Building a precision based 5-Axis CNC for metal work

rajhlinux · Jul 21, 2020

Don't ask why, don't advice to buy one.
Tell me how to build one.

There was a troll at a different forum "hobby-machinist.com" and I got banned for asking this simple question and for pointing out the troll, amazing...

Anyways, with all the trolls put to the side, how can I build a commercial grade 5-Axis CNC lathe?

4ftx3ftx3ft is that a practical size for a 5-Axis CNC for hobby use?
Tolerance of +/- 0.001mm (doesn't have to be exact)

How can I make the cast iron base from scratch?
Water cooled ball screw, how much do they cost?

What would be the practical steps in building one?

Similar to these:

Thanks

theperfessor · Jul 21, 2020

Too many steps to list, if you have to ask how you probably can't do it.

310 Guy · Jul 21, 2020

rajhlinux said:
How can I make the cast iron base from scratch?

Simple. Make a mold, truck it to a foundry and say "Fill 'er up!" Nothing to it...
:popcorn:

thesidetalker · Jul 21, 2020

±1 micron for hobby use? lol

rajhlinux · Jul 21, 2020

Doesn't the cast iron have to be perfectly straight and symmetrical? I'm also thinking to water cool the cast iron frame as well. I heard in the larger commercial 5-axis CNC the frame is water cooled, not sure it will be overkill for a 4x3x3 build. Will do anything for increase of accuracy.

rajhlinux · Jul 21, 2020

I honestly meant +/- 0.001mm

Milland · Jul 21, 2020

You seem to want step-by-step directions on how to build your fantasy machine. I regret to tell you that none of us on the Forum are knowledgeable enough to do so.

So I would suggest that you enter a college and study mechanical engineering. In the course of your work, you can review casting methods, metallurgy, metrology, kinematics, thermodynamics, electrical theory, mechanical system analysis, tribology, stiffness and dynamics of servomechanisms, advanced calculus and computer programming, and all the other elements that go into a machine such as the one you want to make.

After you've spent twenty or so years on all the coursework, you'll be ready to design your machine. And when you're done, you'll be able to come here and tell us how you did it.

Good luck, we're rooting for you!

TheBigLebowski · Jul 21, 2020

It's literally not possible for one person to build this. For chits and giggles, lets say you have a lot of equipment and employees at your disposal, then I would start by designing the machine base.

For this you will need a cad software capable of advanced simulation, probably catia or nx. Expect to pay at minimum 50k for a single seat, perhaps 100k total so you can put several people on the project.

You are going to need to design the machine base in such a way that thermal growth is uniform in all directions. If expansion is uneven, You will not even be able to hit 1/20th of your desired accuracy. Once you are getting close to a thermally stable design, you also will need to begin stress analysis with the saddle mounted to the machine in various positions. Remember that 0.0001" of curvature under the saddle will cause 0.0008" error at the tool holder if its 10" from the machine base!

I expect the above design process with take dozens, perhaps even several hundred iterations. Its important to note that some of the more complex simulations take several days to compile even when you have big network based data centers at your disposal. I expect the design on the machine base to take several years and 500-750k in labor/software costs to complete.

Once you have the machine base design complete, several years and three quarters of a million dollars from now, follow up with a post in this thread and I can give you next steps.

ChipSplitter · Jul 21, 2020

I know you don't want troll responses, but this is just begging for it......... :crazy:

I know you don't want to hear this either: Just buy one.

You (and your wife) will thank me later.

Bill in PA · Jul 21, 2020

Dan Gelbart's shop-built CNC lathe/grinder (good to 1 micron):

High precision air bearing CNC lathe and grinder - YouTube

Bill

Hardplates · Jul 21, 2020

Milland said:
You seem to want step-by-step directions on how to build your fantasy machine. I regret to tell you that none of us on the Forum are knowledgeable enough to do so.

So I would suggest that you enter a college and study mechanical engineering. In the course of your work, you can review casting methods, metallurgy, metrology, kinematics, thermodynamics, electrical theory, mechanical system analysis, tribology, stiffness and dynamics of servomechanisms, advanced calculus and computer programming, and all the other elements that go into a machine such as the one you want to make.

After you've spent twenty or so years on all the coursework, you'll be ready to start all over again but with electronics engineering, then when that is done if you're not 200 years old you'll be ready to design your machine. And when you're done, you'll be able to come here and tell us how you did it.

Good luck, we're rooting for you!

Fixed it for you

Booze Daily · Jul 21, 2020

Maybe talk to the Swissmak guy.

Milland · Jul 21, 2020

Booze Daily said:
Maybe talk to the Swissmak guy.

He's been quiet lately - did the Tongs get him?

DDoug · Jul 21, 2020

It's obvious you want US to doo it for YOU.

And for FREE.

Please try asking over at the cnc-zone.com

EmGo · Jul 21, 2020

ChipSplitter said:
You (and your wife) will thank me later.

Wife ? There's room in mum's basement for a wife ?

DDoug · Jul 21, 2020

No problem-o
Start with this:
Shop Tools and Machinery at Grizzly.com
Add qty (5) steppers, and run it all with Mach 3...or is it Mach 4 now ?

footpetaljones · Jul 21, 2020

rajhlinux said:
Don't ask why, don't advice to buy one.
4ftx3ftx3ft is that a practical size for a 5-Axis CNC for hobby use?
Thanks

If you mean travels with those numbers, you are looking at a multi million dollar machine. Your expectations are seriously out of line with reality. Look at the specs of Matsuura's and Yasda's; their machines are +40000 lbs to make parts the size of a dinner plate.

Even just a cooled ballscrew that long that would be thick enough not to whip would be over 20 grand, to start.

You might consider it "trolling", but you are trying to hit a home run with a toothpick and everyone here and on your other forum are not trying to be assholes by telling you that you do not have the resources to do this.

rajhlinux · Jul 21, 2020

I know it seems like what I'm asking for is like rocket science, but seriously it really isn't, I bet someone will come up with a hobby friendly consumer grade affordable benchtop precision 5-axis CNC.

Logically, I do need a team, it seems like I really want to build a legitimate company aiming for the hobbyist who needs the same level of quality and precision control at his desktop.

Let's be practical, how about we start a serious open source project and then commercialize it?
I know that statement is weird since "open source" is generally geared towards software and hardware...

But hey, it's literally no big deal, if I really need to, I could just go on linkedin.com and find myself a PHD mechanical engineer who specfically builds, advices and engineers on making state of the art 5-axis CNC machines.

rajhlinux · Jul 21, 2020

Booze Daily said:
Maybe talk to the Swissmak guy.

I sure will...

rajhlinux · Jul 21, 2020

digger doug said:
No problem-o
Start with this:
Shop Tools and Machinery at Grizzly.com
Add qty (5) steppers, and run it all with Mach 3...or is it Mach 4 now ?

This is what we need more, solutions...

Building a precision based 5-Axis CNC for metal work

Cast Iron

Cast Iron

Cast Iron

Stainless

Cast Iron

Cast Iron

Diamond

Aluminum

Titanium

Hot Rolled

Stainless

Titanium

Diamond

Diamond

Diamond

Diamond

Aluminum

Cast Iron

Cast Iron

Cast Iron

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