Tired of forgetting to turn on your bed heater?

The firmware doesn't implement the M190 g-code to wait for a set bed temperature. It does, however, have M116; the impressively titled 'wait for everything'.

Thus, the following should work if you put it in 'Start G-code' under the 'Custom G-code' section of the Slic3r 'Printer settings' tab:

M140 S[first_layer_bed_temperature] ; Set bed heater
M116 ; Wait for everything (Bed temp)
M104 S[first_layer_temperature] ; Set hotend
M116 ; Wait for everything (Hotend temp)

The semicolons onwards are comments and therefore optional.

You could set both temps before waiting but the hotend would be at temp way before the bed. Alternatively, you could set a bit of pre-heat and finish it off after the bed gets to temp but the hotend heater only takes ~30sec anyway.

Caveat Printor: I am mid-way through the print that inspired me to investigate this, it is untested, YMMV.

Kev

The Ormerod slic3r profile supplied by RRP already does an M116, although I agree with you that it is better to defer heating the extruder until the bed has reached the target temperature. I prefer to run the bed calibration when the bed is already hot. So my setbed.g file does the following:

1. Set the bed to the target temperature, but don't wait for it yet.

2. Home X and Y.

3. Go to X230 Y200 which gets the head out of the way of the bed, allowing me to clean the bed.

4. Wait for the bed temperature to stabilise.

5. Run bed compensation, which (using my firmware) also establishes the Z=0 point if z-homing hasn't already been done.

Then it's ready to print and the bed temperature is already stable. Now that I'm using ultrasonic z-probing, I usually do G1 X100 Y100 and G30 just before the print so as to get a final z=0 determination. I'll probably add these commands to the slic3r prologue commands.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Oh well, I need to make myself look stupid once per day or I start to believe I'm competent.

Now I've looked at it, the Ormerod profile does bed then hotend too. Mine picks up the temps from the 'Filament Settings' tab though, the supplied profile has them hard coded.

The stuff in the square brackets is to be taken literally, not replaced with your own numeric values. This works with 1.0 RC3, I don't know about prior versions.

EDIT:
Forgot to add, I'm not too keen on bed plane comp, the wear on the Z axis is bad enough without it screwing up and down continuously. I'm levelling manually with a 20mm cube I printed for calibration (that turned out to be within 0.02mm in all dimensions) instead of rolling a drill bit under the nozzle. The only issue is one corner of the glass droops by ~0.1mm. Does the plane comp cater for a twisted plane too?

Edited 1 time(s). Last edit at 02/25/2014 11:25PM by KP.

Quote
KP
I'm not too keen on bed plane comp, the wear on the Z axis is bad enough without it screwing up and down continuously. I'm levelling manually with a 20mm cube I printed for calibration (that turned out to be within 0.02mm in all dimensions) instead of rolling a drill bit under the nozzle. The only issue is one corner of the glass droops by ~0.1mm. Does the plane comp cater for a twisted plane too?

I use bed plane compensation, but I levelled the bed manually as far as possible first so that the amount of Z movement due to bed compensation is small. I think the key to avoiding wear on the Z axis threaded rod is to keep it lubricated with light machine oil. I've also replaced the rod with a hardened steel one, and the nut with a brass one. The idea is that the nut takes the wear and can be replaced easily.

The bed plane comp does cater for a twisted plane if you use 4 points, but not if you use 3. The twist is probably caused by the Y axis rods being not quite parallel. You could try loosening the screws (2 at each end) that hold the acrylic end pieces to the printed pieces and see if you can eliminate the twist.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].