Change print speed mid-print not working

Bambu Lab Software
1

i did search posts, couple similar problems, i did not want to tack onto their 8-month old post.
i start print at 100%
but at about 5 inches height, i want to change speed to about 80%
i go to PREVIEW, and right click at that height, and add custom gcode
M220 S80

but, when printing, print stays at 100%, unless i go onto the display panel and change it to QUIET, 50%

does the gcodes for speed not work when in prieview? any feedback appreciated, thanks

2

Making changes after a print has started isn’t possible as the gcode has already been sent and can’t be modified. The silent, standard, sport, ludicrous speeds aren’t sending new gcode, but are just adjusting the movement speeds.

If you are wanting to add custom gcode at a specific layer height, you need to do that before you send the job to the printer. This can’t be done after the fact.

3 Likes
3

I don’t think the OP is trying to add the gcode during the print.

I think they tried to insert it using the preview tab before transfering the print to the printer.

That being said M220 isn’t the way to slow the print down.

Suggest instead using a height range modifier. The wiki has a great explanation of doing exactly this.

2 Likes
4

I do believe you’re right, my reading comprehension is apparently off this morning :wink:

5

I would think the line probably works… but that’s one line. On the very next line I would think the speed would be reset by the slicer. If I’m not mistaken, nearly every line (if not every line) contain g-code for speed changes.

Jon’s suggestion for a height range modifier make sense to me and is likely your best way to do this easily and quickly.

2 Likes
6

thanks for reply, you are correct, insert the gcode during the preview, before sending to printer.
i will check out the wiki, it was my exact situation item 7 inches tall, and dislodged from bed at about 6 inches. i then added 2 inch tabs at bottom corners, 0.4 mm height, and that solved the second print, but i also manually slowed it down. so i’ll see how the wiki indicates to do it

7

ok, reviewing wiki
one question - in the options, is ther no way to just change the whole speed percent, such as the “normal - quiet- ludicrous”?
it appears that i have to adjust each speed setting, (I can live with that) rather than a general percentage decrease.
thansk

8

Not to my knowledge.