Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: derekbpcnc on July 03, 2010, 12:27:17 PM

Title: My 4th Axis
Post by: derekbpcnc on July 03, 2010, 12:27:17 PM

Hi All,

AT LAST ! my need for rotary is fulfilled  :D

The table uses a 5Nm stepper onto a 2:1 pully driving the worm.
I 'just' need to sort out the CAM and start some serious chomping.
Initially I will use the 4th Axis as a progamable trunion indexer - plan is to use a length of 50mm square mild steel to jig up 5 parts per side which will save a whole load of tool changes on the parts I make.
I'll upload a video to the Tube in a while.
The long term aim is to set it up to do some 'proper 4 axis work' but for now just glad its all working !!!

Mach is great !

Derek


(http://img706.imageshack.us/img706/2229/img7109c.jpg)

Title: Re: My 4th Axis
Post by: derekbpcnc on July 03, 2010, 01:10:47 PM

a short vieo, indexing air :D

http://yfrog.com/0xmvi7112z

Title: Re: My 4th Axis
Post by: Hood on July 03, 2010, 06:51:54 PM

Looks good :)

What kind of backlash do these Vertex tables have?
Hood

Title: Re: My 4th Axis
Post by: Greolt on July 03, 2010, 08:14:15 PM

Quote from: derekbpcnc on July 03, 2010, 12:27:17 PM

I 'just' need to sort out the CAM and start some serious chomping.

That looks great Derek.

The best price wise, real 4th axis CAM that I have found is DeskProto.

They have just introduced special hobby pricing for their full version.  248 euro.  Worth looking at.  30 day trial version.

Then there is the poor man's option of Wrapping XYZ toolpaths. 

A lot can be  done with this method but it is not REAL 4th axis CAM.

CNCWrapper is an excellent utility for this.   http://www.cncwrapper.com/

Greg

Title: Re: My 4th Axis
Post by: derekbpcnc on July 04, 2010, 06:20:34 AM

Hi Hood,

The worm is on an eccentric, and is easilly adjustable (its the bronze coloured ring to the left).
Worm also has a thrust race that is preloaded and the eccentric has a clamp collar to remove just about all the end float.

I  just tested the back-lash, with a DTI touching the jaw of the chuck (max radius) and indexing via mach, backlash of 0.035º or if I try and wrench the table round by hand, there is about 0.04mm of play, but it's more the spongyness of the drive train than "real" backlash.

So that looks good sitting on the bench, wonder what it works out in the real work when cutting some metal !!! time to find out :-)

Greg, I like the look of DeskProto, when I have a moment I'll install the 30 day trial.
ATB
Derek

Quote from: Hood on July 03, 2010, 06:51:54 PM

Looks good :)

What kind of backlash do these Vertex tables have?
Hood

Title: Re: My 4th Axis
Post by: bowber on July 04, 2010, 07:28:11 AM

I have a similar setup but the stepper is direct onto the 90:1 spindle, worm is adjustable on an eccentric and it seems OK for machining however I'm not doing critical stuff with multiple tools, just odds and ends of model engines etc.

Steve

Title: Re: My 4th Axis
Post by: Hood on July 04, 2010, 07:39:36 AM

Sounds like a nice setup Derek, 4th axis is on my plans, maybe one day ;D

Hood

Title: Re: My 4th Axis
Post by: Tweakie.CNC on July 04, 2010, 08:12:45 AM

Nice piece of kit Derek.

Tweakie.