Designing and printing the drag chain tower - and testing various filaments

I have some 3.4mm diameter o-ring cord(?) - the groove dims shd be around 4.5mm x 2.5mm for about 25% compression.

And I shouldn't forget to put some tiny o-rings around the 4 fixing screws. You might argue the screws would be better placed within the large o-ring but that's where I ended up.

Printing this in PA-CF (carbon fibre loaded nylon) didn't look like an option, having tried to print out some of the drag chain covers using the stuff. Apart from the surface texture (rough as a bear's arse), the things snapped along the layer lines without much provocation. They were also pretty feeble in terms of stiffness - all in all a complete disappointment. No amount of fiddling with the slicer settings is going to help. Perhaps it's best suited to large, structural parts.

It fits - but distorts if you so much look at it. And it looks (and feels) shit:

Let's try some PETG and see if that's any better. I'm rather hoping for something that is reasonably rigid, with a clean finish and possibly even a degree of solvent (coolant and way oil) resistance.

Well that is shit - but in a different way to the PA-CF.

Let's try the Creality ABS and see if that's any better:

Well, it looks better - but isn't a whole lot stronger (snaps in half easily). I may simply revert to the PLA, which actually worked well, if you can forgive the fact it's grey, not black. I could always get a reel of black of course.....

However, for the drag chain tower, it may be well suited, given that strength isn't a big issue there.

So, back to the drag chain tower. Let's print that out in ABS and be done with this part of the task. ABS is more fussy when it comes to printer settings, requiring a heated bed, hot chamber and various additions such as extended bed, multiple base layers etc to prevent it lifting around the base.

Well, this looked OK to start with:

The base is lifted at the edges ie it won't sit flat on the table. NVM, I will bugger about with the settings - but in the meantime, let's check out the other features. Those M5 holes for the lid seem to tap out ok:

The lid(s) are both badly warped.

This is with a raft, 5 layers at the base, hot bed, fan almost off. I stopped the print to check how it looked. 

This is a lot better. Pretty decent finish and no warping at the edges. I will now print the tower, noting that it estimates about 10 hours. Ideally it will be ready in the morning then.