3D Printing Capabilities

MJ Engineering has both a metal and plastic 3D printer with very different capabilities. The Markforged Metal X can print Copper, Tool Steel, and Stainless Steel while the Mark 2 printer uses Onyx, a nylon based filament with reinforcement. This printer can reinforce with Carbon Fiber, Kevlar, and Fiberglass materials. MJ Engineering initially used the printers for prototyping and simple bracket mounts, but we have found the strength and quality of the prints could be used more extensively in our projects. We are now printing spare parts, upgrades and finished products for current and past projects. This has directly affected MJ’s ability to reduce the cost and lead time for projects.

For our most recent project, we utilized the Mark 2 printer for numerous parts. We printed the EOAT gripper fingers, a funnel assembly for placing the straws into the bottles, and a complex design for spring-loaded bottle crowders. For more information on the usage of the 3D printed parts see the pick and place straw cell article (Click here).

A powerful capability we have with our printers is the ability to insert hardware into the parts. Hardware such as nuts, bolts, pins, and springs can be embedded in the part. This can allow complex designs that would be impossible to machine, but make assembly easier, isolate wearable features, or add functionality directly where you need it.

The ability to 3D Print ready-for-use parts has expanded MJ Engineering’s capability to reduce lead times and costs for customers’ projects. We keep finding innovative ways to design and use 3D printed parts to create solutions for difficult problems. To see if the printer could help you and your company, please contact us today for a quote and print.

Introducing Metal X




Metal X is a 3D Metal Printer that can Print:

-17-4 Stainless Steel

-D2, A2, H13 Tool Steels




MJ Engineering Knows 3D Printing!

In addition to their fused deposition modeling (FDM) desktop 3D printer (see 3D Printer Series—Part 1), MJ Engineering also owns a stereolithography apparatus (SLA) desktop 3D printer. The SLA printer from formlabs is used to make parts for test fits and dry runs.

3D printing materials-SLA

The SLA printer uses photosensitive thermoset polymers in liquid form. An ultraviolet (UV) laser beam selectively hardens (cures) the polymer resin, layer-by-layer, through a process called photopolymerization, which creates strong unbreakable bonds. As the part is being built, the build platform rises, lifting the part upward, out of the resin bath.

Is an SLA printer worth it?

Although the FDM printer can make parts that are stronger and more durable, the SLA printer is ideal when high accuracy or a smooth surface finish is desired. The SLA printer excels at tight tolerances, to the tune of plus or minus one thousandth of an inch—10 times more precise than the FDM printer.

3D printing materials-FDM

MJ Engineering’s Markforged FDM desktop 3D printer builds parts using a black thermoplastic filament called “Onyx,” which is primarily used when parts are needed to check form, fit, and function. The Onyx plastic can be reinforced with different continuous fibers, depending on the intention for the part being printed. Some examples of fill materials used with Onyx are:

  • Fiberglass—basic, cost-effective reinforcement material
  • High strength, high temperature (HSHT) fiberglass—to maintain strength in high-temperature settings
  • Carbon fiber—to withstand fatigue and improves stiffness and strength
  • Kevlar—to endure high impact and high deflection applications

To add the reinforcement material, the 3D printer uses two different nozzles. One nozzle dispenses plastic (Onyx), while a second nozzle dispenses the reinforcement material in the locations specified by the software. Typically, the reinforcement material is internal to the part and is enclosed in plastic.

Putting parts together

If a part fits within the parameters of the printer’s build plate and height restrictions, it can be printed as one piece. Otherwise, it can be bolted or glued. For example, as a test for a machine MJ Engineering is working on, a part like the one pictured here can be printed out of Onyx on the FDM printer in two pieces and then superglued. Once the finalized design is determined, the printed part can be bolted to the actual machine. “We can make sure it works the way we want it to and there are no flukes,” says mechanical engineer JC Kraml, “before we send it to our machine shop and spend 100 times more.”

To discover more methods by which MJ Engineering is using 3D printing to improve its projects, parts, and processes, check out Part 3 of our 3D Printer Series.

MJ Engineering’s New 3D Printer Adds Value Every Day

When you design custom machines like MJ Engineering does, things don’t always go as planned. That’s OK. Their engineers are experts at solving problems and improvising when necessary. Nonetheless, making customer design changes partway into a project can cost weeks on the schedule and thousands of dollars in parts. To reduce such risks and be more responsive, MJ Engineering recently purchased a Markforged desktop 3D printer.

How it works

The fused deposition modeling (FDM) printer heats a thermoplastic filament to its melting point and extrudes it through a nozzle, layer by layer, to create a threedimensional object. Precisely following a design in a computer program, it can print production-ready parts that are strong, rigid, and durable.

Is having a 3D printer worth it?

“There are great benefits to using these,” says mechanical engineer JC Kraml, one of MJ Engineering’s resident experts at 3D printing. He praises their new printer for helping avoid project bottlenecks, saying, It’s fantastic at quick fixes and helping move projects along; it’s great to have for that purpose alone.

A few of the 3D printer’s many applications include:

  • Rapid prototyping
  • Concept modeling
  • Making replacement parts

Kraml recently used the printer to build a prototype part for a speaker installation jig. It enables us to fail faster,” he explains, meaning we can quickly solve problems that may arise during the design or assembly process. And we save time and money because we manufacture parts inhouse.

Before purchasing the FDM printer, MJ Engineering relied heavily on their machine shops to make parts. After getting the part, which would typically take weeks, there was still a chance it wouldn’t work, meaning more expense and more waiting.

Our new 3D printer allows us to respond rapidly,” says MJ Engineering President Richard Wand. “If a part doesn’t work, or it doesn’t fit the first time, we can tweak the design, reprint it, and have a new part in a matter of hours.”

Despite its advantages, the 3D printer is not going to replace MJ Engineering’s machine shops any time soon. Larger parts and parts that need to be made of metal will still be fabricated elsewhere, at least for now. In the long term, Wand says the new printer will be good for his company.

It will be good for MJ Engineering’s customers, too. In addition to printing prototype and production parts for their own projects, they can print parts for others who may not have enough need or know-how to make a permanent investment in a 3D printer.

Suffice it to say, MJ Engineering’s new FDM 3D printer adds value with every part it prints!