First look at R2 replacement board by Partsbuilt.com

I just got in the first proto of the R2 replacement board by Partsbuilt .com. The picture reflects that I had a defective Ramps board and just popped a new one on top.

Mechanically it drops in nicely. It has 12v and 5v switchers so it is more efficient. Resetable fuses protect the power supplies from shorts, as can happen with the fan connectors. The 12v supply will power the extruder fans at 100% forever without breaking a sweat. Because it uses the common Ramps 1.4 boards you will never have to worry about replacing a board. The stepper drivers are plug in, so when one goes you just plug in a replacement. You can adjust the current on the steppers and I am looking forward to putting in more powerful x,y steppers.

I found and tested an IR board with the Partbuilts board. I am using a flexplate with a microporous glass on top. The IR works great with this, giving me a completely usable result which I never had when not using the glass. When I add the glass to the bed the mass is too much for the auto tuner to handle. ( Works if I take the glass off and reduce the mass of the bed) It just runs away and fails. I found PID values of 200,10,1 give me good regulation with no chance of running away.

 

Almost 100% The fan on the extruder and the case fan are always on. The extruder temp regulation +/- 1.2C unless a modified downtown board is installed. The modified board gives me +/- 0.3C. I do not know if you can convert to a dual extruder. The second extruder driver is there, but there is no way to get another thermister or hotend heater. Other than that I can not find a difference. I do not know what Partsbuilts sales model will be. I do not work for them, I am just doing some proto testing. This is a much more rugged and protected board than the Robo. The forum limits the quality of my pictures.

 

Any updates on the use of the board?

 

I have been printing with it, acts like an R2.

 

Excellent, thanks!

Been looking for a way to update my printer so I can use it again after the board pooped out.

 

I have been doing more testing on the hotend. I am posting two graphs: one before the modified downtown board and one after. The modified downtown board gives identical results to an R2. I have not tested the autolevel board because I do not have one. The wiring is all there as is the code. i am sure Partsbuilt will check it out.

 

Are the stepper drivers any more quiet than the original R2?

Plus it looks like it's still in development.

 

This uses the Ramps1.4 Arduino Mega 2560 board set plugged into a PCB that has the 12v, 5v and connectors to match the Robo system board. The Mega2560 and the 4298 drivers are identical to the Robo system board. The Ramps has the advantage of having individual stepper boards with adjustable current drive. This system uses code that was supplied by Robo to support those people who's system boards died. The Ramps board is compatible with the R2 as shipped but does not have the upgrade to dual extruder capability. The Ramps board gives better regulation of extruder temperature with an isolated thermister. The modified downtown board has a jumper to isolate the thermister. If you can tolerate +/-2C rather than +/-0.3C you do not need the modified downtown board. Using this first proto with the modified downtown board I can not tell the difference, it is functionally identical to the R2. The main PCB has resetable fuses to protect the power supplies. If you short the 12v (as I have with the extruder fans) nothing bad should happen. If your steppers were noisy before, they will be noisy now. Jonah at Partsbuilt.com did a real nice job, and even this first proto works well and needed no modification. I do not work for Partsbuilt, I am just doing testing.

 

Thanks for the info. Good to hear the printer hasn't been totally forgotten!

 

Not forgotten. Braydon Moreno the President of Robo has been giving information to make available all of the parts. Braydon is doing his best to support customers of older machines. Partsbuilt.com is actively involved in making parts. I have released many upgrades on thingiverse. Next thing I am working on is a fix for the x,y stepper motor mount plastic cracking.

 

https://www.thingiverse.com/thing:3063864
https://www.thingiverse.com/thing:3422281
https://www.thingiverse.com/thing:3180056
https://www.thingiverse.com/thing:3504503
https://www.thingiverse.com/thing:3498414
https://www.thingiverse.com/thing:3541074
I also made a "Robo R2" using Scot_3D's Hypercube frame and substituting the carriage design from Robo. I used the same code but set it for dual Z steppers, and a larger print bed. Because it uses two different power supplies for the bed and hotend the temperature regulation is very tight. The output of this design is much better than the R2, I suspect because the bed is rock solid stiff to the print head. I did this before the Partsbuilt.com board proto. With the addition of an additional 24v supply and driver board ( because the bed draws a lot of current) the Partsbuilt board will work just fine. I am always modifying my stuff to improve it, but I could post the latest "as built" if anyone is interested.