Design Choices - Vertical or Horizontal Printing?

[Don McLean]

well the first thing has nothing to do with the printer design.
Nylon ? really ?
Didn't peg you as a masochist :-)

I've been accused of a few things, but never a masochist. Wait, is a masochist someone who makes their own life difficult and tortures them self because of dumb decisions or for no good reason? Mind blown. I might actually be one. Is there a self help book for this kinda thing?

So the most important thing you'll need is a good actively heated print enclosure.
It's probably the hardest filament to use I've come across.

So some of the issues that I am thinking about..........I found these videos on YouTube, I am not affiliated with any of the makers of these videos, I am simply using them to facilitate discussion, so if one of these videos belongs to anyone here, thank you for sharing it!

Some discussion on unheated surfaces for printing Nylon:

phenolic
https://www.youtube.com/watch?v=TgkFS2MeQFI

garolite
https://www.youtube.com/watch?v=WcYnSTZscGc

Interesting in the above video at 9:52 he mentions that the mark forged printers do not have a heated bed. From this it looks like Nylon is easier than ABS is you get the right bed material and make certain your rolls are dry?

Looking at the strength of Nylon:

https://www.youtube.com/watch?v=48NC0KDmcBo

If you look at 7:15 in the above he mentions that the strength of his tests was actually lower when printing horizontally, which I find to be surprising.

Nylon on it's own is too flexible for my application, which is why I have been contemplating a Nylon Carbon fiber mix. I have also been contemplating trying to use continuous strand carbon fiber embedded in the prints. I think I could modify a colour mixing nozzle to do this. If I go with the vertical build, I can't do this anymore as the orientation will be in the wrong direction. But perhaps this would be a waste of time to pursue, given some other simpler options, at this point, I don't know.

You can use MyMatt nylon - non warp doesn't need enclosure - not sure if it's available in the states: http://mymatstore.com/epages/ec7809....oft%20Nylon%22
Amazing stuff - no warp !
I guess the money you save on enclosure could go towards the p&p from spain :-)

As for vertical versus horizontal - it's entirely down to the materials you'll be using and what direction any stress will be applied to the parts.
Nylon and flexibles tend to have much better layer adhesion than the harder plastics.
Get pet-g right and it's also got excellent layer bonding.
Get it a tad not perfect and it's absolute crap :-)
I've just switched the brackets ona slinging target from pet-g to cheap flexible pla on the gorunds the pet-g broke when hit with a large hammer and the flex-pla didn't :-)

Thanks for that info. If the layer adhesion for Nylon is better, perhaps this isn't an issue and I should do whatever is simplest to do? Even though Nylon isn't stiff, but can be made stiff with CF, my understanding is that it has good impact resistance and is hard to actually break, so that's a big reason why I'm considering it.

Some more thoughts that I've had:

Looking at bed lifting on larger parts:

https://www.youtube.com/watch?v=X6_i6DHRLhA

I've been watching a bunch of this gentleman's videos, perhaps he is a member here? Looks like he is using ABS, which I am not planning on at this point, but it seems to me that the larger the print surface in contact with the bed, the more the chance of it delaminating from the bed while printing? Or perhaps this is just an ABS phenomenon?

Lastly, I will be using the Z axis of this printer as a top down DLP printer also. As this kind of printer only has one moving axis, it seems obvious to me to simply incorporate it into the design, mount the projector on the side of the FDM machine frame, have a piece that connects to the printer's z axis from the other side, and bob's your uncle, you could use it for either purpose. The longer Z axis would give me the option of DLP printing longer parts. Although if it turns out that horizontal printing is better for FDM, I could simply make a separate printer with a single axis for DLP.

@ Trakyan, I can't really say what the forces will be, it's more of a thing where if it were made from 3/8" hardwood and hollow in the middle, that would be sufficiently strong. I am more concerned with delamination between layers and stiffness (hence carbon fiber). Impact resistance is also important. Also these parts are much longer than any I have seen in any Youtube vids being printed vertically so issues of Z banding perhaps and print quality, I don't know if they would be an issue, but I would be using much better linear components than you typically find in 3d printers so this should make a huge difference.