One of the most controversial topics of conversation in the BattleTech universe is that of "scaling." This spawns from the question "just how big is a BattleMech anyway?" There is no real good answer and then the subject is complicated by the inconsistencies in canon drawings and descriptions, all accompanied by the fact that Battletech is an offshoot from Macross and that scaling just was "what looked good."
It's kinda like asking a StarWars geek, "So how many seconds/minutes/hours are in a parsec?"
Looking at the Mech miniatures for the tabletop game, even then things don't quite scale up. A spider standing next to an Atlas doesn't look like a 30 tonner vs a 100 tonner, the spider is too big in comparison. If you look at MWO, it's even worse, only in the opposite direction. I think about all we can do as modelers and collectors is to do things that make us happy and understand that when we share out our work, that there will be folk who have issues with it.
For me, as an engineer, what feels right is a volumetric comparison, and to do that, I need a base. I'm going to use the MWO Atlas as my metric of 100 tons and from that, whenever I build up something that's for me, use it as the basis. When I designed the Archer, I used my Timberwolf MkII and the Victor from FCY. The Timberwolf is a 90 Tonne 'Mech and the Victor is 80. I built up the Archer aiming to be just a bit shy on the mass than the Victor and I think I ended up getting it just about right.
In the end, I have the intent to display the 'Mechs against 28mm soldiers and also use them on the rare occasion we do 1/60 Battletech Games. With that as a base, my future plans will revolve around being able to fit 'Mech designs into those functions. Along with that, like every other model builder, I have to have a desire to work on that subject. Some folk like wwII hardware, some like space hardware, some like sci-fi.. As for me, I'm a Sci-fi Hardware kinda guy and there's something about the fluff of the Mechwarrior universe that is just fun. So, over time, I'll continue to build up the 'Mechs I like and have a desire to have adorning some display.
I really only went into all that to set up the conversation about the next one I am going to build up from scratch. I have two on the list that I want to build, both of which are primary scout 'Mechs I use in MWO: the Jenner 7-D and the Spider. Now, both of these 'Mechs are available via Thor in 3-d print, but sadly his scaling is true to the MWO world. That scaling is way off in my estimation for all the light 'Mechs. If an Atlas or King Crab scale out to 100 Tonnes, then the Spider as scaled in the game can't be more than about 13. So, if I want one, I'll need to build it and scale it up a bit.
Essentially, a Spider will be about half the volume of the Archer. Considering the size of the spindly legs and arms, which the Archer has beefed up a bit, the Spider will have to stand close to shoulder-height to the Archer. The thing is, the 'Mech has to have the internal structure and volume for the cockpit/pilot, the weapons, the reactor, etc.. etc. If I build it around the cockpit, then that will, I believe, help me with the scaling as well.
I'll have to play with drawings a bit, just to get a feel for the size and layout of the build, but going from one extreme to the other is tricksy.
I like both 'Mechs, but I find myself using the Spider a bit more at the moment, since my unit pretty much imploded. Running with PUGS, you need to be supportive, but also able to do a good job of fending for yourself. I find the ECM Spider to have the right combination of speed and survivability for PUG groups. The J 7-D is great for a swarm, but you really don't want to be running alone.