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Setting up kinematic model parameters for DMG DMU50v

markp

Member
Im working to get a 5 axis post written for my 2000 DMG DMU50v. Ive been using my old Maho cnc 432 post that actually works ok for 3+2 stuff.
Anyhow, I see that the machine constants MC600-MC699 for describing the kinematic model are all set to 0. Without a kinematic model entered in the constants, the machine cant use the controls internal math for G7,(tilting planes),G141(3d tool comp),G174 and other 5 axis related internal calculations. My post guy wants to be able to use these commands. Anyone out there with one of these machines that can give me a set of constants for 600-699?
 

markp

Member
Well, I did get the DMG manual from DMG tech support for setting the machine constants 600-699 to call a G7 and G141. Its very detailed and not a simple procedure at least to me. If anyone needs it pm me. Again, if anyone has actually done this procedure and has any tips, Id appreciate it.
 

markp

Member
Ok,kinematic chain is entered and now the machine accepts G7 commands, does tilted planes etc. However, it still wont accept a G141 command. The tech that gave me the info for setting up G7 transferred my query to the DMG application engineer dept to get help with that. Still waiting for a call back. I browsed the parameter description and didnt see any ones that looked connected to a G141 not working.(I did make sure MC263 (3d tool function) is turned on.) Anyone more familiar with these controls have any suggestions? Maybe a copy of your parameters from a similar machine so I can compare?
 

WallaceLau

New member
Ok,kinematic chain is entered and now the machine accepts G7 commands, does tilted planes etc. However, it still wont accept a G141 command. The tech that gave me the info for setting up G7 transferred my query to the DMG application engineer dept to get help with that. Still waiting for a call back. I browsed the parameter description and didnt see any ones that looked connected to a G141 not working.(I did make sure MC263 (3d tool function) is turned on.) Anyone more familiar with these controls have any suggestions? Maybe a copy of your parameters from a similar machine so I can compare?

Just send you a PM (at least I think I did), if you could e-mail the kinematic model setup instructions I would very much appreciate it... I can also share my Machine Constant file with you for reference; I know this thread is 3 years old but sometimes it doesn't hurt to have extra info. Thanks!!!



Wallace
 

markp

Member
Too large to post here directly. Ill send the complete file to your email. If you have a recent calibration record its a place to start. I used the one from my machine commissioning sheet for the first try. I measured and redid it to the slightly different new dimensions. The DMG tech i spoke to recommended that the machine be set to MM in the constants before setting and then set back to inch afterwards. He said the control calculates the data better that way.
 

WallaceLau

New member
Too large to post here directly. Ill send the complete file to your email. If you have a recent calibration record its a place to start. I used the one from my machine commissioning sheet for the first try. I measured and redid it to the slightly different new dimensions. The DMG tech i spoke to recommended that the machine be set to MM in the constants before setting and then set back to inch afterwards. He said the control calculates the data better that way.

Thank you for the instructions, I got everything to work! I re-calibrated the probe, checked the table's bushing (it was only 0.0002" off), and used it to re-calibrate the iniital X/Y position of the kinematic chain. Thereafter I picked 15 random places on the table surface for the initial Z value, and finally mounted a block to the table and probed a corner based on the instructions. Some of the current settings on the Kinematic model was as much as 0.0065" off... which explains why it was cutting weird even on 3+2 operations and we could never get the right dimension. (Parts-to-parts tolerance is good, but what good is it if ALL the parts have identically wrong dimensions...)

Thanks again for the help!



Wallace
 

markp

Member
My machine was also offset from the G7 center of rotation. I believe this was due to a crash that the previous owner had (described in an old post in another machinist forum from an op when my machine was at the Lick Observatory machine shop).


But...I dont have probing on my old DMU50v so I had to fix this manually. First, Measured the kinematic dimensions as described in the DMG manual I sent you. Entered this into the kinematic tables. Did this shortly after getting the machine. Before I adjusted the kinematic offset, I compensated for the offset by manually moving the features in 3+2 locations in cam to match the offset I was seeing in parts.

Was repeatable so I left it that way for a while as DMG tech support didnt know or want to tell how to make the adjustments. They actually wanted to send a tech here for god knows how much.

To fix, I made a square test block with pockets on 5 sides. Machined on its perimeter in XY down 2” in XYZ G7 not activated. The block pockets on top, on the left side and in the rear, were aligned within .0005. The pockets on the front side and left side, were shifted .0010 to the left.


