What would cause this?

[SAA3840]

I had two problems come up today. First, I opened the lid mid-carve to do a vacuum-out. I opened the lid and then reached for the vacuum hose but noticed that the "Y" truck kept going. The carve motor had shut down, but the "Z" truck was still lowered and moving back and forth. I quickly closed the lid and the carve motor fired up and continued carving. In order to do the vacuum-out I pressed the stop button and everything worked fine. I'm assuming that the lid switch is stuck but I haven't had a chance to look into it as I had another problem come up about ten minutes later.

I attached a picture of my ruined carve, maybe someone can shed some light on what happened and why. I also attached the mpc so you can see what it was supposed to look like.

The carve region I designed was supposed to be .25" but as it turned out it was actually .24" which is OK. For some reason the machine suddenly started carving at .28" which ruined my carve.

Any ideas as to why?

[Digitalwoodshop]

When you opened the cover and the XYZ were still moving without the cut motor on it must have tried to go down or Z down and with the bit not cutting the encoder lost some counts or pulses and the result is a continued cut at the wrong level.

You must fix the left switch as it tells the computer you opened the cover. You should have gotten a Z stall error.

AL

[liquidguitars]

You could have some sniping on the end of the board this could give a .02 " grooves at the end of the project.

Are you using a sled or adding 4" extra on the end of your board?

try cleaning outfeed rollers and adjust outfeed tables
check for loose Z parts screws and QC ect..

LG

[SAA3840]

Thanks for giving my problems a looking at. I don't think the two are related as there's quite a bit of distance between where I opened the lid for vacuuming and where the elevation changed. No, I wasn't using a sled. I had 3.5" extra on each end so sniping shouldn't be the problem.

The only thing I can think of is that the bid suddenly slipped down in the bit adapter by the .04". Except I checked the bit and it was still quite tight.

Oh well, I ran the carve again and didn't have the same problem.

[liquidguitars]

Your photo looks like you only have 2.50" or less, hence my confusion. I would use the stop key from now on and not the lid.


Also could you just run the project one more time to carve out grooves so its not wasted?


LG

[SpiffyDog]

I can't tell from the picture, but did the object being carved also change in depth or was it just the floor region?

[SAA3840]

OK, I ran this carve project for the third time, AND I found out there's an update from Carvewright. Ran the third carve using the Optimal setting and the carve time went from 2:15:48 for "Best" to 6:36:59 in the Optimal setting.
Ran the carve in Optimal and the attached picture is what I got. The first half and a little bit was indeed the best carving I've seen come out of my machine. BUT the second half was crap! See the picture I've attached.

I plan to try again tomorrow for the fourth time BUT I'm going to run "Best" on one machine and "Optimal" on my second machine. Let you know tomorrow night how it goes.

[liquidguitars]

looks like a loose bit.

LG

[AskBud]

Just a thought:
Is it possible that the actual board is much longer than the required 7".
If so, are you using, and adjusting, an external support roller to carry the weight? Is your normal Out Feed Roller table adjusted properly? It looks like a very "heavy" wood.
AskBud

[mtylerfl]

looks like a loose bit.

LG


Sure looks like a loose bit to me too - check the set screws in the adaptor. One might have loosened up, allowing the bit to "rise and fall" during the carve.

Also, when you put the bit/adaptor into the QC, verify that it is fully seated by cleaning the QC thoroughly first, then use a mirror and a flashlight to make certain that the two red marks are touching. I pull down on the bit/adaptor a couple times to further verify full seating before beginning a carve.

[Amonaug]

After vacuuming it out before starting up again I'd wiggle the bit to make sure it's still tight in the QC. Sometimes fine dust can get behind the set screws and loosen the adapter making it wobble especially on long carves. Check the adapters for wear and "BB" marks.

[SAA3840]

Mtylerfl and Liquidguitars hit the perverbial nail on the head. The bit was loose. I removed the bit and adapter and sure enough, the bid would slide up and down in the adapter, not easily, but enough that the carve was ruined. Apparently the blue Loctite doesn't work too well on the bit adapters so I ran down to the parts house and bought some red locktite and hopefully took care of the problem.

The board wasn't too long, it measured exactly 25". The virtual board is 18".

I'll find out tomorrow.

Thanks again to all of you who tried to figure this one out for me. 'Twas MY screw up, NOT the machine. (Which is usually the case 95% of the time, isn't it? Operator error.)