Unjunking The Junkinator 9000

[rugged furnace]

So I figured it is time for a build log! I lovingly call my build the Junkinator because I am re-using as much stock hardware as I can and want to keep to a pretty low budget. My goal is certainly not to beat Precurssor ('cause ya can't) but a moderately quick CoreXY would be nice. In its stock form, despite being slow as, my Ender 5 Pro actually had very nice print quality. So it needs to match that at its new speeds.

I had acquired a pretty stock Ender 5 Pro which I liked, but wanted something a little faster. In my initial quest to achieve that, I got a BTT SKR3 E3 Mini V3 to run klipper on and modified the printer with belt tensioners. After tinkering with that for a bit, as well as a He3D Ie3 Tricolor (a crazy three in three out machine with three hotends that I tore down to parts because I could never get all nozzles aligned well enough) I was pretty fed up with crappy slow machines so I got myself an X1C Combo and knew I wanted to do a CoreXY conversion on the 5 Pro.

The first iteration I didn't take any photos, but had to completely tear down as the frame was extremely out of square. As in: a full centimeter out of square. I fully squared the top and bottom frames using the flattest surface most people have in their homes: the glass cooktop. Then I put the uprights upright on the glass and well... They are not square or straight. I also managed to get the frame assembled straight and level and square (at least to within a few mm, as best as possible using a tape measure).

For colors, I'm going with Bambu Green (I think) as a highlight and black and I printed the skirts with filament change after the first layer. I really love the effect this gives. I did try painting color using OrcaSlicer, but there's a bug in Orca that attempts to print the painted area in thin air. I ran into that same bug when printing the DIN rail mounts, which therefore also have complete layer color changes.

Whoops post length limit! 😄

[rugged furnace]

Frame built, it is time to think about the layout of the electronics bay. Again I am limited by the fact I would really like to reuse as much existing components and cables as possible. This limits the place of the mcu board to the back right.

Initially, I had placed the Pi at the back left and the buck converter next to the psu in the front right. However, during this I realized that I might be able to use the original stock main board to drive a few additional steppers, for example to enable a certain three independent Z axis mod 😊

As the SKR E3 Mini has an extra fan plug, I decided to mod the PSU so its fan would only run if it is under load. To that end I rerouted the fan cable to the end, crimped on another connector and zip tied the end to the PSU frame.

In order to keep my kids somewhat safe from exposing themselves to 230V I printed a terminal cover which worked perfectly. I also printed a community modded foot to enable a wired Ethernet connection to the Pi but I didn’t pay enough attention and printed the Plus size for my Pro. D’oh.

[rugged furnace]

So after having thoroughly cleaned the carriages and rails in IPA (omg gross!) it was time to reassemble the motion system. I followed the instructions to tighten the rails, with the slight adjustment that I wanted to make sure to have the rails parallel when the gantry was squared. So I printed the two brackets you see that fasten to the front bar using M5 roll-in nuts and M5x8 bolts, as well as to the gantry replacing two M3 bolts.

To keep the toolhead cabling somewhat organized I had the idea to shrink-wrap a piano wire to the outside of the reverse Bowden. That didn’t give enough support for the entire loom, so I added in another piano wire that I screwed to the loom support.

In order to somewhat easily change out parts on my toolhead I decided to make a small holder for all connectors. It sits next to the loom support on the frame and the JST-SM connectors drop right in.

With that complete, I had somewhere to target for my loom wire lengths so I could cut and crimp them. I also started on the frame loom, from my little toolhead board to the main electronics bay and wrapped both. I am pretty happy with how the toolhead loom turned out. It is pretty sturdy and looks nicely organized (to me at least).

I routed the frame loom along the inside of the frame because I think the front of that frame leg will be used by Hydra if and when I get that.

[rugged furnace]

With all the wiring completed and the klipper configs ported from the stock Ender 5 it was time to create some bed meshes. Those showed the bed to be extremely out of whack (a range of 0.4mm). With the mesh done, I printed a single layer across the entire bed, which turned out really bad. Too low in the middle, too high on the sides. It took me way longer than I care to admit to realise I had a bed that was bending and flexing when heated. So I heated the bed to sixty degrees, ran another mesh, which was a lot better at 0.2mm range.

But the real improvement was the new first layer which now went down a lot nicer. Now with the wiring cleaned up, printing working I decided to apply for a serial 🙂

Quite an adventure!

[rugged furnace]

Unjunking The Junkinator 9000

So! With all that said and done, lets un-junk the Junkinator 😄

[rugged furnace]

Almost can’t see it, but as I needed a cart filler to get my free Amazon shipping I threw in a V6 knockoff. It is quite apparent this construction should be much stiffer than the stock hotend, but given that I’ve re-used the heater and thermistor I am not expecting wonders with regards to flow rate.

[rugged furnace]

Based on a few suggestions here I cleaned up the Z wiring slightly. The difference two pieces of velcro make! Another item slightly de-junked!

[rugged furnace]

And there really weren't any, as expected. It still limits at around 12mm^3/s, same as stock. So now a Dragon Ace has been ordered, because on the last print the v6 experienced the blob of doom and I'm not sure I can clean it up well enough to print again.

[rugged furnace]

I actually could clean it up! But I'm struggling getting any decent print quality at decent speeds. Sure if I run at like 40mms outer wall everything looks moderately OK

But I don't want to run 40mms outer walls. I want to outpace my X1C, darnit!

[rugged furnace]

Trianglelab Dragon Ace installed and ready to go! I actually also changed the entire toolhead to the E34M1 and it does feel much sturdier. I did have to adjust the probe mount to fit this old SN04-N I stole off of a printer that is currently in parts in a box (and will probably never be a printer again as I stole a lot of parts off of it for this built and hope to reuse more to build a laser cutter).

I can run the Bambu profile now with very good results. However, I am still pretty flow rate limited to 22mm^3/s. This is probably due to the BMG knockoff extruder. I would print a sherpa mini, but don't have an appropriate motor for it as I only have the square stepper that fits on the BMG.

[golden grove]

You could try this Sherpa heavy which uses the square motor https://www.printables.com/model/549890-sherpa-extra-heavy-with-nema17-update-2

[rugged furnace]

Oh thanks! I had been looking for a mod but hadn’t found anything yet. That goes into the print queue

[rugged furnace]

Whoo! Found my build log again! So I'm gearing up for rebuild ... five? It seems the frame is twisted somehow and I really need to get it absolutely square

[rugged furnace]

Resquaring the frame, again. I’ve figured out this time that beer cans make better shim stock than paper or cardboard, that compresses quite a bit. Then of course I needed thinner shims so alu foil steps in where I need something thinner. Annoyingly enough, the bottom frame still appears to be .2-.3 mm out of square, despite all corners being as square as my tools can measure. Still it certainly sits dead flat now so I’ve got that going for me, which is nice.

Next up: top frame.