This could do with balancing for sure. Its so op it makes upgrading to electric mining pointless. Energy-less mining, at a speed far greater than any mining drill can compensate for, at a super cheap rate that is so cheap that you could practically reach launching a rocket in a day with it.

Make the factory take energy to run.

Factory should have inventory slots, not one infinite slot.

Change factory costs to something Tier 3, the red microchips that I forget the name of.

Make the bots cost something more, red electronics and some high end things.

Energy usage goes up per bot on the factory, or bots have their own energy requirements and must recharge.

Factories have bot slots, one bot per slot perhaps with research to increase slot counts.

Research increases their abilities and efficiency and whatnot by smaller amounts, not a huge 20% bonus per research.

Lots of things to help re-balance this. I don't expect it'll happen though, as there's a lot of people who use this and I'm sure they prefer it as OP as it is. I just wanted to voice some thoughts though, because this would be nice if it were balanced. I thought it was really fun and interesting. Hell, it could have been interesting to use with regular robots and have construction drones drop ores into that open portion at the top and all fly out of that entrance there on the front but anyway, was a neat mod still.

Well, this mod obviously makes the game a lot easier. But there are settings where you need that to happen. Depending on the difficulty the player wants. I recommend this one and the dangOreus mod. I would say it makes dangOreus playable.

If you think it's OP, then don't use it. I find it very useful for complex mods that add complexity to production and you don't have to worry about ores and mining drills setup.
Agree about the power though. I think at a minimum it should require power to operate.

The robot workers are basically free to craft, costing next to nothing at all.

The building doesn't take anything to run, pretty much.

It mines 10x faster than any drilling field could ever accomplish.

There is no way to say that this isn't over power. :P It seems like a cheat mod to me, or more like a demo mod that was made to showcase or test code which ended up resulting in a cheaty mod.

I was merely hoping to see if we could balance it to something that'd be more for the standard challenging gameplay without you having to go out and find mods that make ore harder somehow.

It was made because I enjoy making mods and this was fun to work on

If you think its overpowered that is an opinion you are entitled to,
I don't think adding some restrictions or 'balance' makes the mod more fun,
I also don't think its not balanced just because its 'free'. Its not free in terms of pollution, which is a much more meaningful mechanic than just a bit of extra electric drain.

I don't think building 100+ mining drills is fun, I don't think wiring them to electric network is fun,
This mod was made specifically to not have to run power and build 100 entities to mine some ore, if that isn't what you're looking for then this isn't the mod for you.

The license is open if you want to fork it and add your own limitations or costs, electric charge should be easy enough,
something like making the mining drones eat sandwiches is also possible, and probably more meaningful

Fish 'n' Chips Mod for Mining Drones?
...actually sounds kinda fun, honestly.