When does a set become a MOC?

At the moment I am having a bit of a run at building a number of MOC's and also modifying some official sets.

I have been thinking about the point where an official set becomes a MOC and can be classed as this. I have generally been referring to the models which are based on an official set and then modified as a MOD but again I am not sure what the point is where it is fair to class them as this? Is changing a few parts the same as building a whole new section and changing the main functions to work in a different way?

Thoughts please

My gut feel is anything that starts as a set (or someone else's design) is a MOD, anything that is completely original is a MOC.

if it originates from a set, it's a mod. if it's from scratch and looks fresh, it's a MOC.

If you make a slight change or just a colour change.....MOD......but if it's a totally different creation that the set was then you can call it a MOC.

From the other point of view, when does a MOD cease to be a set?

This loco below, 117, has instructions for motorising as displayed. I have further accessorised with an automatic direction changer and stopping brick for safety. If I went further and added lights, or even Electronic stop/go gear, these are structural changes in addition to ones already made, albeit with contemporary parts. It's a semi-official MOD, and arguably within the manufacturer's intent for potential accessorising.  

Converting to Power Functions or modern couplings would make it a straight out MOD.  

The carriage behind is from Super Train Set 119, but I have simplified the end platforms and replaced magnet with hook couplings to recreate the US Sears catalogue set 118. It's a MORC (my own re-creation) as the idea is completely someone else's. However, because I have shortened the wheelbase to reduce friction and drag on curves, because unsupported brick wheel mounts have very loose attachment, it's 100% a MOD, even for very subtle reasons.  



That I was too lazy to attach the antenna to the station building makes it incomplete, but not a MOD.   

The younger minifigs on the platform are just waiting for the train after, so again, the station is not a MOD.  

Maybe we should invent a term like MUD for when it really isn't clear.  

I guess there is some fog about when the amount of change to a set takes it to another level....but still a MOD is a mod and MOC is still a MOC !

McSet?

With cheese.

Breezy wrote:McSet?

With cheese.

Will you have fries with that ?   

With low calorie salt.

Breezy wrote:With low calorie salt.

Chicken salt ? LOL

Oh, man talking about off-topic ? LOL

You could establish MOB rule by referring to My Own Build.

Same meaning as MOC isn't it ?

Though I like the idea of MOB rule ! LOL

Interesting topic... I have always thought anything elaborated on from a set should be a MOD. Like when I made my modular bank, I considered that a MOD because I used several elements from the set design, but it's quite different to the original set:

This:


Turned into this:


I still consider it a MOD.....

Wow. Really. Wow. Great improvement! A very stylish building as a result of your changes.