I could use some help

fcwilt

@fcwilt
M569 P0.1 S0                                       ; physical drive 0.1 goes backwards
This is what's in the config.g. This makes the jog buttons work correctly.

So a minus Y jog move makes the bed move backwards. Correct?

Frederick

A Former User

@fcwilt yes, clicking on the jog buttons make them do what they're supposed to do. When you click on < Y-10 the bed goes towards the rear of the printer. When you click on Y+10> the bed goes towards the front of the printer.

However, when the bed gets to what it thinks is 220, it stops.

Shite! I was clicking on the jog buttons. I looked at the Status Display. I was expecting to see Y at almost 220.

Right now the bed is 5/8th of an inch closer to the front of the printer than the back of the printer. And Y in the DWC Status Display reports 0.0.

I moved the bed forwards 3 more times. The display is reporting Y at 80. now

Okay, I told the bed to go back to the rear -50, then -50 again. The bed stopped when Y in the display reached 0.0. So it didn't go the full 50mm the second time, because it can't go into negative territory.

So this tells me why the bed pounded on the front adjustment. It's trying to get to 220, which is about ten inches forwards of the front of the printer.

Where is this coming from? What codes are providing this information to the printer?????

fcwilt

@mac said in I could use some help:

@fcwilt yes, clicking on the jog buttons make them do what they're supposed to do. When you click on < Y-10 the bed goes towards the rear of the printer. When you click on Y+10> the bed goes towards the front of the printer.

However, when the bed gets to what it thinks is 220, it stops.

Shite! I was clicking on the jog buttons. I looked at the Status Display. I was expecting to see Y at almost 220.

Right now the bed is 5/8th of an inch closer to the front of the printer than the back of the printer. And Y in the DWC Status Display reports 0.0.

I moved the bed forwards 3 more times. The display is reporting Y at 80. now

Okay, I told the bed to go back to the rear -50, then -50 again. The bed stopped when Y in the display reached 0.0. So it didn't go the full 50mm the second time, because it can't go into negative territory.

So this tells me why the bed pounded on the front adjustment. It's trying to get to 220, which is about ten inches forwards of the front of the printer.

Where is this coming from? What codes are providing this information to the printer?????

It is the homing code that syncs up the physical position of the bed with the logical position.

At the start of the homing code let's assume the firmware has no idea where the bed is.

So the homing code should start moving the bed backwards until it triggers the endstop.

Since the firmware (in theory) knows where the endstop is it now knows where the bed is.

Jogging, even when homing has failed, is going to limit moves, as displayed in the DWC, to the range of 0 to 220, regardless of where the bed actually is.

So the question is, since the jog buttons are working, why isn't the homing work.

Let's try clicking the Home Y button again, please.

It should:

move back at a medium speed until it triggers the endstop and stop briefly
move away from the endstop by 15mm
move back at a slow speed until it triggers the endstop and stop briefly
move away from the endstop until the bed is more or less in the middle of it's travel and stop
the DWC should be displaying 110

Thanks.

Frederick

A Former User

@fcwilt right now the y's at 0.0. My ruler's telling me the bed's at 9 and 5/8th inches forwards of HOME. What would G1 H1 Y-244 F3600 do? (Currently, in homey.g) the command is G1 H1 Y-360 F3600.

A Former User

@fcwilt please read my most recent message. It comes right after yours.

A Former User

@mac

; homey.g
; called to home the Y axis
;
; generated by RepRapFirmware Configuration Tool v3.3.10 on Mon Jun 27 2022 12:50:38 GMT-0700 (Pacific Daylight Time)
G91
G1 H1 Y-360 F3600
G1 Y15
G1 H1 Y-10 F360
 
G90
G1 Y110 F3600 ; this just moves Y to the centerline of the bed - doesn't matter where - it can be any place at all that suits you.

This is the entire homey.g

A Former User

@fcwilt In the Status Display, Y is at 0.0. It's already "Home." It can't go into negative territory.

fcwilt

@mac said in I could use some help:

@fcwilt right now the y's at 0.0. My ruler's telling me the bed's at 9 and 5/8th inches forwards of HOME. What would G1 H1 Y-244 F3600 do? (Currently, in homey.g) the command is G1 H1 Y-360 F3600.

In relative mode (G91) a G1 H1 Y-244 command would move until the endstop triggered OR until the move has covered the distance specified, in this case by the Y parameter of 244mm.

If you did G91 then G1 H1 Y-10 it would only move 10mm "looking" for the endstop to trigger.

So normally the first G1 H1 move in the homing code specifies a distance to be sure the move covers the entire length of the axis while "looking" for the endstop to trigger.

The Y-360 is 10mm more than the distance of 350 that you determined to be the max travel on the Y axis.

Frederick

fcwilt

@mac said in I could use some help:

@fcwilt In the Status Display, Y is at 0.0. It's already "Home." It can't go into negative territory.

Since G1 H1 moves are intended to be used to home and homing is done with the assumption that the actual positions of the axes are unknown, the G1 H1 moves ignore the M208 limits and try to move the specified amount.

This can mean if the move is away from the endstop or the endstop is not working the move can encounter the end of travel but keep right on trying to complete the move.

Frederick

A Former User

@fcwilt I homed again, it went forwards again, and smashed into the adjustment cap again.

A Former User

@fcwilt what if I change the Y-360 to Y 360?

A Former User

@fcwilt

What if I change the code to what's below?

G1 H1 Y 360 F3600
G1 Y15
G1 H1 Y=10 F360

G90 
G1 Y110 F3600

fcwilt

@mac said in I could use some help:

@fcwilt I homed again, it went forwards again, and smashed into the adjustment cap again.

This makes no sense at all.

OK here is a thought. Perhaps the forwards move is the G1 Y110 at the end of the file.

So lets try this:

jog the bed back to somewhere in the middle of it's travel
execute a G91
execute a G1 H1 Y-10 which should be a 10mm move. It's not far enough to smack into anything but it will tell us in what direction the G1 H1 Y-10 command moves the bed.

Thanks.

Frederick

fcwilt

@mac said in I could use some help:

@fcwilt

What if I change the code to what's below?
G1 H1 Y 360 F3600
G1 Y15
G1 H1 Y=10 F360

G90 
G1 Y110 F3600

You are faster than me. I just posted a little test to verify if the G1 H1 move is actually going in the correct direction.

Frederick

A Former User

@fcwilt G1 H1 Y-10 moved the bed 10mm towards the END STOP!

A Former User

@fcwilt Interestingly, Y is saying 0.0

A Former User

@fcwilt I did it again, now Y's saying -10

A Former User

@fcwilt I changed the end to Y-20. The bed went towards the rear 20mm. Y is reporting -30mm.

A Former User

@fcwilt according to my measurements, and my inches to millimeter calculator, if I change the number to Y-92.075mm, the foot of the bed will touch the end-stop.

A Former User

@fcwilt hmmmm, the bed's being weird. I'm sending G1 H1 Y-92 , but the bed is inching towards the end stop instead of going straight for it.

And Y is now 0.0 again, whereas it was -30.