PDA

View Full Version : CNC 4th Axis at work



Lee Roberts
30-07-2009, 07:31 PM
Hey,

Just found this video of a 4th axis in action, i liked the design he was cutting and also think its a good example of what you could do if you went for a 4th axis !


http://www.youtube.com/watch?v=O-RzYjSPzP4

Is anyone looking to add a 4th axis or ?

Lee

BillTodd
30-07-2009, 10:03 PM
Is that a 4th axis or merely a rotary X or Y?

John S
30-07-2009, 10:05 PM
Is that a 4th axis or merely a rotary X or Y?

?????? Sorry can you explain the difference ?

.

BillTodd
30-07-2009, 10:25 PM
?????? Sorry can you explain the difference ?

.
I was expecting to see 4 axes in motion.

John S
30-07-2009, 10:42 PM
Here's one I did earlier :dance:


http://www.youtube.com/watch?v=fps0OR1eF_s

Ignore the dancing about, the X3 was on a transport stand ready to go to the 2006 Harrorgate show and the castors were not locked down.

This is another gear but instead of being done on a rotary table or 4th axis this one is just done in X, Y and Z fixed in a chuck bolted to the table.


http://www.youtube.com/watch?v=RV8Dq6mslnE

The model came out of a CAD parts file off the web as an STL file, programmed in Vectric's Cut3D and cut with a 2mm ball nose cutter.
The video shows the final clean up pass in the opposite direction to remove some of the cutter marks.

It could have been a lot better if I had reduced to stepover but as I'd not done one before I didn't want to waste a lot of cutting time if it didn't work.

Never got round to doing a finer pass gear and some bastard nicked that one anyway [ probably Kip :whistling: ]

Spiral helicals are one of the hardest type of gear to cut and a one off can take well over a day to cut in a home shop.

.

BillTodd
30-07-2009, 10:47 PM
Yup that's a 4th axis alright...didn't think much to the "action"....it was cutting fresh air!

When is a 4th axis not a 4th axis...now that is the question :D

When there's only 3 axes moving! (else I'll claim by engraver is a 9 axis machine - 'cos I've yet to build the other 6! )

[edit] Just remembered it has a unused 4th axis already so only 5 to build ;)

tribbles
31-07-2009, 12:06 AM
Out of interest, is there a general thread for CNC videos?

Lee Roberts
31-07-2009, 01:24 AM
Out of interest, is there a general thread for CNC videos?

No not as such, we do have a Video Gallery (http://www.mycncuk.com/forums/video.php) but it hasnt been used that much. I add video's as i find them, your more then welcome.

adscnc
31-07-2009, 05:28 PM
On the subject of axis'sss whats the diference between 2.5d and 3d ?

John S
31-07-2009, 05:46 PM
Rough difference.
2.5 D is where the Z axis drops to a predetermined depth and the shape is produced in X and Y whilst at this depth. X and Y can work together like doing a circle and it's called interpolation.

Typical example is doing a pocket down to 10mm deep in stages of 2mm at a time.

3D is where the Z axis is changing all the time as the X and Y are moving, imagine machining the aerofoil section on a plane wing.

Virtually all machines with a powered Z can do 2.5D and 3D, the difference is in the CAM software to generate the code.

2.5D is relatively cheap but full 3D starts to get very expensive.

.

adscnc
31-07-2009, 07:50 PM
So the router tables being built here and run with mach3 are all 2.5d ?

John S
31-07-2009, 08:11 PM
No they can be either.
It all depends on the code they are fed.

Mach is capable of 3D linear moves.

.

adscnc
31-07-2009, 08:45 PM
So the trick is generating the code. .. ands that's what cadcam does?

adscnc
01-08-2009, 12:09 AM
I have some g code experience as i have an old Ikegai lathe with a fanuc 6t control on. Also used a mini mill but only as a production machine. Never got the chance to play with it and its now gone.

Would like to build a plasma / router combo 4' x 4' . Have been watching Tribbles link with great interest. Would that convert to plasma ?

I have a decent work shop with a bridgeport vertical mill ( manual) TIG and MIG so have got the gear. Pretty good with PC's but limited electrical experience. Also know my way around solid works.

I guess i'm just trying to convince myself to "have a go"!

Al

irving2008
01-08-2009, 12:16 AM
I have some g code experience as i have an old Ikegai lathe with a fanuc 6t control on. Also used a mini mill but only as a production machine. Never got the chance to play with it and its now gone.

Would like to build a plasma / router combo 4' x 4' . Have been watching Tribbles link with great interest. Would that convert to plasma ?

I have a decent work shop with a bridgeport vertical mill ( manual) TIG and MIG so have got the gear. Pretty good with PC's but limited electrical experience. Also know my way around solid works.

I guess i'm just trying to convince myself to "have a go"!

AlYou have more than enough to get started! And we are all here to help!

John S
01-08-2009, 12:35 AM
You can't have a decent workshop if you have a Bridgeport :whistling:

.