andre
Posts: 72
Joined: Thu Mar 06, 2014 10:53 pm

Slowing down during small tight bends

I noticed the software seems to introduce slower speeds during sharp bends or circles, but there are still a few layers where it runs "full speed" and the bot makes a loud racket. Are there any adjustments we can make to further reduce the speed of bends? I have many parts with screw holes that I would like to slow down a lot more than what S3D allows so that I can achieve a nice round circle, and not shake the hell out of the bot.

I was told there are settings for this, but haven't seen them.
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jimc
Posts: 1124
Joined: Wed Aug 28, 2013 11:02 pm
Location: mullica, nj
Contact: Website

Re: Slowing down during small tight bends

andre, i dont believe the software changes speeds for corners and circles. i have never noticed this at all. you can slow down the print speed for first layer, outlines, support and on small layers that complete under a certain amt of time. thats all i am aware of. if your printer is shaking the best thing you can do is lower the acceleration in your firmware. second thig is you will want to lower the outline speed. this will print slower for your screw holes, etc. you can lower it whatever percentage you want.
andre
Posts: 72
Joined: Thu Mar 06, 2014 10:53 pm

Re: Slowing down during small tight bends

A couple of comments. I don't necessarily believe this has to do with acceleration. I've slowed my bot down to a snails pace, and you can watch it manage circles as if it is negotiating many smaller line lengths than needed. Thus, the bot stutters a bit going around the circle. It almost seems like the slicer needs to be better at negotiating tight bends, rather than "slowing down". It almost seems as if it is taking many unnecessary stops and starts within a circle.

The issue with slowing down outlines is that for large parts, print speed will suffer especially when there are not many circles to deal with.

I came from Makerware where it was even worse when negotiating bends and small radii. It literally shook the bot to death at 40mm/sec. Makerware has this option called Dynamic Speed, which is intended to remedy this very issue. Problem is that it does not function properly, although you notice some circles run very smoothly even at 100mm/sec with this enabled.

I end up with multiple ripples around the circles at worst.
dalew8abz
Posts: 120
Joined: Mon Mar 25, 2013 12:14 am
Location: Cleveland Heights, Ohio USA (4 mi. from MakerGear HQ!)
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Re: Slowing down during small tight bends

Andre,

I don't know if you can get hold of an older version of S3D. Some earlier versions had support for "G2/G3 optimization" --- basically, detecting all those little line segments that make up a circle and converting all those tiny moves into "arc moves" --- your printer would need to support G2 and G3 G-code ops in order to do this. Marlin on the MakerGear M2, for example, supports this. Some of the best MAKE-Magazine-Torture-Test-object columns I ever got were with G2/G3 optimization enabled. I kind of wish they hadn't removed that in 2.0.1. (At least I THINK it was in 2.0.0 --- I'm not sure. But they fixed a number of layer-to-layer and coast/retraction items from 1.1.4 to 1.1.5 to 2.0.0 to 2.0.1, so I'm not going back. Just saying it would be nice to try to see if it makes a difference....)

Dale
Jake
Posts: 8
Joined: Sun Feb 02, 2014 10:23 am

Re: Slowing down during small tight bends

I think this request is a duplicate of this one: http://forum.simplify3d.com/viewtopic.php?f=8&t=654

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