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- Gantry setup with two motors but home switches only on one joint
Gantry setup with two motors but home switches only on one joint
- Louis Cypher
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12 Aug 2019 12:17 #141963
by Louis Cypher
I have been searching and reading quite a bit, but I am still unsure how to achieve what I want. The main reason that there are too many options ![;-) ;-)](/media/kunena/emoticons/wink.png)
My setup:
Gantry Style Machine with two motors on y axis. *The two motors are synchronized via a timing belt*
Since my machine has a timing belt I think homing both Joints doesn't make any sense. I'd prefer to have limit/homing switches on only one joint of the Y axis.
Can I/ should I use the gantry module? I understood to have limit switches on any of the joints. Or should I link the enable, dir and pulse inputs of the first motor to the second motor in the HAL using the net command? Is anybody willing to share a HAL config for such setup?
I already roasted 2 motor drivers, hence I am pretty conservative/ overly cautios .
Thanks in advance,
Louis
![;-) ;-)](/media/kunena/emoticons/wink.png)
My setup:
Gantry Style Machine with two motors on y axis. *The two motors are synchronized via a timing belt*
Since my machine has a timing belt I think homing both Joints doesn't make any sense. I'd prefer to have limit/homing switches on only one joint of the Y axis.
Can I/ should I use the gantry module? I understood to have limit switches on any of the joints. Or should I link the enable, dir and pulse inputs of the first motor to the second motor in the HAL using the net command? Is anybody willing to share a HAL config for such setup?
I already roasted 2 motor drivers, hence I am pretty conservative/ overly cautios .
Thanks in advance,
Louis
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- tommylight
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12 Aug 2019 15:07 #141968
by tommylight
Replied by tommylight on topic Gantry setup with two motors but home switches only on one joint
In that case you should link them in hal or wire them to the same output.
How did you roast them ? Popcorn ! ?![:) :)](/media/kunena/emoticons/smile.png)
What drives and what voltage and type of power supply ?
How did you roast them ? Popcorn ! ?
![:) :)](/media/kunena/emoticons/smile.png)
What drives and what voltage and type of power supply ?
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- Louis Cypher
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13 Aug 2019 10:17 - 13 Aug 2019 10:23 #142020
by Louis Cypher
Replied by Louis Cypher on topic Gantry setup with two motors but home switches only on one joint
One died because of a short in the motor cable, one since the connector was wired for the TB6600 and I connected it to a brandnew DM542 (36V connected to a drive Output). Better don't have a beer when wiring ;-/
I have a 36V China power supply, Nema 23 and a mix of DM542A and TB6600 (to be changed to DM542 when everything is up and running)
*Back to Topic:*
I upgraded to 2.8 and not sure that I understood how to set things up:
In the Ini file there is a definition of the axis as well as a joint definition. Since my Y- Axis has two drives there should be a second joint be defined. What should the numbering of the joint be?
Like this ?:
Or should I preferably use stepconf, set up a XYZA configuration and change the "soft-wiring".
I have a 36V China power supply, Nema 23 and a mix of DM542A and TB6600 (to be changed to DM542 when everything is up and running)
*Back to Topic:*
I upgraded to 2.8 and not sure that I understood how to set things up:
In the Ini file there is a definition of the axis as well as a joint definition. Since my Y- Axis has two drives there should be a second joint be defined. What should the numbering of the joint be?
Like this ?:
[AXIS_X]
MAX_VELOCITY = 19.0
MAX_ACCELERATION = 30.0
MIN_LIMIT = 0.0
MAX_LIMIT = 800.0
[JOINT_0]
TYPE = LINEAR
HOME = 5.0
MIN_LIMIT = 0.0
MAX_LIMIT = 800.0
MAX_VELOCITY = 19.0
MAX_ACCELERATION = 30.0
STEPGEN_MAXACCEL = 37.5
SCALE = 320.0
FERROR = 1
MIN_FERROR = .25
HOME_OFFSET = 0.000000
HOME_SEARCH_VEL = 0.050000
HOME_LATCH_VEL = 0.050000
HOME_IGNORE_LIMITS = YES
HOME_SEQUENCE = 1
[JOINT_4]
TYPE = LINEAR
HOME = 5.0
MIN_LIMIT = 0.0
MAX_LIMIT = 800.0
MAX_VELOCITY = 19.0
MAX_ACCELERATION = 30.0
STEPGEN_MAXACCEL = 37.5
SCALE = 320.0
FERROR = 1
MIN_FERROR = .25
HOME_OFFSET = 0.000000
HOME_SEARCH_VEL = 0.050000
HOME_LATCH_VEL = 0.050000
HOME_IGNORE_LIMITS = YES
HOME_SEQUENCE = 1
Or should I preferably use stepconf, set up a XYZA configuration and change the "soft-wiring".
