547,210 active members*
3,233 visitors online*
Register for free
Login
IndustryArena Forum > General Manufacturing Processes > Milling > Flipped part and chamfers are offset on x axis
Page 1 of 2 12
Results 1 to 20 of 24
  1. #1
    Registered
    Join Date
    Aug 2009
    Posts
    6

    Flipped part and chamfers are offset on x axis

    Need a little help here. So I am flipping my part over to run side 2 which is nothing special just some facing and chamfering. I made a fixture for this part and I am using one of the holes as my 0 so that I would avoid this problem or so I thought. After I ran these parts the chamfers were visibly wrong. They were offset only in the X axis. So as a double check thinking I missed steps I broke out the indicator and swept the hole that I used as 0 again to see if it had moved or something and it had not. So as another check I moved the mill to the other two hole locations and swept those just to see if there was some error there and only found about .0015 error in location. I checked my fixture to see if it was still set square and it is within .001 in all directions. I reposted the program and reran one of them. Still no difference. I’m now not sure what it could be. The pictures are a little tough to see the difference but the left of the holes is a lighter chamfer than the right. The profile chamfer is heavier on the left end of the part and lighter on the right. Any help would be greatly appreciated.

  2. #2
    Member
    Join Date
    Jul 2018
    Posts
    3392

    Re: Flipped part and chamfers are offset on x axis

    Hi SMW - Have you flipped parts before? When you do this the error is potentially twice the "clearance" in the fixture. Have to use chamfered pins or registers that are very tight to get correct registration both sides. Sorry no pics to look at. Peter

  3. #3
    Member
    Join Date
    Aug 2009
    Posts
    1118

    Re: Flipped part and chamfers are offset on x axis

    ...If, the Column (Z axis) of the machine is tilted a few degrees or just minutes (not perpendicular) to the X axis can cause what you have described. Tool length differences would magnify the offset error. Re Tram

  4. #4
    Registered
    Join Date
    Aug 2009
    Posts
    6
    Quote Originally Posted by peteeng View Post
    Hi SMW - Have you flipped parts before? When you do this the error is potentially twice the "clearance" in the fixture. Have to use chamfered pins or registers that are very tight to get correct registration both sides. Sorry no pics to look at. Peter
    No I haven’t but I was wondering if that could be a potential issue. I’m using some of the cam screw type clamps and torquing the right one down first so it pushes the part to the left locking it against the fixture first. I do indicate each one since it’s a converted G0704 mill. Hasn’t really shown me that I need to but still just another double check.

  5. #5
    Registered
    Join Date
    Aug 2009
    Posts
    6
    Quote Originally Posted by machinehop5 View Post
    ...If, the Column (Z axis) of the machine is tilted a few degrees or just minutes (not perpendicular) to the X axis can cause what you have described. Tool length differences would magnify the offset error. Re Tram
    I kind of checked that I ran my indicator across the top of the fixture just to see if it was not flat and it bounced around between .001ish across the 7 inches. It was better than I expected for sure.

  6. #6
    Member
    Join Date
    Jan 2005
    Posts
    12924

    Re: Flipped part and chamfers are offset on x axis

    Quote Originally Posted by smw19822002 View Post
    No I haven’t but I was wondering if that could be a potential issue. I’m using some of the cam screw type clamps and torquing the right one down first so it pushes the part to the left locking it against the fixture first. I do indicate each one since it’s a converted G0704 mill. Hasn’t really shown me that I need to but still just another double check.
    If you interacted the hole X0Y0 and the chamfer is off with that hole, then it has to be in the program
    Mactec54

  7. #7
    Member
    Join Date
    Aug 2009
    Posts
    1118

    Re: Flipped part and chamfers are offset on x axis


  8. #8
    Registered
    Join Date
    Jan 2018
    Posts
    953

    Re: Flipped part and chamfers are offset on x axis

    Quote Originally Posted by mactec54 View Post
    If you interacted the hole X0Y0 and the chamfer is off with that hole, then it has to be in the program
    Either that or, that is the backlash in the machine showing up.

