[cad] Cnc Prototype Idea...

[Brunow]

CNC PROTOTYPING MACHINE
-----------------------

Idea:
-A table size (700x500mm) machine witch is a 3D "printer" (mainly wood - Plastic's)
-CHEAP! (500€ - 600€)
-Use of materials (profile's) witch i can buy from my work
-Work size: Y = 500 x x = 300 x Z = 250

CNC elektronic's
3x 1.3Nm steppers & Drivers
40V
Some gearing (1:3)
MAX COST: 250€

CNC Mechanic's

xyz movement:
-RVS (inox) Leadscrew P:1.75mm (3x 1M ==> 9€)
-HDPE nut (testing fase - Company garbage = FREE)
-SKF bearings (25x ==> €?)

-Slide bearings ... Still looking around, i'm thinking about Composite dry sliding bushings...
Composite dry sliding bushings... How good are they?

Any suggestions are more than welcome!

[Brunow]

Ow yeah i guess i have the perfect cnc design

[cncbob]

Interesting design... I do have two suggestions though.

1). Take care when selecting the diamter of your rails. Due to the size of your machine, it will be difficult to keep them from flexing too much with them being unsupported like that. Just do your homework and it can be done.

2). The interface between the x and z axes looks like it will cause some problems. Since the tip of the spindle is so far below the actual mounting of the rails, the cutting forces generated will cause these rails to deflect. Be careful to design the mount for the z axis in such a way that it is supported in at least two points that are a few inches apart.

Otherwise, I think you are on to someting here.

Have fun designing/building!

[Brunow]

Interesting design... I do have two suggestions though.

Thank you!

1). Take care when selecting the diamter of your rails. Due to the size of your machine, it will be difficult to keep them from flexing too much with them being unsupported like that. Just do your homework and it can be done.

The use of hollow rond rvs (inow) is a good start i think. Maybe relooking at the supports not that bad idea

2). The interface between the x and z axes looks like it will cause some problems. Since the tip of the spindle is so far below the actual mounting of the rails, the cutting forces generated will cause these rails to deflect. Be careful to design the mount for the z axis in such a way that it is supported in at least two points that are a few inches apart.

Yeah some people told me the same thing. Adding some serious guide's and supports would do it

Otherwise, I think you are on to someting here.

Have fun designing/building!

Yeah! thanks mate!

[Brunow]

I did some more thinking about the rail flexing problem...

Now find a way to mount my leadscrew's and i'm back in action!

[Brunow]

Yet another update.

I've been looking for a way to reduce the costs and improve the lineair guide system. You can use lot's of (good!) premade proven system's,
but they are all ... not the thing i'm looking for.

I have a (x) profile that i can buy for a good price so why not use it as an guide? I've been visiting a teacher who is working everyday with axson. Where we will be experimenting with .

So for now a version 3 of my machine.

Hope you like it