NordicCNC's build log

[JAZZCNC]

Ok well I'll answer this question seen as he's mostly following my design.!

It always makes me smile when I see comments like these because while the physics shows that what you are saying is the ideal location the reality is that it makes no difference to the machine and how it works.

To prove this point I'm going to give you a challenge.! . . . Industry demands the highest cut quality and performance, so logic dictates that they would follow the physics and optimum location very closely.?

So go find me a machine from the major manufacturers that place the spindle smack between the bearings.! . . . If you find one then I guarantee you'll have seen ten before it that don't.!! . .. In fact, you'll be lucky if you find any with spindle inside the bearings.!

You all need to stop worrying about the physics and virtual world so much and get building so you can realize just how little if at all, these affect a real-world machine.!

Exhibit: A

Can I just ask what the benefit is of using blocks of profile to sit the gantry profile on, as indicated in the picture?

It seems because of this you were forced to place the bottom linear rail on the front, thereby pushing the spindle further away from the gantry. I'd always though that the idea is to try and keep the centre of gravity of the spindle as close as possible to the bearing blocks the gantry rides on.

This is not in anyway meant to be a criticism, but just me trying to understand if this design means there are benefits to it that outweigh the spindle being pushed further outward.

Cheers

To answer you directly Joe, then to place the gantry further back to bring spindle into line with bearings would actually weaken the machine not make it stronger. To do what you suggest without getting into complex gantry side designs means using plates for gantry sides that can flex side to side and introduce vibrations at the tool.
I can tell you from building many different designs of router that the design he's using is the best possibly way to build a router without getting silly about.
Mike is correct in that having longer distance between the bearings is good but thats a trade off between travel and foot print of the machine. In the grand scheme again it makes very little difference.

As a rule you ideally want the spindle IN the same envelope as your X axis bearings, i would make the distance between these bearings further apart.