Chinese Ramps 1.4 board

Someone down the street is selling a Prusa Mendel that was working for $300. Her hubby died a few months ago and she had to pull the Ramps board to help out one of her husbands customers. As far as she knows everything else is there.

Can I buy an eBay Ramps 1.4 board from China and just plug it in? Will I need to reprogram it? Would I be better off trying to buy a RAMPS board for a ROBO 3D and using it on the Mendel? What's involved in getting it working after I have wired it up?

 

yes, ramps board will work.

You will need to update the firmware on the board to match the specific printer its going on.
even if you buy the ramps for the robo3d you would still need to update the firmware to match the specifics of the printer.

 

Thanks! I'll give it a shot. It would be nice to have a second printer.

 

LOL i cant get mine to print the way i want, not even dreaming about getting another one
Different printer different problems.
Let us know how it turns out, i would like to know if Prusa Mendel is any better then ROBO

 

I'll do that! I bought the printer and ordered a chinese card for it which should arrive in the next three or four days. I think the ROBO 3D is probably better but I'll let you know. The ROBO 3D has a larger print volume. This Prusa does have a few small advantages. The end stop switches seem to be a better quality - there is zero flex in the metal and the buttons stick out further, so they trigger with very little movement. But the big advantage is that the previous owner had this thing perfectly tuned up. His wife showed me some of the stuff he printed and it's amazingly clean and well shaped. I'm getting my ROBO 3D to print better and better every day I tinker with it, but it's not at the level this guy had.

 

for $300 thats nice.
I cant get my robo to print clean, it gives bulging at corners (due to low acceleration settings to reduce noise and shaking of the printer).
Prints come out just as i planed but the bulging and z steps calculation making it look like...... well see for your self.

I normally have to use razor blade to cut corners out when i need precise fit. Other than that, robo is doing what its paid to do.

 

I should probably post a new thread, but I promised to respond to this post about my experience with the Prusa and the Chinese Ramps.

Getting the Chinese made RAMPS board properly configured for the Prusa was a bear. My buddy and I spent at least 12 hours tweaking the configuration.h before we got it right. Plus, the board has not been reliable. I blew up a stepstick driver in my first week of operation. But it’s working now. That’s all for the original topic.

The second question on the thread was how do the two printers compare.

I spent at least 30 hours getting my ROBO calibrated before getting the Prusa-Mendel and I thought I had it working pretty good. The output from the first Prusa made me revise my opinion on the calibration for my ROBO. After two months of tinkering with both printers side by side I've determined that the Prusa is a much more accurate machine which produces better models. However, this isn't because it's a Prusa, but is the outcome of having high end parts everywhere. The guy who built it really knew what he was doing. He and his wife had been building and selling printers and printer parts, to the tune of half a million dollars last year. The printer I purchased is one of fifteen he had been using for their business. (I bought a second one). I would assume that a $500 Prusa from China will not give me anything close to the same results

The ROBO is a better overall design in almost every way you can imagine. But the Prusa-Mendel I bought has Kysan motors, a hot end from Hive76, POLOLU steppers, and on and on. Even the end stops are a higher quality - which makes leveling the bed easier. Those better parts mean it can be more accurate, run longer without overheating, and take less time to calibrate.

I didn't have a clue about those parts two months ago. I’ve had a lot of time doing research since then, and now I understand that if you really want your prints to be excellent, you have to have really good parts on your machine. Those parts cost more.

The ROBO 3D has a lot going for it, but I think the only way to get the prints to be equal to my Prusa is to swap out the motors, the end stops, the hot end, the steppers, and then reprogram the RAMPS board to reflect the new parts. If I can manage that then I can get rid of the Prusa and buy another ROBO 3D. The smaller build platform on the Prusa is limiting. If I had to choose between an eBay Prusa or a ROBO 3D, it’s definitely the ROBO 3D. It’s a better design for the printer, and the ROBO 3D staff provide awesome support.

That said, the last thing I bought from the widow before she left town was a kit for a Lulzbot TAZ. These are much more expensive than the ROBO. Two months ago I would have assumed it was just overpriced. Now I understand that it is a little overpriced, but it’s also in a different class and is actually a better machine. They cost around $2,000 new. I was fortunate enough to get a partial kit for about $400, and I expect to spend another $250 in parts before I have everything I need to finish it. The folks at Lulzbot are about as cool as the team at ROBO. They introduced me to the Lulzbot Flexystruder, which is not only an ingenious method for printing NinjaFlex, but is a better design for extruders in general. I’ve almost finished building a dozen of them. I intend to swap out the extruder on every machine I have for the Flexystruders, and then I’m going to start selling them on eBay under my Dynamic-arts user ID.

In another month or two when I finish the TAZ I’ll give you a new report. If things go well I will buy more printers, and then my wife will kick me out of the house.

 

Yes, those StepSticks are usually built on a 2 layer 1 oz copper Printed Circuit Board (PCB), and the Pololus are on a 2 layer 2 oz. copper PCB. This means that the Pololus can dissipate heat much better than the StepSticks. There is even a "Black Edition" A4988 Pololu, which are built on "4" layer 2 oz. copper PCB. The regular Pololus (green) are rated at 1A without direct or forced cooling, and up to 2A with sufficient cooling. The Black Editions are rated at 1.2A without cooling and 2A with cooling. If you want to drive larger motors that require more power, Pololu also have the DRV8825 drivers, which are rated at 1.5A without cooling and up to 2.2A with cooling. StepSticks on the otherhand vary..... This is due to the many different manufacturers out there and how they build them. If it is built on a 2 layer 1 oz. copper, it should be rated at 1A with cooling.

So, the lesson is, try not to use the StepSticks for your Kysan or Nema 17 (or Nema 23) motors, which are rated at 1.2A to 1.5A. It may only be a matter of time until you blow a stepper driver, or you may not get very accurate results on your prints since the drivers aren't putting enough power to the motors. If you do decide to use StepSticks, make sure you clarify with the seller or manufacturer what the rated current is AND make sure that it is enough to handle the motors you intend to use.

Narnian, I am not sure if this is just pure coincidence or pure luck, but your current situation and experiences with the Prusa and the Robo resembles that of a freind of mine.

 

Hmmmmmmm. Is your friend a master at melting 18 hours worth of 3D parts in the back of his car?