Drill Template for Comgrow E3 Direct Drive Extruder Kit

Two months ago, I upgraded my Anet A8 Plus with a Sovol SV06 extruder.  That upgrade has worked so nicely for me, I wanted to upgrade a few of my other machines similarly.

Rather than to upgrade another machine that's already equipped with a direct drive extruder, I thought I'd like to do one of my Bowden fed machines.  I expected to simply purchase another bare SV06 extruder for $30 and mount its heatsync to the original hotend carriage, but stumbled on to the “Comgrow Ender 3 Direct Drive Extruder Kit”.  The Comgrow extruder kit was a complete tool head with hotend, fans, cabling, tools, inductive bed sensor, carrier plate with pom wheels, and even a silent 32 bit mainboard.  The Comgrow kit was selling for $50.  I thought “that can't be real”, but I'd purchased other upgrade components from that seller on Amazon, so I thought I'd give it a shot.

I do NOT expect the Comgrow kit to be around for much longer.  If I had to guess, I'd say Comgrow intended to sell this kit to people who wanted a machine as capable as the Sovol SV07, but had a Creality Ender 3.  When I ordered my kit, there were 20 kits in stock on Amazon.  I told a close friend of mine about the kit.  He ordered it and was equally as shocked at how complete the kit was and its price.  My friend has an Ender 3, but also has a Sovol SV06 Plus, so he was quite familiar with how nice the SV06 extruder is to work with.  As I'm publishing this design, there is only one kit left in stock on Amazon, and I've not seen them anywhere else, so it may very well be that nobody will have a use for this model.

For those who don't know, Sovol recently purchased Comgrow, so if this kit does resurface under either the Comgrow or Sovol name, I don't believe it will be for $50.  I think the kit is probably worth $100, however, all my machines are of the sub $200 variety, so the thought of paying more than ½ of what I've ever paid for a printer, that cost would be rather difficult to swallow.  I guess we'll just have to wait and see…

While the Comgrow direct drive extruder kit is an OUTSTANDING value, there are two minor problems I've found with it.

1.  The Comgrow branded strain relief for the ribbon cable will cause the ribbon cable to slam hard against the left side pillar when the X axis is homing, or when printing on the far left side of the bed.  I addressed this problem quickly and easily with this:  https://www.printables.com/model/929088-cable-clamp-for-comgrow-ender-3-direct-drive-extru
2. The position of the nozzle is approximately 18mm forward of the stock nozzles location, so that 18mm's of build space is just lost.  While this may seem somewhat invasive, the best solution I could dream up for restoring my full build area was to relocate the entire gantry 20mm to the rear of the machine.

It's for problem #2 that I made this drill template.  Given that the 40x40mm aluminum extrusions of the Ender 3 and similar machines are mostly hollow, I would caution against trying to use this template with a handheld drill.  I designed this template for lining up the detached 40x40mm extrusions in my drill press.  It's intended use is for just that, lining the extrusion up to be drilled in a drill press.  Unless you're extremely steady handed, it's unlikely that you'll be able to keep a handheld drill steady while zipping through 4 separate layers of aluminum, but if anybody does want to risk drilling his/her printer frame by hand, I'd love to hear your results.  Seriously, you should NOT!!!

While I opted to install the Comgrow kit on my least favorite printer, the Tronxy XY-2 Pro, the reason I offset the holes in the template by 20mm as opposed to the 18mm's the nozzle was off is that the kit is for an Ender 3, and most people who've purchased this kit will be installing it on an Ender 3.  The Ender 3's lower extrusion that connects the two outside 40x40 extrusions have either two 5mm screws, or four 5mm screws, regular vs. Pro.  Offsetting my drill template by 20mm's lands the gantry safely behind any horizontal fasteners. 

I don't own a metric drill index.  I know that sounds crazy, but they're stupid expensive here in the U.S.  One day I'll break down and buy one, but for now, I just use what I have handy.  In a perfect world, I'd have drilled the through holes with a 5mm bit, but I instead used a 13/64" bit.  For the underside opening for the screw heads, I would have used a 9mm bit, but instead used a 11/32" bit.  This template only addresses the 5mm screw holes.  I drilled my extrusions on the press with the extrusions clamped upside down.  Upon drilling each of the four 5mm screw holes, I swaped my 13/64" bit for the 11/32" bit, to drill just down to the flat portion of the groove, then swapped back to the 13/64" bit, and aligned the next hole using the template.  I don't bolt the template, I simply drop the screws through the template and original holes and use the next empty hole of the template for aligning the extrusion in the vice of my drill press.  I hope that makes sense to anybody who might use this.  Just make sure you're drilling the position to relocate the gantry behind its previous location, not in front of.  Otherwise, you'll have extra holes to cover up for no good reason…