A print at 6000mm/min I guess because of the ramp up and ramp down speeds , it does not get actually speed up until around one minute in the video.
A close-up of the extruder mechanism. I think it is stripping the filament in this test because I have not yet got the fan working and the motor is red-hot.
Re: exxos blog - random goings on
Posted: 20 Aug 2021 16:20
by exxos
I think the ramp up ramp down speed is hindering efforts as I currently have it set at 150,000mm/min :lol:
Was a bit in the center is broke apart on. Likely could be cured though with a bit of tweaking.
Capture.JPG
Re: exxos blog - random goings on
Posted: 20 Aug 2021 17:56
by Icky
Oh wow thats noisy :)
Re: exxos blog - random goings on
Posted: 20 Aug 2021 18:47
by Badwolf
Crikey, Exxos. You've more patience than me!
Print speed can be limited by a number of things. Slicer speed is one (although your print speed is higher than your movement speed, so movement speed will probably be the limiting factor there), firmware max speed is another, firmware max acceleration, indirectly, a third.
You can keep ramping the number up in the slicer, but at some point the firmware will cap it.
It's the big fan I have on top blowing air, plus my big fan in the window, you can't hear the actual printer other than the stepper motor noise.
Badwolf wrote: 20 Aug 2021 18:47
Crikey, Exxos. You've more patience than me!
Not really, just it's annoying me enough to the point of rebuilding the thing :lol:
Icky wrote: 20 Aug 2021 17:56
Print speed can be limited by a number of things. Slicer speed is one (although your print speed is higher than your movement speed, so movement speed will probably be the limiting factor there), firmware max speed is another, firmware max acceleration, indirectly, a third.
You can keep ramping the number up in the slicer, but at some point the firmware will cap it.
Yeah, I don't think there is enough "length" on the print to hit the higher speeds. I need the acceleration stuff to be quicker.
Re: exxos blog - random goings on
Posted: 20 Aug 2021 19:05
by exxos
The long print as shown in the video..
The centre part is actually a join which shows up in the slicer. I was just experimenting with the fill quickly to get straight lines as opposed to angled lines. There is a little bit of dark areas towards the top of the image which looks to me like the print did not stick to the bed fully on those places more than anything.
Capture.JPG
Next I took the printer to bits to try and work out why the extruder fan was not working anymore..
IMG_6832.JPG
I got distracted as that found in the image above is a horrible wind to it which drives me a little mad..
So I fitted a new extruder fan with Fluid dynamic bearings...
IMG_6833.JPG
Turned out it had a louder whine than the original fan..So I put the old one back in :lol:
IMG_6835.JPG
The fan whine itself was been amplified by the bottom plastic of the case. So I use some longer bolts with some nylon spaces and this cut down the noise greatly thankfully..
Anyway, I was metering out or lay back to the driver MOSFETs for the extruder fans, And could not find anything wrong. :|
After a bit of head scratching I noticed something.. (If you want to play along, stare at this image below for a while until you notice it as well before strolling down)
IMG_6836.JPG
So next up some bodge tape and rewiring..
IMG_6837.JPG
So lesson of the day, don't assume fan connectors follow any sort of standard pinout :roll:
At least it was an excuse to clear up all the crap which had collected underneath the printer on my desk :lol:
I noticed the acceleration was 200 in the printer settings, so changed that to 400 8-)
So should I go faster ?
Re: exxos blog - random goings on
Posted: 20 Aug 2021 19:50
by exxos
So this is at 600 acceleration..
It is starting to break apart on the bottom half of the print now. Was the retraction I think needs a lot of work because it's plopping noticeably on the angle infill on the right-hand side.
I guess with a lot of fiddling I could printing at this speed pretty well. But I am just playing more than anything really :)
Considering that I struggled to get even slow speeds to work previously I think this is a monumental improvement over what it was all before!
It will be interesting to see what the new extruder will bring to the table over my hack job :D
Re: exxos blog - random goings on
Posted: 20 Aug 2021 21:24
by Badwolf
exxos wrote: 20 Aug 2021 19:29
So should I go faster ?
Going by ear, rather than the results. I'd say your acceleration is too low and possibly your max speed is too high.
/**
* Default Max Acceleration (change/s) change = mm/ss
* (Maximum start speed for accelerated moves)
* Override with M201
* X, Y, Z, E0 [, E1[, E2[, E3[, E4]]]]
*/
#define DEFAULT_MAX_ACCELERATION { 1000, 1000, 300, 3000 }
If I were you, I'd set the max speed to around 60mm/s ('medium fast') and increase the acceleration until you see (or hear!) problems. My carriage head is lighter than yours, but yours is probably a better machine. You may get up to 1200, you may fall flat at 800. Who knows?
Find the acceleration it can bear then work up the max speed until you get a good upper bound on both.
The rate you're pushing that filament now, I think you'll probably top out fairly high.
BW
Re: exxos blog - random goings on
Posted: 20 Aug 2021 23:01
by exxos
@Badwolf acceleration was 600 in the last video. Marlin default was 200, at least on mine. I've dropped back down speed wise to go back to my small square I had troubles with originally. I think 600 is to fast for such a small square. Though I am getting much better results now at much higher speeds.
The flash forge firmware didn't seem to have any acceleration at all. It was literally start stop. After about 40mm/sec the printer would be banging around trying to destroy itself. Pushing 60+ and the mech would seem to jam up. It would end up with wonky prints all the time, I think I moaned about all that a couple years back.
Now I can calibrate stuff, I don't have stuff like 20% out anymore. My "new" extruder can push the PLA at any rate I want without sliping, so prints are way better now. Plus the marlin acceleration means I can push higher speeds without the printer traveling across my desk. :lol: