I've started this thread because i think there's a few people in the same boat as i was, i bought a Vinten Vision 3AS head and wanted to be able to swap my camera quickly from tripod to shoulder mount to steadicam.
What's needed is a Manfrotto 357 adaptor, NOT a 577, the 357 has a bigger plate, they both use the same receiver but the 577 doesn't fill up the receiver so a bigger locking block is used.
The 357 almost fills up the Vinten head, it's not quite wide enough, by about 2mm.
So what i did was pack out/inwards the Vinten receiver by sticking a slither of plastic, (a piece of ruler actually)to the angled part of the head to make the receiver not as wide, now the Manfrotto 357 plate drops in the same way as the Vinten plate does.
The only other modification is to the Manfrotto plate, 2 of the lugs on the underside need to be filed away, a 2 minute job, when the Manfrotto plate is dropped into the Vinten head one of the lugs on each side of the plate stops the plate sliding so that full adjustment isn't possible.

357 , the one needed
http://www.collegecameras.co.uk/images/products/mn357.jpg

577, the wrong one
http://www.westbuy.ro/poze/313_logo%20manfrotto%20577.jpg

Hope this helps someone.
Paul

PS sorry about the picture quality, they're just mobile phone pics.

This is great advice, Paul. I'm in the same boat (trying to complete a totally swappable system: shoulder mount-to-tripod-to-steadicam and reverse) and this one is a very good suggestion. The only piece left, for me, was the head because I was wondering how to make my rig interchangeable between my Zacuto, Steadicam Pilot and the tripod head (planning to buy the 5AS). Now I've the answer, thankyou!

Just a question for you about the head. I would like to know, between the 3AS and the 5AS, the one to go. I would use it with my HDSLR body+lens+mattebox+followfocus+zacuto mini base plate+external HDMI monitor. Does the 3AS handles well the weight or it's better to move to the 5AS, in your opinion?

Thanks!

Ciao,

Emanuele

The head depends on how much weight you will be putting on it.
My 3AS head easily handles my EX1 with 2 wireless receivers and a gun mic.
The 3AS and 5AS are the same body, just different springs, so my adaptor method will work on either head.

Paul.

Thanks! ;)