Microtrenching 103: how to choose the right vacuum system and cutter wheel

Having the right equipment for the job is an essential part of planning. If you show up with the wrong gear or without enough material, you’re losing productivity before you’ve even started. To help you prepare what you need for each microtrenching job you take on, you’ll have to consider the right vacuum system and cutter wheel.

When it comes to vac systems and cutter wheels, there are a lot of options and sizes to choose from. Which one is right for your operation? A breakdown of the different wheels and the considerations for vac systems is needed to help you make an informed decision.

Vac system considerations

First, let’s talk about vac systems. Part of planning every microtrenching project involves figuring out what you’re going to do with the dry spoil. A hose from your microtrenching attachment to a connected vacuum excavator can cleanly remove and contain the spoil, allowing you to take it away from the jobsite while you’re microtrenching. But in order to do that, you need a vacuum excavator and a system or process in place.

When it comes to vac systems, there are a couple things you should consider:

1. For microtrenching, you’ll want to choose a vac system that has at least 900 cubic feet per minute (cfm) (25.5 m³/min). Typically, this will be a trailer vac, like the Vermeer LP SGT vacuum excavator, which has 1,000 cfm (1,699 m³/hr).
2. Keep in mind how far away your dumpsite is. If you have to haul it a long distance, think about upgrading to a bigger spoil tank to lessen the number of trips to the dumpsite.

“This is where process can play a key role,” said Ed Savage, Vermeer product manager. “What’s your process for taking the spoil tank to the dumpsite and back? How many trips do you want to have to take? These answers can play a large role in deciding how big of a vacuum excavator or spoil tank you’ll need.”

Cutter wheel options

When it comes to cutter wheels, you have two main options, but there’s variety within those two options and both are compatible with Vermeer ride-on tractors.

First, there’s the microtrencher MTR12 attachment. It has a maximum trench cutting depth of 12 inches (30.4 cm) and a width of 2.3 inches (5.84 cm). There are two varieties of the MTR12 attachment to choose from:

1. Vermeer custom rotary-welded segment – 14 mm .550 tooth. This Vermeer-patented welded segment wheel has fully machined pockets to allow you to optimize all the tooth angles for maximum performance and tooth life. It’s well-suited for cutting asphalt and medium concrete. There are three different sizes of cut to choose from with this cutter wheel: 1.5-inch (3.81-cm) cut, 1.75-inch (4.44-cm) cut and 2-inch (5.08-cm) cut.
2. Vermeer bolt-on PDC cutter. This wheel is considered a cutter mount and has 21 mounts on it. It’s only recommended to be used for asphalt, not concrete. It comes in two different sizes of cut: 1-inch (2.54-cm) cut or 1.5-inch (3.81-cm) cut.

Then, there’s the microtrencher MTR16 attachment. It has a maximum trench cutting depth of 16 inches (40.6 cm) and a width of 2.25 inches (5.7 cm). There are also two varieties of the MTR16 attachment to choose from:

1. Vermeer custom rotary-welded segment – .550 tooth. This Vermeer-patented welded segment wheel has fully machined pockets to allow you to optimize all the tooth angles for maximized performance and tooth life. It’s well-suited for cutting asphalt and medium concrete. There are three different sizes of cut to choose from (also like the MTR12 attachment): 1.5-inch (3.81-cm) cut, 1.75-inch (4.44-cm) cut and 2-inch (5.08-cm) cut. The difference from the MTR12 is that this one requires more teeth on the wheel and can cut deeper.
2. Vermeer bolt-on PDC cutter. This wheel is considered a cutter mount and has 24 mounts on it. It’s only recommended to be used for asphalt, not concrete. It comes in two different sizes of cut: 1-inch (2.54-cm) cut or 1.5-inch (3.81-cm) cut.

“Similar to the vac system, pick the size and kind of cutter wheel that will work best for your operation,” explained Savage. “Are you working with mostly concrete? Then the segmented wheel might be the right call. Will this job be asphalt? If you’re cutting only asphalt, then a PDC wheel would be a good choice.” When it comes to vac systems and cutter wheels, there are several different kinds and sizes, but knowing the options that are available can help you make the right decision. For more information on this microtrenching equipment, contact your local Vermeer dealer today.

Vermeer Corporation reserves the right to make changes in engineering, design and specifications; add improvements; or discontinue manufacturing at any time without notice or obligation. Equipment shown is for illustrative purposes only and may display optional accessories or components specific to their global region. Please contact your local Vermeer dealer for more information on machine specifications.

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