Welcome to the SeeMeCNC Community

I'd like to introduce a new member of the household, Albertus Magnus:
[img]https://lh4.googleusercontent.com/-CR_q ... 183025.jpg[/img]

Now, this won't so much be a build thread per se, as it was built mostly according to plan. However what I wil be showing in this thread are the various modifications I've made during the build, as well as future modifications.

First up is the 24V power supply. In lieu of using the provided 12V ATX supply, I have opted for a supply capable of providing the voltage and current needed to heat the bed quickly.

[img]https://lh6.googleusercontent.com/-CbDt ... 153842.jpg[/img] [img]https://lh5.googleusercontent.com/-aARE ... 164332.jpg[/img]
[img]https://lh5.googleusercontent.com/-sXdl ... 164509.jpg[/img] [img]https://lh6.googleusercontent.com/-oQB6 ... 102107.jpg[/img]

The parts used are:
Mean Well SP-500-24 power supply
Crydom D1D40 solid state relay
Hossen 24V-12V 240W DC/DC converter
Aluminum bar 6.5"x3.5"x0.25"
Sheet metal 6.75"x4.75"x0.0625
Various crimp terminals

It works quite well, and fits with no modifications to the base. I adjusted the voltage down to 19.5V to reduce the power consumption to about 550W peak. As the bed warms up the resistance goes up too so it's not using peak power for very long. It's wired so only the bed is running at the higher voltage and everything else is running at 12V.

Note in one photo I show the FOTEK solid state relay. This is hardly capable of 100A, and it's temperature would get to 60C when running. The Crydom SSR is much better, even though it's rated for 40A it's hardly above room temperature.

The build is great! Nice clear pictures also.
Thanks for sending the pictures, it's always nice
to see another build.
Great Job!

Thanks man!

So I really didn't want to be tethered to a computer for printing. I got myself a Raspberry Pi B+ and installed OctoPi onto it.

[img]https://lh5.googleusercontent.com/-Fu10 ... 163525.jpg[/img]

I also changed some settings so that it would automatically connect to WiFi and also it mounted root as read-only so I didn't have to worry about corrupting the file system when powering off.

The Raspberry Pi is powered from the RAMBo "5V Aux Out", using a small cable going to the 5V on the Pi's header. This supply is good for 3.5A total, so should be plenty for the Pi. I have had no problems powering a webcam and USB WiFi adapter direct from the Pi.

On to the webcam, I bought the Pi Camera and it's pretty neat! It's tiny and has a good picture. However it seems to take a lot of CPU, like 70% just for 640x480 10 fps. This is way too much and causes stuttering when printing.

[img]https://lh4.googleusercontent.com/-fpee ... 163402.jpg[/img]

The Logitech webcam I had does MJPEG compression inside the webcam so this offloads the CPU; usage is more like 10% for this one. I hope to get the Pi Camera usage down but maybe I'll just have to use the Logitech one.

[img]https://lh4.googleusercontent.com/-3U2o ... 163556.jpg[/img]

OctoPrint is still a bit beta but it's got a lot of promise. The web interface is really slick. I might even add the OctoPrint API to Cura/Slic3r so that the print can be started right from the slicer app, that would be cool!

try configuring pi/rambo for 57600 baud and see is stuttering continues.

bubbasnow wrote:try configuring pi/rambo for 57600 baud and see is stuttering continues.

I gave that a shot and no dice, unfortunately. I tried 57600-250000 and it didn't seem to make a difference. It stutters when the CPU idle goes below 30%. I found some others with the same problem:

https://github.com/foosel/OctoPrint/issues/597
https://github.com/foosel/OctoPrint/issues/450

I'm not sure what branch OctoPi ships with, I see there is the CommRefactoring branch that may improve performance.

https://github.com/foosel/OctoPrint/tre ... factoring/

I tried overclocking to 900 MHz and the Pi crashed after a few hours, even though the CPU wasn't hot to the touch. I am also looking into increasing the URB buffers in cdc_acm.

I increased the URB buffers in cdc_acm and it had no effect.

However I've improved the speed of OctoPrint by 3x with my attached patch; this is for the current commRefactoring branch. I need to do more testing but if anyone wants to try it let me know how it goes. I think I can do a few more optimizations here and there as well.

So has anyone figured out the significance of the name "Albertus Magnus"? All my computer names are after philosophers, but I found this guy particularly fitting.

[img]https://lh5.googleusercontent.com/-aARE ... 164332.jpg[/img]

Do you work on plotters and large format printers? That's the exact same PS that I scavenged for my own 24v conversion.

Jimustanguitar wrote:Do you work on plotters and large format printers? That's the exact same PS that I scavenged for my own 24v conversion.

I worked on metrology machines a while back and I designed in this supply. They work really well. This particular one I got used on eBay for $50: http://www.ebay.com/itm/331311561979 The metal plate on top is what I used to mount it, although I trimmed it a bit.

How did you mount your supply?

rpress wrote:So has anyone figured out the significance of the name "Albertus Magnus"? All my computer names are after philosophers, but I found this guy particularly fitting.

According to Wikipedia, he's basically the guy we have to thank for Aristotelian logic having made it to this century. Am I right?

lightninjay wrote:

rpress wrote:So has anyone figured out the significance of the name "Albertus Magnus"? All my computer names are after philosophers, but I found this guy particularly fitting.

According to Wikipedia, he's basically the guy we have to thank for Aristotelian logic having made it to this century. Am I right?

