Ender Extender Review

Mostly assembled Ender 3 Pro with the Ender Extender 400 kit. (my older printer in the background, where it belongs)

I have applied the Ender Extender 400 to my Ender 3 Pro. There are some gotcha’s that need to be considered over and above the extender kit.

The Creality Ender 3, Ender 3 Pro, Ender 3 V2, and Ender 5 printers are popular 3D printers. These are relatively simple to assemble, setup, tune, and get printing with good output. And they are inexpensive compared to other vendors providing similar specifications. The Ender 3 models come with a 220mm X 220mm print bed (or a 235mm X 235mm). This is good for most prints, but can require some models to need multiple parts printed and later assembled or glued together. A larger bed may allow that same model to be printed as a single piece.

Ender Extender provides kits to increase the print area of Ender 3 and 5 printers — including the newer Ender V2. These kits are cheaper than buying a new printer with a larger print bed, and allow the use the existing / trusted electronics.

My experience with the Ender Extender organization has been positive. I placed my order and the parts arrived in a reasonable time. Ender Extender works out of Texas, USA. I live in Alberta, Canada. Shipping and Duty charges added to the expense, moving the costs into a territory that almost negates the benefits. But moving to a larger print bed opens more possibilities than the regular print bed presents. To me, those possibilities were worth the expense.

The kit is well packaged and very straight forward. The installation guide is detailed in the disassembly of the original printer. This is necessary to install the larger T-Slot bars. The guide takes you through to an assembled frame, but does not cover re-attaching the motors and wiring. It also does not cover dealing with the electronics which no longer fit on the frame. So this kit is not best suited for a beginner. You will need some comfort with cutting/splicing/creating wires, and adjusting or customizing your printer. You’ll have to make some choices that the installation guide does not cover.

There were three gotchas that I’m in the midst of dealing with.

  1. The electronics do not fit back into the original location. A 2020 t-slot cross member is added to the front and back of the 2040 base bars to replace the 2040 center cross bar. This prevents remounting the electronics case in the original location. And the back half of the electronics case cannot be secured to the center bar that no longer exists. The fix is to use a custom electronics case — such as this external case. This will require re-routing the wiring though which could be an issue. Using the supplied replacement wires where needed and the existing wires results in a short length for connecting with the external case. That length may not be suitable for your setup though. In my case, I’d need about another 10 inches to place the control box in the best location.
  2. If the power supply is mounted to the frame in the original position, the connector wires are too short to reach the external electronics case. The easy fix is to remove the power supply from the frame and position it closer to the external case. This is functional but a little messy. You may need to consider creating custom wires or a custom electronics/power supply case to help clean this up.
  3. The new aluminium plate is 400mm x 400mm (16"x16")— HUGE compared to the original bed. However, the kit does not come with a build area — glass, PEI, etc. This will need to be sourced separately. Finding a suitable size at a reasonable price is proving troublesome. I favor the flexible spring steel sheet with PEI, and the best price I have been able to find thus far is over $160+ CDN. Even a glass plate of this size is expensive. I have seen PEI sheets without the spring steel for approx $50. These would need to be clipped to the bed in the same way a glass plate would be. Funny enough I found a build surface of the right size for a mere $12.99 USD. These can be found on the Ender Extender site. I have two of them on the way. However these are stickers and not easily removable like the magnetic solutions. Experience tells me that this kind of surface will need to be replaced on a regular basis. Until these arrive though I am using painters tape for my build surface.

These issues are foreseeable given a little thought. And each can be overcome relatively easily. But they are additional costs and considerations over and above the Extender kit.

Other considerations:

  • not really a gotcha, but… Aluminium plates are notorious for being hit and miss with regards to being perfectly flat. It stands to reason that larger sizes would increase the odds that the plate is not perfectly flat. For this reason I would strongly recommend using an Automatic Bed Levelling system such as a BLTouch. This would negate the “warp” issues a great deal.
  • The X Axis now spans a larger area. Reassembly of the X axis must be done with care to ensure it stays level. Measuring the height of left and right sides of the axis to the base should give the same readings. You will likely need to adjust the wheels to be a little tighter to prevent the right side from sagging. The single Z axis threaded rod may not be sufficient to keep the X axis level. For this reason I would also recommend implementing a dual Z-Axis motor solution. Ender Extender sells a kit for this, or you can find similar kits on Amazon. I do not believe these are absolutely required (so far), but I still think they are a good idea.

Other than these points, my experience thus far with the Extender kit is very positive. I’m still taking small steps to get my printer back to full operational state, but this cautious approach is NOT reflective of the kit itself. Rather it reflects on my process and knowledge level.

I am VERY eager to print something that makes use of that new print area. However I know that larger prints require good tuning and troubleshooting, so I am taking my time to get everything right. I am strongly considering getting the Extender 400 Z kit or 500 Z kit to increase the Z height to 400 or 500 mm from the default 250mm. But one change at a time..

I fully recommend the Ender Extender kits to any Ender 3 owners who are looking for a larger print area without paying even more for a larger printer.


Shortly after posting this I came across the Wham Bam Systems site. They list multiple flexible build surfaces of various sizes. The size in particular that would fit my bed — 410mm X 410mm — is listed in a few different options. It looks like it will cost $285 CDN to get the flexible spring steel with PEX, direct from their Canadian distributor (much cheaper shipping options). This looks like the “right” solution but is still rather expensive for my needs. So this will become a “wishlist” item until my usage patterns fully justify that extra expense, or until I find a cheaper alternative.

Technology enthusiast

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store