Ok so I promised a picture tutorial of using dorco carts with the head blade system, here we go!
First off, this is the dorco twin blade cart attached to the head blade sport adapter (which DOES fit on the atx. I've done it many times with no issue. Disregard any statement saying the sport adapter does not fit on the atx). The twin cart requires no mod and fits out of the box.
Here is the dorco pace 4 cart (think hb4) but this all applies to the pace 6 should you prefer 6 blades. First is the cartridge with the dorco adapter we will remove shortly and I set the atx adapter next to it for an early visual.
Simply take a pair of tweezers and wedge them under the dorco adapter to gently pop it out. You can set the cart on a dish towel or hold the sides with your fingers so you don't get cut.
Here is the dorco adapter almost fully off the cart, this is just a visual so you can get a better idea of how it comes off to reveal the slots for the atx adapter posts.
This is the cart with the dorco adapter fully removed and the atx adapter below it, unattached, so you can see what all three separate pieces look like.
And finally here is are two pics of what the dorco cart looks like after their adapter has been removed and the atx adapter attached.
The first couple times you do this it may take you a few mins but honestly by your 3rd-4th cart you'll have this done in 10 seconds tops. It's really easy, saves you a ton of money, and they give great shaves!
I just want to say again, make sure you either hold the cart on the sides or set it down on a dish towel. If you go about it properly you won't get cut but still we are dealing with sharp razors here so exercise a degree of common sense and you'll be just fine. Hope this all helps!
Happy shaving !