The more I see this thing the more I want one. It really has a sex appeal, I mean just look at it! Puts those anet a8 chinesium ones to shame.
I too wonder if a thicker frame will increase print speed. My guess is yes, but marginally. The best way to make a fast printer is just to have less moving mass.
3/8" aluminum frame??? Yes!!!
The more I see this thing the more I want one. It really has a sex appeal, I mean just look at it! Puts those anet a8 chinesium ones to shame.
I too wonder if a thicker frame will increase print speed. My guess is yes, but marginally. The best way to make a fast printer is just to have less moving mass.
3/8" aluminum frame??? Yes!!!
If frame rigidity is the reason it’s bad, then yes.
But there is also extrusion/heater block speed, and moving mass, and sticky/level of the bed. I think it all depends on why you aren’t happy with prints at higher speeds.
You also have to remember that using one number (50mm/s) isn’t really telling the whole story, because some 120mm/s prints I’ve seen slow way down when doing details (as they should), but that’s never quantified. So, if you wanted to go to 80mm/s, just decrease the accel and jerk 
Makes sense. I’m sure I will learn alot building this printer, actually that’s a big reason I want to build it.
6-32 x 3/4" countersinks
Theoretically yes, but most the issue is the accelerations on the bed and extruder (mass). I am working on tuning today some time.
100%, tuning is getting very exciting on this one for some reason. I can’t find any really good info so I will have to sit down and come up a good system to tune with. Part, speed, quantifiable tests. To tune a fast 120mm/s part you have to have a large part and it just takes longer. So I figure tune at 50ish and then speed up when I think it is dialed and I have a firm grasp on what effect each setting is doing.
I think maybe I will make an aluminum bed mount. Might be a good time to try milling some aluminum on my MPCNC?
Might actually be heavier than 1/4" MDF.
There needs to be a better way to visualize it, or at least get some feedback as to what the jerk/accel are doing. The slicers do a good job of illustrating speed in the preview, but they don’t show the trapezoid. Do they show colors for speed if you load up a gcode file? Maybe a script that edits the F speeds in the gcode file based on some parameters could change the F speeds, and then slic3r could display the output?
I also have really wanted to have some indication of the current speed on the LCD somewhere. Like when it’s doing some infill, and you look at it and think, “How fast is that going?”, or if it’s slowing down for a small layer. Even if it updated only every 5 seconds, that would be better than nothing.
The prusa calc page has the trapezoid for acceleration, it is a cool visualization. Really lets you see at what point it hots full speed and how long a segment would need to be to get there.
Correct me if I am wrong please. Jerk will control when an acceleration happens, so a large circle should not trigger acceleration, a small one would. So a 10° corner probably won’t trigger but a 90° definitely should (for normal print speeds).
So I am thinking pick an accel and a speed, hold them constant. Make a part with different angled corners 10-90° in increments of 10 on the X and Y sides. Tune the jerk settings first. This should show at what angle is low enough not to need the jerk (no ghosting), right? Looking for the highest jerk.
This would be tuning for a common speed, anything higher would be a little worse and slower would be a little better? Or does getting the jerk right scale with speed, It should, higher speed into a corner =higher jerk trigger. Getting the jerk right should allow for a faster accel, I think.
I think tuning the Accel just depends on a sharp 90° corner, too slow and it is round, too fast and you get the bump (almost a second corner). So to set accel you are looking for the sharpest corner, but it has to be a 90 to set the X and Y rates independently any sharper and two rates come into play simultaneously. Looking for the faster accel.
With room to spare!
I like this, I know what I will be doing tonight. https://printedsolid.com/blogs/news/a-solid-foundation-for-high-quality-corners found the link in the SeeMeCNC forums.
Ooo, I want the file for that. 
Awesome work on the design of this, alted!
Couple of questions if I might?
F
Does this machine share all the same spacing between smooth rods on x axis?
Is there any particular rseason for the spacing on the x axis to be different from the prusa printers?
I’m assuming it has to do with better stability? Just something I’ve always been curious about.
I’m very excited to start building one of these. Thanks for your hard work!
Mattercontrol will show print speed by color.
Ubaldo, I just made the spacing work for what I was doing. Making it work with Prusa’s parts also means his belt and belt spacing. It is much easier to just do a fresh build. If I was going to make it work for his stuff I would just end up making a frame to fit his parts…that’s no fun, on second thought that actually might be kinda cool.
I have to look, now that you mention it S3D does but it doesn’t/can’t account for accel and jerk, but would be awesome if it could!
Been cutting parts on the RowRider for a few hours…Updates come to mind…
I like how you added your logo into the parts.
Thanks, as much as I love to see it I am sure most don’t so I tried to make them inconspicuous.
Inconclusive? A few hours later I learned a lot. I disabled all slicer enhancements, coast, min layer time, so this should be raw plain gcode. The test was only 90° corners so I would assume no jerk came into play it was set a 4=X and 2=Y (never changed them forgot to make them equal just in case). Same printer, same gcode, same filament, same room temp, same speed 50mm/s. To do the tests I only changed XY DEFAULT_MAX_ACCELERATION and Default Accel all three numbers where always equal. I ran them alternating fast and slow zeroing in on a speed that sounded good and looked good. 500mm/s/s to 5000mm/s/s.
[attachment file=51371]
Sat parallel with the Yaxis (bed), should show X axis ghosting.
[attachment file=51372]
Sat parallel with the Xaxis (extruder), should show Y axis ghosting.
[attachment file=51373]
X again, with accels labeled.
So now the odd thing…the clean one was at 75mm/s! 100mm/s failed as the time between layers was too short and it just squished but was looking great before it died horribly. Once the accelerations are where they should be I think you can really crank up the speed. It all makes so much more sense now. I could go a step further and tweak the two axis separately but I think a little belt tension experiment is up next. Then figure out how best to set the jerk.
I mean I have been very happy printing at 35mm/s forever, this made 50 look simple and 75 was really not that bad. At those high of speeds though first layer time and minimum layer time need to be dialed in or it fails fast. I only ever bothered to tune the MPCNC ( I will be revisiting it very soon), Why did I never tune a printer…Dang!
The printer starts to sound a little rough at 1500 and 3000 sounds pretty harsh. The first pic shows why I honed in on 1500, could go either way a few hundred depending on how you where planning on printing, fast-less acceleration, slow- a little more, so 1500 seems like a sweet spot. I know it might sound a little sluggish but it is not.
[attachment file=51377]
It is getting to full speed in about 0.8mm.
With this and coasting enabled I think the corners would be perfect and it would be smoking fast.
