Commercial Style Cartesian Bot

Please take a look at my design, It's taken from commercially available linear positioning systems, and is fully modular and relatively cheap. Using 3 bipolar stepper motors in a

yes, true...
but with that alone you can't do the job.
You have to built a frame that lifts the x-axis to have the vertical movement BELOW the z Axis not above (where it is at the very moment),
then you'll figure that you have a serious problem with a tilting y-Axis what makes you come to the conclusion that you need to have support on both ends of the y-Axis.

And you'll end up with something completely different again

'sid

btw, is that the new autodesk inventor?

Thanks for the suggestion Regarding the z axis, but I had thought of the y-axis, I

Version 2.1



Thanks sid, you were right about the z-axis.
how about this one then?

Anthony

um...

well...
If you add a second zAxis it'd be fine
That way you not only need static support but a second zAxis.
And because the zAxis is mounted on the xAxis.. another one of that too

Those modules are very nice but connecting all three together is not that a good idea.
Mount all on one frame but independently (connect just x and y or y and z)

take a look at hydraraptor, nophead uses modules like that for example.
That's a good layout (the frame could be stiffer, but who cares)

'sid

ps google sketchup? wow pretty close to the output of inventor (not regarding the workflow nor interface and such just the result I can see here)

Edited 1 time(s). Last edit at 10/22/2008 07:36PM by sid.

I don't see the need for another z-axis, or x-axis...

Could you please explain...
thanks

sure..

as soon as you lift the zAxis the yAxis will surely tilt.
No matter what kind of frame you have you'll need a guided support on the "free end".

And even worse than that as soon as you move the xAxis the guides have to move too, therefore you need a second xAxis (both the second x and the second z don't have to have a stepper they can be moved by belts for example)

I can't imagine how your frame would look like to support that layout.

Just take a look at nopheads hydraraptor and see how he mounted the parts
(x and y are sled to sled connected afair)
Or take a look at some cnc portal mills (most commercial cnc mills are portals)
See how they are constructed and let the inspiration do the rest

'sid
And for comparance:
my layout (rendered with inventor9, see.. not much difference //backgroundcolour is a matter of preference)

Of course, your's, Sid, depends entirely on the rigidity of the rods you're using.

it surely does.

The rods in the rendering are much longer than in the final cartesian.
they are 600mm long on x and 450 on y) the final cartesian is more likely 450 x 350 for x and y because they're only 10mm in diameter.
but the longer rods make a much more elegant picture for a rendering
for the same reason I didn't show the baseplate motors stabilizers threaded rods (well they take too long to render because they are threaded not only bumpmapped)
and some other minor parts.
If I'd go for a size like that I'd upgrade the rods to 16mm at least ...
especially for enough rigidity to do some minor milling too
But let's not talk about that one here, I just wanted to show how close the sketchup rendering is to a inventor rendering that's all

But I'm sure we will find the time to talk about my cartbot some other day

'sid

ps and now, its 2:30 am and my eyes start to drift off. gn8 everyone

ok... I think I understand.

But if I slightly Mix V2.0 and 2.1, this will mean I only have to add another x-axis, and not another z.



I think I'll add a rail system for the other x-axis. using 4 skate bearings and a "T" shaped piece of aluminium.

Edited 1 time(s). Last edit at 10/22/2008 08:54PM by Pheobot.

Here you see the y-axis carrying a 300x300 mm printing plane. The x-axis forms the crossbar of a gantry mounting the z-axis. You mount the extruder on the xz working plane and let it print on the y printing plane.

[3dreplicators.com]

Here you see the x-axis mounted on the y-axis forming an xy printing plane. The z-axis is mounted on a cross-bar gantry and carries the extruder.

[4.bp.blogspot.com]

If you have a good support on the free end of the yAxis this may work.
I'd go for six skatebearings and two aluminium angles of ~130

I'm in the process of making "those Linear Stages" as an alternative to a standard

Good luck!
The aluminium L shape extrusion you can buy at the hardware store here are known not to be perfectly straight sometimes.
So check twice

Did I see correct.. no guideing rods.. just the L-shapes?
Do you intend to grease or do you have some sort of ptfe foil material to make it slide easily?

'sid

Aluminum on aluminum has a terrible friction coefficient.

construction of the printer

Hi, friend folks need to build the printer to make solid designs, I can help, as comienzzo, Thanks

OK, got it...
Al on Al, BAD.
Guideing Rods, GOOD.



I'll see what else I can come up with for V3.

Thanks for all your help.

I notice that you have direct connections from your motors to the threaded drive shafts. This I found to be one of my main problems on rep strap Bertha. My inability to get the shafts perfectly aligned to each other caused unacceptable wobble.
Here is how I solved this problem. [repstrapbertha.blogspot.com]

---

Bodge It [reprap.org]
=======================================

---

BIQ Sanguinololu SD LCD board	BIQ Stepcon	BIQ Opto Endstop
BIQ Heater Block PCB	BIQ Extruder Peek clamp replacement	BIQ Huxley Seedling
BIQ Sanguinololu mounting	BIQ standalone Sanguinololu or Ramps mounting	Print It Stick It Cut it

My rep strap: [repstrapbertha.blogspot.com]

Buy the bits from B&Q pipestrap [diyrepstrap.blogspot.com]
How to Build a Darwin without any Rep Rap Parts [repstrapdarwin.blogspot.com]
Web Site [www.takeaway3dtech.com]

Or you can simply go the mcWire path and use some silicone tube, faster and easier to "make" (i.e. cut to desired length), cheap and best of all it's almost impossible to ruin your stepper or cartesian even without endstops

'sid

I used windshield washer tubing...like the kind you have in your car for the autowindow washer. I used 1/4-20 althread and it worked out great. Just another option if you happen to have that sitting around.

Demented