Warco VMC Turret Mill - CNC Conversion

[antsals]

I've been in the process of converting a Warco VMC Turret mill for quite a while. I have recently up'ed the stepper motors to slightly more powerful but I have a niggle on the machine.

The Warco major build log is a good starting point as I can see a few items like the gib strip screws have been modified.

I'm using eazicnc system and g-code generated from featurecam. The main problem I'm having is that as I am machining for example a circle every so often the machine just goes off on a striaght line? The g-code is perfect it seems to be the machine. What I think it is is the x axis is jamming up and overloading the steppers so that the motors arn't turning therefore the circling motion goes out of sync.

My first question is has anyone out and about tried converting this type of machine and what have you done to mount the x - y axis ballscrews?

At the moment I have a temp x-axis mount so I could test the machine but keep encountering this problem. I'm really not sure what to do next looking for some guidence I'm even thinking the ballscreaw could be bent between the two fixed bearing mounts?

I have been cutting aluminium only 1mm cuts with 16mm endmill at 400mm/min? Whats your thoughts should I be able to run faster? Deeper cuts?

Any thoughts I would appreciate.
Cheers
Ant

[antsals]

Also have a link to video of the machine cutting:-

http://www.youtube.com/watch?v=A5z_nX987b8

[M250cnc]

I'm using eazicnc system and g-code generated from featurecam

Do you mean the POS made by CDE

Phil

Sent from my HTC Desire using Tapatalk

[antsals]

Yep the software from CDE

[M250cnc]

Yep the software from CDE

I take it the hardware is made by CDE also, if so that i suspect is the problem (Hardware).

To test i would remove the motors from the machine run the code and see if any motor stops when it shouldn't. That will eliminate any machine binding issues.

I would also check the power supply voltage they have some pretty low output votages, i just cut my losses and sold the system.

Phil

[Robin Hewitt]

I have been cutting aluminium only 1mm cuts with 16mm endmill at 400mm/min? Whats your thoughts should I be able to run faster? Deeper cuts?

Hi Ant

Suds! You want a suds pump if you are cutting aluminium.

I am no stickler for mathematising speeds and feeds and all that malarky, I go for what works for me.

Looking at it... If your holdfasts can take the strain, for a good start setting I'd probably try half the revs, half the feed, four times as deep and a good flow of suds :naughty:

best

Robin

[antsals]

Hi Ant

Suds! You want a suds pump if you are cutting aluminium.

I am no stickler for mathematising speeds and feeds and all that malarky, I go for what works for me.

Looking at it... If your holdfasts can take the strain, for a good start setting I'd probably try half the revs, half the feed, four times as deep and a good flow of suds :naughty:

best

Robin

Robin,
I'm thinking of getting some of the stepper drive units you hve on your machine from Zapp Automation.

What size stepper motors have you got on your machine? The Warco machine you have is very similar build to mine. Did you hve to machine any of the bed below the table to fit your ball nut in? Did you have ny problems re-fitting the gib strips?

What types of speed and feed do you get from the machine cutting aluminium and steel? What size cutting an d depth of cut do you acheive?

Thanks,
Ant

[Robin Hewitt]

3.5Nm NEMA34's.

Had to open the ends of the bed out a bit to clear the nuts but only for ease of taking apart/putting together. Had to grind some metal away below the bed to get the full X travel.

The Gibb strip adjusters were horribly loose and prone to adjusting themselves. I added a fine adjustment with pinch bolts to lock them in place.

I haven't tried it in avengeance yet, been pussy footing about with sub 8mm tooling. When I think about ripping off the excess with fat cutters at high rates I start to worry about overloading the ER32 chuck vertically. If the tool slips down the job is scrap. Even if it doesn't slip the column will bend deepening the cut and forcing a seperate finishing pass if the tolerances require it. Makes me cautious.

Rule of thumb for DOC is tool radius but I won't go >4 or 5 mm, OTOH you won't get the column flex I do. I think you have to find what the mill likes, it should purr through the metal like it wasn't there, hammering or screechy noises are a sign that you've got it wrong :naughty:

[M250cnc]

If the tool slips down the job is scrap. Even if it doesn't slip the column will bend deepening the cut and forcing a separate finishing pass if the tolerances require it. Makes me cautious.

The column is made from cast iron, and cast iron does not bend. When you say deepening in what axis is it deepening the cut.

Phil

[Robin Hewitt]

The column is made from cast iron, and cast iron does not bend. When you say deepening in what axis is it deepening the cut.

Anything can bend, but you don't necessarily notice until you start chasing those last few elusive microns