18th August 2024 19th August 2024 By Bzzz In editorial note 3d printer3d printingadaptercockroach modeender 5 pluslinear rails

The Ender 5 PlusPlus on linear rails (#E21F6)

In the recent weeks, I printed quite a few parts for work. Some large ones (post incoming) several times, with the opportunity to optimize slicer settings, some others in very large sizes, with the opportunity to tweak the printer to the max settings, even beyond the actual printer bed (390mm along Y!), and some small ones in search for the perfect settings for clear PETG. My fluidd klipper interface apparently only keeps a history of 50 jobs, and that list doesn’t even cover five days.

So after all the software tweaking, I figured it’s time for another hardware printer modification: (Dual) linear rails for the Y axis.

The X axis has been running on linear rails for quite some time now, I’ve ordered a 500m unit from Amazon back in early September 2023 (18.99€ at the time). Now I’ve ordered two more, black ones (as they were cheaper for some reason than standard ones?!), same “CNCYEAH” vendor, same 500mm, at 21.01€/piece. Clearly not high-end stuff at that price point, but they’re not bearing any significant load or run at high speeds for extended periods of time, so that’ll do. If they ever wear out, I’ll buy proper ones, I promise.

X on the ender is a relatively simple mod, as it’s only one rail and one “only” needs to attach the hot end assembly to it, job done. Bit more complicated since I don’t have a standard hot end (and I don’t know which one exactly was put in there by the previous owner), but it attaches to a metal backplate and getting that to stick to a rail carriage is certainly doable. From there, the printer is ready to print parts for self-improvement again, so any wobbly rail attachment can be improved in the next print and part revision, and so on. X is a prime upgrade point for the Ender since the standard three-wheel guide isn’t exactly precise.

Y is two rails, one side is just there to guide the assembly, the other one also carries the X motor. And since the X axis sits on top of it, and every Y rail is by default equipped with four wheels and two eccentric screws to make it somewhat adjustable (mine always ran on three wheels, terrible system), it’s a bit of work to remove the assembly, change things, and put them back together again for a functional printer.

So I had some fun changing just one side to a linear rail, optimizing the mount, and then replicating the thing on the more difficult side with the motor attachment.

I did start with this pre-made part from thingiverse – https://www.thingiverse.com/thing:4928100 – and quickly noticed this wouldn’t cut the mustard. The author describes that he wasn’t satisfied with the free models out there and he decided to roll his own, but unfortunately, I have to state the same. Great starting point, don’t get me wrong, but the guy made the belt attachment so thick and high above the rail that a new belt is needed. And while he did achieve his goal of making the belt mount as flush as possible with the aluminium extrusions for a more even transfer of force, changing a 925mm belt for an, I don’t know, he didn’t specify, 950mm belt (?) is a stupid proposition.

There is another set of STL files from a different guy, those seem promising – but they’re using the bottom row of the 20×40 extrusion, which I cannot do, as those carry my set of LED light panels. For everyone not doing this stupid thing, using the bottom rail is probably an excellent idea, since this will allow the stock mounting plate to be mounted flush and held from the top, not from the bottom, which has space restriction issues as discussed below.

And when realizing all this after I disassembled the printer already…I had to make it work for the moment. After all, this is my only printer that I can print improvement parts for this very printer with, and for that, it has to work somehow. In true post-apocalyptic cockroach fashion, and with the help of a Shinto rasp (perfect for PETG, 100% recommendation!), I slimmed down the offending parts, were able to attach it to the rail sled (offset by half the part width), slide a piece of teflon tape underneath to make the saggy end part not scratch the aluminium extrusions and…

…well, had a usable printer again (since I was too lazy to put everything back to stock spec!). Close-up: Half of the sled sticks out on the bottom-right, and the printer attach point with the brown-yellow teflon tape is seen on top-left.

With some printer config adjustments to not use the full Y rail since the X carriage is offset by about 10cm, I had a somewhat functional printer again – to print a better part

And that’s this, minus the two M8 heat inserts. The left X attachment plate has some two center holes for X rail mounting (M5 screws, hole size usable for M6 taps), two holes usable for M6 taps for spacers on one side, and two holes suitable for M8 taps for the former eccentric screws on the other.

Since the side M6 ones will collide with the rail carriage when protruding the adapter, and I wanted to keep it as low as possible for the mentioned belt reasons, those holes are present in the model, but not actually used. I think M6 heat inserts start at 4mm height, maybe one could make this M5 as those are available with 3mm insertion height. But they would need to be tightened quite a bit or otherwise kept from moving around – on the other hand, attaching just the two M8’s is certainly stiff enough for my purposes here.

Also, the center M6’s have to be modified to accommodate countersunk screws, but the aluminium plate is thick enough to do this. Otherwise, the default pan head screws will create an additional height offset – and I don’t want that. When using full-length 500m rails, the outer screw is also a bit tricky to get in once the rail is mounted, so a hex screw would be a better fit than my torx ones here – but it’s not that bad, they don’t need to be removed all that often. The inner one is fine (at front or back position, not accessible at all in the center due to the bed mounts).

And from here, it’s just the regular evolution of parts, since the printer is fully usable again. Here’s version 2 to feed your faces-in-places pareidolia:

I did smoothen the sides that enclose the aluminium extrusion a bit and added teflon tape, but this should never come into contact with the actual rail once the right hand side of the printer is also upgraded. Since this tape some day might come loose and I’m too lazy to make a two-part adapter to clamp it between two printed pieces, I actually wouldn’t recommend this – just sand down the top faces to get rid of any imperfections and it’ll do.

Version 3 is just trimming excess, making a couple sides a tighter fit, and optimizing the thing for my 0.35mm layer height / 0.6mm nozzle printer setup. It can be found here as a direct download, or on thingiverse (thing 6735381). I couldn’t be arsed to take a photo of it, so here’s a rendering

Materials needed for mounting:

• Four M3x10 screws (washers or flange heads recommended) on the side, connecting the rail carriage
• Two M8 heat inserts of 6mm height (the larger ones do not offer better grip, they just have a longer guidance tip)
• Two short M8 screws (M8x10-ish, but can be double the size, just sticks out) for the carriage plate
• Two M5x20 countersunk screws for the 20×20 X profile attachment
• Suitable drill to make the two countersunk holes

And that’s the left side of my Ender5++ on linear rails – time to change the right side as well