machineman8625
Member
- Joined
- Jul 7, 2011
- Messages
- 10
- Reaction score
- 0
Hi, I have a Bridgeport type mill with a SARGON x and y digital read out. It skips on one of the read outs. Any one have any idea how to fix it. Thanks, Larry
DRO skips
- Thread starter machineman8625
- Start date
Help Support Home Model Engine Machinist Forum:
Admiral_dk
Well-Known Member
- Joined
- Jul 15, 2010
- Messages
- 166
- Reaction score
- 0
It's like any other kind of problem solving - divide and conquer.
I'll guess that all tree axis have the same kind of connector.
If that's so, try to change the connector on the bad with the connector from one of the working channels - If the problem changes channel too => you've got a bad sensor or cabling to it - like wise, if the problem doesn't change you got a bad readout unit.
If it's the sensor or cabling - if the cabling can be disconnected at the sensor, try to swap the cable - does this solve the problem - if so, inspect the cabling or better yet measure it with an Ohm meter.
If not, try to inspect the sensor. Many of those are a two part "unit" - a stationary part and a moveable part. Are they both correct mounted - most require a rather constant distance between the two parts.
I'll guess that all tree axis have the same kind of connector.
If that's so, try to change the connector on the bad with the connector from one of the working channels - If the problem changes channel too => you've got a bad sensor or cabling to it - like wise, if the problem doesn't change you got a bad readout unit.
If it's the sensor or cabling - if the cabling can be disconnected at the sensor, try to swap the cable - does this solve the problem - if so, inspect the cabling or better yet measure it with an Ohm meter.
If not, try to inspect the sensor. Many of those are a two part "unit" - a stationary part and a moveable part. Are they both correct mounted - most require a rather constant distance between the two parts.
- Joined
- Oct 20, 2010
- Messages
- 913
- Reaction score
- 132
Does the skip occur in the same area of travel each time or is it random. If random locations look at the connector, clean, check for loose pins, alignment etc. If in the same area earch time, check alignment, oil swarf, remove scale, and see if its still the same dead zone, if so its the scale most likely.
What kind of "skip" are you seeing? I know nothing about the sensor technology on the unit you have, but it would help to determine what kind of skip you have. One kind would be where the display fails to show any numbers for a portion of the carriage travel but eventually picks up again without losing where it is. The other would be where the carriage moves but the encoder fails to "see" the motion and then picks up again at some random spot. This is worse because you have lost your position and, while the display may be displaying, it has no bearing on where the carriage is relative to where it started. My DRO went "funny" a while ago and it turned out to be that one of the mounts for the scale had come loose. Looked like a bad problem, but it was a simple fix. So , look for something simple first. It may be esier than you think.
Indeed, some more info is needed. If it's an optical DRO, it may be harder to diagnose. If it's mechanical, process of elimination will get you there. Some other things to consider:
If it's a repetitive skip, and reasonably consistent in space, a gear tooth may be broken somewhere. If the skip is always in the same area of the table movement, it could be swarf causing a mechanical part to bind temporarily (or an optical sensor not picking up its location due to swarf) as mentioned, cleaning ways and swapping DRO connectors can help narrow down the issue.
- Ryan
If it's a repetitive skip, and reasonably consistent in space, a gear tooth may be broken somewhere. If the skip is always in the same area of the table movement, it could be swarf causing a mechanical part to bind temporarily (or an optical sensor not picking up its location due to swarf) as mentioned, cleaning ways and swapping DRO connectors can help narrow down the issue.
- Ryan
