Secondhand AGM mg 42

Stripped out the frame completely, checked out with a straight edge, ......7mm out of alignment! This is going to be a cut and re-weld, pity it's not steel as I don't have ally weld facility.......but I probably know a man who does.
If I don't true the frame the nozzle doesn't run straight in the hop unit, I can already see scoring inside, it's not bad but would only get worse, seeing as the hop unit is soft monkey metal and the nozzle is plastic.
So it's a good job it didn't work properly from the off, as it would probably be totalled by now......every cloud has a silver lining!

Hi you can get aluminium solder,search for this on ebay,i have joined pure al. with this
Most likely the parts you have will be zamac,a mix of zinc and aluminiium,dont know if this material can be joined or not
I met you at the weekend i was in the base of the big fern tree at the very end of the day,you blasted me in the back.
I have some broken airsoft crap on the workshop,will let you know if it works

I remember giving you the blast!...apologies if it was painful.
Thanks for the idea, I'm under the impression it's some form of weldable alloy as the frame is made from three parts, and welded together, nice neat welding too! Shame whoever the operative was, couldn't put it in the jig right.
I will check that stuff out though, on eBay. May be useful somewhere else.
Andy

Well - I am looking at my AGM MG42 and I can't find a single Philips screw in it - all are hex cap. Even on Friday evening I doubt they had anything else than hex screws - I am afraid yours was a little worked on before you got it.
on the other hands - despite I was sure it is steel pressed frame - it is not. IN the end there must be a reason for weight difference from G&G.
Based on thickness of the stamped parts I would say it is aluminium and not pot metal / zamac. Good thing this is weldable - you might need to take it at a carshop were they do body work.
About everything else - you are right - Chinese parts - but might get it right easy since everything seems to be V2 compatible inside (except motor which is V3 - short type).

Good luck!

There are no Philips head screws in the mg42, I wrote cross threaded.
I've started on the gearbox rebuild, nothing wrong with gears, which are v2 and v3 compatible, found a bit of "shorting out" burn marks, where the motor terminals are, and yes it's a short type motor, this will be replaced with a torque motor. a rewire to have a longer lead to the battery, which will be hanging in a brass catcher bag, bigger lipo!
I know a guy who repairs alloy wheels, has some good equipment for small light work, so once the thing is aligned, I will visit him, haven't started on that yet.
I've read reports of a weak link on the bipod hanger, being monkey metal, it's not suprising it breaks, if I find the time I will fashion one from steel. even if this mg had been a good one, I would not have been able to resist pulling it apart anyway, must have it doing at least the same rpm as the real steel.
Andy

Over the Easter weekend, I cut and straightened the mg42 frame,( I have taken photo's of all this, but as yet, I'm inept at setting up the photo bucket nonsense) my contact to ally weld the repair says this gauge aluminium is too thin for his equipment to weld, can't turn down to a low enough volt/ wattage.
So I'm making a fish plate to sit inside and either bolt through with 3 mm dome headed hex screws, or pop rivet, luckily the cut I've made sits under the magazine, so it won't be seen.
This will also give me he opportunity to make a brass catcher mount ( to hold bigger battery) to clip the bag to. Gearbox is shimmed now, and bits have arrived to upgrade the piston section.
So this might well be ready to bring to the next battle as a spare weapon.

Update on the old klonker! Spent most of today fitting the mg back together, rewired to take 11.1 lipo with deans connectors, all went well. I still have to make the "brass catcher " bag.
Have also fitted shs torque motor, runs well according to my chrono, 1349 rpm, but Fps was low. Fitted another spring not much better, the strongest spring I have is an M 140, even with this only getting 250-256 Fps on chrono.
Must have an air leak around cylinder head or nozzle, will have to come apart again......but not today! Still it shoots in a straight line, the rpm is what I wanted from it, so not too far away from finishing it.
I do like the design of the split gearbox, not too far from the ICS system used on many an M4, ( still make them I believe) the para 249 is similar too.
Andy

Put a few bb's through this now, no change will definitely have to come apart again, have noticed what a poor fit the magazine is to the gun, anyone else have this problem?
Seems loose when fitted, catch doesn't seem to close all the way home, it works ok, just a loose rattley fit,.....this will have to change too! Can't have this, I have read or heard of them falling off when in use. Good job this is real metal, will at least be able to weld or heat up to make a proper fit.
Andy

The hanger bracket/feed tray ears are made from soft material and deforms easily; manhandle them until the drum fits tight.