Last edit: 13 Aug 2019 10:23 by Louis Cypher. Reason: Additional information
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- Louis Cypher
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13 Aug 2019 10:26 #142021
by Louis Cypher
Replied by Louis Cypher on topic Gantry setup with two motors but home switches only on one joint
What would be your preference?
- wire two controllers to one output (maybe more reliable but maybe have electrical problems like too low resistance)
- connect in HAL (Maybe lost sync between due to realtime Problems?)
- wire two controllers to one output (maybe more reliable but maybe have electrical problems like too low resistance)
- connect in HAL (Maybe lost sync between due to realtime Problems?)
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13 Aug 2019 15:10 #142030
by tommylight
Replied by tommylight on topic Gantry setup with two motors but home switches only on one joint
Both of them will work properly, no worties.
You can also use 1 drive for 2 motors but that is a bit tricky, great care should be taken during wiring not to fry the drive.
Also for the 6600 and 542 i would not recomend anything over 24V as they tend to give up the ghosts easily. 542 should handle a bit more, but to risky for the quality of the parts used.
You can also use 1 drive for 2 motors but that is a bit tricky, great care should be taken during wiring not to fry the drive.
Also for the 6600 and 542 i would not recomend anything over 24V as they tend to give up the ghosts easily. 542 should handle a bit more, but to risky for the quality of the parts used.
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13 Aug 2019 17:24 #142049
by pl7i92
Replied by pl7i92 on topic Gantry setup with two motors but home switches only on one joint
a gantry shoudt be homes to both sides otherwise it does not give you a benefit of the gantry
so get a second switch there
if you want to leve it the way just direct the signaƶ of moving to the second driver stage thats all
so get a second switch there
if you want to leve it the way just direct the signaƶ of moving to the second driver stage thats all
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- Louis Cypher
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13 Aug 2019 18:10 #142059
by Louis Cypher
Replied by Louis Cypher on topic Gantry setup with two motors but home switches only on one joint
Sorry, sadly I don't get your point yet. The advantage of a gantry to my undestanding is that you have no torque applied to the linear rails, only forces. I do not see the advantage in rectifying your gantry over and over. I prefer to rectify once and have a hard synchronization via the belt. Or do you think the belt will be less accurate than having another home switch? That would be a valid explanation to myself.
- Would you then suggest to wire it in series with the other y-axis Limit switches? (no Inputs left anymore)
- How dou you home both without bending the gantry whenever homing is done?
- Would you then use the gantry module? Would you mind posting an example hal and ini or a link?
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13 Aug 2019 18:12 #142061
by Louis Cypher
Replied by Louis Cypher on topic Gantry setup with two motors but home switches only on one joint
thanks for the PS hint. I am using the powersupply delivered together with the motors and the drivers by Longs Motors, hence I thought the drivers should be capable of running at those voltages.
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13 Aug 2019 22:24 - 13 Aug 2019 22:24 #142088
by andypugh
Replied by andypugh on topic Gantry setup with two motors but home switches only on one joint
Run two stepgens in HAL, but connect them both to the same joint.N.motor-pos-cmd pin.
Configure as a conventional XYZ machine.
LinuxCNC does not need to know that you have two motors and two stepper drivers.
Configure as a conventional XYZ machine.
LinuxCNC does not need to know that you have two motors and two stepper drivers.
Last edit: 13 Aug 2019 22:24 by andypugh.
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