board sensor

[raye321]

I installed a new board sensor a few days ago. I checked the reading when I installed it- it read over 150. Now I cant get it much above 90. I blow it out, removed and cleaned it but still same reading. Bad new sensor? What else would give a low reading? Where do the wires from the plug on the sensor go to?

[Digitalwoodshop]

Are you using white copy paper not wood? Head cranked down?

AL

[raye321]

I used the wood I normally use, a light tan pine. Head cranked down.

[bergerud]

Do you have dust collection? I would think, if anything, it is dust. There is a narrow channel behind the window leading to the IR sensor. The smallest amount of dust in there makes a difference. It is not easy to blow out. Some have taken out the window to do it.

The wire for it goes up inside the truck to the little circuit board behind the truck that the z motor wire and the FFC wire connect to.

[raye321]

Ok, I'll check that. I have taken the sensor out. How does the window come out?

[bergerud]

First look closely to see if there is any dust inside. One has to cut the sealant to get the cover off. I would leave this as a last resort. With it out, compressed air may be more effective.

Also look closely at the circuit board. Sometimes components can get scraped off by the plug.

[200k]

Cancel posting. Bergerud beat me to it again!

[raye321]

I managed to get the sensor up to about 108-110. The truck moves across the rail to the opposite side of the keypad but doesn't touch the bit to the touch plate, instead it goes down and stops about 1/2" above the plate then back up so when it comes over to the work piece it starts carving about 1/4" above the wood carving air.

[fwharris]

Check the Z rails and bearing to insure they are clean and lubed. Look for any obstruction that would keep the truck from lowering all of the way down to the bit plate. Most often is the the flex shaft core rubbing on the opening in the cover.

[raye321]

Ok I'll check that. It did work for one piece then wouldn't work. I had to keep trying several times, it would do what I described then it worked once then again couldn't get it to work.