2007 VF3SS Tool Releasing Too Soon

Its Monday again, time for another one of our machines to have issues. This time its our 2007 VF3SS that we just installed a few weeks ago. Its been running fine up until today, it has jammed several times on the tool change resulting in alarm 673 TT or B SERVO TOO LARGE. I thought I noticed the tool releasing too soon over the past few days but figured maybe it was just my bad eyes. Well as of today it has gotten worse and the tools dont sit properly and just jam. Here is a video of the tool change in action, you can see the tool slowly release. During the cut its fine, no surface issues so I dont think its a drawbar issue:


Slow Mo


Anyone know what the issue might be....proxy sensor?...... something simple I hope?

Thanks,
Jim

My first guess would be a contaminated or clogged solenoid valve that's controlling the TRP
(tool release piston). But try to get Haastec's attention, he's the best one to answer this.

If you manually use the tool release button (no tool in spindle), does the action sound "crisp" and quick, or does it seem like it takes a while for the movements to start/stop?

Well, having actually looked at the videos, it's a little more than my guess. The TRP is being actuated (and the toolholder dropping down a bit) before the arm comes and engages the toolholder. That should not be happening! The rest of the issue (the tool arm not completing it's cycle) may be a consequence of the earlier out of sequence actions.

My hunch would be that you have a bad prox switch. I don't know if you can see how the ladder logic works on a Haas or not. Anyway, I would think that the tool should not release until the swing arm is engaged. So, probably the prox switch that tells the machine that the arm is engaged is bad and is signaling the machine to release the tool too early.

On a side not, if that is the case, that's some shitty logic programming by Haas. The machine should alarm out if it sees both prox switches on the swing arm since both should never be made at the same time. A couple of lines of code could have taken care of that.

Yea the tool jams in the spindle due to it releasing early so I it becomes crooked......that causes the alarm so it never finished the cycle. I can recover and get it out but it just does it the next time. The TRP sounds good, nice and crisp.

ewlsey said:

My hunch would be that you have a bad prox switch. I don't know if you can see how the ladder logic works on a Haas or not. Anyway, I would think that the tool should not release until the swing arm is engaged. So, probably the prox switch that tells the machine that the arm is engaged is bad and is signaling the machine to release the tool too early.

On a side not, if that is the case, that's some shitty logic programming by Haas. The machine should alarm out if it sees both prox switches on the swing arm since both should never be made at the same time. A couple of lines of code could have taken care of that.

Click to expand...

I'm hoping it's just a proxy switch. Gonna call Haas in the morning and get some insight but I'd figure post and see if anyone else had this issue.

jimmyfab said:

I'm hoping it's just a proxy switch. Gonna call Haas in the morning and get some insight but I'd figure post and see if anyone else had this issue.

Click to expand...

I doubt that it is a proxy switch and the Haas machines do not have ladder logic like what is found on most Fanuc type controllers.

I suspect you have an issue with the precharge set to high or an issue with the tool release piston (TRP) assembly. The job of the precharge is to gently lower the TRP onto the drawbar without having it slam together. If the precharge pressure is to high, then it will start to push on the drawbar causing the tool to lower slightly similar to what you are witnessing. Another cause could be with the TRP, in that something could have broken or come loose essentially causing its dimensions to change which in turn causes the tool to start to release early.

The service manual has information about the TRP and how to set the precharge. I would suggest checking both of those systems out first.

Good luck!

haastec said:

I doubt that it is a proxy switch and the Haas machines do not have ladder logic like what is found on most Fanuc type controllers.

I suspect you have an issue with the precharge set to high or an issue with the tool release piston (TRP) assembly. The job of the precharge is to gently lower the TRP onto the drawbar without having it slam together. If the precharge pressure is to high, then it will start to push on the drawbar causing the tool to lower slightly similar to what you are witnessing. Another cause could be with the TRP, in that something could have broken or come loose essentially causing its dimensions to change which in turn causes the tool to start to release early.

The service manual has information about the TRP and how to set the precharge. I would suggest checking both of those systems out first.

Good luck!

Click to expand...

