X Axis Rework for Tronxy XY-2 Pro

Recently, my Tronxy XY-2 Pro has been acting as my test bed for extruder upgrades and such.  I first adapted the machine to work with a direct drive extruder kit from Comgrow, which essentially installs a Sovol SV06 planetary gear direct drive extruder on to an Ender 3.  That kit, while not great, turned my historically least favorite machine into one of my favorite Cartesian style FDM printers, but there was quite a bit of hefty lifting to get it there.

A few weeks later, I was talking with a friend who owns a Creality Ender 3 S1 Pro with a Sprite extruder, and he was telling me how great it was, so I thought I'd look into it.  The first thing that struck me was its cost.  The Sprite Pro extruder kit is selling on Amazon for $109.00.  Sorry, I can't see paying more than ½ of what I've ever paid for a printer, just to try a new extruder.  A few weeks passed and I caught the Sprite Pro kit on TEMU for $75.00, which was still a bit rich for my blood.  Another week passed and I got a TEMU notification telling me the price dropped on the Sprite to $59.00.  At that point I figured heck, it's only $10 more than what I paid for the Comgro SV06 extruder kit, why not.

Most of the changes I had already made to my Tronxy for the Comgrow SV06 extruder upgrade were going to work fine, but a couple had to be walked back.  I had drilled new holes in the lower frame extrusions so that I could move my gantry 20mm to the rear so I'd have full access to the entire build space of my Tronxy.  The drill template I included in this package is specifically for the Comgrow kit, which places the nozel nearly 20mm forward of the stock mounting location of the nozzle with the original Bowden extruder.  I moved the gantry back to its stock location since the Sprite extruder places the nozzle in the same location as the Bowden fed stock hot end.  I had also installed a Creality style cover that mounts the X axis endstop switch, replacing the steel bracket for the switch, and making it look like the rest of my Creality & clone machines.  It turns out Sprite didn't like the stock position of the Tronxy's X axis endstop switch, so I reworked that cover and essentially relocated the switch to where it would fall on say an Ender 3.  The Tronxy XY-2 Pro has a build volume of 255mm X 255mm X260mm.  While the updated X axis motor/endstop cover allows printing all the way to the left edge of the build plate on its X axis, the screw holding the upper right POM roller on the toolhead of the Sprite will butt up against the right forward X axis carrier plate.  If losing 5 mm of build space on the right of the X axis is problematic, I'd suggest cutting a notch in that carrier plate so the screw will clear the plate.  I treat the outer most 10mm edge of my build plates as “dead space”, so I did nothing to address that issue.

I tried to name the STL files in such a way to where there would be no question which part of the kit to use with which extruder.

There's a file named “Sovol_Mainboard_Mount.stl”.  This part is designed for installing an Ender 3 main board in place of the proprietary Tronxy board that came with the XY-2 Pro.  My Tronxy currently has installed an unbranded 32 bit silent Sovol board that came with the Comgrow extruder kit.  Being the ultimate cheapskate, the board I most frequently use for updating outdated machines is the Makerbase MKS Robin E3.  I'm using the unbranded Sovol board because I have it, so there's no reason to throw money at another new board.  The Tronxy board wasn't bad, and it was silent, however, it's pretty much married to that horrible color touch screen display, and it connects to the extruder/hotend end using that awful 40 pin ribbon cable and break-out board at the rear of the X axis stepper motor.  This mount I made for an Ender 3 form factor board merely centers the board on the location of the OEM board, with the USB interface and Micro-SD card slot facing back, but it's use is quite invasive.  By invasive, I'm saying that you'll have to cut holes in the back plate of the machine to make the boards external interfaces available for use.  I used a die grinder and diamond disc to cut a long rectangular slot opening to make those connections accessible, but that's a modification that can't be undone, so if you use it, be sure you're OK with a permanent modification to your machine, and that hopefully, at the time you install it, that your machine is out of warranty.

The rear carrier plates included in this kit are designed to correct a design flaw inherent with Ender 3's, CR-10's, and all the copy cat machines.  The inside POM rollers for each of the carrier sets as designed by Creality and many other manufacturers use a cam nut on one side of the wheel, and a spacer on the other.  The nutted end of axle should NOT be hard mounted to the side opposite the cam nut.  That flaw will often cause the axle to cock horizontally left and right as you're adjusting the cam nut for tension, causing the roller NOT to sit flush in the V-Slot groove.  Removing the spacer and using a shorter 30mm M5 screw for the axle allows for the POM roller to be tensioned properly without tweaking it to an improper angle.  I'm crediting “Egco” for the inside POM roller fix as his “Ender 3 V2 Dual Z-Axis Upgrade” is the first design I stumbled upon that addresses that problem.  All of the purchasable 2nd Z axis lead screw kits I've seen to date include that same flaw inherent to the left side lead screw setup.  If you're adding a second lead screw, why not do it right?  The purpose in the spacer for each side is for connecting the rear carrier plate to the X axis extrusion solidly, while allowing the POM wheel with the cam nut to be free on one side.

