Archive for October, 2013

SainSmart RAMPS is not worth it

I’m building another Prusa i3 to be done as a group printer build weekend in a similar way to the http://botbuilder.net/ one that happened recently. To try to reduce costs I figured I’d try the SainSmart RAMPS bundle which at $80 is about $40 cheaper than the other sources I considered. http://www.sainsmart.com/starter-kit/3d-printer-parts/sainsmart-mega2560-a4988-ramps-1-4-3d-printer-kit-for-arduino-reprap.html

The pieces arrived in a couple weeks in bags in a plastic box. Unfortunately nothing protected the pins of the stepper drivers and RAMPS board so a few pins were bent. None of the pins were bent bad enough they couldn’t be bent back.

SainSmart order box, a jumble of everything

SainSmart order box, a jumble of everything

Bent pins on stepper board. These were annoying but not bad enough that I couldn't bend them back.

Bent pins on stepper board. These were annoying but not bad enough that I couldn’t bend them back.

 

I installed the stepper drivers in the RAMPS board making sure they were correctly oriented, twice, because I didn’t initially notice that the micro-stepping jumpers were not included. That’s okay for this one because I have a bunch of those I can use.

When first powered on the Arduino Compatible Mega 2560 released its magic smoke. That’s not supposed to happen. (I know that it can happen if the stepper driver boards are installed the wrong way around, but I am certain they were not installed wrong)

On further inspection, the current adjustment on all 5 of the stepper driver boards spins freely. These stepper drivers probably don’t even work.

The RAMPS board was tested with a stepper driver borrowed from another printer, and a working Arduino Mega 2560, and seemed to behave fine. I ordered new stepper drivers from Maker Farm where they shipped with the pins protected in foam via first class mail and arrived before the weekend.

So, yesterday I was able to try with another Arduino and the new stepper drivers. Motors moved, bed gets up to temperature, fan gets up to speed, but I wasn’t getting any heat out of the hot end. The hot end heater appeared to be working, but a meter wasn’t showing any voltage on the heater output. We fixed this by replacing the MOSFET.

I also bought their makerbot-style endstops and MK2 heated bed which work as expected.

The heated bed was not shipped well and has a gouge on one edge and is not flat, but didn’t destroy anything.

I will not be buying any further printer parts from SainSmart. I don’t mind spending $40 more to get the micro stepping jumpers, heat sinks, and electronics that actually work.

Those blue Micro-Stepping jumpers are not included.

Those blue Micro-Stepping jumpers are not included.

Dead ATMega 2560.

Dead ATMega 2560. This was toasted when power was applied to RAMPS.

 

Gouge on edge of heated bed.

Gouge on edge of heated bed.

The leftmost MOSFET didn't work. Also, a 10k resistor nearby seemed broken.

The leftmost MOSFET didn’t work. Also, a 10k resistor nearby seemed broken.

 

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