Semi not correctly firing.

.K.A.L.I.M.A.

I recently put in a new spring guide, spring and cylinder, changed the wiring to the rear, and shimmed the gears in my gearbox.

First problem I had was the sector gear not catching the piston, but the tappet plate moved fine. After getting that sorted, when I put everything back together and fired it again, I noticed that safe worked, semi would always leave the piston back (It would fire the one shot) and auto worked fine.

I looked around and heard about 'Gear timing', but wouldn't the cut-off lever fixed that straight away? I may have not put the sector gear in the one o' clock position that it should be in, as the trigger kept popping out on me.

Would shimming the gears affect the semi in any way?

Any help appreciated.

DeBurca

Gear timing is a myth and does not exist
Yes there is a relationship between the spigot for the tappet plate and the pick-up tooth on the sector but that is “cast in steel” so to speak by the maker and cannot be changed

Reassembling the gearbox with the sector gear in the 1oclock position is a position used by most people when putting a gearbox back together as it keeps things out of each others way
You can just a easily set it in the 4oclock position when putting it back together and all will be fine
I normally have it midway between 2 and 3oclock when putting any of mine back together

.K.A.L.I.M.A.

DeBurca wrote: »

Gear timing is a myth and does not exist
Yes there is a relationship between the spigot for the tappet plate and the pick-up tooth on the sector but that is “cast in steel” so to speak by the maker and cannot be changed

Reassembling the gearbox with the sector gear in the 1oclock position is a position used by most people when putting a gearbox back together as it keeps things out of each others way
You can just a easily set it in the 4oclock position when putting it back together and all will be fine
I normally have it midway between 2 and 3oclock when putting any of mine back together

I just tried now moving the bevel gear using a flat head until I reached the point where the sector chip started to meet the tappet plate and I tried semi, but I'm still getting the same results.

Would it be because of the new spring? I installed a new SHS M90 and SHS Spring Guide.

YbFocus

So the gun is firing it's shot in semi and then drawing back the piston some distance back again?
It sounds as if the cut off lever isn't cutting it at the right time.
I'd check that man, just my two cents.

DeBurca

YbFocus wrote: »

So the gun is firing it's shot in semi and then drawing back the piston some distance back again?
It sounds as if the cut off lever isn't cutting it at the right time.
I'd check that man, just my two cents.

What you are describing is "overrun"
The cut-off lever is tripping the moving trigger contact so no more power is going to the motor
However the motor does not stop dead due to its inertia and the inertia of all the other moving parts, it take time for all the moving parts to come to a stop, yes it is a very short period of time but during that time those parts are still moving and will retract the piston a bit

As you have done a SHIM job and obviously a good job so as to reduce the friction of the moving parts and they now spin more freely in their bearings so they now take longer to come to a halt which will retract the piston further then before

So if you done like it this way then you have a few options
1/ fit and AB (active breaking) MosFet which when the cut-off lever trips the moving trigger contact then sends a pulse of current in the reverse direction which brings the motor to a complete halt mega quick
2/ fit an extra shim to the sector gear so as to make it slightly stiff and therefore increase the friction which will cause it to move less freely and the gearbox to have less overrun

Personally I would leave it alone and if it really bothered me I would then fit an AB MosFet
Under no circumstances would I EVER contemplate doing anything to undo the good work of a proper shim job by deliberately adding a extra shim and thereby introduce something into the gearbox that would increase the overall friction within the gearbox that could/would cause damage at a later stage

.K.A.L.I.M.A.

Thanks for the help guys. I'll open the gearbox tomorrow and have another look. I'm not the best at shimming gears (First time), so I'm just going to check that, or add an extra shim to the sector gear.

Just a video of what's going on:

biz96

DeBurca wrote: »

So if you done like it this way then you have a few options
1/ fit and AB (active breaking) MosFet which when the cut-off lever trips the moving trigger contact then sends a pulse of current in the reverse direction which brings the motor to a complete halt mega quick
2/ fit an extra shim to the sector gear so as to make it slightly stiff and therefore increase the friction which will cause it to move less freely and the gearbox to have less overrun

Option 1: correct
Option 2:eek:: incorrect
Dont fit any extra shim to your gearbox.

DeBurca

I think you may have misunderstood what I was saying about fitting an extra shim
Yes it will cause the gearbox to stop faster but it is doing it by increasing the overall friction levels in the gearbox and will ultimately cause damage
It was a suggestion with a lot of sarcasm implied which I obviously did not convey very well and I never expected it to be taken seriously

I have watched your video and just because the gearbox stops with the air-nozzle in the retracted position does not mean there is anything wrong
As I said due to the overrun of the gearbox it is has retracted both the piston and the Tappet Plate which also withdraws the air-nozzle, nothing wrong there

If you re-read my post you see that I stated that you had done a good Shim job and listening to the video I have no reason to change my mind
So my advice is leave it alone and DO NOT fit any extra shims

.K.A.L.I.M.A.

I'll leave the gears the way they are then. Any recommendations for an AB MOSFET? Not too dear, but able to do the job. If possible, are there any that you can just plug-in?

YbFocus

QUOTE=.K.A.L.I.M.A.;85683498]I'll leave the gears the way they are then. Any recommendations for an AB MOSFET? Not too dear, but able to do the job. If possible, are there any that you can just plug-in?[/QUOTE]

I've been looking at that idea too man because wiring and me don't go well together, I was going to buy an ASCU which is drop in but I've been hearing of problems with them.
In theory they sound fantastic, ditch the trigger area and put that in place of it, take out the ant-reversal latch and route the wires and job done!

