What is this fishing line that everyone talks about??

Yeah Jago, what are you talking about

Also, does your coupler make a "clicking" noise? Mine does--not sure why! But it doesn't seem to be hurting anything.

I haven't noticed any clicking around that part. The funny noise I had a hard time figuring out was the cable chain scrunching a bit against the foamboard case when the carriage moves left far enough.

I Just got a rod I knew would be a little too long and let it stick out the other side. Doesn't hurt anything, and if I ever decide I need to add some kind of thrust bearing to keep the oldham coupler from falling apart, there is plenty of rod to play with :-).

I've been having a bit of issue with this actually since switching to fishing line. I think it's an issue of tension, but my ultimate solution is going to be to put 6x13x5mm flanged bearings into the frame to replace the bushings. The fit should be tight enough that it will prevent the coupler from sliding apart. I've noticed, though, that even if it's almost completely apart, it still drives the system--I'm waiting to come back to the coupler just spinning on its own and the carriage going nowhere...

Also, does your coupler make a "clicking" noise? Mine does--not sure why! But it doesn't seem to be hurting anything.

I'll have to cut it to the approximate length, and then try it, take it back and cut it to the right size.

Thanks

Scott

Anyone able to give me a pointer?

Thanks

Scott

I hate ringing.

At >1000Nm/rad, evidently you do!

Edit: I just looked up the Nema 17 motor spec and it produces up to 45 N-cm (0.45 N-m) torque. That is not the stock motor, but my better replacement that I got and I'm not running it at the max, obviously, so its less than that.  Even the non high rigidity coupler is rated for 1.2 N-m so the high rigidity coupler rated for 3 N-m is way overkill.  I would still like an opinion if the allowable misalignment on that top one is actually too much for this application. 

At the end of the day, it might not even matter which of these two I use.

+1 on your last sentence, they both look ok

* Set screws are ok, of course can be used without a flat as long as you button them up tight!
* Torque rating should be nice and high!
* Only worry about the maximum allowable misalignment - the plastic one is actually a bit more liberal (3 degrees / 1.5mm rather than 1.5 degrees / 0.5mm). I'd actually say the plastic one was the better option here for a flexible solidoodle frame...
* 20mm plastic one is 60 Nm/rad, while 17mm brass one quotes 1000 Nm/rad, so the brass one definitely less springy. I think both are more than stiff enough, but if you're scared of ringing, the brass one is better!

To be honest, I think you'll be hard pressed to really see any advantage to a high quality coupler over an ebay spider coupler for $5, but it would be interesting to see the results or even a comparison, so I'll leave that up to you!