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VF-2 spindle tool release issues

BBerney

Plastic
Joined
May 19, 2023
I’m having two, possibly related, issues with the tool release on my VF-2SSYT.

When manually inserting a tool holder, sometimes the mechanism takes a long time (like 20-30 seconds) to grab the tool after I release the button. I can hear some air flowing while waiting for the sequence to finish. It’s not a lot and think the air flow is normal, but not sure. Eventually, the sequence will complete, after what seems like timeout period.

The other issue is that during a tool change (SMTC) the tool coming out of the spindle seems stuck and makes a loud noise when it is grabbed by the tool change arm. Definitely not normal. I’ve been able to reduce the frequency of the sticking by putting red grease on the tip of a tool holder pull stud, and manually inserting and removing a few times, but the issue still occurs intermittently.

I’m not sure the two issues are related, but it seems like they could be. Any tips are appreciated.
 
  • Wipe the inside of your spindle with a clean rag and a light spindle oil once a day. Clean and inspect all your tool tapers semi regularly.
  • Don't overtorque the pull studs. After buying a pull stud socket, I discovered I had been over-torquing them for years. Most holders only want around 40 ft/lbs. Any more causes the top of the taper to swell and deform.
  • Park the spindle empty at the end of use. That sets it up to wipe it first thing when you open the doors and before power-up/restart.
As for the lazy tool change, it sounds like one of the valves is getting slow. You didn't say how old the machine is but, there is a pre-charge valve that meters out low-pressure air to get the tool release piston down to the drawbar before applying full pressure. That, or the switches in there are probably misbehaving.

Here's a video on the subject. He also sells the repair kits and whole valves:

 
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I do leave the spindle empty, and periodically clean the bore. I’ll try the other tips, and will check the video. I hadn’t found that one before.

Thanks for the feedback :-)
 
It might be the air solenoid feeding the tool release piston (TRP).

I had the same issue recently with a relatively new UMC500. What year is your machine?

I bought a new solenoid but ended up not needing to install it. While waiting for the new solenoid to come in, I took apart the existing one, put it back together, and the machine's fine now.
 
It was built in 2022…maybe 2021. I’ll do some research into the solenoid. Thanks :-)
 
I disassembled the valve this morning and the shuttle moved back and forth smoothly. No obvious particles. Put everything back together, but haven’t run the machine yet. The valve on my VF-2 is the same type, but they used SMC. https://www.smcpneumatics.com/VP342K-3H1-02NA.html

I have a new one on order and will replace it if the challenging tool changes continue. I’ll update again when there is something to report.

Thanks :-)

IMG_1780.jpeg
 
Pretty sure youre chasing the wrong thing, it more likely the drawbar. Either broken bellevilles binding up, or the bellevilles have worn into the drawbar itself and are dragging, or just overall corrosion.

Haas drawbars leave a lot to be desired, which is why they can sell the entire assembly for hundreds, not thousands like most other machine manufacturers.

Check your drawbar force, if its out of spec, order a replacement and when you take it out the problem will be obvious.
 
Pretty sure youre chasing the wrong thing, it more likely the drawbar. Either broken bellevilles binding up, or the bellevilles have worn into the drawbar itself and are dragging, or just overall corrosion.

Haas drawbars leave a lot to be desired, which is why they can sell the entire assembly for hundreds, not thousands like most other machine manufacturers.

Check your drawbar force, if its out of spec, order a replacement and when you take it out the problem will be obvious.
This is along the lines of what I was originally thinking might be the problem, and it could very well be, but the suggestion to change the valve is really easy and relatively low cost, so I'll try that first.

The tool change problem is intermittent, and so far at least, is mainly an annoyance. I'll update once the valve is replaced, and/or if I need to dig deeper into the drawbar assembly.

Thanks for the feedback :-)
 
Ya, I see many many failed haas drawbars every year, so it would be no surprise to me.

I would try to diagnose asap because low retention force can be a safety risk if the spindle were to throw a tool.
 
Its a new machine, I had a slow tool piston deal also, super annoying, wait wait wait, it broke in eventually, our machines are used 8 hours a day every day though.
cycle that dude a bunch of times in the morning, you could even make a program that did it for you until break in.

tool pop can be if you ran the machine hard roughing, heat.
But as Donkey mentioned, a slight coat of WD40 in the taper, but also, Haas recommends greasing the pull studs, I don't know how many times I mention it,
but it does actually affect the whole popping tool thing in a Haas machine.

Make sure you have clean dry air, as in, a refrigerated air drier, or desiccant,
No, a water trap isn't dry air.

Also try running at the upper limit of the air pressure recommended for a bit.
 
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Ya, I see many many failed haas drawbars every year, so it would be no surprise to me.
A drawbar test is easy for someone who has the tool. I'm not saying it's not a valid point but, do you actually see 2-3 year old machines already having drawbar issues?
 
I’ve been periodically putting some grease on a pull stud and cycling the tool in and out a few times over the past few months. Hard to say if it helps since things still stick. I like the idea of raising the CDA air pressure. I have the lab system set at 90psi, but can raise it. My compressor is an Atlas Copco SF4+ with an air dryer. Plumbing is all indoor temperature controlled…and I’m in California, so air should be dry. At least nothing ever collects in any of the system water traps.

I haven’t checked, but the spindle hours have to be relatively low since this is used intermittently for prototyping. I would be surprised if there were more than 300 spindle hours total. Ha…maybe that’s the problem. I don’t use it enough and it’s being grumpy at me ;-)

I think the new valve arrived last night, so hopefully I’ll have time to replace the valve this week and report back.

Thanks all!
 
You keep the pull studs greased, not just to get some grease up in the balls, but on each tools pull stud.
You can find Haas recommend this all over the place, but because its not standard practice for other machines people ignore it.
 








 
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