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Post by stukaace on Jan 22, 2007 22:37:22 GMT -5
I'm in the process of Schmitty's wonderful fake-bake treatment, I packed the mechbox back together after removing the selector and realized that the performance on full auto left a lot to be desired. Stripping the gun down, I noticed that when I pushed in on the air nozzle, it would not move back out afterwards. I've looked on other forums, and I think this is the cause of the erratic full auto performance. Any clues as to what would cause the air nozzle to be immobile?
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Post by CharleyNovember on Jan 22, 2007 23:27:28 GMT -5
Going by other V3 AEG designs..tappet plate is not engaging the nozzle. or the spring on the tappet plate is missing or not engaged or something is binding once you put it back together. It is essential that the nozzel moves back and forth. It moves back as the piston moves back allowing a bb to enter the hop then it moves forward to close off the hop making a seal just before the piston is released to push the bb out of the barrel. If it ain't working the gun will perform crappy due to loss of air and from misfeeds. This is a guess from what you have described but hard to say if I haven't seen it in person.
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Post by schmitty on Jan 23, 2007 0:16:17 GMT -5
The quality of the plastic parts of the Chinese MP-40's is not that good. I noticed that the tappet plate and nozzle both had a lot of burs on them (excess plastic left over from the molding process) Take the gearbox back apart and sand those parts smooth with 400 grit sandpaper. Lube the track the tappet plate moves in and re-assemble. Tell us about your results.
Good luck
Schmitty
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Post by stukaace on Jan 23, 2007 17:07:02 GMT -5
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biged
Master sergeant 
Posts: 468
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Post by biged on Jan 24, 2007 6:09:30 GMT -5
With the cylinder assembly disassembled:
1. Put the cylinder head into the cylinder.
2. Put the nozzle on the tappet plate. (Nozzle in the groove)
3. Slide the nozzle & tappet plate onto the cylinder head.
4. Attatch/hang the tappet plate spring on the tappet plate.
5. Install the whole assembly into the gearbox. (You will have to rotate it to get it in.)
6. Connect the tappet plate spring to the gearbox.
Before installing (compressing) the main spring. (And putting the other half on the gearbox.)
Push IN on the nozzle - It should spring back. Watch how it slides/operates.
Compress the spring and put on the other half of the gearbox.
Put in one screw - does'nt matter which one.
Push IN on the nozzle - It should spring back.
(If you can, run the gearbox with it outside of the gun.)
If the nozzle is operating normaly it may be dragging/hanging/misaligned when in the gun.
///ed///
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Post by schmitty on Jan 24, 2007 10:38:18 GMT -5
Everything looks good in the pictures. Either the nozzle is to tight on the cylinder head or the tappet plate is getting squeezed when the gearbox is re-assembled. Check the fit of the nozzle on the brass tube it slides on. (with the pieces out of the gun) It should be snug but slide easily. If not sand inside the nozzle as needed and lubricate. Put the gearbox together without the piston,spring, cylinder, cyl head, and tappet plate spring. reach in through the holes where the cylinder would be and see if you can slide the tapet plate, if not sand the tappet plate until you can easily slide it and lubricate the tracks it slides in.
Schmitty
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Post by schmitty on Jan 24, 2007 12:25:36 GMT -5
P.S. I agree with everything Ed said. If the nozzle moves freely when it is not in the hop up it may be dragging against the sides of the hop up indicating the barrel and gearbox are not aligned within the gun. It's probably more likely an internal Gearbox issue though.
Schmitty
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Post by stukaace on Jan 27, 2007 12:26:20 GMT -5
I thoought I put the gun back together properly, with the nozzle engaging the tappet plate and providing reistsence when pushed in and smoothly popping out when the force was removed. The gun appears to be feeding fine, but the velocity and range is pathetic. I've uploaded a short video that shows my plight. The BB's are dropping after maybe 30 feet, on every setting possible for the hopup. Any suggestions? www.youtube.com/watch?v=1QSP7tkf8tA |
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Post by CharleyNovember on Jan 27, 2007 12:37:29 GMT -5
Well if everything with the mech box is ok You could move on down the line to the hopup. perhaps it is not engaging the bb and therefore not aplying backspin.
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Post by stukaace on Jan 27, 2007 12:42:07 GMT -5
Even when the hopup is turned completely off, there problem persists. I've compared the sound of my gun firing to the one on youtube www.youtube.com/watch?v=xv_I5qoEjao , and the one on youtube appears to cycle much, much faster. It could be that my battery charger did a poor job of charging my battery, as now it appears it is once again dead. Do any of your battery chargers have the red light glowing when charging? Mine fails to glow at all. |
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Post by CharleyNovember on Jan 27, 2007 13:19:22 GMT -5
my wall charger has a red light while charging. The RC car charger I have works a bit different. Low battery shouldn't affect how far the bb shoots. Either it pulls back the piston and loads a bb or it is too dead of a battery to do so. Things like piston seal nozzle seal hop up effect how far the bb shoots.
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Post by neillblume on Jan 29, 2007 8:10:05 GMT -5
It could well be the hop. Mine was shooting off to the right I fixed it by installing a new barrel with a maruitype hop rubber and packing Its fiddly and there is no way back once you start but mine fires fine now. i get the occasional misfeed but only when the mag is near empty.
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biged
Master sergeant
Posts: 468
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Post by biged on Jan 29, 2007 19:54:41 GMT -5
Stukaace, I just noticed something in your 1st picture.
Your cylinder is in BACKWARDS!! --- (I've put them in backwards before by accident too..)
There is a hole in the cylinder which should be towards the back of the gearbox. Just flip it around and it should be back to normal.
