New Start.gcode for Replicators

[Jetguy]

Here is my suggested start.gcode for a Replicator 1 single headed
print to drop into the alterations folder.
The main thing changing here is order of of a few items, one being
homing and the M6 wait to reach temp(s) command. The history on this
is that MBI used too small of a poser supply to run the heated bed, 2
extruders, and 5 motors at the same time from a cold start. The
heaters darw more power cold and taper the power as they get hotter
(resistance increases with temp). This is normal and it's why an
incandescent lightbulb works. The point is, shortly after release,
they made these changes and announced it here
http://www.makerbot.com/blog/2012/03/14/update-o-rama-replicatorg-0034-replicator-firmware-5-2/

Two faster ‘Warmup’ steps

ReplicatorG 0034 includes a change to make theMakerBot Replicator heat
faster by doing two smaller, faster heating steps. This means that
when you generate new Gcode for a Replicator, you’ll now see the
heating status bar twice: once while the platform is heating, and a
second time while the extruders heat up. By doing this as two steps
and using our power supply more efficiently, the bot actually warms up
faster.

That's fine, they can put their spin on it and say it works faster
(cough, BS, cough, cough). The truth is, they had to make that change
or else run the risk of burning up components from overload. That
said, they also did some very poor workarounds in the start.gcode.
They reduce the current to 0 in the botsteps for the X and Y axis
after you have homed. This means you can move an axis during the
warmup phase after it's homed and should be locked. If you do bump it
or it moves at all, your print will then be off center of the build
platform.
The below code corrects the sequence so that the bot heats, then
homes, then starts the print. The "Right" way it should have been all
along.


(**** beginning of start.gcode ****)
(This is start code for The Replicator running a single material
print)
M73 P0 (enable build progress)
G21 (set units to mm)
G90 (set positioning to absolute)
G10 P1 X16.5 Y0 Z-0.3 (Designate T0 Offset)
G10 P2 X-16.5 Y0 Z-0.3 (Designate T1 Offset)
G55 (Recall offset cooridinate system for T1)
M18 (added to ensure steppers are disabled during heating)
M104 S220 T0 (set extruder temperature)
M109 S100 T0 (set HBP temperature)
M6 T0 (wait for toolhead parts, nozzle, HBP, etc., to reach
temperature)
(**** begin homing ****)
G162 X Y F2500 (home XY axes maximum)
G161 Z F1100 (home Z axis minimum)
G92 Z-5 (set Z to -5)
G1 Z0.0 (move Z to "0")
G161 Z F100 (home Z axis minimum)
M132 X Y Z A B (Recall stored home offsets for XYZAB axis)
(**** end homing ****)
G1 X105 Y-70 Z10 F3300.0 (move to waiting position)
M6 T0
M108 R3.0 T0
G0 X105 Y-70 (Position Nozzle)
G0 Z0.6 (Position Height)
M108 R4.0 (Set Extruder Speed)
M101 (Start Extruder)
G4 P1500 (Create Anchor)
(**** end of start.gcode ****)

[Martin Bogomolni]

Any major differences I should be aware of for the dual-head Rep 1's
to change the start.gcode?

-M

> --
> You received this message because you are subscribed to the Google Groups "Jetty Firmware" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to jetty-firmwar...@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
>
>

[Jetguy]

The same thing is true for a dual. What I'm saying is, I have a dual, and you need to change it in the alterations folder first, then I need to locate the start.gcode used in the dual mode.

 

Understand that you always use this code, especially if you uncheck "use default start.gcode" in print-o-matic when doing a single print.

 

Then for dual prints, the start.gcode location is identified in the machine.xml (AKA machine type)

Also, then the replicator folder inside the machines folder is where the "default" start.gcodes are located.

 

dualstart="machines/replicator/Dualstrusion_start.gcode"

start="machines/replicator/Dual_Head_start.gcode" end="machines/replicator/Dual_Head_end.gcode"/>

 

It's a simple edit,

You are simply ensuring a M18 to disable steppers is BEFORE the heater temps get applied. Then putting the M6 T0 wait command so that the machines sits there until temp is reached and it's safe to enable the motors and not draw too much current.

Finally, you are removing the reduction in stepper current lines and the "extra" M6 that's there for fun?:

G130 X20 Y20 Z20 A20 B20 (Lower stepper Vrefs while heating)

M6 T0 (wait for toolhead, and HBP to reach temperature)

G130 X127 Y127 Z40 A127 B127 (Set Stepper motor Vref to defaults)

 

Ideally what I'm saying is, edit all possible start,gcodes for your machine to match the sequence and remove the botstep vref change.

[Jetguy]

I should note, this does change the behavior. When you print, most
people are expecting the bot to begin moving to home right away. Now,
we heat first, then home. We could double home, but that's just dumb
IMO. The point is, common sense should say NEVER disable the stepper
currents after homing. It's things like that that cause the bad
attitude towards MBI.

> > On Thu, Apr 18, 2013 at 11:18 AM, Jetguy <vernon...@gmail.com<javascript:>>

> > wrote:
> > > Here is my suggested start.gcode for a Replicator 1 single headed
> > > print to drop into the alterations folder.
> > > The main thing changing here is order of of a few items, one being
> > > homing and the M6 wait to reach temp(s) command. The history on this
> > > is that MBI used too small of a poser supply to run the heated bed, 2
> > > extruders, and 5 motors at the same time from a cold start. The
> > > heaters darw more power cold and taper the power as they get hotter
> > > (resistance increases with temp). This is normal and it's why an
> > > incandescent lightbulb works. The point is, shortly after release,
> > > they made these changes and announced it here
>

> >http://www.makerbot.com/blog/2012/03/14/update-o-rama-replicatorg-003...

> > an email to jetty-firmwar...@googlegroups.com <javascript:>.
> > > For more options, visithttps://groups.google.com/groups/opt_out.- Hide quoted text -
>
> - Show quoted text -