- Ease of Use
The Stratasys Mojo is a professional-grade 3D printer designed to be used in the office as easily as one would use a traditional 2D printer. Everything about it has been designed to be intuitive and user friendly. It is intended to be used as a prototype model maker, like most printers, and most of the advertising shows happy and productive engineers in the office showing off beautiful models of their work.
While the Mojo can deliver those models, the cost of doing so is far too high to ever justify making the model in the first place. If you are looking to print parts industrially, forget it; even a later-model Makerbot would be a more economically sound choice. The truth is that the Mojo is overpriced and underperforms compared to today’s consumer printers.
What’s in the Box
The Mojo comes ready to use out of the box, however there are trained technicians who can help you get it up and running on your network within an hour or so. The Mojo comes with one spool of “ABSplus” filament and their SR-30 soluble support material. Both shiny foil cartridges slot into either side of the machine and the filament is locked into place similar to the way inkjet cartridges are installed. A few removable and reusable print beds are included as well.
The Mojo also comes with the WaveWash 55, which is used to wash the SR-30 support material off of parts that couldn’t be removed mechanically (snapping it off). We will go over this machine later in the article.
The Mojo is a printer designed to only work with Statasys’ “ABSplus”, and instead of heating the print bed like most printers do, it instead heats the entire build volume. A few other printers have this feature and it is good for printing with ABS plastic, it keeps it from warping by preventing it from cooling too quickly. The Mojo features a locking door mechanism that prevents the user from opening the printer while everything is heated and possibly ruining a part by accident. The interior also features self-cleaning brushes that is uses to clean both nozzles before a print and buckets to catch the plastic that they remove so that it can be easily disposed of. The print volume itself is 5in x 5in x 5in (127mmx 127mm x 127mm) and is okay, but in the opinion of this author it is small for a printer these days.
Startasys has also included an intuitive software UI that will make printing with the Mojo as easy as printing with a traditional printer. It makes choosing the orientation of a part a breeze and selecting the amount of support material to use just as easy. Users have reported that the print time estimate is also spot on, being accurate to the minute. That feature may be the only one that this author likes.
The Bad (REALLY)
The Mojo simply does not perform as well as other printers available on the market. Stratasys also has a tendency to use units and measurements not ‘standard’ to the industry (if the term can be applied to 3D printing.) This makes comparing the Mojo to other printers more difficult, and makes some features look more impressive than they are.
For starters, let’s look at the minimum layer height. This statistic is used to measure the overall printing quality of printers the world over and is generally given in millimeters or microns (Which are 1/1000th of a millimeter). A smaller minimum layer height means a part can be more detailed and layers are less visible. The Mojo is listed as having a layer height of .007 inches. This looks impressive at first until you convert it into millimeters, where it turns out to only be .178mm (or 178 microns). The average minimum layer height on the market today is .1 mm (100 microns), with some FDM machines being able to reach 20 microns or less.
Next we have the print speed. It is “faster” than other “genuine FDM machines”, that is all Stratasys ever gives you. The print time estimate is accurate, however the one video that shows a part and it’s respective print time showed that it was printing slower than 100mm/s.
Then there’s the plastic cartridges. They are supposed to be easy to use and provide “80 cubic inches of material”.
Once again we have the odd units. Traditionally plastic spools are listed by weight, and typically come in spools of 1lb, 1Kg, or 5lbs. After digging through the MSDS of Statasys’ “ABSplus” (to be referred to as just ABS from now on because that’s what is) to find the density of their product, it turns out that 80 cubic inches of ABS is 3lbs, or about 1.36Kg. This will let you print for longer than a normal 1kg ABS spool would otherwise let you, but for anyone who will be printing enough to offset the cost of the printer (which will be covered in the next section), this spool will likely last around a month or two at most.
The cartridges come with a few more brilliant features that are a good idea on paper, but utterly useless in the real world. The first is a chip that counts how much plastic is left on the spool inside the cartridge. The chip tells the printer how much is left and whether or not the print can be completed. When the chip senses that there is zero plastic left, the cartridge will not work any longer and need to be replaced. There is no resetting the chip or refilling the cartridge’s spool.
The second feature is a new hot end with every spool. By including the hot end with the plastic, Stratasys claims to be preventing wear and tear normal hot ends go through and ensures that you always have a fresh hot end. This is a lie. Typical brass hot ends do not wear when plastic is pushed through them; the brass is too hard, it’s simple material science. Hot ends wear down when they are crashed into metal or glass beds and gummed up with tape, inferior plastics, or specialty carbon filled plastics. This author has had the same two brass hot ends for two years now and both work perfectly well despite crashes and clogs. The only reason there are two is to switch nozzle sizes.
Speaking of cartridges, you better be sitting while you read this next part, because there’s a reason this section is called the ugly.
Are you seated comfortably? You’ve been warned.
Each cartridge of ABS and SR-30 is extremely expensive compared to most other brands.
By now you are probably wondering what the WaveWash 55 is. The WaveWash is Statasys’ machine for removing their proprietary SR-30 soluble plastic support material that couldn’t be snapped off by hand at the end of the print. The WaveWash uses hot water and a detergent tablet to gently dissolve the SR-30 support material over the course of its EIGHT HOUR cycle.
To really appreciate how inefficient this is, let’s look at the power consumption of both the Mojo and the WaveWash. The Mojo uses 6 amps at 120 volts (720W) or 2.5 amps at 240 volts (600W), while the WaveWash uses 7 amps at 120 volts (840W) or 4 amps at 240 volts (960W) This means that the WaveWash uses more power than the printer itself and for any part that took less than 9hours and 20 minutes to print on 120 volts (or 12 hours 48 minutes to print on 240V), you would end up expending more energy to clean the part(s) than to actually make them.
Frankly the WaveWash 55 is another scam. The SR-30 that is used could easily be replaced by more commonly available support materials, for example HIPS. HIPS is a plastic that dissolves in Limonene and is already used with ABS as a support material.
The Stratasys Mojo looks like a good printer at first, but in the end it is an extremely over-priced, underperforming machine whose costs far outweigh any conceivable advantage it may have in the 3D printing market. This is not a printer for hobbyists, and I wouldn’t want to unleash this money vampire on any shop, engineering firm, studio, or even some Hollywood-evil corporation. So here’s an alternative.
Buy 2-3 Ultimakers (with dual print head conversions) or Flashforge Creator Pros, as well as enough ABS and HIPS (Or even PLA, another popular printing plastic; and PVA, a water-soluble plastic that can support PLA) to run those machines nonstop for a full year. You will spend about the same amount of money as the Mojo, and get comparable if not better print quality on much larger parts, faster and cheaper than the Mojo could ever hope to achieve.