[Calico]

It'c a Mill CNC with 1.3meter square of travel moving table.
load is 100Kg max

does anyone have a good idea how to build rigid cheap construction table ?

is it made of Alumunium or any metal ?
plywood ?

any website / photos about this ?

regards
ruddy

[chuckknigh]

That's just 4 feet 4 inches of travel for each axis. Members here have built machines over 4x8 feet in size.

Take a look around the board and look especially at some of the older threads. Lots of big projects in there. Also check out the CAD_CAM_EDM_DRO list on yahoo, as well as DIY-CNC on the same site.

Having said that, there are certain similarities between most of the big machines. Common parts of their construction included a metal framework, made from either 8020 aluminum extrusions or tack welded cold-rolled steel, and a freestanding framework. Most of them are also moving gantry designs.

You could build it out of anything you want, though. ParaLam beams, for example, are strong, stable, and cheap...

Be prepared for some sticker shock, though. Cheap can be a VERY relative term, especially when talking about big routers.

Have you built a smaller one, yet? You could use a smaller one as a learning experience, and use it to produce parts for the big one.

-- Chuck Knight

[skippy]

Chuck, I think Calico's looking for a fixed head/moving table setup.

Calico, why do you need a moving table style instead of moving gantry style? What clearance/height do you need from bed (table) to end of cutting tool? i.e. how high are the jobs you need to machine? When you say "Mill", are you sure you don't mean "router"? Mill GENERALLY implies: super heavy construction to cope with milling steel using a large diameter cutter (i.e. huge forces/strength required). The term router GENERALLY implies: lighter construction to cut non ferrous or plastic materials using maximum 1/2" (13mm) tool bits (remember I said generally). What materials will you be trying to cut/mill?
Phil

[ger21]

http://www.campbelldesigns.com

[Calico]

thanks guys for helping me out.
I think Mill is the word, Router is more to little for me.

my Z travel is 45cm
X and Y travel is 1.3 meters
I choose moving table because the material I'm going to cut is less than 100kg.
may be 50kg.

the Z axis I bought is 20kg, I'll post the picture as soon as I got the stuff arrived .
I bought second hand from Panasonic brand,

the material I will cut is mostly wood and Epoxy/fiberglass.
I'll cut alumunium also if capable.
What I'm trying to make is a molding for fiberglass.

I know I prefer over weight/size, but I think I'm going way way way to far, it's because I already bought the Z axis 45cm travel which is 20kg.
I can;t explain in detail because of my language is not good. but I'll post it.

here is my draft draft frame
please any comment are welcome,

rud

[skippy]

If I'm understanding your drawing correctly then:
(A) the Z axis and spindle or router will be mounted on the front side of the "bridge" and when it descends, the force will be applied to an area of the table that is not supported (an area that is overhanging the support bearings). The two rails will transfer the weight back to the support bearings no problem but if it were mine I would lay the bridge back a bit to form a triangle with the back supports and from there go straight up vertically to mount the Z axis assembly. this way the tool bit descends to a point directly above the front crossbrace and front bearings.
(B) If your drawing is to scale and you have +/-1.3m between the uprights, then it would seem that your X axis I beams and rails will be at least 2.6m long which is going to be expensive and heavy as well. Once again, if it were mine I'd make the X axis I beams and rails about 2m long (1300mm of the table plus 700mm of support). Unless of course, you're going to use some "el cheapo" system such as steam pipe or whatever, in which case a bit of extra length won't matter.
Phil
p.s. let me know if you can't understand what I'm saying and I'll draw it up (in 2D and very basic of course) in AutoCAD for you.

[Calico]

please make a drawing to explain

rud

[skippy]

Personally I would go with a gantry style machine modified to suit your long travel of 45cm in the Z axis. You're not going to be milling steel so I don't see the need for a moving table/fixed head design. Unless I'm mistaken, moving table/fixed head designs are normally only chosen when heavy forces are involved (eg. milling steel with a big cutter/tool bit) or a complex or super-heavy head design is involved (5 axis mill or laser for example). Anyway it's your machine and your choice so as promised, here's a rough CAD drawing. 1300 x 1300mm working area with 600mm in the support area equals +/-1900mm rails with a 450mm travel Z axis. As you can see, a long travel Z axis presents certain problems to obtain the full clearance (i.e. for a job that is +/-430 high to pass under the bridge. I also included a drawing of how I interpreted yours and you can see that the tool comes down (and applies force to) to an area that is unsupported PLUS by having the tool descend with the area supported by the bearings you are reducing the length requirement of the rails. Let me know if you prefer dxf instead of dwg.
Hope it helps
Phil

[Calico]

Phil,
thank you for the drawing, I see now, by doing your design the spindle/cutter can be "supported", compare with my design, specially when cutting down deep.

I choose moving table is because of the load is lighter, I'll upgrade to 5 axis later on and it's more accurate using moving table.
correct me if I'm wrong, any comment please do....
hey I'm learning here and you are the teachers... that's why i'm here.

regards
ruddy

[skippy]

Hey Ruddy,
here's a machine that looks surprisingly like what you're talking about except bigger.

http://www.nmine.com/5axis/images/CN...to-Motion3.jpg

I can't remember why but I was doing a search (cnc) at Google Images when I came upon this one. It seems to be a good source if one is looking for cnc building ideas.

EDIT: I just clicked on the homepage link to that machine and it turns out the guy who built it is located in the next major town (Valencia) north of here (Alicante). Strange thing is the claimed working area of the table. In the picture it looks huge but he claims:
5-axis workspace 750 x 400 x 250 mm
3-axis workspace 950 x 600 x 350 mm

Phil

[ger21]

Phil, that's a commercially manufactured machine. http://www.cncmotion.com/multiaxis.htm

[skippy]

Oops, you're right. I read the info on his website http://www.nmine.com/5axis.htm a bit closer now and that would explain the size difference. i.e. what he wants to build versus the picture shown. What threw me was the statement "it was built with.....(components)" but in fact he was referring to the manufacturer. As well as that there's a cncmotion sticker on the front corner of it. Gonnngggg!!!!