Piston tooth shaving/ determining AoE(angle of engagement)

original article by: sdobbins
AoE or angle of engagement refers to the angle of the first tooth on the sector gear as it comes into contact with the pickup tooth on the piston. Here is a picture before adjustment:




Note the poor alignment angle of the sector gear. In order to correct this a shim or buffer material must be used to move the piston body back. The goal is to align the piston so it contacts the first tooth on the sector gear with the most surface area possible.
Here is a pic of the piston head with a shim.




heres the washer in between the piston head and piston youll need a longer screw to secure it on tightly




I use a 2 part nylon washer although only one is pictured, a smaller one to fit he piston head post and a larger one to match the size of the head. The larger fits around the smaller washer and they are not stacked. This is the less desirable of the two options as the strength of the piston assembly is compromised. The prefered method is to add rigid foam or soborthane rubber to the piston or cylinder head. It is available from a couple different websites and is worth the $10 for a 4x4 sheet. I use the 1/8" 70 hardness with great results.
Here's a pic after AoE adjustment.



Removal of piston/sector gear teeth

There are 2 reasons to remove teeth on the piston and sector gear , pick-up timing and short stroking.
Pick up timing refers to the aligment of the piston and sector gear to provide optimal surface contact and avoid interference which leads to piston/gear failure.
Short stroking is done to increase ROF. By removing teeth from the sector gear the psiton is not drawn back as far thus creating a shorter cycle time which equals higher ROF but a lesser FPS. Removing the corresponding teeth on the piston is not necessary but the teeth are strictly dead weight at this point so I remove them.
Here is a picture of a AE piston that has had the second to last tooth removed, the third to last shaved to avoid contact with sector gear's 2nd tooth, and two teeth have been removed of the front to allow for a shorter stroke.



Here's a picture of a potential interference with high ROF setups:


That's the reason for removing one or two piston teeth:



Original post by sir.Corvid

The two teeth removed are the ones you need to take off. On this piston you can also see the results of premature engagement on the other teeth. The pickup tooth is showing signs of being run at high speed without the piston's angle of engagement being adjusted. It has only been used for a short time however: that kind of wear is normal when using a brand new piston with the AoE correctly adjusted. It stops at this point, and does not progress. Without the AoE adjusted it simply gets worse.


before

after

short stroking






thanks for viewin!!!!!!ayuyahhhhhhh!!!!!!!!!!!!!!!!!

Would be good if you could add credits to the owner of photos 9, 10 and 11. If you don't know of the owner, I'd be most interested as to where you found those photos.

My apologies sir corvid! found the pics in either of the 7 airsoft websites I've been surfin (FAS, airsoft mech.,Evike,airsoft retreat,BAC,ACM,AGL) might have mixed up some, kindly acknowledge if these are your photo's,so i can address the credits to you or the owner. The airsoft community would have been so greatful to this contribution.

No worries bro, virtually everyone does give credit when
they use those photos. Unfortunately the odd few don't, and when someone else
then uses them they are unable to give credit to the right person, or can only
credit the wrong person!

Cheers,

Corivd

Well said sir! and thank's for visiting and even registering in our website. Your welcome, and we would like to hear more from you.

hooorahhhh!!!!! but I'd rather say Ayuyaaaahhhhhh!!!! our native version battle cry... :boogy:


Mr.suave