    Quote Originally Posted by smw19822002 View Post
    No I haven’t but I was wondering if that could be a potential issue. I’m using some of the cam screw type clamps and torquing the right one down first so it pushes the part to the left locking it against the fixture first. I do indicate each one since it’s a converted G0704 mill. Hasn’t really shown me that I need to but still just another double check.
    When you did both sides. Did you zero your WCS for X from the same table side (ie left side / corner)?.
    If you do so, one of the sides will be against the backlash of the machine. If you have say 0.002" backlash in the machine this would show up on ONE of the sides.

    When you flip it you should do for example..... on side 1- come in with cutter from bottom left corner.... flip it...... then come in from bottom right corner on side 2.
    This means your cutter will be coming in from the SAME position for both x+y on both sides. If you've done it right, the spindle will have past any mechanical baclash when you set your starting position on each side.

    If my dodgy explanation makes any sense to you.

  9. #9
    Member
    Join Date
    Jan 2005
    Posts
    12924

    Re: Flipped part and chamfers are offset on x axis

    Quote Originally Posted by dazp1976 View Post
    Either that or, that is the backlash in the machine showing up.



    When you did both sides. Did you zero your WCS for X from the same table side (ie left side / corner)?.
    If you do so, one of the sides will be against the backlash of the machine. If you have say 0.002" backlash in the machine this would show up on ONE of the sides.

    When you flip it you should do for example..... on side 1- come in with cutter from bottom left corner.... flip it...... then come in from bottom right corner on side 2.
    This means your cutter will be coming in from the SAME position for both x+y on both sides. If you've done it right, the spindle will have past any mechanical baclash when you set your starting position on each side.

    If my dodgy explanation makes any sense to you.
    If you indicate a hole ( X0Y0 ) the Backlash if any, would not be the cause of this much shift in cut

    He needs to check his drawing to see where the problem is
    Mactec54

  10. #10
    Member
    Join Date
    Jan 2005
    Posts
    12924

    Re: Flipped part and chamfers are offset on x axis

    Quote Originally Posted by machinehop5 View Post
    If tram is his problem he would see it in his part thickness and the edges would not be square to the machined top surface
    Mactec54

  11. #11
    Member
    Join Date
    Aug 2009
    Posts
    1118

    Re: Flipped part and chamfers are offset on x axis

    Quote Originally Posted by mactec54 View Post
    If tram is his problem he would see it in his part thickness and the edges would not be square to the machined top surface
    ...yes everything would be out of whack. and when Fly cutting would be easy to spot if, you know what to look for.

  12. #12
    Registered
    Join Date
    Aug 2009
    Posts
    6
    Quote Originally Posted by dazp1976 View Post
    Either that or, that is the backlash in the machine showing up.



    When you did both sides. Did you zero your WCS for X from the same table side (ie left side / corner)?.
    If you do so, one of the sides will be against the backlash of the machine. If you have say 0.002" backlash in the machine this would show up on ONE of the sides.

    When you flip it you should do for example..... on side 1- come in with cutter from bottom left corner.... flip it...... then come in from bottom right corner on side 2.
    This means your cutter will be coming in from the SAME position for both x+y on both sides. If you've done it right, the spindle will have past any mechanical baclash when you set your starting position on each side.

    If my dodgy explanation makes any sense to you.
    I did I use the same side for both operations. The closest left on side 1 and the hole on the left on side 2. I did think also that the backlash might be getting me so I re-ran the same code with the backlash turned off and still have the same result.

  13. #13
    Registered
    Join Date
    Aug 2009
    Posts
    6
    Quote Originally Posted by mactec54 View Post
    If you indicate a hole ( X0Y0 ) the Backlash if any, would not be the cause of this much shift in cut

    He needs to check his drawing to see where the problem is
    I thought that to and I honesty can’t find anything in the model wrong but there is always a chance that I am overlooking something so I am going to take a look again this evening

  14. #14
    Registered
    Join Date
    Aug 2009
    Posts
    6
    Quote Originally Posted by smw19822002 View Post
    I thought that to and I honesty can’t find anything in the model wrong but there is always a chance that I am overlooking something so I am going to take a look again this evening
    Finally had a chance to go back over this thing. So i studied my model as close as I could and cannot find that the 0 point is wrong or offset to one direction. Chamfers in the simulation look to be even all the way around.

