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Y and A not working together nicely

From the original Synthetos forum (2011–2025)

Started by LTMNO on in TinyG Support. 8 replies, last activity Jul 8, 2013.

LTMNO #

Strange thing, I have the A Mapped to Y for Motor 4 to 2 and when i have them both connected the y-axis is fighting itself. or it seems that one motor is moving faster than the other.
So i did some testing and disconnected one motor and tested it and then connected the other and tested it.
I did a simple advance of 200mm and this is what happen.

Motor 4(A)
tinyg [mm] ok>
posy:29.272,vel:16000.000,stat:5
posy:95.363
posy:160.133
posy:199.999,vel:66.112
posy:200.000,vel:0.000,stat:3
tinyg [mm] ok>
posy:177.192,vel:15586.781,stat:5
posy:111.246,vel:16000.000
posy:46.477
posy:0.188,vel:1057.847
posy:0.000,vel:0.000,stat:3

Motor 2(Y)

tinyg [mm] ok>
posy:-3.320,vel:5966.943,stat:5
posy:-62.318, vel:16000.000
posy:-127.087
posy:-190.834,vel:11768.594
posy:-200.000,vel:0.000,stat:3
tinyg [mm] ok>
posy:-199.926,vel:595.041,stat:5
posy:-154.866,vel:16000.000
posy:-90.097
posy:-24.087,vel:15851.239
posy:0.000,vel:0.000,stat:3

I can see that my one more is working in reverse and I was trying to fix that with polarity, but perhaps that is not the way. The other motor which is on (A) is acting like it should and moving from front to back in the Positive manner.

I assume if I can fix the action of Motor Y(2) then this might fix the problem if there is not velocity/speed issue.

Thanks.

Exciting to see the machine move.

aldenStaff #

Can you please post your settings for the motors and axes? I'd start by looking at the configuration.

Question: Are you trying to run a dual motor Y gantry? If so, then the best way to do this is to set up Y normally, then map motor 4 to the Y axis by setting $4ma=1 (the Y axis). You may also need to make sure the Y on motor 4 has polarity reversed. All other settings should be the same.

LTMNO #

Hi Alden, from the looks of it, the Y and A are different. But I never set any of this in Y so I assume the default is true. Well, i did follow the setup guide for x,y,z,a
I don't recall having to set the jerking, etc...

[xam] x axis mode 1 [standard]
[xvm] x velocity maximum 16000.000 mm/min
[xfr] x feedrate maximum 16000.000 mm/min
[xtm] x travel maximum 220.000 mm
[xjm] x jerk maximum 5000000000 mm/min^3
[xjh] x jerk homing 10000000000 mm/min^3
[xjd] x junction deviation 0.0100 mm (larger is faster)
[xsn] x switch min 1 [0=off,1=homing,2=limit,3=limit+homing]
[xsx] x switch max 0 [0=off,1=homing,2=limit,3=limit+homing]
[xsv] x search velocity 3000.000 mm/min
[xlv] x latch velocity 100.000 mm/min
[xlb] x latch backoff 20.000 mm
[xzb] x zero backoff 3.000 mm

[yam] y axis mode 1 [standard]
[yvm] y velocity maximum 16000.000 mm/min
[yfr] y feedrate maximum 16000.000 mm/min
[ytm] y travel maximum 220.000 mm
[yjm] y jerk maximum 5000000000 mm/min^3
[yjh] y jerk homing 10000000000 mm/min^3
[yjd] y junction deviation 0.0100 mm (larger is faster)
[ysn] y switch min 1 [0=off,1=homing,2=limit,3=limit+homing]
[ysx] y switch max 0 [0=off,1=homing,2=limit,3=limit+homing]
[ysv] y search velocity 3000.000 mm/min
[ylv] y latch velocity 100.000 mm/min
[ylb] y latch backoff 20.000 mm
[yzb] y zero backoff 3.000 mm

[zam] z axis mode 1 [standard]
[zvm] z velocity maximum 800.000 mm/min
[zfr] z feedrate maximum 800.000 mm/min
[ztm] z travel maximum 100.000 mm
[zjm] z jerk maximum 50000000 mm/min^3
[zjh] z jerk homing 1000000000 mm/min^3
[zjd] z junction deviation 0.0100 mm (larger is faster)
[zsn] z switch min 0 [0=off,1=homing,2=limit,3=limit+homing]
[zsx] z switch max 1 [0=off,1=homing,2=limit,3=limit+homing]
[zsv] z search velocity 800.000 mm/min
[zlv] z latch velocity 100.000 mm/min
[zlb] z latch backoff 20.000 mm
[zzb] z zero backoff 10.000 mm

[aam] a axis mode 1 [standard]
[avm] a velocity maximum 60000.000 deg/min
[afr] a feedrate maximum 48000.000 deg/min
[atm] a travel maximum 400.000 deg
[ajm] a jerk maximum 24000000000 deg/min^3
[ajh] a jerk homing 24000000000 mm/min^3
[ajd] a junction deviation 0.1000 deg (larger is faster)
[ara] a radius value 1.0000 deg
[asn] a switch min 1 [0=off,1=homing,2=limit,3=limit+homing]
[asx] a switch max 0 [0=off,1=homing,2=limit,3=limit+homing]
[asv] a search velocity 6000.000 deg/min
[alv] a latch velocity 1000.000 deg/min
[alb] a latch backoff 5.000 deg
[azb] a zero backoff 2.000 deg

LTMNO #

other than the obvious.. i changed the a motor settings to y

[aam] a axis mode 1 [standard]
[avm] a velocity maximum 16000.000 deg/min
[afr] a feedrate maximum 16000.000 deg/min
[atm] a travel maximum 220.000 deg
[ajm] a jerk maximum 5000000000 deg/min^3
[ajh] a jerk homing 10000000000 mm/min^3
[ajd] a junction deviation 0.0100 deg (larger is faster)
[ara] a radius value 1.0000 deg
[asn] a switch min 1 [0=off,1=homing,2=limit,3=limit+homing]
[asx] a switch max 0 [0=off,1=homing,2=limit,3=limit+homing]
[asv] a search velocity 3000.000 deg/min
[alv] a latch velocity 100.000 deg/min
[alb] a latch backoff 20.000 deg
[azb] a zero backoff 3.000 deg

LTMNO #

Okay I fixed the problem.... ;-)
I reversed the polarity of my $2PO=1 and then kept the $4PO=0

That is making them work together now and they are set the same thanks the motor configurations.

maybe now I can try the Hello World program. Everything is working as planned... as per the setup guide.

Thanks for stepping me in the right direction.

LTMNO #

Hi Alden,
Thanks for the link....
So I guess I need to remap the motors and move the wires over a space.
I have now. X | Y1 | Z | A(Y2)

So I guess I should fix this?

aldenStaff #

As long as it works you are fine. There's no reason you can't use motor4 for the Y2. The mapping is completely arbitrary. I know people that re-arranged their motor mapping because their machine wiring was too short on one axis and moving the axis to the edge of board saved 3 inches! (they shall remain nameless).

LTMNO #

Nice, Thanks... This is my pre setup to the real setup. As in, I just wanted to get the Hello World Written and then I am on to the larger build.

Stay tuned...

Thanks again.

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