Hazer wrote:

As a note, that print got trashed because RH could not keep up.

He was very succesful at 500mm/s.

In what way could it not keep up?

Here is his blog on that 750mm/s print: (hint translate the page in google)

http://ichibey.exblog.jp/18477752/

Here is a complete print at 500mm/s to see final quality (which I think is pretty good considering the speed trade off), but also realize that if you read his blog that he has since made significant modifications since that print.

http://ichibey.exblog.jp/18401224/

The USB, like I suspect with skips on long jobs with lots of circles on my mac
isn't there a simple mod to eliminate the USB power bottle neck and just run off the brick? (IE I know this also stop you from communicating without the brick plugged in.
not to hijack, but on power,m I assume the upgraded Ramps 4 boards eliminate the power issues by allwoing more current?

I disagree. RH is simply a gcode repeater during printing, which is nothing more than a character sender. Low speed USB can move so much faster than the required speed of the gcode strings. High speed gcode has been done on RS-232 for decades. Now, how well your PC/MAC is setup with its USB drivers and other clutter is a different matter.

It would be interesting if there was a test done using both RH and a SD card print for comparison. In my own experience, I have been getting close to 500mm/s speeds on my HBOT and I have seen the occasional 'pause' while the printer is waiting for RH to catch up. But it never trashed the print.

isn't there a simple mod to eliminate the USB power bottle neck and just run off the brick? (IE I know this also stop you from communicating without the brick plugged in.

not to hijack, but on power,m I assume the upgraded Ramps 4 boards eliminate the power issues by allwoing more current?

As a note, that print got trashed because RH could not keep up.

He was very succesful at 500mm/s.

In what way could it not keep up?

He was very succesful at 500mm/s.

This guy does 750mm/s:
http://www.youtube.com/watch?v=zhV2jwhb9n8

How has his X-stepper not melted!

Stepper motors are constant power devices. They actually run cooler under load, as more of the power is devoted to producing work instead of heat.

The exception is that some motor drivers decrease current when the motor is idle, but I don't think the cheap (A4988/DRV8825) drivers do this.

This guy does 750mm/s:
http://www.youtube.com/watch?v=zhV2jwhb9n8

How has his X-stepper not melted!

I have really dialed my printing in over the last year and have not touched the speed settings. I will do bearing upgrade to the XYZ this week first to minimize drag, skips etc then play with some increased speeds.

I have printed bigger parts that are detailed and they come out ok but they take so long it is time consuming to wait and especially if I am doing trial and error for some dimensions on fit. to print part every 4 hours.

Most parts are 30-45minutes. If I can cut that in half it would be awesome. so 110mm/s infill and 60mm/s print speeds.

I will get this running great first with bearings and I think to get speeds in the 100mm/s range I need a new design printer? having 100+mm/s print speeds would seriously open up the fun factor for printing bigger, detailed parts for me

30-60 here. Infill at 45 because for some reason with a faster infill my extruder skips and doesn't push filament through.. Only on infill though, it's weird. Bridging at 20 else any faster and the strands snap. I have run everything but infill and bridging at 100 before with no problems but slower does produce better quality.

Do you "infill every X layers"?

I have a volumetric outflow limit, so I stopped really using infill ever X layers. It can be compensated by upping the temperature though

http://www.youtube.com/watch?v=zhV2jwhb9n8

but I will print out bearing holder for rear rod, do z, then try cranking my # up by 2x to see if it helps.

the rest is gravy