Designing for FDM 3D Printing: 9 Important Tips

Posted On: May 07, 2018

FDM printing is one of the most widely used 3D printing processes. We found this article helpful when considering how to design a part to use this process from Manufactur3Dmag.com.

NavMac is able to help you design and construct your 3D model. Our in-house capabilities include two FDM 3D printers. Check out our R&D Informational Page for more information on our services.

REFERENCES

Manufactur3D Magazine. (2018. April 24). Designing for FDM 3D printing: 9 Important Tips [Blog Post]. Retrieved from  https://manufactur3dmag.com/designing-for-fdm-3d-printing-9-important-tips/

Newly Designed Dust Collector for Odysseus Saw

Posted On: April 26, 2018

At NavMac, we take pride in providing quality products. This means continuously improving our products to fit our customer needs. One of our customers wanted to keep their shop area clean and requested a better dust collecting apparatus for the Odysseus Saw. Our product design team got to work and completed the dust collector within two weeks of their request.

The dust collector consists of a 55 gallon drum with one pipe connecting to a vacuum and another opening at the end of the abrasive saw blade.

This design created the airflow needed to draw airborne dust and particles into the bin. A metal frame was also specially designed to allow the drum to move up and down with the saw. Our tests determined that with the newly designed dust collector, we were able to reduce airborne dust and particles by up to 90%.

For more information, visit the Odysseus Product Page on our website.

How Do You Measure Temperature During Welding?

Posted On: April 09, 2018

Temperature Sensors

Below are the most widely used temperature sensors used today in welding.

Temperature-Indicating Crayons

Temperature-indicating crayons are a popular and economical method used by welders to measure temperature of the base metal. The weld area is marked by these crayons. Once heated, the material will melt when the metal has reached its desired temperature. A couple of disadvantages are that temperature is only controllable at one single point and it is difficult measuring overheating.

Thermocouples

Another commonly used method is the use of thermocouples. This sensor consists of two wire made of two different metals. The wires are welded at one end, creating the sensor. This is where the temperature is measured. Thermocouples are inexpensive, have a high temperature limitation and range, and are durable.  Thermocouples only measure the temperature it has reached as opposed to the surface temperature it is measuring. Unfortunately, this means that the heat needs to be conducted from the material to the thermocouple. Attaching the thermocouples to the welding surface can be challenging. Attachment methods include heat resistant tape, clamping, welding, or cement. Depending on the size of the sensor and temperature range, attachment methods may affect temperature readings.

Infrared Sensor

Most recently, there has been an increased use of infrared thermometers or pyrometers. The pyrometer captures the infrared radiation and converts it to a temperature value. Although, infrared sensors can be expensive, they are quite accurate and does not need to be in direct contact with the surface it is measuring. Furthermore, the sensor can measure the surface area of the optic focus. This results in a more accurate temperature reading.

Conclusion

Temperature plays a crucial part throughout the whole welding process. It regulates the weld’s structural integrity, as well as strength.  As the welding industry continues to grow, new methods of heating and temperature control are continually being introduced to the market making it easier for the welder to control. Having the right heating methods and temperature control tools in hand can make a difference between a successful weld and a scrapped part.

NavMac has over 25 years working with high strength metals and alloys in the manufacturing industry. We developed an easy-to-use, versatile temperature controller using an infrared reader for use with an induction heater.  The temperature controller includes a power supply, data save capabilities, touch screen controller, and programmable recipes. More information can be found on our website at Horus Temperature Controller.

Common Heating Methods Used in Welding

Posted On: April 03, 2018

In this post, we will introduce three of the most common methods used in welding to heat material – torch heating, induction heating, and electrical resistance heating.

Torch Heating

Torch heating, as the name implies, uses a gas torch to heat the specified area to a predetermined temperature. Although this method is affordable and portable, there are a few drawbacks. It is difficult to get the metal to the right temperature or get an even temperature throughout the work surface. On thick pieces of metal, the temperature does not stay constant throughout the whole welding process. Additionally, there is the possibility of carbon contamination from the flame.

