Why is a print prepared for an S3 not compatible with an S5?

[Molgineer 2]

For my work, I have an Ultimaker S3 and an S5. I love how well they work in the digital factory. However, a print sliced for an S3 cannot be printed in an S5 

As far as I know, the only functional difference between the two is the build size, so a print sliced for an S3 should be able to fit in the bigger one.

I now keep two copies of every model in the library, sliced for a different printer, so I can still choose on which machine I want to start. 

It would be nice if both printers show up in the compatible printers list, when a model is sliced for an S3.

 

Thanks for reading.

[ahoeben 1,948]

There are subtle differences. You can't just change the scale of a printer and expect it to print exactly the same. For example the bed of an S5 is understandably heavier than the bed of an S3. So the speed at which you can move the z axis up and down without introducing a wobble in the printer is different. The same with the print-head; though (I think) the axles have the same diameter, you can imagine that the S5 axles have a slightly higher tendency to sag and introduce vibrations at high speeds. That is why there are tuned profiles for all combinations of printers, cores and materials with sometimes very subtle differences.

 

Though often the differences are negligible, you would then start to have to make a list of what type of difference between prepared prints is and is not acceptable, and it just becomes easier (and more reliable!) to say "no, a print prepared for one printer will not work on another printer".

[Molgineer 2]

3 hours ago, ahoeben said:

There are subtle differences. You can't just change the scale of a printer and expect it to print exactly the same. For example the bed of an S5 is understandably heavier than the bed of an S3. So the speed at which you can move the z axis up and down without introducing a wobble in the printer is different. The same with the print-head; though (I think) the axles have the same diameter, you can imagine that the S5 axles have a slightly higher tendency to sag and introduce vibrations at high speeds. That is why there are tuned profiles for all combinations of printers, cores and materials with sometimes very subtle differences.

 

Though often the differences are negligible, you would then start to have to make a list of what type of difference between prepared prints is and is not acceptable, and it just becomes easier (and more reliable!) to say "no, a print prepared for one printer will not work on another printer".

Thanks for the explanation. I realise it's not as simple as it looks and that there is a whole lot of work behind a printer profile beyond build size.

[gr5 2,167]

A print sliced for a um2go will print just fine on a UM2 (although somewhat towards the corner).

 

There may be a more serious reason.  Possibly the spacing between the nozzles is part of the gcode and that may be different on the S3 versus S5?  I doubt it.  Or maybe the gantry height is different which would mean there would be a few rare gcode files that are printed "one at a time" meaning 2 or more parts printed one then the other but on one of the printers the part is just tall enough that the cross bars will knock it over when it goes to print the second part.

 

The acceleration excuse... is complicated.  If you turn off acceleration and jerk control it doesn't matter a huge amount as the printer itself has safe defaults.  But the profiles do have tuned values to reduce ringing if you have accel and jerk control enabled.  Also the time estimation to complete a print may be different on the 2 printers if they have different accel/jerk defaults.  if.  Again - minor issue but customers complain about the seemingly smallest things.

 

A huge reason is most likely testing.  Testing the S5 profile on an S3 is a pain!  And doing vice versa.  There are already hundreds of profiles to test.  Imagine doubling your work testing S5 profiles on S3 and the other way around!