I've labeled the spacers according to which side carrier they go with.  Be advised that the left side spacer is 2mm taller than the right and has one flat side on the cone end connecting to the extrusion.  The added length of the left spacer is to address the fact that on the left, the spacer butts up against the extrusion just in front of the forward carrier plate while the right side spacer butts up against the forward carrier itself.  The flat side of the left side spacer should be facing the forward carriers edge, and is present to provide clearance for the forward carrier plate.  Both spacers are intended to be fastened to the X axis extrusion using a M4 X 40mm screw and T-nut, although the T-nut on the right hand side will be opposite the right side forward carriers rear face.

When my Tronxy was still Bowden fed, I had no interest in a left side rear carrier, however, after upgrading it with the Comgrow extruder kit, I found that gigantic steel bracket would cause interference with the new kits ribbon cable, and I wanted to mirror the changes I made on the right side of the machine so I did, and added support for the X axis stepper motor and corrected hole positioning for access to the screws retaining the forward carrier plate to the extrusion.  Prior to my left rear carrier, I had removed the 8mm spacer for the inside POM roller and replaced the 40mm screw with a 30mm screw for correcting the problem I outlined earlier.  Unfortunately, the cam nut for the left side, as is on the Ender 3's and the likes, is on the rear carriers side.  I didn't want to have the cam nut adjusting tension on a plastic part, so I moved it to the front steel carrier plate.  Yes, another invasive modification that can't really be undone is coming…  I removed the X axis aluminum extrusion from the machine with the forward left carrier plate still attached, and set it up in my drill press with the carrier plate up.  With a 13/64" drill bit, I centered the threaded hole of the forward carrier plate where the adjustable POM roller axle anchored, then drilled all the way through the plate and X axis extrusion.  The purpose in that through hole is for providing similar access to the axles screw head as what's seen standard on the right side of Ender 3 style machines.  I followed that up, by leaving the X axis extrusion in the same position on the drill press and swapped the 13/64" bit for a 9/32" bit, then drilled through just the forward carrier plate, and the top most part of that V-slot groove, allowing for the cam nut to be used on the forward plate and providing space for the screw head of the axle to fit through the outer lips of the V-slot.  If you're from a land where metric drill indexes are cost effective, you should actually be using a 5mm drill bit in place of my 13/64" bit, and a 8mm drill bit in place of my 9/32" bit.  Yeah, I'm a cheapscate, living in the U.S. where metric indexes are just stupidly overpriced…

My final note on the two rear carrier plates:  Some of the modifications I've made to my Tronxy were done so long ago that I don't recall some of the original hardware.  I want to say, I believe the brass nut for the original lead screw of the Tronxy was a Creality style nut with two flat sides.  I designed my rear carriers with the round Prusa/Anet style nuts in mind, simply because those are what I keep on hand.  Actually, for the last year, I've been replacing all my round brass nuts with round POM nuts, and thus far, they've performed so much better for me than the stock brass nuts, but that's irrelevent since they are identical in form factor so either will work with my carriers.  I like the new POM nuts because they fit lead screws more snugly and quite oddly, hold up much better than the brass nuts which seem loose even when they're brand new.  Also, I'm not so much a fan of anti-backlash nuts because the spring tension between the two halves causes the brass to wear out even quicker.  My apologies for the tangent…  My carriers will work directly with the round nuts, not the flat sided nuts.  I haven't provided versions for other style nuts because I don't use them on anything, however, if your machine is using a different style nut and you'd like to use either of my carriers but are unable to remix them yourself, drop me a note and I'll revisit the design, providing a version that will fit the flat sided nuts.

All of the parts included in this kit are intended to be printed as oriented in the STL's without any need for supports, except for the left rear carrier plate, which requires supports “to buildplate only”, due to the elevated stepper motor opening, but that single piece of support material is extremely easy to remove.

As with most of my printable machine upgrades, I print these with PETG and using 100% infill for strength.  My machines are all exposed to the open air, are inside the house, and I print only non-toxic materials, PLA, PETG, and TPU.  Once I'm better set up here, I'd like to move a couple machines into the garage for printing more exotic materials in a heated enclosure.  If you're going to use any of these parts on a machine in a heated enclosure, I'd recommend printing them from nylon, poly-carbonate, or some other material less prone to warping while printing from a heated enclosure.

UPDATE 10042024:  I removed the two ribbon cable management parts from this project since they're relatively unrelated to the X axis, but will be moving them to a project they're directly a part of.  https://www.printables.com/model/1027706-24-pin-extruder-ribbon-cable-cleanup-kit

UPDATE 12152024:  I added a version 2 for both left and rear carrier plates.  The original plates used the Anet style round brass nuts with 4 screw holes.  The version 2 plates use the flat sided brass nuts with threaded screw holes.  Be sure to download and print the version of plate that matches the brass nut you intend to use on either side of your machine.

UPDATE 09102025:  I added a version 2.5 for both carrier brackets.  JDS noted that the throughway hole for the brass nut on my Ender 3 dual Z axis upgrade is too small to fit anti-backlash nuts.  JDS mentioned that he may remix the Ender 3 carrier for anti-backlash nuts so I'm leaving that model as is for now, but opened up that hole from 11mm to 14mm on both left and right carriers for my Tronxy design.