What's new
What's new

Parameters question on VMC15

Hobby Shop

Hot Rolled
Joined
Mar 20, 2014
Location
Michigan
Hey Guys. I bought a VMC15 a few months back and finally got it online last night. The guy I bought it from said it was running perfect, needed nothing and had the machine checked out and battery replaced by the “tech” before he sold it to me.

I tried to do a tool change and the Z axis won’t raise high enough. It’s 1-1/4” to low. I put an indicator on the spindle and measured Z.
From the indicator to the DRO.
.100” indicator = -.162” DRO

Full disclosure: I don’t know the first thing about anything CNC but flipping through the pages I found this. I think these numbers are for a VMC4020? I haven’t changed anything just looking at the moment.

Any and all help would be greatly appreciated.

Thanks
Andy
 

Attachments

  • EED36DCC-314E-4D38-8B50-C29BE58426B1.jpeg
    EED36DCC-314E-4D38-8B50-C29BE58426B1.jpeg
    927.8 KB · Views: 6
  • 5CBA3F07-341F-463D-AB02-CF56A8857130.jpeg
    5CBA3F07-341F-463D-AB02-CF56A8857130.jpeg
    601.2 KB · Views: 6
  • ADEC42CE-864E-419E-9429-00DDE9729669.jpeg
    ADEC42CE-864E-419E-9429-00DDE9729669.jpeg
    741.8 KB · Views: 6

Wade C

Stainless
Joined
Jul 21, 2004
Location
Wiggins CO. USA
Open the pendant door... should be a sticker on the back with all the original parameters. Verify those with what is in the parameters (SETP). Just by looking at your first pic, Id guess either the battery died again, or wasnt replaced, or was replaced but the parameters were not set.

Your issue with the Z is likely that the parameters are for metric screws and your machine has inch screws. But seeing 4020 and 10k spindle makes me feel like none of the parameters are right, and are likely just the default set.
 

RC Mech

Stainless
Joined
Jul 21, 2014
Location
Ontario, Canada
4020 is the default. Parameters are incorrect for the machine. I’ve read that the machine power should be cycled after parameter changes, and also that it doesn’t matter. I command “2” then “Return for power off” to return slides to zero then cut power.

Start it up again and check the values in SETP.
 

Hobby Shop

Hot Rolled
Joined
Mar 20, 2014
Location
Michigan
Thanks again for all the help. I’m heading out to look at it now. I took a picture of the parameters inside the pendant but cannot post them because the resolution is too high with the new iPhone.

Andy
 

Hobby Shop

Hot Rolled
Joined
Mar 20, 2014
Location
Michigan
Just a follow up. I had the tech out. The battery was good so maybe the parameters weren’t installed after the battery change. He installed the parameters and so far so good and now the tool change is spot on. He showed me a few things and it didn’t hurt to bad. Only $175

The good, X & Y axis only have .0004”backlash. I did a quick sweep of the table in a 3” circle and the indicator didn’t move.

The bad, I have to dig into the Z axis. With an indicator in the spindle, I can move it .005” by pushing up and the backlash is showing .004”. Looks like it’s time to change the thrust washers.

Thanks again for the help.
Andy
 

ducesrwld

Aluminum
Joined
Mar 27, 2008
Location
S.E. WI
on the Z you are in for new bearings not washers. still relatively cheap fix on these machines. i've got a vmc15 the spindle drive is going out and my X axis servo just went out. you are getting off pretty easy didn't know a tech would even show up for under couple hundred bucks these days.
 

triumph406

Titanium
Joined
Sep 14, 2008
Location
ca
The bad, I have to dig into the Z axis. With an indicator in the spindle, I can move it .005” by pushing up and the backlash is showing .004”. Looks like it’s time to change the thrust washers.
Is that .005 spindle movement in relation to the Z-axis ram itself?

Or in relation to the table? If so then you may also be getting a contribution from Ram movement with that check.
 

Hobby Shop

Hot Rolled
Joined
Mar 20, 2014
Location
Michigan
Is that .005 spindle movement in relation to the Z-axis ram itself?

Or in relation to the table? If so then you may also be getting a contribution from Ram movement with that check.

Yes. It’s the Z axis, ceiling to floor movement. There is zero movement on the indicator when I do a slight pull front to back. I did a sweep of the table and it’s good there too. Hopefully I’ll get lucky and and it’s just the thrust bearings.
 

triumph406

Titanium
Joined
Sep 14, 2008
Location
ca
Yes. It’s the Z axis, ceiling to floor movement. There is zero movement on the indicator when I do a slight pull front to back. I did a sweep of the table and it’s good there too. Hopefully I’ll get lucky and and it’s just the thrust bearings.

Put an indicator base on the bottom of the ram, with the needle on the bottom of the leadscrew, any movement between the 2 will be backlash in the ball screw, subtract that from the .005 will be thrust bearing backlash.
 

triumph406

Titanium
Joined
Sep 14, 2008
Location
ca
Looks like it’s time to change the thrust washers.
Some people change the Belleville washers that provide tool retention force every year. As it's an unknown machine, might as well change those as well.

 








 
Top