MendelMax 3 3D Printer Review

If you have used or read our reviews of the Makertoolworks printers; MendelMax 1, 1.5 and 2, this new version is nothing like your usual RepRap-style printer. Unlike its predecessors that have off-the-shelf fasteners and rails, and many printed parts, this MendelMax 3 3D printer comes with many custom sheet metal parts.

The MendelMax 3 printer comes in a beautiful, powder-coated black color and has many OpenBuilds V-slot profiles. The metal parts, together with the profiles, give the printer quite some weight.

For this MendelMax 3 review, we used the all-out dual extruder version. This printer has a 250 x 315 x 200mm build space, two E3D v6 hotends and a heated bed running off of the 24V supply. The printer is controlled by an authentic Ultimachine RAMBo, has matching rails on all axes, and OpenBuilds Extreme Solid wheels. This machine also has some LED lighting that acts as a smart status indicator.

MendelMax 3 Review Guide

  • Introduction to MendelMax 3
  • Building the MendelMax 3
  • Design and Features of the MendelMax 3
  • Reviewing the Mendel Max Software
  • Printing with MendelMax 3
  • Conclusion and Recommendation

MendelMax 3 Build Guide

MendelMax 3 doesnít come as a ready-to-use printer. Instead, it is a printer kit that you have to build from scratch. Setting it up is pretty interesting. You will only enjoy the setup process if you love assembling printers and wonít mind spending hours on it. We spent 5 hours to get the printer set up.

Most parts of this printer kit are machined. Therefore, assembling them is no big task as they almost perfectly fit instantly. Every sheet metal part has spot-on tolerance with no sharp edges. The OpenBuilds V-slot profiles are cut to the required lengths, are straight, and well anodized. A high quality hex wrench is also provided.

The only pieces that were troublesome for us were the few printed parts, some of which needed their holes reamed.

The MendelMax 3 printer kit has so many fasteners; t-nuts and regular nuts, washers, and screws. The good news is that there are good quality wrenches to help you with them. Therefore, although building the printer is challenging, itís a lot of fun.

The setup instructions provided are however a letdown. The instructions arenít very clear and you may find yourself redoing several steps. For example, you may end up assembling some parts in the wrong sequence or assembling stuff mirrored.

According to the instructions, you are sometimes required to use no washer or maybe one or two washers for specific sections. However, when you continue reading ,you donít get supporting information. Sometimes, you find a contradicting instruction. Towards the end of the instructions, some sections are only written ìassemble this part.î

All in all, we managed to set-up the printer correctly despite lacking clear instructions and images, especially for some of the sub-assemblies. Therefore, youíll have to hack the setup, especially considering that most of the parts will easily fit perfectly together.

If you are a newbie and need support, check out Makertoolworks web support platform. Thereís an IRC channel that always has a Makertoolworks support person available to help. You might have to wait for several minutes for an answer, but this is definitely faster than logging your question into some anonymous support ticket system that will redirect you to some customer support agent in India or something. We hope Makertoolworks will produce an improved guide soon.

If your 3D printer kit comes with some missing parts, your assembly may take longer. Our printer was shipped without some washers and metric screw. Luckily, we always have some of these in our studio.

MendelMax uses 100% metric parts. However, there are parts from the second extruder kit, sheet metal parts and corner brackets that we couldnít easily replace.

Mendelmax 3 review: the assembly

Design and Features of the MendelMax 3

After finishing the assembly part, your next task is with the bed. The whole assembly is basically clamped onto the bed platform with three brackets. One of the brackets is fixed while in the other two, thereís a screw below which allows you to adjust the height. The bed has a Kapton heater stuck to an aluminum heat spreader and a glass sheet on the top.

Adjusting the bed is the real challenge when setting up the printer. You have to adjust the screws from below the printer and only when the nozzle is on the opposite side of the spot youíre trying to adjust to the correct height. This is obviously a poor design. Moreover, tramming the bed takes way longer than should be the case.

Makertoolworks should have included an inductive sensor in this printer to do all the tramming jazz. Doing this would not only have made the assembly process a lot easier, but also have been fair for the person doing the building.

All in all, the MendelMax 3 printer full design is unique and canít be found in most other full-size printer kits in the market. The only complaint in the final-assembled printer is the bed.

The printer layout provides all the essential components you need to start your printing. Other items that you donít necessarily need have been omitted. Weíre talking things like filament guides from the printhead to the spool mounts, air guides for the part cooling fans, fan mounts and even drag chains. All covers for the mains wiring inside the printer are also not included.

Important: While the instructions donít advise you about the exposed mains wiring inside the MendelMax, you should add some electrical tape over them. Alternatively, be extremely careful when reaching below the frame because itís very easy to get your fingers on those.

