd like a look-see all the same. Link to post Share on other sites
creepingfear Posted March 18, 2007 Report Share Posted March 18, 2007 This probably isn't any use as it relates to an M2's real operation but I thought you'd like a look-see all the same. CozGau16_1.wmv Oh, nearly forgot. For things like gun mounts and stuff you could try www.milweb.net Link to post Share on other sites
Wedgie Posted March 18, 2007 Report Share Posted March 18, 2007 This probably isn't any use as it relates to an M2's real operation but I thought you'd like a look-see all the same. CozGau16_1.wmv Oh, nearly forgot. For things like gun mounts and stuff you could try www.milweb.net <{POST_SNAPBACK}> That looks horrifically complicated. Link to post Share on other sites
Catman Posted March 19, 2007 Report Share Posted March 19, 2007 Cheers for the vid and link, +1 to you More work to be done on it tonight so stay tuned for pics Link to post Share on other sites
swedge Posted March 20, 2007 Report Share Posted March 20, 2007 its lookin good... appreciate the rep mate...tanks... lols at the design plan! Link to post Share on other sites
Strike Posted March 20, 2007 Report Share Posted March 20, 2007 Gotta say I've been following this project for a while now and it's really good reading . Great going guys, keep it up. Link to post Share on other sites
Catman Posted March 20, 2007 Report Share Posted March 20, 2007 Day 5 - Monday 19th, March Not a huge amount of material progress made today, some parts didn't arrive in the post so we're stuck in a few areas until they do. Piston bracket partially made and a rough prototype lever put together: We tapped the drill holes on each side of the body Not a lot else to show atm rest of the time was spent measuring and overcoming problems with the internals. Hoping to get my paws on the sandblaster attachment for the air-compressor so we can make it look all bling-bling shiny Edit: oh good I can still edit this post... has anyone got the detailed plans for the M2? We're after CAD drawings we can use to measure up the side panels as we're having a little trouble working out the detailed bits - especially the cocking handle section. I can find some "blueprints" online but they all want to charge money for paper versions If you got what we need please PM me, cheers! Link to post Share on other sites
Hauk Posted March 22, 2007 Report Share Posted March 22, 2007 http://www.thedisease.net/ Hey Catman. You may be able to find it there. They have 101 thousand other guns. And lots of other articles on surviving in the wilderness too. Good luck with the project guys. I wish I had that type of enthuasiasm. Hauk Link to post Share on other sites
Catman Posted March 22, 2007 Report Share Posted March 22, 2007 Cheers Coo, no worries though, if I get lost in the woods I'll just ask Gentle Ben for directions or a pack of Lassie's. Trawing around the web last night, I found the "M2 M3HB Tutorial Version 2" and "Browning Machine Gun Caliber .50 HB, M2" PDF variations of the field manual as well as detailed blueprints of the two side panels and a few internal bits but nothing else. Really need to find the blueprints/CAD drawings of the trigger, handle assembly and the upper and lower body parts. The barrel parts would be handy but we can live without those. The build is being held up atm as we need some parts from RS and they haven't arrived - and naturally they're the important bits we can't do much without. Most of the project build time is now spent with us taking it in turns behind the frame making machine gun noises and going "It's gonna be soooo brilliant!". Link to post Share on other sites
MDK_Marshal Posted March 22, 2007 Report Share Posted March 22, 2007 looking absolutley smegging awesome. Get more pictures of it up ASAP! Link to post Share on other sites
MadDog Posted March 22, 2007 Author Report Share Posted March 22, 2007 RS Parts now arrived, We now have a barell, a drill bit (to make the heatsheild) and some liner ball bush bearings. We still have quite a way to go but things should start moving again now. Link to post Share on other sites
Woodco Posted March 23, 2007 Report Share Posted March 23, 2007 Have you made up your mind on your internals yet? Link to post Share on other sites
Bengali Posted March 23, 2007 Report Share Posted March 23, 2007 its 100% official Bengali is in love with MadDog and Catman the projects looking awesome, when you guys finnish im going to visit where you guys skirmish and blag a go with the beast Link to post Share on other sites
gunfighters Posted March 23, 2007 Report Share Posted March 23, 2007 looks real good guys. a few "questions" on the firing system test rig, what PSI were you running to hit the 300 mark I see a 3 way valve an what I will pusume is a single acting clinder with a spring return and a counter. you guys seem to have a handle on your pneumatics. but i thought I would offer a few thoughts on making the system more efficant and get more FPS per psi, not to "break" any 1j limits, but to give you more shots per bottle of gass. feel free to tell me to shove it but i have a bit of experance in this area 1st move the counter to the cylinder side of things. All that volume is robing the barrel of power, on the outher side it will be adding power. 3 way sonloid valves can be very slow, instead use a Quick Exust Valve that is driven by your solnoid. http://cgi.ebay.com/SMC-NAQ2000-SOLENOID-V...4QQcmdZViewItem sence the ebay listing wount last heres a stable one for long turn viewing http://www.grainger.com/Grainger/wwg/itemD...emId=1611628429 they make a MAGOR diffrance in your flow speed do to the speed or the valve and the reused drag of the system. they are made for just this task, dumping air as fast as posabul for a cylinder (so it will cycle faster) if it is at all possabul go with a clinder with larger ports (and thus a QEV with larger ports, the "pilot" solonoid can stay the same) this will reduse you drag, giving you faster flow speed and more fps. lastly have you thought a bout putting in a simple strafer type system? let it buzz away @ 75+BB a sec, while a pulsing relay makes a 2 way piston with a 4 way valve go "chunk a chunk a chunk". gives you the "feel" but still makes the 11v lipopoly w/high speed gears cry mommy top it off you run the vents in to the chamber and you don't loose much engery, and its a open a ball valve and dump in BBs loading with no moving parts on the firing side of things edit I think I just found my next project Link to post Share on other sites
