Key Takeaways
- Learn to make 12-inch and 24-inch EMT stubs.
- Explore how to calculate and use gain for precise bends.
- Discover essential tools and setup for accurate conduit bending.
Overview of EMT Bending
Back-to-Back 90s Explanation
Creating back-to-back 90s on EMT conduit involves bending two 90-degree angles close together. For a 12-inch stub, use the arrow on your bender. Position the arrow 7 inches from the end of the conduit to account for the bend difference. This technique ensures precise measurements, making the process efficient. Additionally, understanding how to manage gain—the extra conduit length added by a bend—can optimize your layouts.
Arrow and Star Bender Techniques
The arrow and the star are essential tools for achieving accurate bends on EMT conduit. When using the arrow, align it with the mark you have adjusted for the bend distance. For instance, a 24-inch stub requires positioning the arrow at 19 inches on half-inch conduit.
Switching to the star involves a different approach. The star mark is placed exactly where you want the bend. For a 24-inch stub, mark directly at 24 inches. The hook of the bender should face the opposite direction compared to the arrow method. Both techniques yield nearly identical results in stub height, usually just shy of 24 inches due to basic variances in bend execution. These methods are useful for ensuring your bends are plumb and properly aligned with precision tools like laser levels.
Creating a 12 Inch Stub
Using the Arrow on the Bender
To create a 12-inch stub, start by positioning the arrow on the bender at a mark seven inches from the end of the conduit. Apply firm pressure to ensure the conduit remains in place as you bend it to a 90-degree angle. Once bent, the stub should measure twelve inches.
For accurate alignment, you can use tools like a laser line to ensure every section is level and plumb. During this process, you'll notice a specific gain in length due to the bend. Measuring from the center, the gain for this setup is typically around two and 3/16 inches. This is crucial for precise conduit layout and installations.
When working on multiple stubs, using these measurements saves valuable time. Additionally, make sure to subtract any slight discrepancies—such as being a sixteenth of an inch short—from the final figure to maintain accuracy in your bends.
Detailed 24 Inch Stub Demonstration
Mark and Bend with the Arrow
To create a 24 inch stub using the arrow on your bender, you should begin by marking the conduit at 19 inches from the end. Since this is a 1/2 inch conduit, subtract 5 inches from your desired 24 inches to make your mark. Place the arrow of the bender at this 19-inch mark, ensuring firm ground contact to prevent movement. Bend the conduit to a precise 90 degrees and then check the accuracy using a laser line to ensure the bend is plumb. Expect the stub to come up just slightly short, about a sixteenth of an inch less than 24 inches. Notably, this method results in a gain of 2 and 3/16 inches on center.
Mark and Bend with the Star
For a stub using the star, mark your conduit exactly where you want the bend, in this case at 24 inches. Use the star symbol on both ends and ensure the hook of the bender faces the opposite direction compared to using the arrow. After bending, confirm the conduit is square using a square checking tool. Again, you may notice the stub appears slightly shy of the full 24 inches. This technique often provides more accuracy in positioning the bend exactly where needed, but it should result in a similar height and gain as using the arrow.
Comparing Arrow and Star Bends
When comparing the two methods, the stubs bent with the arrow and the star should exhibit nearly identical heights, both slightly under 24 inches. They share the same gain measurement, making them equally effective in terms of resulting conduit length. Both techniques have their unique advantages, with the star allowing for precise marking placement and the arrow offering a traditional approach. Consider writing the gain measurement of 2 and 3/16 inches on your bender for future reference during conduit layout.
Calculating and Using Gain
When creating 90-degree bends with conduit, understanding gain is crucial for accurate measurements. Gain refers to the extra length added to the conduit due to the bend. For a 90-degree bend, the conduit doesn't simply extend horizontally and then vertically; it gains some length.
Steps to Calculate Gain:
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Measure Your Stub:
For a 24-inch stub created using the arrow on a bender, you can expect it to be roughly 23 and 15/16 inches. This slight discrepancy needs to be accounted for in your calculations.
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Determine the Gain:
The gain is measured by placing the bender's arrow at a mark 19 inches from the end of the conduit. When bending with a half-inch conduit bender, expect a gain of approximately 2 and 3/16 inches. This is from the center of the conduit, ensuring precise alignment and accuracy.
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Adjust Your Calculations:
Always subtract the 1/16-inch shortage to ensure the final measurements reflect an accurate stub length. This adjustment helps to align the conduit over exact points using tools like laser levels for precision.
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Document Your Findings:
It's beneficial to mark this gain value on your bender handle for quick reference during future projects. Doing so can streamline your process, making it more efficient.
Using gain calculations not only optimizes your workflow but also increases accuracy when working with conduit. Remember that consistent practice and reference tools like tape measures with conduit tables can enhance your expertise.
Setting Up the Work Area
Using the Dewalt Green Cross Line Laser
To ensure precise bends, you'll utilize the Dewalt Green Cross Line Laser. Start by aligning the laser line two inches on center from the middle of your conduit. This setup helps maintain accuracy for both the arrow and star techniques.
Place the conduit such that the laser line indicates perfect alignment and level. Verify the laser line is centered on the conduit over the entire length. This allows you to quickly see if the bends meet the desired precision and helps in comparing different stub heights to maintain consistency in your work.
By following this approach, you can check the plumb and level of the conduit, ensuring your measurements hold true. The laser ensures that each 90-degree bend is accurately aligned, offering a visual guide to assist in making precise adjustments.
Precise Measurements and Verification
When working with 90-degree stubs on EMT bending, achieving accurate results requires trust in the measurements and verification tools at your disposal. Using either the arrow or the star on your bender, you can precisely control the length of your stub. By aligning the arrow at 19 inches, you achieve a close approximation of a 24-inch stub, falling a mere sixteenth of an inch short.
To ensure the accuracy of your bends, employ tools like the Dewalt green cross line laser. This allows you to verify the alignment and height of your stub against the laser line, confirming precision. Gain calculations are also crucial in understanding how much length your bend adds to the conduit. Recorded as two and 3/16 inches using the arrow method, this gain is an essential factor in planning your layout.
Marking techniques differ with the tool: the arrow involves subtracting measurements, while the star places the mark right where the bend is desired, often leading to faster setups. Make sure to document your findings, perhaps even noting them on your tools for future reference. This structured approach aids in achieving consistent, reliable results in your conduit work.
Tool Recommendations
Dewalt Impact Driver
The Dewalt 12-volt max impact driver is quick and light, offering a practical advantage for projects. While it may not be as powerful as the 20-volt max model, its lightweight design makes it a favorable choice for those who prioritize speed and ease of use. Using this tool can streamline tasks without the need for excessive power.
Klein Tape Measure
Consider the new Klein tape measure, featuring conduit bending tables right on the back. This design adds convenience, especially when performing precise conduit bending. Having the necessary tables directly on the tool can save you valuable time and reduce the need for additional reference materials onsite.
Klein and Dewalt Power Tools
Both Klein and Dewalt offer valuable products that can enhance your toolkit. The new Klein laser bubble level, for instance, provides a cost-effective solution for creating level lines, though it lacks the self-leveling feature. Meanwhile, Dewalt's 6-amp power charger charges batteries more efficiently than the older 4-amp models, allowing for quicker project turnaround.
Milwaukee Bandsaw
The Milwaukee 3 1/4 inch mouth bandsaw is noted for its lightweight and fast cutting capabilities. It offers an efficient solution for various cutting tasks. This new model promises quick and effective cuts, making it a reliable addition to your collection of tools.