Covering the mains should therefore be at the top of your upgrade list with this printer. You can print the other items like drag chains, piece by piece as you continue tailoring your printer to your preferences.

mendelmax 3: adjusting the bed

Mendel Max Software Review

When it comes to the software, the MendelMax 3 runs a customized version of Marlin to support those LED strips. The LED strips have their own Arduino and back power supply to control them.

The host provided by Makertoolworks is the branded and licensed version of Repetier Host. Although this host software is sometimes confusing to get into, it really does a good job. The installer features a Slicr3r profile and it gives you the freedom of using it even without the Repetier host software.

The default profiles make an excellent starting point. A small amount of tuning on the minimum layer times and the retract settings would have made a big difference. The good news is that you can customize and tweak the settings to come up with something favorable.

The default profiles donít have things like optimized extrusion widths for the first layer or custom start gcode. However, they work just fine without these.

mendelmax 3 repetier

Printing with MendelMax 3

The extruder-hotend combination of the MendelMax 3 machine efficiently prints with Nylon, PLA, or ABS material. Perhaps, in place of the brass drive gear that has been used here, a stainless steel filament drive gear would have performed better and been more durable. However, the printer works just fine as it is. The print results are however somewhat shoddy, which shows that the core mechanics of this machine lack quality.

This machine features a dual extrusion V6 mounted into an aluminum holder. The holder allows you to individually clamp each of the hotends with a pair of grub screws to get them to the same height. This design makes the assembly process more complex and bulky, especially considering that the two hotends donít perfectly match up.

Printing with the dual extrusion was a flop for us. We used the stock settings and managed to print a half-hazard dual extruded part. The two-color item that we printed was disappointing.

Overall, the extruder is heavily built and complex. It also has an adjustable tension and once you get ther desired settings, you wonít need to fiddle with it any more.

The framework is compact mainly because of the OpenBuilds wheels and rails used. The rigidity of the frame is also partly due to the high-quality pulleys, belts, and motors incorporated. The Z-axis is completely stable due to the proper machining on the ends of the spindles. which make them perfectly fit the couplers. So you shouldnít expect any Z-wobble at all.

mendelmax 3d dual extrusion

Conclusion and Recommendation

By no means is the MendelMax 3 a plug-and-play printer. However, once you have successfully assembled it, you can be sure of producing decent prints.

The printer definitely needs some improvement. You could even completely convert it. For instance, if you wanted to, you could mount a Dremel-style rotary tool on it since itís beefy enough to accommodate it.

MendelMax 3 is ideal for anyone looking to upgrade from maybe an older Printrbot or a Velleman kit. However, we recommend it for intermediate or expert users. Unfortunately, this is not the best 3D printer for beginners.

Although the machine mimics high-end RepRaps, it is not a self-replicating RepRap nor a current Open Source design.

You can get the single-extruder version of the MendelMax 3 at $1,495 and the dual extrusion for $1,645. There are a lot of ways the design of this printer could have been manipulated to make this machine cheaper. However, the price is still not a deal breaker. Besides, this is a one-of-a-kind printer and there are really not many other alternatives out there.

mendelmax 3 benchy

2019 Update

This printer has matured since this review, and is worth another look. Weíve been using it for just about two years, and have only gotten happier with it.

Four major upgrades have occurred that are now standard. These have really changed the character of the machine.
1) Machined aluminum bed. No screw adjustments. Still uses a glass and aluminum/kapton heater sandwich, which works just fine. The machined bed is a huge improvement. There’s no screw leveling adjustments because there’s…
2) Automatic bed leveling. Your choice of flavor, infrared or ABL Touch. We have the latter, and it works very well. This has vastly improved print quality and reduced maintenance.
3) Dual extruder mounting upgrade. More stable, more secure.
4) The E3D V6 hot end has been upgraded (independent of MakersToolWorks) and assembly is considerably easier. (Thermistor was a real PITA, now it’s a cartridge.)

Software Change
The recommended program is MatterControl. It is easy to use and intuitive. There have also been several firmware updates.

These guys finally addressed documentation that really was very problematic. It has been upgraded by someone who is comfortable with technical writing.

Business and fulfillment model
Kits are now correctly stocked. Support now includes the ability to create a support ticket in addition to IR chat. And, they are nice guys


  • Assembly needs experienced fingers. This should not be a first project.
  • Two V rollers have cracked and have needed replacement. Not hugely expensive, but a little surprised.
  • Pulley tensioning is harder than it needs to be. Simple design change would make this easier in both the X and Y axes.


  • Consistently really good prints. We mean, really good prints. W certainly have had prints fail, but that has not been because of hardware or firmware failure.
  • MatterControl is a good program. We wish it had a couple more bells and whistles (e.g., assign different infill densities to different object on the bed) but it certainly gets the job done.
  • Massively built. Massive means stable and rigid. Stable and rigid means good prints.
  • 3D printing is a new technology. Having built the printer, we know how to fix it, upgrade it, and modify it.
  • Support is excellent.

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