1200mmX900mmX170mm 4axis cnc

[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.

[Nickhofen]

Bump.....!!!!!

[Nickhofen]

A guy near by me sells one of those as a kit, only the frame, are there any good ?
If I drop some Nema 23 ,3 or 4Nm.
http://www.cnc1.eu/en/KH1000GSKIT.htm
What a headache.

[johngoodrich]

hi. I think your design will be much stronger than the one you have linked to.. There should be no problem with the removable section for your 4th axis as long as it lines up with the rest of the bed

[cropwell]

Looking at that link, my first reaction is that the gantry sides are way too flimsy. They need some triangular bracing at least.

[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.

[hanermo2]

Hi nickofen !
*Everything* depends on your goals ..
and capacity and productivity depend on rigidity above all else.

Ex.
I could cut about 0.1-0.2 mm deep with a typical setup, using a 50 mm wide 4 insert apkt facemill.
(12" Lathe, upgraded ac servo spindle 2.5 kW continuous.)
I built a modular vice using 4 pieces of 50x100-300 mm solid tool steel billets, cross-drilled for 16 mm hardened industrial grade 12.8 bolts.
Vice took 3-4 days to do, and the 4 parts mass == 50 kg.

I could then cut the same piece, about 200x200x80 mm, with 3.4 mm deep cuts at double the rpm.
The difference in productivity is about 10:1 - 20:1.

I don´t think there is a "right" answer, but vastly bigger and heavier and thicker is usually the right choice for *everything* in lathes and mills and routers.

They deliver about 20x the performance, typically for 100-150€ more in steel costs and 2 days extra work in assembly work and fitup, per assy.