That's true, but not quite what I'm going for. He is rumoured to have discovered the "philosopher's stone" which he used to create "alchemical gold" by way of "transmutation". And similarly my printer can turn common plastic into valuable items.

http://historyofalchemy.com/list-of-alc ... us-magnus/

Silly and obscure, I know. But that's how I am, heh.

rpress wrote:

lightninjay wrote:

rpress wrote:So has anyone figured out the significance of the name "Albertus Magnus"? All my computer names are after philosophers, but I found this guy particularly fitting.

According to Wikipedia, he's basically the guy we have to thank for Aristotelian logic having made it to this century. Am I right?

That's true, but not quite what I'm going for. He is rumoured to have discovered the "philosopher's stone" which he used to create "alchemical gold" by way of "transmutation". And similarly my printer can turn common plastic into valuable items.

http://historyofalchemy.com/list-of-alc ... us-magnus/

Silly and obscure, I know. But that's how I am, heh.

I think that may be even better than what I named my printer for haha

He should have gone with Edward Elric.

g.

I've unlocked a few more CPU cycles on the Raspberry Pi. I've bypassed the USB connection and I'm going direct from the serial pins on the R-Pi header to the serial pins on the RAMBo board. To get 250000 bps I needed to add init_uart_clock=16000000 to /boot/config.txt. The USB cable is now unplugged, thereby freeing the CPU from dealing with that USB overhead. With this change the R-Pi is no longer the limiting factor, the RAMBo board is, and the R-Pi has 85% CPU utilization at the worst.

geneb wrote:He should have gone with Edward Elric.

g.

I like it, an Anime twist!

I noticed the stepper drivers on the RAMBo were kinda hot. Not real bad, but I figure cooler is better. I put on some teeny adhesive heatsinks, to the top of the chip and also underneath on the circuit board. http://www.amazon.com/Cosmos-Aluminum-C ... B007XACV8O
[img]https://lh5.googleusercontent.com/-l1vo ... 012_180004[/img]
You can also see my serial port direct connection, the black/white/gray wires.

I installed the Arduino tools on the R-Pi so I can compile the firmware and upload it direct. This way I don't have to mess with the USB cord to update the firmware. I had to make a bunch of changes to the Repetier-Firmware to get it to cleanly compile but it seems to be working fine. I fixed some things like the knob direction, quieted down the beeper, and went back to the stock menu. With the menu change I can look at the internal buffers to see if they are running out.

Aurora900 wrote:I think that may be even better than what I named my printer for haha

So yeah I just had to know what you named your printer, so I read your build thread. It's a fun read, and I like your printer's name too! When a name has an interesting back story it's more fun that way.

rpress wrote:

Aurora900 wrote:I think that may be even better than what I named my printer for haha

So yeah I just had to know what you named your printer, so I read your build thread. It's a fun read, and I like your printer's name too! When a name has an interesting back story it's more fun that way.

Thanks. Yeah, I don't usually name things, I never come up with anything good... but this one I didn't have to think twice about, I knew exactly what it had to be

You probably didn't want to do that. Those driver chips are designed to "route" heat into the board they're soldered to. A heatsink would be more effective if you were to attach it to the back side of the RAMBo where the drivers are.

g.

geneb wrote:You probably didn't want to do that. Those driver chips are designed to "route" heat into the board they're soldered to. A heatsink would be more effective if you were to attach it to the back side of the RAMBo where the drivers are.

g.

I didn't post a pic of the back because it was already together. But yeah I put them on the back to start and because I had 20 of them I put them on the front too.

rpress wrote:I put on some teeny adhesive heatsinks, to the top of the chip and also underneath on the circuit board.

I mounted up the E3D V6 hotend with the SeeMeCNC plywood adapter. I grabbed a few 1-3/8" #6 stand-offs from work, and it worked out great. I need to figure out some kind of LED so I can see with my camera when the lights are off. It doesn't need to be that bright.
[img]https://lh3.googleusercontent.com/-hacC ... 015_164338[/img]

And I got my Raspberry Pi camera working, I needed a 24" cable to reach the Pi. The camera has quite good image quality, but it does take a lot more CPU than my Logitech webcam. I don't need any kind of frame rate so I set it to 1 FPS and 1080p, and this uses hardly any CPU. I have an iPhone 0.67x lens on there and the quality is great.
[img]https://lh5.googleusercontent.com/-YuJ6 ... 015_164107[/img]

Here is the view from the camera itself.
[img]https://lh6.googleusercontent.com/2nBAa ... 62-h541-no[/img]

Finished the FSR bed sensors for auto leveling. JohnSL's board works great, they're quite sensitive.

[img]https://lh6.googleusercontent.com/-xfTc ... 135418.jpg[/img]
[img]https://lh5.googleusercontent.com/-Tt6U ... 140909.jpg[/img]

Perhaps some more info on the sensors.
I understand how they work but I am curious what software you will use to
make them act as bed levelers.

They act the same as a Z probe, but with virtually no offset. The three sensors are combined by the board to one limit switch input.

For now I am using the G32 in Repetier-Firmware for calibration. Seems okay so far. I have read of some error in this function so maybe I will switch to a host controlled software leveling like MatterControl has (I think). Even without auto leveling, the printer can show the Z height for each tower so it makes manual adjustment very easy.

I installed some LEDs into the platform, now I can use the camera when the room lights are off. There are 2 parallel strings of 3 LEDs in series, with one 47 ohm resistor for current limiting. Measured current is 23 mA per LED. It's driven by 12V off the hotend fan.

http://www.digikey.com/product-detail/e ... ND/4515696

[img]https://lh3.googleusercontent.com/-II36 ... 022_171454[/img]

Love the Raspberry Pi w/ camera mounted. I have been looking for something to do with my RP for a while and this would be awesome to check up on prints while I'm at work.