I put together a short video showing how the Fostech Echo functions.  As you can see in this video it uses two functions to prevent hammer follow.  First is a trigger block, the trigger cannot be pulled unless the carrier is closed.  Second it uses a back up disconnector on a cam.  This prevents the hammer from dropping unless the trigger is pulled all the way to the rear.

Here is the video:
https://youtu.be/u4Q404KWGUM


The back up disconnector is cammed off the hammer by the trigger block when the trigger is fully depressed.  In this picture I've got a small bushing around the back up disconnector's cam surface.  The bushing causes it to release earlier.


I'm not a video pro, I shot the video with my phone and didn't do any post video processing.  Hit the pause button a few times and that's it.  Thought some people would enjoy seeing it work.

Looks like a lot of stuff that can break.

It definitely has a few extra moving pieces.  I haven't read of any parts breakage yet, but it's still new and only time will tell.  It's a great way of legally getting a reliable 700RPM capable carbine.  Controls like full auto, so I enjoy it

The Franklin Armory Gen III BFS is definitely a simpler design.  I'll probably make a short video on it in a few weeks showing how the hammer is used to change the disconnector position every cycle.

Nice video. I like your custom mods to the display housing.

Thanks Mike. It didn't turn out nearly as pretty as I wanted. Milling on a drill press never looks pretty, lol. It does let me see the hammer block interface which I wanted exposed.

thanks for taking the time to make the video , it really helps visualize what's going on in there

Your welcome   It's been fun playing with the jig

Go on.  Drill one more hole.  A big one.  

I need more range time with this thing

Thanks man. You are making another purchase decision easier to justify.

Glad I could help

are you going to make a video about how you filed down the bolt carrier?

I'm not sure it really deserves it's own video. I just took a dremel to it and put a bevel on the trip surface. I removed just enough to let the carrier fully close.  Here is a picture.


I should point out that while I removed enough material to work in my rifle, it wasn't enough to work in mbell's rifle. It needs to be cut to the length that works best in your rifle. If you don't remove enough the carrier gets held partially open by the trigger block. The upper may not close on your rifle and if fired it might prematurely peen the trigger block. The bolt is also going to unlock earlier than it should because the cam pin is already part way down it's path.