Induction Heating

This is a common method using in the metal fabrication industry. Although it is a more expensive alternative compared to torch heating, it provides a quicker and more even method of heating. Induction heating works by winding a copper coil around or bordering the work piece. It uses non-contact heating. Heat is generated in the part by placing it in a high-frequency magnetic field. Induction heating generates heat inside the part by created a magnetic current that excites the part’s molecules to generate heat.

Benefits of using this method of heating is the control over the temperature of the work piece, the speed it takes to heat the part, and the efficiency of the energy used – 90% of the energy used is into heating the part versus 45% of energy used by the torch heating process. The temperature is stable and controllable generally through the use of a thermocouple.

Electrical Resistance Heating

Electrical resistance method makes use of flexible ceramic pad elements. The pads are wrapped around the work piece and heats from the outside in. The heating pads allows for temperature control in more than one area and are simpler and more durable to use in field applications. Some of the drawbacks for using electrical resistance heating is the time it takes to set-up, and the time to heat the work piece is longer.

NavMac has over 25 years of working with high strength metals and alloys in the manufacturing industry. Contact us for more information about heating your metals to the right temperature.

Why is Heating So Important Throughout Welding?

Posted On: March 28, 2018

Heating the material to be welded before, during, and after welding may determine the success or failure of a weld. This article highlights why heat plays such an important role in welding.

Importance of Heating Correctly

Preheat Temperature

Preheating can be a crucial step in many welding applications and may save you from costly rework. Adding this step is necessary when working with steels, cast irons, copper (and its alloys) and aluminum. Preheating is the process applied to raise the temperature of the base metal before welding. This is beneficial because –

  • The slowdown in the cooling rate between the weld and the base metal reduces the risk of cracking and distortion mainly through thermal stresses.
  • Thick pieces that have been preheated allows use of less heat in the welding arc as well as ensures proper heat dispersion into the weld area.

Interpass Temperature

Interpass temperature is the temperature of the base metal in the weld area immediately before the second and each subsequent pass. Preheat temperature applies only to the first welding pass but interpass temperature affects the properties of all subsequent welding passes. Thus, measuring and maintaining the interpass temperature is just as important as getting the preheat temperature right.

Post Weld Heat Treatment (PWHT)

There are two main benefits of PWHT. The first is reducing hydrogen induced cracking (HIC) and the second is stress relieving.

Components that lead to hydrogen induced cracking (HIC)
  • By heating the material after welding, it allows hydrogen to diffuse from the welded area thereby eliminating HIC cracking. In order for HIC to occur, John C. Lippold, a professor in the Welding Engineering Program at Ohio State University states that three components must be present – susceptible microstructure, tensile strength, and hydrogen. “Seek to eliminate the one [of the three factors] you can most easily control.  Avoiding hydrogen in the weld is typically the easiest to affect, followed by control of microstructure.”
  • Relieving residual stress occurs when the part is cooled at a slower rate. “Welding, in particular, because of the rapid thermal expansion and contraction created along a very localized area, is a prime source of residual stress.” states Andrew Cullison of the American Welding Society. The most commonly used method to relieve stress raising the temperature of the welded area and then slowly cooling the part.  This prevents the weld area from becoming too brittle and more ductile.

Temperature measurement and control is key to getting heating right. NavMac offers an easy-to-use temperature controller that can heat the part to the desired temperature and keep it there for as long as you need. Visit the Horus product page for more information.

References:

Lippold, J.C. (2015). Welding Metallurgy and Weldability. Hoboken, NJ: John Wiley & Sons, Inc.

Cullison, A. Stress Relief Basics. Retrieved from https://app.aws.org/wj/2001/09/0049/

Are You Using the Right Tool for Cutting Metal?

