PDA

View Full Version : Intermittent Scanning Probe operation



tomt
12-19-2010, 05:26 PM
The scanning probe will intermittently stop with the message Please Check Probe
Press ENTER to Proceed. If I move the probe and hit Enter the scan will continue for 3 -4 passes before stopping with the same message. I have had the probe for almost two years with no issues. I have ran the sensor checks on the probe and they all pass. I opened the probe cleaned all of the contacts and reinserted with the same result. I then rewired the probe, bench checked it with a meter all ok. The problem remains. I have also checked and reseated the connections on the Z-Truck. When I connect to the cover connection point, the Probe cannot determine depth it will act like a dart. I have always used the Z-Truck connection
The probe can find starting point - Ending Point and depth ok. Is there another area that I can check? Or is the probe showing signs of wear ( I would guess 80 hours of use ) that would require a replacement?

mtylerfl
12-20-2010, 12:18 PM
The scanning probe will intermittently stop with the message Please Check Probe
Press ENTER to Proceed. If I move the probe and hit Enter the scan will continue for 3 -4 passes before stopping with the same message. I have had the probe for almost two years with no issues. I have ran the sensor checks on the probe and they all pass. I opened the probe cleaned all of the contacts and reinserted with the same result. I then rewired the probe, bench checked it with a meter all ok. The problem remains. I have also checked and reseated the connections on the Z-Truck. When I connect to the cover connection point, the Probe cannot determine depth it will act like a dart. I have always used the Z-Truck connection
The probe can find starting point - Ending Point and depth ok. Is there another area that I can check? Or is the probe showing signs of wear ( I would guess 80 hours of use ) that would require a replacement?

Hi Tom,

Here is a link to a thread with several suggestions for resolving the problem...

http://forum.carvewright.com/showthread.php?16132-Scaning-probe-keeps-stopping&highlight=Check+Probe

tomt
12-20-2010, 01:18 PM
Thank You Michael

I have tried all of the solutions except removing the flex cable from the z-truck. I will also run the scan again and when it stops with the request to check the probe I will remove the probe plug connection to the z=truck and check the continuity with a meter, if it is displaying open then I know the issue is with the probe. I did the wire shake test while in the sensor diagnostic test and it passed. I will post the result.

mtylerfl
12-20-2010, 01:40 PM
Hope you can get it worked out soon. Yes, please post your progress.

AskBud
12-20-2010, 01:52 PM
Since I do not know what your model looks like, I'll point you to this link where I speak of holes/voids in the model being scanned. It may apply to your situation.
AskBud
http://forum.carvewright.com/showthread.php?16789-Nother-Scanning-Problem-Question&p=142326#post142326

tomt
12-21-2010, 12:47 PM
I finally had some time to get my arms around this issue. I had stated the scan and it preceded as usual stopping 3% into a 13 hr scan. I have already completed 3 of these scans this past week and have only two more to go. Well I removed the probe connection to the Z-Truck and placed my meter across the connector (digital meter set to infinite ohm reading with tone on for continuity. The reading was open so I move the connection wires around with no change. I then tapped the probe housing and continuity returned. I tapped the housing again and I can the resistance bouncing from a short to 4 -200 ohms. Connected an analog meter which is much better to see these changes and confirmed the resistance changing with slight tapping on the probe housing. Removed and opened the probe, inspected with a magnifying glass, individually checked each wire all ok. All connection points are clean. Adjust the spring tension with the same end result. I will need to have this confirmed but I would not think the resistance reading should change with tapping on the probe housing, because any movement of the probe produces and open infinite resistance and upon returning to the home position displays a dead short. So I figure the vibration of the scan itself is causing the probe to produce an in-between reading neither open nor shorted. I have also soldered the copper traces to eliminate the possibility of a hair line crack!!!!! No luck I will take a break and come back in an hour or two and see if I can figure this one out. I will keep you posted.

tomt
12-23-2010, 01:09 PM
Update with good news which I hope will help the carving community out if anyone encounters a similar issue with their scanning probe. The Scanning Probe is working once again and the fix was actually an easy one. You will need a meter digital or analog and two alligator test clips. Attach the alligator test clips to the connection point on the probe that attaches to the Z-Truck, one on the inside of the band one on the outside of the band. You should have a reading of 0.00 if there are a resistance to the right of the reading touch your meter probes together and see if they are all zero, if you have a reading in the 10ths or 100s it should be ok. Move the probe a few times to make sure it returns to zero, If you have a reading like I did on the left from 6.xx ohm to 270 ohm then you will have to disassemble the probe including the probe tip the part the actually touches the object being scanned.. The connection points will need to be cleaned I used fine sandpaper 220 grit, also clean the area where the probe connects along with the eyelet to the white wire. While you have it open it wouldn’t hurt to get a magnifying glass and check all copper traces especially the one where the probe connects for any cracks. Once that has been completed re-assemble the probe and with alligator clips connected tap lightly on the side of the probe housing. You do not want to see any resistance reading to the left of the decimal point X.00. Since there are only copper traces and the two wires on the probe. There should be no resistance to measure in the normal state. I suspect that I had poor connection points and the area under the probe needed to be cleaned. The Scanning Probe had been running now for 25 + hours. The scans I am current doing are from 13 -14 hours each.

TerryT
12-23-2010, 01:27 PM
Yep, I have had to do it a couple of times over the last few years. I think the contacts oxidize over time depending on temp and conditions. The same repair also works for the "Close cover" error some folks get. Just snap the cover switch apart, clean contacts with an emry board or very fine sandpaper and snap it back together and you're good to go.

mtylerfl
12-23-2010, 04:00 PM
Excellent, Tom! Great post for others to read in case they run into the same issue. Thanks for the update!