Well this will slow things down. Snapped stepper motor drive.

Robo and I were going to be a part of the Midwest reprap fest this weekend but it looks as though she doesn't want to go.
I've been getting the best prints yet over the last few weeks, this happened over a tiny one hour print too, I heard the grind from the other room and it was already too late.
First thought for me was too tight of a Y belt but I had it set right to the factory white lines and it felt just right to me so I don't know.

Note to a few others that have mentioned sometimes getting the grinding noise at the last little bit of the Y axis when homing, I know there has been some recent posts about it as I have mentioned having it too. I'm thinking after this it's a bit more serious of an issue.

Welp, I guess I'll spend tomorrow tracking down a new motor with hopes of still making Robo3D a part of the festival.

 

Holy crap! was your belt too tight?

 

I don't think it was TOO tight, Originally it was far too loose, I was getting layer shifting and heavy banding. So loose it was kind of floppy, not pluckable at all. I tightened it about a month ago right to the little white lines as suggested in the early assembly video and it felt great. firm but with a good feeling tug to it. Good lower pitch twang, not like a high pitch shrill twang when plucked. I was getting PERFECT layers up untill this point and I thought it was running great.

On close inspection though, they shave one side of the shaft flat for the drive gear set screw to bite into, I think they went a little too deep on this one. It snapped right at the deepest, lowest part of the grind. Hard to get a good picture of it, you can almost see it in this pic if you have good glasses, but the grind kind of bit in at one point and that's right where it broke.

Good thing the motors are cheap, it just sucks as I said I was going to leave today to set Robo up at the Printer Festival this weekend.
C'est la vie.

 

Here is where I mean;



You can see how far down the grind went and how it kind of bit in right where it broke.

 

By the fracture shape on the edge it looks like a combination of sheer and torque did it in.

 

Ive seen this before on other motors coming from china, the shafts are a hit and miss on quality.

no belt driven 3d printer should ever have a shaft break off like this.. .. for one the belt will slip before the shaft should ever break.. GT2 BELTS WILL GIVE.. if there is too much force. You will fray the belt before you ever break the shaft (at least on quality stepper motors)

that being said.. it does look like someone shaved off too much material from the shaft.. it should only need a slight flat on one side...

 

As an update Robo contacted me right away in a message and offered to send out a new one. Even better as the hope was to get to the Midwest Reprap fest tomorrow morning, Mike actually got me lined up with someone going there as well that will bring a compatible motor for me so I will be up and running in no time once I get there.

I woke up today and had a penny stuck to my backside, I told my wife that means it will be a lucky day lol. Looks like I was right .
Thanks again Mike!! Owe ya' one!

 

Fixed it and up and running at the festival!! I Was the Only Robo there so glad to show it off and talk about how much I love mine. I'm pretty new but it didn't stop me from being a part of it and printing some stretchlets for the kids there.
It was a blast and I wish I had all weekend. I will post some pictures in another thread for those on the forum that want to see more of the festival.

 

Glad to see a RoBo on those benches