1200mmX900mmX170mm 4axis cnc

[Nickhofen]

Any thoughts about the design and the dimensions of the steel tube I use?

[Clive S]

Any thoughts about the design and the dimensions of the steel tube I use?

I think 3mm is a bit thin for tapping into

[Nickhofen]

I think 3mm is a bit thin for tapping into

Hi Clive.
Nice input,thanks!
I will then go for 50x50x4, maybe?

Nick.

[Paul3112]

Hi Clive.
Nice input,thanks!
I will then go for 50x50x4, maybe?

Nick.

Hi, May I ask what rails/tracks/guides you are using and what is the method of attachment? What do you want to cut?
The span of the section is where you need to pay attention. Mass/stiffness can be your friend.
Welding can be you enemy with shrinkage and distortion. The 50 x50 x3 might be used for bracing , but the main rail support might be stiffer with 75 X 50 X 5.0 RHS.
Tool load and weight of the material you are cutting will also dictate frame material properties. Sorry not many answers and a lot of questions.

Paul

[Nickhofen]

Hi Paul, thanks for your participation to this thread.
Rails I am planing to use HIWI linear square rails, attached with screws .
I am planning to cut wood mainly and I will be glad if the machine can cut aluminum also,I know that I can not have a cnc that can do both works well, so the main purpose is to build a cnc foe woodworking-guitar building.
Thanks for the input about the main rails, i will use it at my upgrate workbench design.

[Nickhofen]

I have a lot to learn....

[Nickhofen]

Is there a reason not to go with that design on the bench?I mean the lower section for the 4 th axis? The bench will have a movable section at the one end that will cover the 4th axis and when is needed I will remove that part so I can machine big parts that are going to be heleded at the A axis.

[hanermo2]

You will probably dislike my advice ..
Which is unfortunate, since it is excellent and will help You a lot.

All, absolutely all cnc and mills/routers/machines depend on rigidity.
A common error using linear guides is comparing the max strength of a linear guide to actual work, or load.

A typical old manual lathe, 11-12", has 50 metric tons "strength".
But cutting loads are 50-100 kgf.

The reality is that modern machine tools are about 2% loaded at max vs strength.

[Nickhofen]

Thanks for the advice Hanermo2!
What do you suggest me to do ?
Hola to Sevilla ,Malaga,Barchelona....I can't recall other cities I have visited,it's been a long time.

[Nickhofen]

Fail number one!

And the fail number two is that I make a hike for an e-stop and one for emergency stop...