Icey101 Posted March 23, 2007 Report Share Posted March 23, 2007 its not supposed to have super high rate of fire...... Link to post Share on other sites
1st Commando Posted March 23, 2007 Report Share Posted March 23, 2007 550RPM realistically but then so should a G3 with an AK only slightly higher I would say around 1000 rpm would suffice though at absolute max Link to post Share on other sites
MadDog Posted March 23, 2007 Author Report Share Posted March 23, 2007 The system we were going to run is a single acting cylinder, though a 3/2 valve. We are looking at using a roller actuated valve that will sit on top of a dog plate, this dog plate will be actuated by the tappet plate which is directly connected to the piston. Doing it this way will reduce air consumption as the only air used will be the air used to move the piston back, which is then exhausted out the barrel. I completely agree with the flow situation, we already upgraded to a bigger valve, but we may get a bigger one yet, looking for a good flow coefficient, the valve I have in mind has a cv of 1.0 and a 25mm squared orifice, so that should give us plenty of flow down a 6mm OD bore (that has a 28.27mm squared orifice) Thanks for the link on the valves, I will have a look at them when I get home, although I will have a look for some manually actuated ones as I don’t want to have gas and electric, would rather just one or the other, and as space is an issue I was going to steer clear of having pilot valves. Excuse the diagram in paint, not exactly what we are doing but demonstrates the idea. Thanks for the input, i would add to your rep but i can't, i'm sure catman will though. Link to post Share on other sites
Tecro Posted March 23, 2007 Report Share Posted March 23, 2007 Exactly, I'd have suggested an inline vortex chamber if not for the 450-500 max ROF. A QEV/paintball style bolt is a good idea, but it would be better to build a small piston valve that acts as the bolt as well. And with a QEV, you'd also need to build a system to turn on and cut off the airflow in order to actuate the valve. Granted, though, you could just take a paintball system (ick ). Hope this isn't getting too complex. HowStuffWorks and a number of spudgun sites have some information on things like this. Link to post Share on other sites
Catman Posted March 23, 2007 Report Share Posted March 23, 2007 Yeah we're looking at about 450-650rpm. FPS, we're looking at achieve 280-350fps. We're going to have adjustment valves within the gun so we can regulate both settings. We'll try and get a more detailed pic explaining the internals in greater depth later. With any luck we'll be doing more building over the weekend Link to post Share on other sites
Insanity Posted March 23, 2007 Report Share Posted March 23, 2007 This is bloody awesome. Link to post Share on other sites
Catman Posted March 23, 2007 Report Share Posted March 23, 2007 [...]when you guys finnish im going to visit where you guys skirmish and blag a go with the beast <{POST_SNAPBACK}> Sure thing, well by the time we finish we should be playing at our new CQB/Woodland. It's quite cheap to get over here on the Ferry from Liverpool Link to post Share on other sites
Guardsman Posted March 24, 2007 Report Share Posted March 24, 2007 how cheap???? i think i will be making this trip... Link to post Share on other sites
Catman Posted March 24, 2007 Report Share Posted March 24, 2007 It varies, seen it as low as £20 return by foot on the ferry from Liverpool. Prices skyrocket a bit when motorbike events are on (TT race events, end of May thru to June). Theres another big motorbike event at the end of August as well so if, like me you didn't know about it you'll end up sharing a ferry with a load of blokes in leather If you want to fly then the flights are classed as domestic - no idea about putting airsoft stuff on a domestic flight though. Oh most planes out to here are small and are turbo-props Well we have our barrel and our barrel-bushings so tomorrow is another build day Link to post Share on other sites
Catman Posted March 25, 2007 Report Share Posted March 25, 2007 Day 6 - Sunday 25th, March With the barrel and barrel bushings arrived some more work could be done The 25mm HSS drill bit had also arrived so the heatsheild could be worked on. Here's the barrel shoved in to stage up what it'd be like, a Desert Eagle and a cuppa give you an idea of scale These are the bushings we're going to use for the barrel: Working on the Heatshield: First we drilled some pilot holes....which weren't big enough so we drilled them out to 13mm then used the 25mm. It took a very long time to drill through the metal as the pillar drill needed to be set to slow. We'd been spraying it with oil in case you're wondering All the 13mm pilot holes drilled out: After a few hours of drilling and tinkering with the pillar drill the last hole is drilled out: While MadDog was drilling the Heatshield out I worked on the piston mount. Welding it onto the lower body - bit of an horrid weld but really needed to make sure it'd stand up to the punishment (Arc welding is hard to get neat and I'm a n00b at it anyway ) That's fresh from the welder - that's why it looks wet The heatsheild all drilled out: Needs some touch up but we'll do that tomorrow Link to post Share on other sites
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