can you feel my heart?
Alrighty, I'll start off by helping you with this one part, at least. :c
...Where to begin? There are quite a few problems with this specific Pokemon alone. Firstly, let's take a look at Machamp's base stats:
Special Attack: 65
Special Defense: 85
Machamp's best stat is its Attack. When you make sets for Pokemon, you very generally want to work with their best stat, with a few exceptions. Giving Machamp a Choice Band is a step in the right direction, but not all the way. Focus Blast, the move you have listed first, is a special move, meaning it uses Machamp's Special Attack stat. Looking back at the base stats, his Special Attack is literally half of his Attack. It'd be much better to use a powerful physical Fighting-type move than an unreliable special move. Which one, though? We'll get to that in a second.
Do you know what a Choice item does? It increases a stat (depending on the item: Specs = Special Attack, Band = Attack, Scarf = Speed) by 1.5 times as much as it was before... the equivalent of a +1 boost (like a Howl, for example). But they come with a restriction - when you use them, you're stuck using the first move you pick. Now, what good would being stuck into Substitute be for you? When you're using a Choice item, you should almost never run non-attacking moves because they'll usually get you locked into a move that does nothing and forces you to switch out - a great situation for your opponent. So running Substitute on a Choice Band Machamp is definitely a no-no.
When you build a set for a Pokemon, you have to try to take advantage of the things that make it good. Machamp, for example, is really good but for one particular reason - it has this ability called No Guard. No Guard makes every move hit when Machamp's out, no matter what. This means that Machamp can use moves like DynamicPunch, a move that's really powerful but usually no one uses it because it has 50% accuracy! DynamicPunch & No Guard should -always- be on Machamp because that's what separates it from other bulky Fighting-types like Conkeldurr.
The next thing is something that isn't too easy to explain, at least to someone who's just beginning. Earthquake isn't a very good move to run on Machamp. Do you know why? It's because Ground- and Fighting-type moves have very very similar coverage. For example, Ground hits Steel super-effective... and so does Fighting. Ground hits Rock super-effective... and so does Fighting. Ground does no damage to Flying types... and Fighting is resisted by them. You'll get more mileage out of running a different move to give you more type coverage. :)
Also, a small note, you should run Stone Edge - you don't have to worry about it missing because of No Guard.
Lastly, on EVs: 255 looks like it's maxed out, right? But it isn't! The games calculate the increase in stats from EVs by numbers divisible by four. Therefore, every 4 EVs = 1 stat point. When you hit 252 EVs in one stat, you can't get any more boosts out of it - and when you have 252 in another, you have 6 EVs left over. These can be invested in another stat to give it a little bit of oomph.
So let's run over everything:
1. When you build a set for a Pokemon, play to their strengths, whether that's an ability or a stat or anything!
2. Make sure you know exactly how your items & moves work.
3. EVs can only be maxed at 252 - the extra three won't help! Invest them in another stat.
If you've followed along with me so far, I'd like to see if you can patch up that set a little bit. I think I explained mostly everything but to check your understanding I'd like to see what you got out of that tl;dr. :)
Flame orb gives you the same boost as choice band and allows you to change moves. If you want to use a choice band use machamps no guard ability. Replace Focus punch with dynamic punch and substitute with something else. Cant think of it right now
Ehhh, not really. You shouldn't run Substitute + Flame Orb unless you want to die of external damage, without the opponent even attacking you. Plus, like I said ^ up there EQ is bad coverage with Fighting-types. No Guard is what makes Machamp good - if you wanted to run Flame Orb you should use Conkeldurr, who has Guts, a higher base Attack, recovery in Drain Punch, and priority in Mach Punch. Guts Machamp is really just not as good as Guts Conkeldurr.