Definately a scrapyard challenge

[Jonathan]

Don't need to worry about being inferior because of K:E bull shit

I think you'll find just about everyone apart from you agrees kinetic energy isn't 'bull shit' and is very important, I'm not even going to argue this point because it's so widely accepted. No matter if a machine is made in a home workshop or professionally, it can't escape the laws of physics. A 3nm Nema 34 motor wont go as fast as a 3nm Nema 23, it's due to exactly the same calculation!

my machine use's 5mm pitch geared 2:1 it's absolutly no problem and in no way limits the performance. Actually IMO it's a bennifit because it's just a simple belt/pulley change to gain resolution.

As far as I'm aware you've not tried 10mm pitch rails on your router, so I can't see how you could possibly know that. I'm well aware that you don't respect calculation, and that might well be true for you, but for just about everyone else, calculation plays a hugely important role, and if it didn't work like you say, the theory simply wouldn't be there.

it's just a simple belt/pulley change to gain resolution

That clearly also applies to 1610 so it's not a benefit. Since you only recognise empirical evidence, your version of the Mayan calender I cut on 1:1 looks amazing.

99.9% of the time you'll be lucky to cut any where near quarter the speed 10mm pitch allows.!

It's not about cutting faster, it's the acceleration gain from using 10mm pitch that's most important. You told me your acceleration on the Y-axis is 900mm/s/s, with 5mm pitch. I now have mine set to 2000mm/s/s with 10mm pitch (more shakes the machine too much).

I get the impression you think I'm saying 5mm pitch won't work, seeing as you say "it will work fine". I agree with that, but when designing a machine I think it's foolish to aim for it working fine, you should aim for it to work as well as possible, not just well enough and 5mm pitch screws will simply limit the potential of your machine.

I'm not going to say anything more on the subject since apparently it provokes a particularly strong reaction, I think motoxy has all the info to make an educated decision. Good luck.

Motoxy: There's a quote for that - The more I know, I know, I know the less. (John Owen)