Stell frame cnc 1500X1000. Adjustable table your opinion please

[ba99297]

After so many months of studding the cnc world, i finally realize that that the myth about lightweight gantries ( that i had in mind ) bites the dust. I am talking about my machine and not for every cnc. Thanks to Deans advices and thanks to Jonathan calculator, i see that 20-30 and even more kgr at the gantry weight doesn’t affect torque needs of the motors. I understood that the most torque will be needed to move pulleys and ballscrew than the gantry that slides on the carriages. Also Syliavsky Eddy, and Ger21 mention that. Thank you every one. After that i will make some changes to Y axis and then go on with the Z axis. So far my gantry weights about 65-70 kgr( without the motors ballscrews of y axis and without the Z axis that need to be designed.
A last photo of the gantry



Vagelis

[JAZZCNC]

Hi Vagelis,

Sorry I've not been replying to your emails or thread but I've been very busy. I've just today managed to open the file you sent me so have a better idea and can see it's mostly what you posted here.

As I told you before and now others have also confirmed for you that Gantry weight is not such a big issue with Servo's so won't go further on about this.! . . What I want to point out thou is that your complicted Jigsaw puzzle won't really stop the steel from warping while welding.
10mm plate needs serious heat to weld even with Tig and you will experience some warping and for this reason I suggest you design the gantry so it can be welded up completely then important surfaces machined after it as stablised.
Because of your welded and fixed ridged gantry design then you have less areas of adjustment so it becomes important surfaces are machined true and parallel.

I think I've said this before but really for cutting wood then this design is massive overkill unless your planning on attaching a high powered spindle cutting deep and fast 12hrs a day.!
I know your thinking to cut Aluminium with the machine but even then the gantry will be strong enough for light/medium duty work. If you want deep depth's of cut and high quality finish then the size of the machine and Gantry router design will be more the limiting factor not just the Gantry design or strength.

End of the Day you CANNOT have the perfect all round machine at this size so My advise Again is to build it to be the very best it can be for the Purpose you intend to use it for most.! . . . . . . I would rather have a machine that is excellent at one thing than just average at anything and you will only have one or the other.!!