Rooky1

The Vid you put up is of the ASCU 2 and are an extremely reliable unit in my experience. I have personally fitted 8 of that particular unit and never had one come back. I have 2 in my own AEGs as well with no problems.

The newer ASCU3 is an all enclosed unit and to be honest is not a simple drop in fit as they suggest and it has a couple of problems with it as well. Trigger response is not en par with the ASCU2. But they have since revised this unit to address those issues.

Personally the Chimera MK2 is where I would spend my money.

There are also loads of just AB mosfets available.
The Extreme Fire ones being my favourite, although Fireworks Airsoft do a copy of that unit and it works very well indeed.

Most of the AB Fets will have to sit in your stock tube if you are rear wired, so this can be a pain if you don't use a crane stock or a full stock.
If you are front wired it shouldn't be a hassle as the units only really take the same space as a fuse assembly.


Should of mentioned as well that your vid of your gearbox sounds and performs normally as has already been said.
An AB Fet will get it stopping much quicker and give you a much improved single shot:-)

.K.A.L.I.M.A.

Mentioning the Chimera, I went back through the 'Reviews' section and I just had a quick read of you'r review about it. I also watch the video as well. You'r opinion, as of now, of it?

I'm not looking for something expensive, or to increase the ROF, as I'm pretty happy with the way it is now. If it has AB, it'll work perfect. I'll do a bit of research on the Extreme Fire and Fireworks Airsoft.

Just to mention shimming, I'm s***e when it comes to it (First time, as mentioned). Motors connectors snapped in the wiring, so to pass the time, cleaned the gears and shims, and spent two hours shimming the gears. I got them to the point where I like them now.

Rooky1

Very happy with the Chimera, but from your replies you aren't looking to spend that kind of money.

Fireworks AB mosfet; (UK based)
http://fireworksairsoft.webs.com/apps/webstore/products/show/1229407

Extreme Fire; (US based)
http://extreme-fire.com/2011-SW-AB-LONG.html

The fireworks is a copy of the Extreme fire one. Both work well.

Both offer AB and a resettable fuse. You will have to wire these into your gearbox and store the unit in your stock tube as mentioned before.

.K.A.L.I.M.A.

Rooky1 wrote: »

Very happy with the Chimera, but from your replies you aren't looking to spend that kind of money.

Fireworks AB mosfet; (UK based)
http://fireworksairsoft.webs.com/apps/webstore/products/show/1229407

Extreme Fire; (US based)
http://extreme-fire.com/2011-SW-AB-LONG.html

The fireworks is a copy of the Extreme fire one. Both work well.

Both offer AB and a resettable fuse. You will have to wire these into your gearbox and store the unit in your stock tube as mentioned before.

Cheers for the links Rooky. I think that the FireWorks should fit the job. I'm using a battery pouch on a LE Stock, so I should hopefully fit it in there.

Rooky1

.K.A.L.I.M.A. wrote: »

Cheers for the links Rooky. I think that the FireWorks should fit the job. I'm using a battery pouch on a LE Stock, so I should hopefully fit it in there.

Battery pouch is cool, but I would fit the mosfet into your stock tube. Less likely hood of the mosfet wires being damaged.

Southern Dandy

.K.A.L.I.M.A. wrote: »

Cheers for the links Rooky. I think that the FireWorks should fit the job. I'm using a battery pouch on a LE Stock, so I should hopefully fit it in there.

I use the GATE NanoAB fet, I was not going to suggest it to you on a account that it will not fit in the buffer tube but as your using a battery pouch it should do the job. Cheap, easy to install, does the job.

http://www.gatee.eu/index.php?option=com_content&view=article&id=56&Itemid=27&lang=en

A few AB options to pick from. I would order directly from them, some retailers put quite a significant markup on these units. GATE.EU customer service is excellent, Marcin is a gent and will answer all your questions.

.K.A.L.I.M.A.

Southern Dandy wrote: »

I use the GATE NanoAB fet, I was not going to suggest it to you on a account that it will not fit in the buffer tube but as your using a battery pouch it should do the job. Cheap, easy to install, does the job.

http://www.gatee.eu/index.php?option=com_content&view=article&id=56&Itemid=27&lang=en

A few AB options to pick from. I would order directly from them, some retailers put quite a significant markup on these units. GATE.EU customer service is excellent, Marcin is a gent and will answer all your questions.

Seems like a nice MOSFET. What's you'r opinion on it, and are they standard deans, or the mini?

Southern Dandy

.K.A.L.I.M.A. wrote: »

Seems like a nice MOSFET. What's you'r opinion on it, and are they standard deans, or the mini?

Standard deans. What I can recommend though is get yourself some heatshrink to give the two communication cables a little extra mechanical protection.

But yeah they are a decent bit of kit. If your looking for a bog standard mosfet with an AB then I'd look into my suggestion. What Rooky suggested is no doubt an excellent choice if your looking for a fet with a multitude of programable settings along with all the other bits and bobs then I'd go with Rookys recommendation.

Rooky1

The Gate mosfets are a nice unit indeed.

The 2 units I suggested (extreme fire SWAB and the Fireworks one) are just AB mosfets with resettable thermal fuse. There isn't any programming functions with those.

My personal favourite is the SWAB, I have fitted loads of these to my own and others aegs without failures.
The fireworks one is a copy of it and works just as well and is a little more affordable.

They both fit comfortably in a standard stock tube.