My new 6040 improvement plan.

[Zeeflyboy]

I wouldn't bother tbh... just get it up and running. If you want to revisit ideas later on after having actually put some use on it then do so.

The biggest flex for me on the unsupported rails came from the ability for it to twist (eg apply a force on the bottom of the cutter which is after all where the cutting forces come from) pushing it towards the back of the machine. The top rail will bend forwards and the bottom rail will bend backwards. The deflection is very measurable (and even visible) with quite moderate loads. Your solution of the rear panel doesn't do anything to change that, nor does a single wheel. Two wheels would go someway to solving half the equation (the rail being pushed towards the back) but not the other half (the rail being pulled away from the back). Even then I doubt you would see much benefit with the wheel slop/flex/wear.

In the nicest way possible, don't try to re-invent the wheel on this one. Get your machine up and running, get some use on it and if you find you need to improve on it then feel free, but in all honesty you'll probably come to the conclusion that you are better off building a new machine than trying to improve the 6040.