I spoke to my HFO this morning and they said the SS machines should have 30psi pre-charge. I checked the pre-charge and had about 25psi so I cranked it up to 30 psi and the tool blew out before the arm could even get there. So for the heck of it I lowered it to 10psi and to my surprise the early unclamping was gone and tool changes are perfect. I just got off the phone with my HFO and they were a bit baffled but said if the lower PSI works then go with it. The book calls for 4.1 PSI on 40 taper machines with TSC which I have.....then later in the book is another section with a note saying SS machines should be 30 psi. Im a bit confused, Im going to try the books recommendation or 4.1psi and see if there are any issues. What are your thoughts?.....30psi just seems way high!

So the culprit seemed to be the pre-charge solenoid. It was self adjusting itself to all sorts of random pressures and at one point lost all pressure causing loud pops when the TRP would move. Just installed a new HAAS pre-charge solenoid and set it to 5psi. So far everything is working properly, lets hope this regulator doesnt have a mind of its own.

I do have a question, is there a pre-charge for removing tools manually with the tool release button on the head? Im noticing that tool changes during a program sound perfect but when I remove a tool from the spindle with the tool release button it sounds a bit louder.

jimmyfab said:

So the culprit seemed to be the pre-charge solenoid. It was self adjusting itself to all sorts of random pressures and at one point lost all pressure causing loud pops when the TRP would move. Just installed a new HAAS pre-charge solenoid and set it to 5psi. So far everything is working properly, lets hope this regulator doesnt have a mind of its own.

I do have a question, is there a pre-charge for removing tools manually with the tool release button on the head? Im noticing that tool changes during a program sound perfect but when I remove a tool from the spindle with the tool release button it sounds a bit louder.

Click to expand...

Yes the precharge is used during manual tool release also. I have noted the difference you refer to also, but have never figured out, or taken the time to figure out, why this is. I suggest bumping up your precharge pressure some.
You may also want to try it again at the recommended 30psi and see how things work and sound. If it behaves similar to before then adjust it back down some. If it looks and sounds good, I would try running it at the 30psi for a while then make a decision.

Good luck!

haastec said:

Yes the precharge is used during manual tool release also. I have noted the difference you refer to also, but have never figured out, or taken the time to figure out, why this is. I suggest bumping up your precharge pressure some.
You may also want to try it again at the recommended 30psi and see how things work and sound. If it behaves similar to before then adjust it back down some. If it looks and sounds good, I would try running it at the 30psi for a while then make a decision.

Good luck!

Click to expand...

Sorry my previous reply was not accurate. We thought it was the pre-charge regulator at first (not solenoid)so I installed a new regulator and adjusted the pressure to 5 psi...ran a bunch of tests and everything was good. Put the head cover on and not a minute later back to loud bang tool change again. Pull the head cover off AGAIN and sure enough there was no pre-charge pressure. Now the regulator is acting up but its brand new so something isnt right, we cant get more than 5 psi from the regulator even full open. So I take it off again and try manually activating the pre-charge solenoid and there isnt much air coming out. I cycle it a few times then a big burst of air comes out. That tells me the solenoid was sticking which could be the root of all my problems. I took it out to clean it and found some nasty debris in the screen. Got it all cleaned out like the Haas video shows on you tube, now its back in and working good so far. If I run into this issue again Ill just replace the solenoid.

As for the pre-charge pressure, 30 PSI just blows the tool out of the spindle so that cant be right even though the book says 30psi for SS machines. Maybe thats for NON TSC SS machines? Ours has TSC and operates great at 5psi. Head cover is going back on, fingers crossed the solenoid wants to cooperate this time. The good news is I can remove the head cover in less than 5 minutes now....Im a bit of pro at it

Gotta love taking off that head cover....

For awhile I couldn't do without breaking that Tool Release Button. Kept spares here...that solved that problem.

Cordless 3/8 impact and a 5/32 hex socket. I wonder how many times I've had one of those off...

ewlsey said:

Cordless 3/8 impact and a 5/32 hex socket. I wonder how many times I've had one of those off...

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I like to break them loose by hand and use the impact to back the bolts out. Ive stripped a few in my day with the impact, some of our older machines the bolts are pretty tight. If they strip I use a cut off wheel, cut a straight slot down the middle of the head and use a big flat head to remove them. Worked every time so far! Glad to see Im not the only one who is pro at the head cover removal haha