PDA

View Full Version : Possible solution to many Z axis errors.



Marzluf
02-07-2007, 01:39 PM
Not sure if I stumbled upon anything new because I vaguely remember reading something about this..

Anyway.... I was out in the shop today and fired up the carver. A couple days ago durring a project I noticed a dip in the Z axis on my design but chucked it up to slightly colder than specified temperatures.

So today I begin a 4 piece project. 1/2" into the project and it changed it's cutting height so that it was now reproducing the same design, but now it was 1/16" or so lower... A little further along and it did it again. I stoped the unit by opening the lift door and manually moved the Z truck up and down to see if it had any play. No play was found in vertical, front to back, or side to side directions. Good... Next I checked the belts etc.. Everything looked and felt good.

Ok..... so I load another piece and begin again. Same story. It got about 1/2" or so into the design when the Z aixs began to stammer around making up it's own mind what depth it was going to cut at..

Ok........ I stoped the run again and took the cover off. All cables/ribbons looked and felt secure. Nothing out of the ordinary. I put everything back together and continued with the design only to find the same thing happening.

Well then.......... I was starting to get a little frustrated. 6-1/2 hours of run time on the machine and all I've done is rave about this unit since day one.

I started looking at the Z truck a little closer.... I moved it manually up and down, up and down... side to side and side to side..... It all moved so nicely that I just could figure out what the issue could be. Searched the forums here and saw the repeat of people ordering Z truck motors, boards or some other item so I called and left a message for Chris.

Back out to the shop to look things over again.. I manually moved the truck up and down again kind of whimpering to myself that my new toy was broken but glad to know that a service call would fix everything..

Well....... all of a sudden my eye caught something... I looked closer and saw that every time I moved the truck all the way down, the ribbon that penetrates through the truck would look like it was tugging.. Like it needed more slack when in that fully extended position. That's when I had a memory flash. Maybe it was de-javu, who knows... Anyway, I grabbed a jewelers flat screwdriver so that I could get under the ribbon. With a finger on the backside of the truck where the ribbon enters, and the screw driver under neath the ribbon on the front, I gently fed the ribbon through so that it had more slack on the front side (where the truck actually moves up and down.)

I started my design again on a new piece of wood. BINGO !!! It was cutting better than ever. Nice smooth transitions, flat bottoms, and the horizontal wave that I had in the design was comming out clean.

So....... I don't know if someone actually posted about this before, although I REALLY do think I remember reading something, othes that are having this problem may want to check that ribbon.

Again....... this is NOT the ribbon that others have talked about comming off the back. This is a much smaller ribbon (maybe 3/8" wide) that runs THROUGH the truck and down toward the cutter. You have to slide your truck all the way down to see if it's pulling. All of this can be seen looking through the front lift window directly at the business side of the truck.

Anyway...... thought I'd share.

I'll take a picture for better description in a bit when it's finished with this project.

Aaron B
02-07-2007, 01:43 PM
Thanks for the update on that. When you get the chance the picture will help.

rickyz
02-07-2007, 06:55 PM
I think this is the ribbon you are talking about. Having problems with mine and I saw that that ribbon looks like it got chewed up a bit somehow. That is the only thing I see wrong. the pic isn't the best. it's from my cell.

Marzluf
02-07-2007, 07:33 PM
Yep, that's the ribbon. Here's a little better pic I just took along with a couple pics of the problem as it showed up on the carving. Flexshaft removed for clarity.

http://pic20.picturetrail.com/VOL96/791874/9102838/228847721.jpg

http://pic20.picturetrail.com/VOL96/791874/9102838/228847700.jpg

http://pic20.picturetrail.com/VOL96/791874/9102838/228847672.jpg


Here's another shot of the ribbon. Before, with the truck all the way plunged like this the ribbon was being pulled on. Now, as you can see from the little screwdriver holding it out, there's slack in the ribbon even with the truck all the way plunged.

http://pic20.picturetrail.com/VOL96/791874/9102838/228847648.jpg

And finally..... a shot of the final piece after making the adjustment to the ribbon. Hard to tell from the pic but other than the stars and vine work, there's a vertical wave texture to the background. That gives it an odd appearance in this pic though.

http://pic20.picturetrail.com/VOL96/791874/9102838/228847762.jpg

BobHill
02-07-2007, 11:01 PM
Marzluf,

Use care that the ribbon being as loose as you show it is very likely to get caught at some time when the head goes up and down. This could also cause you much grief. With the Head all the way to the bottom, the ribbon should be snug against the back and held in the slot by silicon or the like.

Bob