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Help upgrade my KM4 SR7


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#1 xXxBlizzxXx

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Posted 25 March 2014 - 12:37 PM

Just bought a KM4 SR7 and now I want to upgrade it internally/externally to achieve a higher ROF and change the outer barrel to delete the front side post. I'm currently running a 11.1 1800 MaH LiPo butterfly.  Any or all suggestions is welcomed and there is no budget.

Edited by xXxBlizzxXx, 25 March 2014 - 07:09 PM.


#2 BLATEY

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Posted 25 March 2014 - 01:35 PM

First if I where you I'd wait untill my warranty is up, if yours is then I'd be happy to lead you ( in the right direction... Hopefully) in making a reliable aeg.

#3 gcw360

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Posted 25 March 2014 - 03:51 PM

View PostBLATEY, on 25 March 2014 - 01:35 PM, said:

First if I where you I'd wait untill my warranty is up, if yours is then I'd be happy to lead you ( in the right direction... Hopefully) in making a reliable aeg.
Ditto that, And assuming the warranty is up, what ROF and FPS are you looking to achieve?

#4 xXxBlizzxXx

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Posted 25 March 2014 - 07:04 PM

View PostBLATEY, on 25 March 2014 - 01:35 PM, said:

First if I where you I'd wait untill my warranty is up, if yours is then I'd be happy to lead you ( in the right direction... Hopefully) in making a reliable aeg.
Hpnestly im not too concerned about the warranty, if it breaks I will deal with it :lol:

View Postgcw360, on 25 March 2014 - 03:51 PM, said:

Ditto that, And assuming the warranty is up, what ROF and FPS are you looking to achieve?
  And I havent chrono my KM4 ROF yet but posts generally say its around 20 and im trying to acheive 30 range and FPS isnt a big concern since its currently at 354 and my local field caps at 400

#5 tales

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Posted 28 March 2014 - 09:43 AM

View PostxXxBlizzxXx, on 25 March 2014 - 07:04 PM, said:

Hpnestly im not too concerned about the warranty, if it breaks I will deal with it :lol:

  And I havent chrono my KM4 ROF yet but posts generally say its around 20 and im trying to acheive 30 range and FPS isnt a big concern since its currently at 354 and my local field caps at 400

You can get around 30RPS or close to it without opening the gearbox. Im on the same budget as you. But you don't have to spend a lot.
Suggestions: a High Speed motor, ZCI, HC or SHS ( SHS run a little hot) I hit 30+ with a Lonex A1 & Tienly 4500 ($90) one of the best AEG motors my son uses.

Also you will need a 11.1V lipo  I hit 30+ RPMs with Azimuth full metal tooth piston, SHS ported full metal tooth piston & Madbull allen green metal tooth piston (great piston - pricy)  with a POM ported piston head. I don't see any problem with KWAs piston, I prefer metal teeth. Thats me. Also i never tried the ZCI, HC high speed motors. But i was told by seasoned players there great & easy on the pocket. I have tried the high torque motors, well built Good motors.

Links:
http://clandestineai...s&x=-349&y=-146

http://www.airsoftgi...oducts_id=16024

Something like this, higher mAh will be nice, try hobby king
http://www.all-batte...kpack31600.aspx

Just suggestions
Good Luck!

Edited by tales, 28 March 2014 - 09:51 AM.


#6 gcw360

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Posted 29 March 2014 - 06:42 AM

View Posttales, on 28 March 2014 - 09:43 AM, said:

You can get around 30RPS or close to it without opening the gearbox. Im on the same budget as you. But you don't have to spend a lot.
Suggestions: a High Speed motor, ZCI, HC or SHS ( SHS run a little hot) I hit 30+ with a Lonex A1 & Tienly 4500 ($90) one of the best AEG motors my son uses.

Also you will need a 11.1V lipo  I hit 30+ RPMs with Azimuth full metal tooth piston, SHS ported full metal tooth piston & Madbull allen green metal tooth piston (great piston - pricy)  with a POM ported piston head. I don't see any problem with KWAs piston, I prefer metal teeth. Thats me. Also i never tried the ZCI, HC high speed motors. But i was told by seasoned players there great & easy on the pocket. I have tried the high torque motors, well built Good motors.

Links:
http://clandestineai...s&x=-349&y=-146

http://www.airsoftgi...oducts_id=16024

Something like this, higher mAh will be nice, try hobby king
http://www.all-batte...kpack31600.aspx

Just suggestions
Good Luck!
All I would add to this is, if you go above 30 RPS at 350 FPS there is a good chance for pre-engagement of the piston.  Basically the piston hasn't come all the way forward as the sector gear reengages and you risk a piston failure.  I had this happen in a system I was running that was shooting 400 FPS at 33+ RPS.  My guess is that 30 at 350 would be close to the same dynamic.  I increased the FPS to 455 and the ROF was dropped to 30 RPS and no more pre-engagement.

