big budget cnc

[pet30]

Very interesting

https://www.youtube.com/watch?v=fwbkWM0mWfs

what are your opinions for this type of linair rails? could i use them

my budget was about 2000€ but i think i will need a lot more.

[Desertboy]

Very interesting

https://www.youtube.com/watch?v=fwbkWM0mWfs

what are your opinions for this type of linair rails? could i use them

my budget was about 2000€ but i think i will need a lot more.

Looks a lot better than makerslide but still not proper rail! If you want actual production you need to expand you budget

I think if you double the budget you could build a very decent machine

[Boyan Silyavski]

That rails could be good for a month, but will need constant tweaking later. Its a better solution than roller bearings or V rails but... I dont know how you value your time but when actually working, any hit and miss day will cost you hundreds of $$$ missed profits.

My opinion again is to buy used machine, some times people from forum sell good ones. or pay sb to do it for you and start making money from day 1. Yes i build my machine, but it was a do-all-extraordinary and if i have to buy similar i have to pay more than 20k for it so there was a reason for the wait. But for pure woodworking, i wouldn't think twice and buy even Chinese, so to start making money faster

[pet30]

Bying a cnc here is stil 20.000 euro or its a old machine etc.
I will go for the supported rails not the bearings.

Now the problem is i still have that big gantry of 3000 mm

How would you guys make that gantry strong so it don't flex and twist?

if its really difficult then i have to turn the machine 90° so the gantry is 1600 mm .

[Desertboy]

I'd extend the frame a little so the gantry can move out the way completely so you can remove the work piece then it's irrelevant which way the gantry is. If you mount the hiwin's and ballscrew on the sides you can enclose them enough that when you access the piece it's not an issue.

Go for 1.6m gantry NOT 3m simple any other choice is just nuts.

[Boyan Silyavski]

if you make the gantry like my gantry/ look at my signature, second build/ it will work perfectly at 3m span.

BUT:

-you will need 3m straight edge, not 2m. So instead of 250euros you are looking at 500-600euros. And nope, you can not build a machine like that without straight edge that spans on top of the longer rails/ Y and A/

-it will weight 250kg. Thatch not a problem but you will need servo motors which are expensive even second hand


Basically you want to build a machine like that so you have smaller machine that could do bigger jobs. Thats the reason for that setup.

I dont understand why is the problem? You only have to load it from side, so just make that side rails lower than the working bed. Thats all.

[pet30]

thats a good idea i would have never thought on raising the bed of the cnc

then i will go for a 1600 mm gantry i think this is the best and strongest .

a beam of 160x80x5 mm will not work then?

mayby it best to take your cnc gantry design then.

can u give me advice on witch steppermotors to use?