Quick Q…
I know I’ve seen it answered before - but buggered if I can find it here!!! 
How do I HALF an active loop??? And how do I midi map it to a single button??? Can it be done without modifiers???
So - hit loop (set to Loop Size 8 bars), hit button x (Loop Size halved to 4 bars), hit button x (Loop Size halved to 2 bars), hit button x (Loop Size halved to 1 bar), etc, etc…
Also - I want the START position of the loop to change - NOT the end position… 
Help!
You can easily do it with the end position moving using the Loop Size Selector.
If you want the start position to move to create a loop roll effect, you’re better off using the Slip Roll effect on your DJM or the Beatmasher in Traktor.
I don’t think you’ve understood the question, makar1…
The Loop Size Selector will let you halve the loop on button press, but it will move the end position, not the start position.
If you want to create a loop roll buildup to a drop, you can use Roll or Beatmasher FX, or use standard loops along with a hotcue at the drop position, or even standard loops in Flux mode.
Edit: After trying out some mappings, you can halve the loops moving the start position. Map the “Deck Common: Move: Size Selector” and set it to Direct Mode, with the value as “Loop”.
Then map the same button to “Deck Common: Move: Move”, with it set to Button, and interaction mode “Dec”.
I found this post over at NI:
Works PERFECTLY!!!
I couldn’t figure it out.
addin(“loop size select + set”) → modifier(“is in active loop”, value=“0”) → type(“button”) → interaction(“direct”) → value(“forward”);
addin("loop size selector) → modifier(“is in active loop”, value=“1”) → type(“button”) → interaction(“Dec”);
addin("move) → modifier(“is in active loop”, value=“1”) → type(“button”) → interaction(“Direct”) → value(“forward”);
Then I set the move size to “Loop”, logically it makes sense, but I think you will need to use modifiers
The mapping I posted above works perfectly.
You still need to set a loop size and activate separately (not a problem with the Zomo’s Loop size select/activate Push Encoder!).
Then I just mapped a separate button for the Loop Size Half Mapping…
Move size as Loop seems to work fine without modifiers here, as long as you make sure to map the Mode Selector to Loop In.
I’m glad it works - but I just wish it was easier to understand HOW ON EARTH you’re supposed to fin out how to make these things work.
For example - how are you supposed to know that the “Cue/Loop Move Size : Loop” command HALVES the active loop???
I managed to make your mapping from scratch just before you linked it; the only thing I wasn’t aware of beforehand was the Move size: Loop, which removes the need for complicated modifiers.
If you think of it in the Increase mode, it moves the marker by the same amount as the size of the loop. Decreasing it by half is the only thing that makes sense, and performs the opposite of the Increase function.
Okay - odd thing. This doesn’t seen to work with Flux Mode.
Anyone know why that is? Flux mode doesn’t seem to engage unless the loop is stored as a hotcue???
Flux only works when you hold down a hotcue/loop, otherwise it won’t know when to go back to the normal track.
So no way of using my little Loop Half Size macro with Flux, then? 
Isn’t that by definition the DJM Slip Roll effect?
Do you use “Set Loop”? The flux mode would ignore “set+size” and “active on”.
These are the commands I use:
[quote]Map the following actions to one key to achieve this effect:
This way you halve the loop size by moving the end of the loop. You can do the same by moving the beginning (Mode : Loop In) forward (move : forward)[/quote]
It still works as along as you set the full size loop and store it beforehand.
Ok - that’s cool. But I’m talking about actual engaging loops in flux mode that you made a question for.
Map that set loop command in push encoder and you’re all set. If you still want to set certain size you can map loop size selector to the same push button
type = button / interaction = direct