Random additional steps - interference?

[jens55]

I had a chance to check the motor pulley on x and y and they are tight. The same model as printed before but with considerable speed reduction (300 mm/s to 200 mm/s) produces a much better surface finish and only two small position shifts in only one axis. I left the acceleration at 15000 but am now printing again with a reduced acceleration of 10000. I still have infill and inner wall speed set at 300 mm/sec.

The only other issue I have are the zits that appear randomly. There are two kinds of zits - some are sitting on the outside of the wall and these can be scraped off with only a finger nail. There are however little bumps that are completely enclosed and I am thinking these might be caused by issues with the faster infill speed. These last bumps are not really a problem but more of an annoyance.
Anyway, I was just printing too fast. This is with a Jubilee printer and quite honestly it's a bit disappointing that I can't go faster.

[bubblevisor]

BINGO! I turned off the default stealthchop and enabled spreadcycle via M569. Completeley solved the problem.

Default Stealthchop switches back and forth between spreadcycle and stealthchop when the speed is low. This seems to create a print blemish when this happens. My advice is STICK TO SPREADCYCLE!

[bubblevisor]

@dc42 THanks for your help. You were spot on!

[dc42]

Glad to help.

[droftarts]

@bubblevisor if you set the changeover speed to below the jerk value, then at least you get quiet motors at standstill.

Ian

[bubblevisor]

@droftarts Yep, I see your point. Personally I am not concerned about the noise benefit over the already quiet spreadcycle. Additionally, I am astonished how the stealthchop mode so profoundly ruined the overall print quality. Given I was running the "standard, out of the box application" of it (unbeknownst to me) I would prefer that the default was not to have stealthchop enabled. Think of all the people out there who suffer stealthchop-induced bad print quality and are unaware of it.

[Phaedrux]

@bubblevisor said in Random additional steps - interference?:

I would prefer that the default was not to have stealthchop enabled.

In 3.4 onward spreadcycle is the default.

[bubblevisor]

@phaedrux Really? This is my firmware from the printer in question. "RepRapFirmware version 3.4.0beta5+1"

[Phaedrux]

@bubblevisor said in Random additional steps - interference?:

3.4.0beta5+1"

[bubblevisor]

@phaedrux Do you mean releases after 3.4.0?

[Phaedrux]

3.4 final.