VF3 Y-axis thermal expansion

[RCS-Machine]

I have a 2016 VF3 and I'm having problems dealing with the thermal expansion in the Y-axis. I'm sad to say that this has been an issue since the machine hit the floor but it has taken me this long to narrow down what/where the problem has come from.

It started when I'd start the machine for a new day of work and noticed the X and Y was always off a little bit from the previous days G54 zero/zero offset. I figured it was due to the power-up cycle and hitting the limit switches.

Over time I started to notice cutter lines not blending from one program to another when the machine sat idle for awhile.

I have figured out that if I run a 20 minute "warm-up" program, sweeping the X and Y in a large circle, I get things warmed up and they hold their zero. The problem is, if I let the machine sit idle for 30 minutes to an hour, say over
lunch, my X-axis is still dead on G54 zero but the Y can be .0005 to .0008 off. As soon as I run another "warm-up" program, this time about 10 minutes since the machine has been in use, the Y-axis goes back to G54 zero.

Haas and their Factory Outlet reps say this is normal and a cost of doing business. I'm having trouble believing them as this the 3rd VF I've run and neither of the other 2 have had this issue.

I've played with the different Y-axis thermal expansion settings but nothing I do will keep the Y-axis at G54 zero as the machine cools down.

I can place indicators on the table at the end of the day, both X and Y, and by the next morning, the X indicator hasn't moved while the Y has moved .0008 to .001. So something is heating the Y-axis up and causing the screw to expand.

Do you think that it is just the way these newer machines act or did I get a problem machine and my Haas guys just aren't telling me since they don't know how to fix it?

Thanks.

Ed Wendt
RCS Machine and Tool

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[Jim Dawson]

Last night when I shut my machine (a BP clone knee mill) down I moved the X & Y to 0,0 and hit the Estop. I noticed this morning when I was ready to fire it up that Y was at 0.001 and X was at 0.0001. So something moved and there was a pretty large temperature change over night. No problem on that machine because the scales are on the table, not reading lead screw position. A temperature change would be my guess.

On my son's Haas TM-2P, the X seems to lose the G54 position on power down, the Y seems to be OK. Sitting idle for a few hours or even overnight seems to have no effect on the position as long as the main power is left on and the computer hot, with the machine just Estopped.

[generaldisarray]

I thought Haas used stretched screws? I would ask them to do a Ballbar test. Haas has great historical data to call upon.

Maybe its because you have such a super early prototype, I mean they have 88 years to figure it out.

https://www.haascnc.com/service/trou...ing_Guide.html

[RCS-Machine]

I thought Haas used stretched screws? I would ask them to do a Ballbar test. Haas has great historical data to call upon.

Maybe its because you have such a super early prototype, I mean they have 88 years to figure it out.

https://www.haascnc.com/service/trou...ing_Guide.html

Thanks for the link generaldisarray. You had me scratching my head on the early prototype until I saw my typo. It's a 2016 not a 2106. Hopefully by then it will be someone else's problem