MG42......DONE!. Now running 345-350 fps, slightly off aim to the right, but I can live with that, might loosen rear sight to see if it will move to the left a tad.
Made a " brass catcher" to hold the the bigger battery, might weather it in a little. It's now ready for the October battle. If I have time, will try to make a Lafette stand.......or at least my rendition of one..... don't fancy running about with this thing, purely a stationary piece for defence.
Andy

All has been well with the mg,.........but just tore the the gears out, all teeth off of pinion gear, thought it might be torque motor too powerful at first, but it was the anti reverse latch ! Come out off shaft bearing and flipped over taking the teeth with it. Bearing mounts were a bit sloppy anyway (what do you expect from an AGM product!)
So now using 3 mm brass tube as a tighter bearing mount, found a slightly longer lever for the job too, and some liquid metal resin to build a back buffer so it cannot flip back again.
I have a feeling that this mg42 is always going to be a "problem child".
Andy

Mate you want to get some JG gears from WGC shop.
I bought a second hand JG HK 416 made in 2008,and although the outside of the gun has something fall of every time i use it,the gearbox inside is solid.
Despite the. Gun having a double feed problem ,now cured,for some time which i would expect to cause some piston teeth or even gear damage,when i opened it the piston and gears looked like new,despite having the crap shot out of it for years,and the gears were on plastic sold bushes which i got rid off,the bevel gear had about a 1 mm side to side play the worst shimming i have seen in a gun,The bevel gear and motor pinion had smooth teeth ,no damage or wear.
Just goes the show this obsession people have with shimming to very small clearance is not as important as is made out,this above mentioned bevel gear was obviously pushed up the bearing bushing by the motor pinion and as long as the gear teeth had about 0.05mm
Mesh clearance it made no difference how much gap there was between the other side of the bevel gear and its corresponding bushing.
Same with the other 2 gears in your mechbox,as long as the sides of the gears do not touch another gear face or the inside of the casing a bit of play is not a problem, the reason gears loose teeth is because they are sintered metal,thats metal powder compressed in a mould and them baked,the quality is very variable.Some gears just go and go forever and some chew,burr and snap very quickly.
Now over shimming ,where the gears cant spin freely once the casing is fully closed that will **** it up totally,been there and done that when a shim got awol when trying to close the case,and made a guess where it came from.

I don't think the gears were at fault, although the bevel gear got destroyed, it was the anti reversal latch, that was loose in its mount, with that coming out and turning upside down, something had to go! It won't come loose now it's been bushed and guided, it can't go anywhere now (except where it should!) have got some good gear sets to choose from anyway.
The gears that were in it were A&K, had the same gears in a para 249 no probs at all, but like you say, you can never tell! Some do ....and some don't, I have used recommended nuprol gear sets supposed to be super strong, and they have let go, so it's nearly rebuilt now, we will see what happens on the weekend!
Andy

As for JG gearboxes, I have three v2 JG boxes in guns and yes, they are good solid lumps. Two now have been converted to quick change spring.
Andy

Nuprol stuff is WE products rebranded and distributed by a European company.
Thats what i was told,not much of a WE fan personally,some say they rush lots new
products that then has quality and design issues like a Katana M4 a friend had,big problems there,and big price tag too
,they totally rebranded their BB lineup someone joked you could not shake them out the bottle let alone feed them through your
Gun,although the ones i tried seemed OK.A lot of airsoft stuff has quality issues though comes hand in hand with where it's made

On rebuilding the gear box, noticed the bearings were not too good, these were ball type, not great to use with torque motors, so they re out and solid metal ones fitted.
As the gearbox on these is in two parts, I haven't checked the top half since the very first rebuild, so I took it apart,.......piston fine, piston head.........in pieces! This could have been the gear stripping problem, new head, all back together, running fine. ..........for now!
Andy

Presumably you'll nickname the gun Trigger's broom?

If I have to replace anything else, that would be a very apt name!
Andy