Quircky R2E4

[AlSi]

We have a Boss9 R2E4 that has been running great. It has developed a bit of a problem. Some times when it sits for a minute or two between runs the z axis will move up to the upper limit switch or down about an inch, also sometimes when you are moving it down will drop down real fast for an inch or so and then catch itself. After any of the above happen the machine has to be rehomed.

On Saturday I ran all morning with out problem. I left for lunch and it acted up when I returned. Monday it acted up from the get go. No rhyme or reason for when acts up.

In the manual there are a number of things that it could be. Can you help with any suggestions.

Thanks
Alan

[Kevin Taylor]

Start with the limit switches on the Z axis . does it return to setup after a part if so maybe the jog button is bad or sticky the switches in the front of the head get oily may be a lose wire look at the easy things first maybe a bad encoder start with the switches Good luck Kevin

[fredhh47]

We had a sort of similar problem with our R2E3, because the cavity behind the access panel for the limit switches kept filling up with lubricating oil. Sometimes it would cause the switches to stick, or even fill up with oil. We finally had to add a drain (I think there was actually supposed to be an overflow) to get rid of some of the excess oil, but not all of it. If you take off the access panel and get a flood of oil, this may be your problem.

[machintek]

Once the machine homes, the only switches that make a difference are the limit switches.
If the Z axis moves, what is the display doing?
If the Z axis moves slowly with no change in the display, you have a open position loop. The fault could be the encoder, cable, or FMDC board. We unplug the encoders on the FMDC to set the drift.
If the Z does a rapid move to get back to a previously displayed position that it was at, then there is a logic problem with the FMDC or a logic power supply problem.
If a drive board hickups and causes a monitored axis to move, the control will give a grosss positioning error as it has not commanded this move and the position is out of tolerance.

George

[AlSi]

One of the problems is I have not actually seen it move. Its almost like its playing a game with me.

I will try to get it to do the rapid drop while I am moving it down using the control panel. I will attempt to view the display at the same time.

It will return to a home position not always in quite the same place if I do a Quill Up. It sometimes will run fine for awhile. It has been sitting for a few days.

Alan

[machintek]

The quill up does not search for the home switch. It is going back to a position that it was told was home. If it does not go up all the way it is because you had a failure of the position loop and the present distance to home has changed.

George

[AlSi]

That is interesting I just assumed that Quill Up ran it up until it activated the limit switch. What if the home position has gotten messed up and is set higher than the limit switch. How do you set home position. For as long as we have the machine it has been working fine and I have not worked with that.

Alan

[machintek]

The BOSS 8 and 9 had a fault, maybe even the V2XT.
Doing a quill up before homing has made many machines' quills go up past the limit switch and jam up.
The solution is to take some "channel locks" to the motor pulley and un-bind the axis.

Once a machine homes, it remembers this position unless emergency stop is pressed Or there is a control error. Then it needs to rehome. If it has a fault with the position loop and you do a quill up, it may stop before going all the way up, or go too far hitting the limit switch. All depends which way the counting fault is.

George

[AlSi]

I used compressed air computer dust cleaner to blow off the boards as a last resort. So far it has run for three days without a hitch. Coincidence or problem solved I do not know. Time will tell I guess.

Alan

[fredhh47]

If removing some dust or a few small chips helped, I would sufggest pulling and thoroughly cleaning all the boards. Your manual should outline how to do that. It takes a little time, but can prevent a lot of frustration. As to the possibility it may be a coincidence, I'd say, could be. Our machine had a problem with the encoders. The axes would do all sorts of strange things and we kept getting error messages about encoder errors. (BTW, doesn't this machine have a FIST log, at least I think that's what it was called, that keeps track of all the odd behavior?) We had the encoders all repaired at least once, finally got them replaced (this was while the machine was still under warranty). Replacements were not the same model as the originals and worked a lot better.