To test for this you will need to take several (10) FPS readings of the FPS on semi-auto.  Then switch to full auto and check the FPS.  If there is a drop in the FPS then you are pre-engageing.  A tooth's worth of pre-engagement is like 10-15 FPS.  Another, less sensitive way, to check is to see if you range drops off on full-auto.  This would occur if the FPS id dropping from pre-engagement.  There are several approaches to fixing this.  They include dropping the ROF, short stroking, or lightening the piston body assembly (e.g., lighter piston, lighter piston head, Swiss cheeseing the piston body.  If you run into it, let us know.

Hope this helps.

#7 tales

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Posted 29 March 2014 - 04:17 PM

View Postgcw360, on 29 March 2014 - 06:42 AM, said:

All I would add to this is, if you go above 30 RPS at 350 FPS there is a good chance for pre-engagement of the piston.  Basically the piston hasn't come all the way forward as the sector gear reengages and you risk a piston failure.  I had this happen in a system I was running that was shooting 400 FPS at 33+ RPS.  My guess is that 30 at 350 would be close to the same dynamic.  I increased the FPS to 455 and the ROF was dropped to 30 RPS and no more pre-engagement.

To test for this you will need to take several (10) FPS readings of the FPS on semi-auto.  Then switch to full auto and check the FPS.  If there is a drop in the FPS then you are pre-engageing.  A tooth's worth of pre-engagement is like 10-15 FPS.  Another, less sensitive way, to check is to see if you range drops off on full-auto.  This would occur if the FPS id dropping from pre-engagement.  There are several approaches to fixing this.  They include dropping the ROF, short stroking, or lightening the piston body assembly (e.g., lighter piston, lighter piston head, Swiss cheeseing the piston body.  If you run into it, let us know.

Hope this helps.

OK, we did discuss this in 10 pages of PMs. With your help (and i thank you :D) all pistons including the ones you sent me were tested without any pre engagement (overspin yes) And they clocked 30-33RPS Also using the battery you recommended for a ROF test as my son uses semi  

You helped me get those numbers with parts i posted, and they worked!

This forum seems to have turned into a competition & not helping others, I hope I'm wrong! This post was unanswered for days, Then i get another drive-by :(

xXxBlizzxXx disregard my post, Sorry!

#8 gcw360

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Posted 29 March 2014 - 04:44 PM

View Posttales, on 29 March 2014 - 04:17 PM, said:

OK, we did discuss this in 10 pages of PMs. With your help (and i thank you :D) all pistons including the ones you sent me were tested without any pre engagement (overspin yes) And they clocked 30-33RPS Also using the battery you recommended for a ROF test as my son uses semi  

You helped me get those numbers with parts i posted, and they worked!

This forum seems to have turned into a competition & not helping others, I hope I'm wrong! This post was unanswered for days, Then i get another drive-by :(

xXxBlizzxXx disregard my post, Sorry!
Thank you for posting the results, I wasn't trying to undo the the good information you posted and was only adding, what I hoped would be, cautionary advise based on what I had recently seen in my own setup.  What you posted is spot on. My post was referring to a ROF over the 30 RPS you referenced.

I remember the exchanges we had and unfortunately I didn't recall the results that you are mentioning now.   I'm glad that you are able to confirm that there was no pre-engagement in your setup and thank you for setting the record straight.  I meant no harm in my post and certainly did not mean to seem competitive.  I hope you know from our personal exchanges that I only want the best for these Forums.

Again, my apologies for offending.

#9 xXxBlizzxXx

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Posted 30 March 2014 - 12:41 PM

View Posttales, on 28 March 2014 - 09:43 AM, said:



You can get around 30RPS or close to it without opening the gearbox. Im on the same budget as you. But you don't have to spend a lot.
Suggestions: a High Speed motor, ZCI, HC or SHS ( SHS run a little hot) I hit 30+ with a Lonex A1 & Tienly 4500 ($90) one of the best AEG motors my son uses.

Also you will need a 11.1V lipo  I hit 30+ RPMs with Azimuth full metal tooth piston, SHS ported full metal tooth piston & Madbull allen green metal tooth piston (great piston - pricy)  with a POM ported piston head. I don't see any problem with KWAs piston, I prefer metal teeth. Thats me. Also i never tried the ZCI, HC high speed motors. But i was told by seasoned players there great & easy on the pocket. I have tried the high torque motors, well built Good motors.

Links:
http://clandestineai...s&x=-349&y=-146

http://www.airsoftgi...oducts_id=16024

Something like this, higher mAh will be nice, try hobby king
http://www.all-batte...kpack31600.aspx

Just suggestions
Good Luck!

I really appreciate the motor options. Im going to try the tienly motor. Battery isnt a issue though since I already run a 11.1 1800mah.




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