Z-Banding reduction using helical beam coupling (Page 1 of 2)

Wow. VERY nice approach! The community is strengthened by users like you. Thank you!

After reading your previous post about this, I started to look at getting the coupler shown and found that there's a version with rod clamping instead of set screws. Is there a reason you didn't go that route?

Although I admit that your nut and washer alignment solution is a lot cheaper than the price difference - that's a nice solution!

Thanks for the support and thanks for your mod suggestions.

Here's the same print with a 1 cent coin:
0.05mm brain slug and 1 cent coin
0.05mm brain slug and 1 cent coin

I'd like to say that I considered the design you pointed me to and weighed up various pros and cons. However, in truth I just hadn't seen it. I don't know which method would be better and I suspect there will be little to choose between them.

I currently shoot with an Olympus OM-D EM-5 and 12-50mm kit lens. The latter has a pretty good macro setting so it's easy to get these shots.

I got it from amazon. This is the link:
Ruland FSMR19-8-5-SS Set Screw Beam Coupling, Stainless Steel, Metric, 8mm Bore A Diameter, 5mm Bore B Diameter, 19.05mm OD, 31.75mm Length, 3.51 Nm Nominal Torque

Good luck and if you pick one up please let us all know if it worked for you too.

This post sold me.  I've been debating and researching which 3D printer I would get for a few weeks now (if at all).  I'll be ordering an SD3 tomorrow (sleep on it just to be sure).

Edit: purchased 6-Apr-2013

I think the helical coupling is a good, robust, way to address the banding that many people see. My own - very limited - experiments suggest that aluminum is too soft/pliable/flexible in this type of coupling to lay down good quality layer heights. I certainly am not advocating the exact coupler I bought - there will be many other sources of helical coupling solution. My only guidance is to ensure that the coupling is relatively stiff for the layer height issue I saw. If those links are to stainless steel couplings then you have probably got yourself a bargain!

I hear you but I have two thoughts:

• The time spent on a good print is long, and the design stage before that usually even longer. If you consider that - and the satisfaction with the quality of your final piece - I consider this good value. As ronsii has noted, there are other couplings that will be cheaper and I'm sure will do at least as good a job. I'm just telling you what worked for me.

• I am super lazy and amazon happened to have what I wanted. So I clicked the friendly orange button and waited for my new toy to arrive. Even on minimum wage, 8 hours of searching and driving around equals the price of one of these (pricey) couplings.

Some more small prints this time printed at 0.20mm layer height and with acetone smoothing.

The piece is the evil ducky from thingiverse.

I put a one cent coin in the picture for scale against the ducks in the picture

So how is the sd2s z rod attached from the factory? When I look at mine it looks like it is all one piece with the motor shaft? Do you have to cut the rod off the shaft to apply this fix?

So if I understand this right. The long skinny z rod is put into a press and then is pressed into the z motor? Wouldn't that just beg to bend the rod?

If you pressed it from the far end and it took more than say 200 lbs to seat it then yes...  but I would guess they thread a nut on the bored end and use an extension to press it on which would eliminate the probably of bending. From the 'bent z' issues I have seen I am thinking the bore was not aligned and sometimes not centered in the rod causing problems.