ALL your air is rushing out that hole. So you are getting not compression - except for that TINY space in the front of the hole and the cylinder head.
Cylinder the orientation does not matter. I like to have the hole in line with the piston. (Some cylinders - Type 0 don't have one) That way you can see the piston side rails, which just helps in making sure the piston is in straight.
///ed///
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Post by stukaace on Jan 29, 2007 21:19:13 GMT -5
You saved me probably 100 bucks easy in repair fees, biged. I turned the cylinder around and sure enough, the thing is shooting like a champ. I cannot begin to thank you for your input.
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Post by CharleyNovember on Jan 29, 2007 22:14:15 GMT -5
Great eye Biged!! Glad he got it sorted out.
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Ersatzjack
Corporal
"That silly Franz... he thinks we are winning."
Posts: 1,093
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Post by Ersatzjack on Jan 29, 2007 22:57:35 GMT -5
Or maybe... stukaace has everything backwards but the cylinder? Huh?
biged - your name aptly describes the value of your posts. You always have something "big" to offer.
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biged
Master sergeant
Posts: 468
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Post by biged on Jan 30, 2007 6:12:35 GMT -5
I'm glad I could help. My bloodtype is my attitude, B-Positive.
These toys are'nt cheap. Having someone work on it is'nt cheap either.
It's hard to give an estimate to someone when there can be one or several things wrong with a gun. It's even harder to tell someone it required more time to re-package the gun, than it did to repair it.
Advice and tips are free...
///ed///
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Post by shellshokt on Mar 22, 2007 17:48:08 GMT -5
This thread has just rescued my ability to skirmish my MP40 this weekend  Started the fake & bake treatment with removal of the selector switch.....carefully removing last tiny screw in mech box.... kerching!! springs, gears tappets plate etc all over the place  removed the parts I needed to, found all the other bits, put it back together. I have never stripped an airsoft mech box before. Anyways, a long one short, after a couple of hours of rebuild, test, rebuild, test, etc I decided to search this site and found this thread. Turns out I had put the cylinder in back to front and the tappet plate was not located on the air nozzle correctly  Thanks again to all who contributed 'shokt |
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Post by anj4de on Jun 5, 2007 4:09:27 GMT -5
Hello all Sorry for highjacking this thread but I am totally new to the Airsoft arena...just fell across the AGM MP40 last Friday and bought it right away. Sofar I already had a lot of fun with it, in the garden ;D Since I am rather mecanically minded I had to see what's inside. So I took it all apart, re-greases it and put it back together. One thing though...the brass cylinder has a rather large hole in the back, what it this one for at all? All in all the AGM MP40 is a wonderful toy...and so cheap! cheers Uwe PS: What, apart from the price, is the difference to the TOP MP40. Would it be worth getting that one as well? I love MP38/40s...  |
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biged
Master sergeant
Posts: 468
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Post by biged on Jun 5, 2007 5:13:56 GMT -5
The volume of area in the inner barrel should be matched to the volume of area in the cylinder. (The shorter the barrel the hole in the cylinder moves forward.)
The hole in the cylinder allows the extra air to flow out of the cylinder before puffing the bb down the barrel. If you install a "type 0" cylinder (no hole) you may lose fps because the bb is getting pushed out the barrel before the piston can complete it's stroke thus maximizing air compression.
I have heard you can move up one cylinder size if you install a 6.03 tightbore. However, each gun is different, and this will depend on the type of ammo you use. Plus 6.03 tightbore barrels take 3-4 bags of bb's to break-in. They get better with age.
Cylinder type - Inner Barrel length
Type 0 Cylinder - 450 - 590 mm (M16 length)
Type 1 Cylinder - 360 - 460 mm
Type 2 Cylinder - 220 - 430 mm
Type 3 Cylinder - 110 - 170 mm (MP5K length)
///ed///
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2nd Bat
Master sergeant
Posts: 11,813
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Post by 2nd Bat on Jun 5, 2007 13:26:17 GMT -5
The TOP MP 40 (In fact everythingmade by TOP) is a contradiction to the usually valid statement that you get what you pay for. In this case the TOP MP40 is far more expensive then the AGM MP40 and while it is a better replica in terms of detail and authenticity it doesn't shoot worth a crap and based on most peoples experiences seldom survive a single skirmish without breaking. Stick with the AGM and avoid that nightmare. I had 2 TOP M-60s ($1,200.00 each) They were by far the worst airsoft guns I ever owned. It was happy day when I sold them both even though it was less then half what I paid for them. Forget what I had to spend to get them functional again! As you can tell I am not a TOP fan.
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Post by anj4de on Jun 7, 2007 15:08:12 GMT -5
Hi Guys Thanks a lot for the last replys...in summary that means for me to... a. Get a spare gearbox for the AGM MP40 and start experimenting with tuning parts (maybe a second gun since they are cheap ) b. Not to think about the TOP Mp40 any more. Maybe I will try to marry some Marushin parts to the AGM version. I have already checked out an original MP38 magazin that I have, by cutting the top off the internals of the AGM fit inside...so I will get some MP40 ones (cheaper than MP38 ones) and do some conversion work. I have also found a great page here... www.ssd-weapon.com/produkte/bd38/bd38.htmThis guy lives only 1,5 hours away from my place. He makes brand new MP-38s and sells spare parts seperately www.ssd-weapon.com/downloads/bd_38/preis_ersatzteile_bd38.pdfSo I will pay him a visit to check out the possible fit of the bakalite parts and some other things... cheers Uwe |
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Post by ck on Jun 17, 2007 22:14:06 GMT -5
Wow, I would be very interested in knowing that as well (If the bakelite grips fit somehow w. modification)
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