Won't stop measuring PVC

[MarkJamesDesign]

I'm trying to cut out some letters from 1/4" PVC board and the machine homes, measures across the width and then the readout says measuring board and it spits the board out and just keeps trying to find the end. I stuck a piece of 3/4 poplar in with the same file and it loads up fine. The PVC is bight white but I'm in kind of a dimly lit area if that makes any diff. Any suggestions? If I need to mask it off, do I mask top or bottom?

[edzbaker]

You can try masking tape on the TOP of the PVC at the ends. But it's also possible that the 1/4" thickness is harder for the machine to read with infrared. If the Maskint tape doesn't do the trick, try stacking the PVC on another piece -or- a piece of wood, with some double sided tape between them. I hope this helps.

[Sarge]

Run some tape around he whole darned thing, you can't be sure where it's having problems finding the edge. Find a small light to hang or stand near enough to throw some light on the inside of your machine.. GOOD LUCK

[MarkJamesDesign]

Thanks Ed,
I thought about putting a backer board on, but would my backer board hato be the same dimensions?

[edzbaker]

Yes, it would need to be the same length and width, or it could cause another error.

[MarkJamesDesign]

I guess tommorrow is gonna be sled and jig buildin' day.

[edzbaker]

Ahhhh I just remembered that firmware 1.119 had that problem with some machines.. If your using 1.119 you might want to try 1.115 and see if the problem clears up. If not,, I'd give the masking tape a try.

[Cliff]

Mine doesn't like anything less than 1/2 inch either, so I mounted my work on another board and adjusted the thickness in designer and reloaded. Carefull about the sandpaper belt drives, the constant attempts to measure the thin board caused my rear belt to drift and I had to re-adjust it before it had a chance to tear.

[pkunk]

1/2" is minimum thickness according to the manual. I'd use a sled.

[MarkJamesDesign]

yep, 1/2" is what the manual says. Wonder why the software let me set workpiece thickness at .250.

BTW pkunk, how'd you get to be so smart....check the manual.....that's using your noodle.

[MarkJamesDesign]

I think I'll try some light spray adhesive and put 2 sheets together. Cut through both and I'll have a couple.

[pkunk]

yep, 1/2" is what the manual says. Wonder why the software let me set workpiece thickness at .250.

BTW pkunk, how'd you get to be so smart....check the manual.....that's using your noodle.
I been around awhile. It tends to grow on 'ya.:rolleyes:

[Digitalwoodshop]

I believe the real problem with the 1/4 inch material is not the thickness of the material but the location of the board detector. It is far enough back that it is over the rear sand paper belt. What the board detector is seeing with 1/4 inch material is the sand paper belt and never see the transition from board to no board. It always sees the belt.... See pictures.... I am doing 1/2 and 1 inch white PVC no problem. Tried 1/4 inch red engraving plastic but it drove right out and kept going. Put white paper tape over the red and same thing. Put a 3/4 inch board under the 1/4 inch plastic worked fine.

AL

[Digitalwoodshop]

Added a picture of the board detector above the belt. Sorry about the dust.... was playing today without dust collection as it is raining here. Just a short test but what a mess....

AL

[Digitalwoodshop]

Here is a better picture.

AL

[Digitalwoodshop]

Here I am again HOGGING the post, talking to myself..... Again....

Had a thought last night trying to sleep.... Since the Board Detector is seeing the Sand Paper Belt at 1/4 inch why not move the detector....?

I thought that a great project for a Circuit Board Guy like me would to make a remote sensor addition for the existing board sensor and move just the LED Transmitter and the Photo Eye, 2 parts, 2 wires each, forward 1 inch or so toward the gap between the belts. Leaving the electronics inside the head and just a shielded 2 wire cable and a mounting device to move the sensors. The result would be a shift of 1 inch of the project on the board in length but not a problem for me as I always leave 4 inches of board under the rollers. The Left / Right would not change as long as the position of the sensor was the same. This way a 1/4 inch board would not be a problem for the sensor.... As long as it didn't crush the sensor and the drive could move the material.....

Called Customer Service and spoke to a great Service / Sales Tech and being up front and asked if I could purchase a board sensor for my experiment. The answer was No at this time as all parts were needed to support Warranty repairs. I didn't want to lie and say please send me a board sensor as my sensor is broke.... I just don't play games like that.

So for now, that part of the project is on hold. Unless someone has a broken board sensor that I could purchase?

The second idea on this project is using a Omron Fiber Optic detector. http://www.omron247.com/Industrial-Automation/Store/OmronFamilyView_10051_10051_-1_12103 When making Picture tubes at Sony we used a Omron Detector that was a small box that connected to the PLC or Program Logic Controller. In my case, a beam of red light emitted from a 1/8 inch piece of fiber optic cable. It had another piece connected to the receiver port. When the tips looked at each other the detector outputted a high or low logic level. Block the light with a picture tube base cap and the computer knew a base cap was loaded.

I wonder if you pointed both fiber cables at a board and would reflected light cause a transition? The Fiber optic cables were over 2 feet long and the box had sensitivity or teach adjustments. In theory the sensor could be mounted outside the carve machine and the fiber cables taped to the drive cable and move back and forth with the head and be in a position to look into the void.... A Selector switch could switch between the normal sensor and the fiber optic sensors......

Just a thought.....


This is the one we used. It has a teach mode to teach it the transition point. Some have a bar graph and others have a screw sensitivity adjustment.

http://www.omron247.com/Industrial-Automation/Store/OmronFamilyView_10051_10051_-1_12103


http://www.omron247.com/Industrial-Automation/Store/OmronCategoryView_10051_10051_-1_12098


This would make a nice remote sensor.....

http://www.components.omron.com/Products-PM-NonAmpReflect.shtm


This is the style used for the old Z axis home sensor.

http://www.components.omron.com/Products-PM-NonAmpTrans.shtm

Rant over.... Back to work.

AL