Scara manual control

Fuzionline

When I am using the Pendant (Joystick) or Manual Control and I try to enter an area that I know it cannot reach due to being a SCARA, because it originates from (X0, Y0). Is it possible to define a restricted area around the SCARA,like M208? Because what happens is that since it cannot reach through that path, it changes rotation and tries to reach from the other side, and on top of that, it increases speed. This situation happens with the pendant or manual control DWC
config (4).g
Tks

droftarts

@Fuzionline In your config.g you have the angular limits of the joints with M669, and area limits with M208, already specified:

M669 K4 P765 D475 A-156:156 B-151:151 C0:0:0 S100 T1 R450	;V4 Arm-Clay Kinematics Config, Min Radius 400 ATENCAO SUPORTE RUA
...
; Axis Limits
M208 X-1200 Y-1200 Z0 E0 U0 S1        ; set axis minima
M208 X1200 Y1200 Z1000 E1000000000 U100000 S0         ; set axis maxima

Are these sensible settings for the work area? Is it these that you find you can go beyond?

There is a part at the end of your config.g that seems to control the limiting of axes:

M564 S1 H1 ; Permitir movimentos sem homing

M98 P"macro.g" ; Chame a macro idle.g quando a impressora está idle
M98 P"0:/macros/LimitarMovimento.g"  ; Executa a macro de limitação de movimento ao iniciar

Maybe check that there is no M564 S0 H0 command in the last two macros.

Also please post what version of RepRapFirmware you are using. This bug was found in 3.5.1 (and possibly earlier):

Soft machine axis limits on Linear Delta, SCARA and other nonlinear kinematics were not respected for moves that did not specify X and Y and Z coordinates (issue 997). This was a new bug in RRF 3.5.0.

This was fixed in 3.5.2.

Ian

Fuzionline

@droftarts
Thanks,
The R value of M669 was 430, but I set it to 450 to avoid the risk of collision.
The R value was obtained by measuring from the center of the proximal axis to the center of the extruder nozzle on the distal arm in millimeters.
Regarding the M98 P"0:/macros/LimitarMovimento.g", it was created to try to solve this problem, but I couldn't, and it doesn't have any M564.
The version is RepRapFirmware for Duet 2 WiFi/Ethernet version 3.5.2 (2024-06-11 17:13:43) running on Duet WiFi 1.02.

Fuzionline

@Fuzionline
Thanks,
I tried another one with M564 S0 H0 and without M564, but the behavior is the same.
When the distal arm is approaching the endstop (passing under the proximal arm) at an angle of -151, the distal arm rotates in the opposite direction and moves to an angle of 150 to stay on the same X line.

droftarts

@Fuzionline Sorry, I don't know enough about Scara machines to know if you limits are sensible. What limit is it possible to exceed? Those set by M208? If so, it's possible the bug mentioned above has not quite been solved.

Ian

Fuzionline

@droftarts
tks
But is it possible to create a restricted zone that the machine cannot access, like with M208?

droftarts

@Fuzionline Sorry, I though you meant that it was going beyond the limits set by M208. Can you test if the M208 limits work?

You can define an area that you don't want the tool to go into, with M599. Is that what you mean? See https://docs.duet3d.com/en/User_manual/Reference/Gcodes#m599-define-keepout-zone

Ian

Fuzionline

@droftarts
tks
In relation to M208, via the pendant or DWC, it does not exceed the defined values, which is great. Since (X0, Y0) is the center of the SCARA, there is an area around this base that I want to prevents the pendant from mistakenly exceeding the area."
My duet is a 2 wifi , the M599 don´t work ?
tks

Fuzionline

@Fuzionline
Good afternoon! Are there any updates?

droftarts

@Fuzionline Ah, yes, M599 doesn't work on Duet 2 due to memory limitations.

Looking at your config.g, you seem to have your machine limits set to allow the Scara arm to go anywhere in a donut shape around the centre. Your M208 XY limits are +/- 1200mm, which is roughly the length of your proximal (765mm) and distal (475mm) arms, with a central no-go area of 450mm radius (ie 900mm diameter). Is this correct?

If you command it to go into any area within the 900mm diameter central area, I would think it should stop at the point it gets within 450mm of X0 Y0. If it continues to attempt to get there, I think that sounds like a bug. Can you confirm that's what you see?

Ian

Fuzionline

@droftarts

@droftarts said in Scara manual control:

Looking at your config.g, you seem to have your machine limits set to allow the Scara arm to go anywhere in a donut shape around the centre. Your M208 XY limits are +/- 1200mm, which is roughly the length of your proximal (765mm) and distal (475mm) arms, with a central no-go area of 450mm radius (ie 900mm diameter). Is this correct?

Regarding the M208 limits, everything is fine; when it reaches -1200/1200, it doesn't allow further movement.
However, there is an issue with the R value. I even increased it to R500, but it exceeds this value and continues until it reaches the limit defined by the distal angle, which is 150(endstop). If it continues to be commanded in that direction, it moves in the opposite direction and stops at the -151 distal angle.
It seems to me that the situation starts with it ignoring the value set in R.

@droftarts said in Scara manual control:

If you command it to go into any area within the 900mm diameter central area, I would think it should stop at the point it gets within 450mm of X0 Y0. If it continues to attempt to get there, I think that sounds like a bug. Can you confirm that's what you see?

No.Only stop when reach the 150 distal angle(420mm of X0 Y0 approximate).

droftarts

@Fuzionline said in Scara manual control:

No.Only stop when reach the 150 distal angle(420mm of X0 Y0 approximate).

I think that's the default. From 'Serial SCARA' tab of M669 https://docs.duet3d.com/en/User_manual/Reference/Gcodes#m669-set-kinematics-type-and-kinematics-parameters

Rnnn (optional, RRF 2.03 and later only) Minimum permitted printing radius from the proximal axis. If not specified, it will be calculated to be slightly larger than the distance between nozzle and proximal axis when the distal axis is homed.

So it does look like R is being ignored. I'll report it to @dc42 and see what he says.

Ian