Machine is Air Carving

[SharonB]

Over the weekend I took the machine apart. Went completely through the z-motor and didn't find a thing wrong with it... the bearings were tight, no broken teeth and even the encoder was clean. Relubed everything. Then taped a dime to the swing plate.

Today I ran a project with both a pattern and centerline text in a carve region. Both carved great. In fact the text was the best I've seen since the machine was new. It carved the letters nice and deep and the depth of the letters was the same through out the carving. Also, I was surprised to find the carvelines in the bottom of the carve region was less than they have been in a long, long time. Another observation...there was no air carving at all. In fact the bit went down into the wood a fraction more on the first bite than I've observed any time in the past.

My question is: By putting the dime on the swing plate how does this make the bit carve deeper? And if having less lines in the bottom of a carve region was the result of putting the dime on the swing plate what would be the reason behind this.

I'll be making more projects in the next few days and will be watching if there are any changes from what I saw today

[bergerud]

I wish you had tried the dime before you took it all apart. Maybe you "fixed" something by taking it apart. You will have to try it now without the dime. Good news that the problem is gone though.

[RMarkey]

By putting the dime on the swing plate how does this make the bit carve deeper?

It shouldn't. The position of the mechanical plate has nothing to do with the depth of the carve. Something else affected the depth... most likely the board surface test.

[eelamb]

It shouldn't. The position of the mechanical plate has nothing to do with the depth of the carve. Something else affected the depth... most likely the board surface test.

That is what I was thinking. The bit plate only measures the bit, to detect bit changes. the board is measured by touching the base by key pad, and the surface of the wood, difference being the thickness of the wood. And the surface tells it where the surface is to start carving.

[SharonB]

I will certainly play around with dime/no dime in the next few projects and see what happens. I couldn't see the correlation between the swing plate and the depth but something sure made a difference. Just removing the motor and re-installing it doesn't seem like it would make that much difference either....unless the pin holding the z-motor could have been slightly loose. The pin didn't seem loose when I removed it but I didn't try to tighten it first either. These machines are sure a learning experience in mechanics. I always feel grateful when I get it all back together and don't have any parts left over.

[Digitalwoodshop]

Wrong again... Bummer....

So much for the 2 cents.... trick...

AL

[guido5286]

Hey I just saw this thread and I thought I could help. I'm a CNC Machinist and When you add the dime to the bit measuring plate you are basically lying to the machine about the length of the bit. This will make it go deeper because it thinks the bit is longer than it really is. That is what it is doing when it touches the plate is measuring the length of the bit. We do this all the time in the shop but we can manually enter the tool data so we just change the numbers. I hope this helped!

Now that I think about it if it thinks the bit is longer it won't go as deep hmm? Not sure about that one.

[chebytrk]

Wow..... I've read this complete thread because I too have this problem with my new "C" machine. It's about 3-4wks old and after the 2d week I started noticing this "air carve" as well. What I did (& do) is pause the machine and pull out the bit from the adapter (I eyeball it) just a "tad". I place it back in the CT and start carving. It does fine. I do recall seeing something right before it started doing that. I had just finished a project and when I pulled out the board I heard something fall on it as I slid it out. It was the top part (head) of a hex bolt. I noticed that it was actually broken off. Of course after a few nice words with my brand new machine I started to hunt it down. I couldn't find anything anywhere that was broken. I asked Chief2007 about it to see what he th oughtit might be. He suggested a few things and all was still there. I assumed that maybe this might have happened when it was being tested or checked out back at LHR so eventually I let it go cause everything was still running fine. It was after that (about 1wk) that I started noticing the initial "air carving" and started pulling down the bit by hand while eyeballing. It worked so I continued until I figured out what was causing that. Well.... it happened on a new carving one day. The Z truck went loose as it was measuring and it was the roller bearing (lower left side). It fell out and THAT's where the broken hex bolt came from cause the other piece was still in the roller. Lucky for me that I ordered a set of roller bearings when I purchased my CW cause I wasn't about to send it back under warranty and pay the shipping to replace 1 roller bearing. So I changed the roller bearing and all works fine except...... I still get the initial air carving so I still pull down the bit by hand. I know this isn't the right way to do it, but when I get a chance I'll start pulling all the tests that I can on it to see if they're all good. I had hoped that someone had figured out what it was so I could go straight to the culprit and fix it. When I get a chance, I'll do some testing and post my results.