Input on machine design. Metal machining. 1200x2000x500mm

**Join** · 04-12-2017, 05:56 PM

Hi.

My name is John, and have been working with CNC machines more than 7 years.

Now I want to build a big 3-(4-) axis CNC router to carve steel (and lighter materials).

Machine design it's not my forte and because of that I feel the need to discuss design with the people that come from a more experienced background when it comes both to design and machining.

I am building a garage with a upstairs room/workshop at home.

Limitations:
#1: Due to building restrictions my upstairs will be only 1,89 metre tall.
#2: Weight. Due to building limitations of the garage, the machine can be max 1000kg, and say a work piece of about 500kg.
#3: Size. The room will be about 6,6x4 metre, there will be stairs for access, a door to a storage room and a work bench, so moving gantry router seems the way to go.
#4 Power supply. 230V 63A due to wiring to my house.

The idea is to build a machine capable of precision work, that can do hard machining in steel and have some degree of speed to it.

I want to be able to line bore a engine block, facing, headwork, make a cast engine block?
Accept small series of work for companies and others. Tapping of M16-M20 thread.
Try to make it flexible for most jobs out there.
Double duty as a lathe? (4th-axis)

A lot of wishes but challenging limitations.

First off, what do you think?

-John-

Similar Threads:

**Join** · 04-13-2017, 05:11 AM

I have been looking at bigger machines hoping to scale down to my size.

**A_Camera** · 04-13-2017, 07:15 AM

Originally Posted by Join

...

First off, what do you think?

It is not clear for me if you want to build your CNC upstairs or on the ground floor. But...

That's a HUGE machine, especially if you want to make it metal machining capable. I don't think that it can be made as light as you want it with those dimensions and capabilities. Metal machining 1200x2000x500mm requires a huge mass and I don't think 1t is enough, especially if by "metal" you mean steel, but in that size even milling aluminium would be a challenge.

**Join** · 04-13-2017, 11:06 AM

Originally Posted by A_Camera

That's a HUGE machine, especially if you want to make it metal machining capable. I don't think that it can be made as light as you want it with those dimensions and capabilities. Metal machining 1200x2000x500mm requires a huge mass and I don't think 1t is enough, especially if by "metal" you mean steel, but in that size even milling aluminium would be a challenge.

Yes, I certainly have doubts in regards of size. Mass is the key-word in stability for roughing passes and precision work.

Maybe a horizontal mill design will do better here, the Y-axis can extend to the roof, the Z-axis can be longer due to working on short lengths except long bores etc.

For a 1000x1000xx1000mm work area the machine should be be able to fit into 2500x2000mm of space, and as close to the roof as possible. I can still do what I want to. That is acceptable.

Then there is weight. Is it possible to make it rigid enough within my limitations to run reasonable cutting data?

I got a deal with a local shop to borrow their tools and machines to fabricate parts.

I am building a 1000kg lifting arrangement and a opening from the main floor to the attic, to move stuff up and down.

**oscilloman** · 04-13-2017, 12:29 PM

Hello fellow Norwegian !

I have also been looking into designing and building a CNC machine for similar types of work. I ended up purchasing a vintage used machine. If you are lucky you can find a used machine that is mechanically sound. But might need to upgrade the electrics. Below i have listed a few sites that sells new and used machines usually for reasonable prices.
ltsmaskin.no
prmaskin.no
metalsupply.no
finn.no

I think that a machine that have a 1000*1000*1000mm work area and is going to machine metals without scattering is going to weigh several times more than 1000kg

-Mathias

**Join** · 04-14-2017, 10:22 AM

Originally Posted by oscilloman

Hello fellow Norwegian !

I have also been looking into designing and building a CNC machine for similar types of work. I ended up purchasing a vintage used machine. If you are lucky you can find a used machine that is mechanically sound. But might need to upgrade the electrics. Below i have listed a few sites that sells new and used machines usually for reasonable prices.
ltsmaskin.no
prmaskin.no
metalsupply.no
finn.no

I think that a machine that have a 1000*1000*1000mm work area and is going to machine metals without scattering is going to weigh several times more than 1000kg

-Mathias

Hello!

Thank you for your addresses. I have been looking around for used manual equipment, but to get a useable work-area, machines get too tall and heavy to fit my needs.

Last night I made a drawing with a horizontal milling design.

It went fairly well, ended at 850kg for the main structure and z-axis ram.

Then I added a 800x800x50mm steel plate for rigid x-axis, it came out at 260kg. Still ok-ish.
But, my choice of a 1000x1000x100mm work table that double duty as a rotary lathe-table ended at around 800kg alone!

Rotating that amount of mass, add a workpiece, possibly little out of center.. And I start worrying about the integrity of the main structure in the garage!

I got to drop the lathe-function here, as long as the machine is not bolted to a concrete foundation. A rotating b-axis should help mill most of the stuff that need turning.

So, around 1100 kg+ 1000 mm square work table(aluminum?), drives and other hardware..

I am hoping for a total design of around 1500kg.

**Join** · 04-14-2017, 05:31 PM

I am making a drawing, trying to scale the machine.

Is a 90mm shaft sufficient to support the 1000x1000x100mm aluminum work table on the rotating b-axis without flexing machining at maximum distance away from the connection point?

Is there a way to calculate the required shaft size without the trial and error approach?

Cheers.

-John-

**Join** · 05-12-2017, 03:48 PM

Hi guys.

I have been tinkering with two different designs. One that will let me have a work envelope xyz of 1000x1000x900 the one in the drawing and one router design with a xyz 1000x1000x750mm.

For this one I've made a drawing to get a idea of scaling and how it need to look, and weight.

What do you think?

-John-