Replacing the 3D printer Controller

[Mickster]

Maybe what I read originated here:

 

[rjenkinsgb]

From a quick look at that firmware source, it appears to be using a lot of floating point maths rather than fixed point & the interpolation routines, as well as being floating point, are horrendously complex rather than using such as Bresenham's algorithm, which once set up for the particular move angle just uses comparisons plus a few additions and subtractions per increment.

Some parts appear to be optimised to the extreme, whilst others appear very inefficient - but from a five minute look and not knowing the entire methodology behind it, I don't know the reasons behind that.

 

[sleepless]

Exactly! The printer just has to take a string of XYZ coordinates in G code format and move to those points at whatever speed is set.

Our system did virtually everything other than reading G code and the operator display in fixed-point 32 bit maths.
No trig needed for a linear axis system, including multi axis interpolation, tool offsets and 2D arcs.
The first ones used a 4MHz Motorola 6809, later ones an 8MHz version!

(And I'd think a delta printer only really needs occasional trig calculation updates, with interpolation between points. With a CPU vastly faster, it _should_ still be a trivial CPU load.)

A linear axis printer does not even need 3D interpolation, 2D is OK - but a delta type must calculate all axis positions for any move & needs 3D interpolation, but that is still mathematically a low CPU load task.

Could you please tell me does the marlin latest 1.1.9 firmware supports resuming of printing after accidental power shut down?This has become a big problem and wastage of time.Thats why i think atleast i should update the firmware not the whole controller.

 

[Pommie]

Not as far as I'm aware. You can pause the print to insert captive nuts etc. I don't know of anyway to resume a randomly stopped print.

Mike.

 

[rjenkinsgb]

It looks like you can, if printing from SD card and you know (or the machine stored) the exact stop point.
It's probably an optional inclusion, dependent on the compile settings.

https://marlinfw.org/docs/gcode/M024.html

My Overlord printer has stop & resume, but it also has a lithium battery in the power pack so it can run for quite a while through a mains failure & I'd guess do an auto shutdown before the battery fails; I've never had a problem due to power glitches, but I have UPSs on all computer & network gear.

I'd be tempted to add a cheap UPS for the printer if you live somewhere prone to power problems.

 

[sleepless]

It looks like you can, if printing from SD card and you know (or the machine stored) the exact stop point.
It's probably an optional inclusion, dependent on the compile settings.

https://marlinfw.org/docs/gcode/M024.html

My Overlord printer has stop & resume, but it also has a lithium battery in the power pack so it can run for quite a while through a mains failure & I'd guess do an auto shutdown before the battery fails; I've never had a problem due to power glitches, but I have UPSs on all computer & network gear.

I'd be tempted to add a cheap UPS for the printer if you live somewhere prone to power problems.

Hi thanks to all i have successfully upgraded the firmware but got some issues (marlin 1.1.9) it crashes when auto home also i am not seeing the values of XYZ on LCD instead i am seeing the question marks blinking(?).Any soloution.

 

[unclejed613]

I don't see how you can - the speed and quality is determined by the actual process used, the melting and setting of the plastic filament.

those are parameters set in the slicer software. slicers usually come with a few default parameter files for "high precision slow print" "draft quality fast print. some of the settings control the feed rate of the filament, braking and acceleration of the printhead. sometimes these defaults need a bit of tweaking to get the results you want. you could crank up the printhead speed, but that might not work very well, and a lot of settings are somewhat interactive. if you change the printhead speed you have to adjust the feed rate and the printhead temperature to compensate.