Posted On: February 15, 2018

Having the right tool for cutting metal is crucial to any manufacturing process. Whether its resources spent on materials or labor, you want to make sure it’s not wasted.  But which saw is the best one for your needs? We took some time researching three types of saws widely used in today’s industries and compared them to the Odysseus Revolutionary Saw:

Band Saw

The band saw dates back to 1809 when a British man named William Newberry patented the idea. The tool was originally designed to cut wood for furniture but has since evolved and is now used to cut a variety of material.

A couple of advantages for choosing the band saw would be its ability to cut large work pieces and its ability to cut through a variety of material. Unfortunately, the accuracy of the cuts are not tight and the process can be very slow.

Fun Fact: In 1941 during World War II, Popular Mechanics published an article on how to make your own tools. One of the tools was the band saw.

Cold Saw

A cold saw uses a circular toothed blade to chip metal away from the work piece. The process allows the heat generated during the cutting process to be transferred to the metal chips. The cold saw is best used when cutting smaller pieces of metal tubing, or solid material and can be used to cut more accurate pieces.

The biggest drawbacks of using a cold saw is the limited size of the work piece and the use of a coolant or lubricant needed to keep the blade cool. The cut edge also exhibits burrs.

Fun Fact: Many people have claimed to be the inventor of the circular saw. Gervinus of Germany is credited with the invention but others from England, Germany, and Holland have also claimed to have invented the tool.

Abrasive Saw

Abrasive saws use a different blade from the band saw and cold saw. Its blade grinds down the material rather than “cutting” with saw teeth. The abrasive saw has the ability to cut metal to a tighter tolerance and can be used on harder metals.

A couple of the disadvantages when using the abrasive saw are the operating noise and the heat generated on the work piece which can cause work hardening or cracking.

Fun Fact: In the 13th century, the Chinese used seashells “glued” onto parchment as an abrasive material. 200 years later, the Swiss used paper coated with crushed glass.

Odysseus Saw

Merriam Webster defines revolutionary as 1) motion of any figure about a center or axis and 2) a changeover in use or preference especially in technology. Odysseus is properly termed “revolutionary saw” because it uses a completely unique way of cutting metal unlike any of the saws above.  Odysseus rotates the work piece as the blade is lowered. This allows for several advantages:

  • The diameter of the workpiece no longer determines the size of the blade. You can cut larger pieces with a smaller abrasive blade.
  • Due to the circular motion of the workpiece, the cutting time is also determined by the wall thickness of the workpiece. The reduced cutting time minimizes the heat generated on the blade and on the workpiece.
  • Reduced heat generated means there is no need to use a lubricant or coolant.

Fun Fact: The Odysseus saw is named after the legendary Greek hero.

Visit the Odysseus page on our website for more information or take a look at the PDF comparison sheetIt’s time to revolutionize your metal cutting process.

Why Work Hardening Should Scare You

Posted On: February 07, 2018

Work hardening is often an unintentional part of the machining process, where the cutting tool generates enough heat in one area to harden the work piece. This makes for a much more difficult machining process and can lead to scrapped parts, broken tools, and serious headaches. Read the full article by Harvey Performance Tools.

Using our revolutionary saw, the Odysseus, reduces the time and heat applied to the work piece and can reduce or eliminate work hardening in certain alloys.

How Can Odysseus Saw Save Us Money?

Posted On: January 29, 2018

Using a patented technology, the Odysseus saw can save you time and money. The work piece rotates as the saw lowers a blade for cutting. This equates to several advantages over traditional cutting methods:

  • Purchase a smaller blade to cut large pieces, as the blade only needs to pass through the wall thickness of the part
  • Reduce cutting time by up to 50%
  • Eliminate work hardening and cracking in certain alloys
  • Shorten post machining time with the smooth cut surface
  • Specify a cut length and the machine will automatically cut to length needed.

Check out how the Odysseus Saw can start saving you money!

Welcome to NAVMAC!

Posted On: May 25, 2016

We’re so glad you’re here!

Please feel free to browse the site and contact us with further questions!

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