Last year, I bought a 3D printer. Since then, 3d printing has become a bit of an obsession. I’ve owned quite a few printers over the last year and I figured it’s time to do a run-down and some recommendations. In this post, I’m looking at the SeeMeCNC RostockMAX v4.

Summary: A great (but proprietary) workhorse printer

The RostockMAX v4 was my upgrade from the Monoprice Mini Delta. (Yes, I’m pretty sure the Rostock can print a full size model of the MPMD.) My criteria at the time were pretty simple: Must be a delta, must come fully assembled. I was still very new to 3D printing and I knew I wasn’t ready for something that required a lot of hand holding. The options, particularly in 2019, were limited. Really, the Rostock was the only choice.

The “Rostock” delta printer was originally prototyped in 2012 by Johann Rocholl, named after the city of their birth in Germany. The RostockMAX is a variant produced by SeeMeCNC, after a successful IndieGogo campaign. Since then there are have been three major revisions, all sold as kits, with open designs. The RostockMAX v4 is the first model from SeeMeCNC that is not an open design. Kits are not available and the printer is only available in “ready to print” form directly from SeeMeCNC.

Hardware-wise, the RostockMAX v4 is a Duet v2 Wifi controller, a custom-built hotend, and SeeMeCNC EZR Struder extruders. If one wants, SeeMeCNC sells a dual extrusion kit which I got with mine. Mesh bed compensation is handled by a custom strain gauge in the hotend, similar to the Duet Smart Effector.

I wanted a workhorse delta printer that I didn’t have to think much about. The RostockMAX v4 is certainly that. Out of the box, you hit the “FIRST PROBE” macro on the built-in LCD display and watch the printer auto-calibrate. Then you print stuff. It’s that easy. And since it’s a delta with an unmoving bed, as long as nothing physical changes, you never need to calibrate again. If you change the nozzle, you can run that original macro again and keep on going.

The Duet control board is brilliant and extremely well supported by the community. I miss some octoprint plugins with it but the software is solid and works right out of the box. All the SeeMeCNC “customizations” are in the form of macros provided on the sd card so you can upgrade to the latest firmware with no unusual problems. The LCD up front is clear and easy to use and has a built-in SD card slot.

Printing

The only printing issues I have with the RostockMAX are common to all deltas.

It has a very long bowden tube, nearly a meter long. This leads to big retractions (somewhere between 3mm and 4mm is typical) and stringing problems. Flexibles are almost impossible even though the hotend is more than capable as the filament compresses and rotates in the tube.

The MAX can print fast, on the order of 200 mm/s steady state. Travel speeds can be over 300 mm/s. Thing is, printing that fast is actually a problem. Prints become really inaccurate; corners round out; stiffer filaments must be printed a lot hotter to keep them flowing. If you want high quality prints, you’ve gotta print slower, on the order of 60 mm/s. But if you don’t give a shit, for instance in protoyping, then you can crank out prints very quickly.

These issues are common to every delta and should not be held against the MAX. I mostly mention them for expectation management in case someone lands here who is new to deltas.

Beyond those minor nits, the MAX can handle pretty much anything you can throw at it. I don’t think the hotend is rated high enough for Nylon or PC or any of the fun stuff but it can certainly handle PLA, PETG, and ABS. Out of the box, the MAX comes with a brass nozzle but SeeMeCNC also sells stainless steel nozzles for more abrasive filaments.

Proprietary Hardware

Herein lies my major concern with SeeMeCNC’s printers. They are chock full of proprietary hardware. There are three major subsystems to consider.

The Power Supply

The PSU is a 24V 10A unit that lives in the base of the printer. It is of unknown origin. Of all the pieces, this is the one that can probably be swapped out with an alternate vendor with minimum consequences. However, it is important to note that the SeeMeCNC PSU has mounting holes drilled so the unit slots into the Rostock properly. A third-party vendor is unlikely to have those holes which will lead to the possiblity of the PSU sliding around if the printer is moved.

The Extruder(s)

I am not a fan of the SeeMeCNC EZR Struder. It’s an all plastic unit with a single hobbed gear and a quick release lever. It provides minimal access to the gear and has a weirdly unconstrained filament path. It is a very long filament wide filament path up to the gear and it can be really difficult to get not-perfectly-straight filament where it needs to go.

The hobbed gear is probably the largest problem. On any extruder, the gear will gather bits of plastic over time and need cleaned. The EZR doesn’t offer easy access to the gear which makes cleaning a real challenge. It can be difficult to even see the gear well enough to know if it’s dirty. The only way to get full access is to remove the extruder from the printer entirely.

There is good news, though. If you don’t like the EZR, the extruders can be pretty easily removed, as they are mounted externally on standard nema17 motors. I replaced mine with Bondtech BMGs in a few minutes. Just remember to recalibrate your steps.

The Hotend

The MAX v4 features a SeeMeCNC SE300 hotend, a completely custom unit. No part of this can be externally sourced.

The nozzle is technically a standard M6x1 threading so it will take E3D v6 nozzles. However, the heat block itself is about 1mm shorter than a standard E3D style block. Thus, third-party nozzles stick down about 1mm further than a SeeMeCNC nozzle. That doesn’t seem like a big deal at first but that extra distance lets the filament cool a bit before getting squirted out. I’ve had no end of clogging problems with third party nozzles and stopped using them. SeeMeCNC does not, however, offer any hardened nozzles beyond regular stainless steel so working with abrasive filaments is an exercise in nozzle replacement.

As mentioned, the heat block is custom and very short. Standard silicon socks won’t fit at all. This is also something to keep an eye on when printing at high speed. The smaller block means the filament has less time to heat up. As you print faster, you’ll need to up the temperature to compensate.

The heat sink is custom as well with a inner PTFE liner. I’ve seen this advertised as an all-metal hotend but it isn’t. The bowden tube enters the heat sink via a standard connector, which is attached to an inch long piece of additional tubing. This is notable for two reasons. First, that liner means you simply cannot print super high temperature filaments. PC, Nylon, etc need not apply. Second, the connector screws into the heat sink, on top of the PTFE. If the connector is screwed too tightly, it deforms the PTFE which can constrict filament flow or provide an avenue for melted filament to escape. If the connector is too loose, the PTFE is free to move around, providing a path for both melted and pre-melt filament to escape. Getting it just right is extremely difficult.

There are ways to swap out the hotend, if you so choose. Kits exist, notably from 713maker.com, to attach a standard Duet smart effector to the MAX v4 instead of the SE300. This is extremely complicated surgery and only suitable for advanced users who are willing to rewire the controller entirely.

Summary

I know I just spent time trashing on the proprietary hardware. But the thing is, I love this printer. Yes, a bunch of the hardware is proprietary, the hotend being the biggest problem. However, SeeMeCNC supports their hardware really well, and spare parts are readily available from their web site. They even have a service where you can mail them your busted hotend and they’ll fix it up. Support doesn’t really want to talk about software and printing issues but support will chat your ear off all day about the hardware itself.

So, my recommendation? I have no problems recommending the RostockMAX v4, as long as one keeps its proprietary nature in mind. I do suggest swapping out the extruder for something higher quality like a Bondtech BMG but I’m a bit of a snob that way.