To fix this, changed parameter MC603 (X distance to pivot center) by adding .0010” to the -distance.
This moves the front face and the rear face to be aligned properly.

Now the left face and right face were shifted out of alignment .005”
Added .005” to MC607 (Y distance to pivot point) - distance.
Now all pockets on faces and top (non G7)are aligned.

Z distance after transformation is still off. Checking Z0 after a G7 B5=90 C5=0 L1=1 transformation (Z transforms to Y axis) shows it is .007” out of alignment towards the back of machine.

Add .007” to - dimension at MC 619 (Z axis pivot point to B and C axis).

Now all axis are aligned within .0002 during G7 transformations. You can also see this in the axis position output. It does not change after rotations if the offset is correct. Then confirmed by a final test block pass and CMM check of block. I also created a radius on the top of the part from all four directions to check blending.

.
 

WallaceLau

New member
Hot damn that's a lot of work... I am glad we've got probing function on our machine! The whole point we want the kinematic model to work is so we can load a very troublesome part (that we know every single one is a little bit off and hence can't fixture accurately with any repeatability), probe each one to find a defining feature that we used as origin in CAM, so the zeros are set dynamically and correctly for each part. Thereafter, we use G7 transformation to machine additional features onto several faces AND have those features intersect each other correctly. Pretty standard stuff on 5-axis machining, but without the correct kinematic model, our own cut would be off... now we can machine those items very accurately! Yay!
 

Twallin

New member
Hello, Could you send me the kinematic model setup instructions also. I just got a DMU 50 and I also need to setup the MC600s. I would greatly appreciate.
I also tried to send you a PM but not sure if it worked.

Thanks
Todd
 

Twallin

New member
I tried to send you a PM but it said you have exceeded their stored private messages. It sounds like you need to delete some PMs
Thanks
Todd
 

five7

New member
Ok, As above, Ill have to have an email address. try to PM again. Thx

Off (sry)
Hello. Sorry for boothering you markp. I get this error message when i tried send pm to you.

"Errors
The following errors occurred with your submission

markp has exceeded their stored private messages quota and cannot accept further messages until they clear some space."
Can you free some space? Or can i write here the email? (i think it is not accepted here...) thanks in advance
 

sius

New member
Hi, markp
Sorry for bothering
I've sent PM request the kinematic manual?
I'm not sure if its really already sent?
could you confirm that?
 

Imtellectual

New member
Ok, As above, Ill have to have an email address. try to PM again. Thx
Hello markp, Could you send me the kinematic model setup instructions. I lost the center of rotation of the G7 (DMU 50V). I would greatly appreciate. I can’t send you private messages, they are full of you
 

rdbojan

New member
Hi all,
I have problem with 5axis simulataneous for DMU50V with MillPlus v410.
I use FeatureCAM and I have solved 3+2 axis with using of G7 function.
Problem is with G141. We get error on machine G301 - "Original block contents incorrect".

Here is the program:

%PM1001
N1001 (1001)
N10 (T1 D=10 CR=0 - flat end mill)
N11 G90
N12 G17
N13 G54
N14 G71
N15 G40
N17 G7
N18 G74 Z-1 L1
N19 (Swarf1)
N20 M9
N21 T1 M6
N22 S5000 M3
N23 G54
N24 G0 B0. C0.
N25 M8
N26 G141 L1=1
N27 G0 X-23.591 Y-24.807
N28 G0 Z-1.969
N29 G0 B48.387 C17.624
N30 G0 X-17.48 Y-22.866 Z-11.587
N31 G1 Z-15.593 F1000
N32 G1 Z-19.599
N33 G1 Z-23.606
N34 G1 Z-27.612
N35 G1 Z-31.618
N36 G1 X-18.907 Y-18.373
N37 G1 X-20.334 Y-13.88
N38 G1 X-21.762 Y-9.387
N39 G1 X-23.189 Y-4.894
N40 G1 X-24.617 Y-0.401
N41 G1 X-26.044 Y4.092
N42 G1 X-27.471 Y8.585
N43 G0 Z-11.587
N44 G0 X-33.583 Y6.644 Z-1.969
N45 G40
N46 G17
N47 M9
N48 M5
N49 G74 Z-1 L1
N50 G0 B0 C0
N51 M30

 








 
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