    Completely removed the fixture and trammed the head. The head was out about .002 in the X direction and about .001 in the y direction. I adjusted the X but didn’t bother with the Y. I’m not making super critical parts so being out that little bit is never going to hurt anything not to mention it is a pain to adjust that column. After it was all done I checked it with the indicator and it is .0005-.001 out in a 6 inch circle in the table so I’m pretty happy with that.

    I put the fixture back on and re-ran the same code just to see that it’s still the same result.

    I appreciate all the input you all provided but I’m not really sure where to go from here.

  15. #15
    Community Moderator Jim Dawson's Avatar
    Join Date
    Dec 2013
    Posts
    5103

    Re: Flipped part and chamfers are offset on x axis

    If you are locating on the hole with the indicator in it, it could be that the hole is not where you think it is. Might be offset very slightly. From the pictures, it looks like you need to shift the part to the right one or two thou relative to the tool.
    Jim Dawson
    Sandy, Oregon, USA

  16. #16

    Re: Flipped part and chamfers are offset on x axis

    Maybe I missed it, but are you indicating the hole center by using two opposite sides of the hole?

    EDIT: For the center in x

  17. #17
    Member
    Join Date
    Jan 2005
    Posts
    12924

    Re: Flipped part and chamfers are offset on x axis

    Quote Originally Posted by StrawberryBoi View Post
    Maybe I missed it, but are you indicating the hole center by using two opposite sides of the hole?

    EDIT: For the center in x
    If you are indicating a hole you are doing the X and Y axis X0Y0 Point, this is the only way when using an indicator for this process
    Mactec54

  18. #18
    Quote Originally Posted by mactec54 View Post
    If you are indicating a hole you are doing the X and Y axis X0Y0 Point, this is the only way when using an indicator for this process
    I just want to confirm they're not indicating only one side and taking the radius for the x-pos. It's unlikely they would do it this way, but just as you must ask oneself if the device is indeed plugged in and turned on, you must ask oneself even the most seemingly obvious things when troubleshooting.

  19. #19
    Member
    Join Date
    Jan 2005
    Posts
    12924

    Re: Flipped part and chamfers are offset on x axis

    Quote Originally Posted by StrawberryBoi View Post
    I just want to confirm they're not indicating only one side and taking the radius for the x-pos. It's unlikely they would do it this way, but just as you must ask oneself if the device is indeed plugged in and turned on, you must ask oneself even the most seemingly obvious things when troubleshooting.
    You could not set a hole center at all, with an indicator by just touching ( 1 ) side of the hole, not even with a probe, this would not work, you have to sweep the hole with a minimum of ( 3 ) Points, for an indicator, all ( 3 ) positions must be 0.0 on the indicator to give you a X0Y0 position. using a probe you normally do ( 4 ) points
    Mactec54

  20. #20
    Registered
    Join Date
    Jan 2018
    Posts
    953

    Re: Flipped part and chamfers are offset on x axis

    Quote Originally Posted by mactec54 View Post
    You could not set a hole center at all, with an indicator by just touching ( 1 ) side of the hole, not even with a probe, this would not work, you have to sweep the hole with a minimum of ( 3 ) Points, for an indicator, all ( 3 ) positions must be 0.0 on the indicator to give you a X0Y0 position. using a probe you normally do ( 4 ) points
    Depending on the hole size, I kept a load of broken end mills of varying sizes.
    I use the shanks of these fitted into the spindle nose to line up to a drilled hole. Generally between sizes 3-8mm.

Page 1 of 2 12

Similar Threads

  1. Part work offset
    By astral in forum Okuma
    Replies: 5
    Last Post: 03-13-2021, 10:16 PM
  2. Fillet and chamfers - 3 axis milling - CW4SW
    By itolond in forum CamWorks
    Replies: 1
    Last Post: 06-27-2018, 11:41 AM
  3. Replies: 2
    Last Post: 02-17-2013, 06:37 PM
  4. FLA-100. Flipped part wont line up! Software or mechanical?
    By Zeppelin1007 in forum DIY CNC Router Table Machines
    Replies: 23
    Last Post: 11-15-2012, 01:54 PM
  5. 5 axis chamfers and dovetails
    By gwb in forum Mastercam
    Replies: 0
    Last Post: 02-03-2012, 09:29 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •