[Patuc]

Hello,
I will build X axis 1900 mm, Y axis 1500mm, Z axis 500mm cnc machine. But I can't decide which design to choose. I will use for X axis ball screw and 2 stepper motors for both side of x axis. I think about something like this:
https://id2cnc.files.wordpress.com/2...ht_woodtop.jpg
https://id2cnc.files.wordpress.com/2...axis-sbr16.jpg
https://id2cnc.files.wordpress.com/2...axis-sbr16.jpg
https://id2cnc.files.wordpress.com/2...axis-sbr16.jpg
https://id2cnc.files.wordpress.com/2...axis-sbr16.jpg

In photoY axis linear rail is not in one row, but one rail is on top, I think to make both rails in one row.
For X axis screw is over the rail, so I think make like this how it is show in photos.
Or maybe for X axis rail have to be not on top, but on the side like this: http://www.probotix.com/image/cache/...9-1140x380.jpg

I will make frame from steel ractangle (http://cdn.shopify.com/s/files/1/036...g?v=1452298597)

[Patuc]

Are there people who can help? Or this forum is died?

[Patuc]

143 views and no help, sorry, but cnc zone is died. May be someone can recommend another forum which is active?

[iwaskevin]

Ask in the router table forum

[Patuc]

Ask in the router table forum

I feel sorry for you, this your answer show that you have no imagination, sorry, but if you want make a joke, you have to try harder why you post sarcastic amazon link? https://www.amazon.com/gp/search?ie=...e&linkCode=ur2
Or you have no idea that I ask about CNC frame? This your answer just prove that cnc zone is old and there is no people who communicates.

[hanermo]

This is a communications problem, ...
We don´t understand what You are asking.

Also, it is common to have done some work and suggestions, yourself, asking for ways to improve a particular proposed solution.
Also, You are proposing making a machine of vast work envelope.

The approx cost of same will be somewhere in the 10.000-15.000€ range.

Are You aware of this ?

Usually, anyone planning something like this is doing so with industrial money, and not a hobby build.
Ie a commercial-use machine, for making money.
Industrial use would never use round rails, but profiled rails.
Industrial use, ie commercial, will almost never use steppers today, but servos.
Commercial use means a toolchanger with a drawbar, ie ATC spindle.

Going from y: 1200 to y:1500 increases your work cube or volume about 25%.
Now the machine needs to be 25% more rigid, and 25% more heavy.

Z: 200 to 500 mm increases 2.5 times or 250%.

Total = 250 % x 25% = 3.15.

If a mechmate-style on linear rails == 800 kg, for you solution your machine should be somewhere around 2000 kg or more.

And the z axis gantry should be about 250x600 mm in 10 mm (+) steel, on widely spaced size-25 linear guides.
This would give about 350 mm z axis movement.
Hope this helps.

For reference, I have a machine of this size, on x, z and potentially y.
It is about 10x more rigid than a mechmate, as it is a mill and not a router.

It is a double-column milling machine, with moving table.
A bridge mill design, ie not a moving-gantry like most routers.

The "gantry" is about 700 kg in mass, and only goes up-down on z.
Uses 12 linear trucks, on 35 mm linear guides, for rated 50 tons rigidity.

It is still very very light, relatively, and I use 20 mm thick tool steel everywhere.
No mild steel rectangles.

My widest spacing is 1600 mm on x, workpiece size, with 1200 mm movement on x.
This means the beams need to be 2000 mm tall, front and back, and 20 mm thick tool steel.
So they are 2200 x 200 x 20 mm, about 100 kg each.
Size 35 mm linear rails, 2200 long, are another 15+ kg, each.

A router could use thinner steel, like 10 mm.
Still, it is a major undertaking.

Just finishing the last upgrade has taken 6 months, and another 1200-1400 kg steel, and == 600 work hours.
The rigid, fixed columns, are 200 x 400 mm boxes, at each end. 1500 mm tall.
20 mm front and back, 10 mm steel sides.
2 ribs, 20 mm thick, 200x400x20 mm, in middle, for box-in-box construction.

Just pointing out that a really large work envelope has serious implications in mechanical terms.

My expected rigidity (z axis, vertical) is approx 0.03 mm / 80 kgf load, or better.
= 800 N / 30 um = 26 N/um.
HTH.

[vegipete]

why you post sarcastic amazon link?

That link was not put there by iwaskevin. The forum software adds these (sometimes annoying) links by itself as a way of helping to pay for this site so we can have a place to come and complain about not being instantly helped.

Rails are harder to align if they are not on the same plane. If you can fabricate with adequate precision, rails mounted on different sides of the structure can be a bit stronger because the rails are farther apart and because those split bearing blocks are stronger/stiffer in certain directions compared to others.

[zevrap99]

This is a communications problem, ...
We don´t understand what You are asking.

Also, it is common to have done some work and suggestions, yourself, asking for ways to improve a particular proposed solution.
Also, You are proposing making a machine of vast work envelope.

The approx cost of same will be somewhere in the 10.000-15.000€ range.

Are You aware of this ?

Usually, anyone planning something like this is doing so with industrial money, and not a hobby build.
Ie a commercial-use machine, for making money.
Industrial use would never use round rails, but profiled rails.
Industrial use, ie commercial, will almost never use steppers today, but servos.
Commercial use means a toolchanger with a drawbar, ie ATC spindle.

Going from y: 1200 to y:1500 increases your work cube or volume about 25%.
Now the machine needs to be 25% more rigid, and 25% more heavy.

Z: 200 to 500 mm increases 2.5 times or 250%.

Total = 250 % x 25% = 3.15.

If a mechmate-style on linear rails == 800 kg, for you solution your machine should be somewhere around 2000 kg or more.

And the z axis gantry should be about 250x600 mm in 10 mm (+) steel, on widely spaced size-25 linear guides.
This would give about 350 mm z axis movement.
Hope this helps.

For reference, I have a machine of this size, on x, z and potentially y.
It is about 10x more rigid than a mechmate, as it is a mill and not a router.

It is a double-column milling machine, with moving table.
A bridge mill design, ie not a moving-gantry like most routers.

The "gantry" is about 700 kg in mass, and only goes up-down on z.
Uses 12 linear trucks, on 35 mm linear guides, for rated 50 tons rigidity.

It is still very very light, relatively, and I use 20 mm thick tool steel everywhere.
No mild steel rectangles.

My widest spacing is 1600 mm on x, workpiece size, with 1200 mm movement on x.
This means the beams need to be 2000 mm tall, front and back, and 20 mm thick tool steel.
So they are 2200 x 200 x 20 mm, about 100 kg each.
Size 35 mm linear rails, 2200 long, are another 15+ kg, each.

A router could use thinner steel, like 10 mm.
Still, it is a major undertaking.

Just finishing the last upgrade has taken 6 months, and another 1200-1400 kg steel, and == 600 work hours.
The rigid, fixed columns, are 200 x 400 mm boxes, at each end. 1500 mm tall.
20 mm front and back, 10 mm steel sides.
2 ribs, 20 mm thick, 200x400x20 mm, in middle, for box-in-box construction.

Just pointing out that a really large work envelope has serious implications in mechanical terms.

My expected rigidity (z axis, vertical) is approx 0.03 mm / 80 kgf load, or better.
= 800 N / 30 um = 26 N/um.
HTH.

Wow. Can you share a picture of your machine

Thanks