FAQs on Self-Tuning Mass Dampers
If Assembly Instructions, Application & Design Specs and our Product List are of interest, you probably have questions about tool holder selection, installation, troubleshooting and more. That’s why we’ve complied a list of FAQs that should help you get the most out of your machine tooling.
How do you select a tool holder?
Tool holder selection depends upon sizes of the components you’re going to machine. Large-diameter tool holders are most preferable because they offer higher rigidity. If your workpiece has an internal ID of 20mm (0.787 inches), for example, it can only accommodate a 16mm (0.629 inches) bar to avoid colliding with the work piece.
After selecting the correct-diameter tool holder, you need to consider the tool’s overhang length. Less overhang length means higher rigidity, and you need: a) enough tool holder length to process the part and b) enough tool holder length to connect effectively to the spindle (tool turret in turning machines). The length needed to connect a tool holder to the spindle depends on the type of coupling method available, such as mechanical, hydraulic or shrink fit.
A standard MAQ product can cover a length-to-diameter (L/D) ratio of 8 or 9. In the case of longer overhang length, a special tool (soon to be standard) with an L/D ratio of 10 or -11, NS even up to 14,is required.
How do you install a tool holder on your machine?
To install a MAQ tool holder on your machine, it is best to use an adapter for mounting the tool, via means of mechanical-screw clamping, hydraulic clamping or shrink-fit clamping. Generally, when installing an adapter, avoid using a screw to engage with the toolholder surface as a clamp because direct contact may damage the dampening system and will cause the tool holder to vibrate.
During installation, make sure the cutting point is aligned with the center line of the machine. Either measure the cutting point manually or use a level that can be installed on cutter head to check the cutting point’s horizontal alignment. It is also a best practice to use in-machine or stand-alone measuring and aligning devices where available.
How do you troubleshoot a problem with your tool holder?
Vibration can come from the tool holder or the machine, and it is often difficult to pinpoint the source. Every tool has a preferred operating condition, which normally refers to the L/D ratio range for which the tool is best suited. For mass dampers to function well, it is necessary to match the mass damper’s frequency with the machining tool’s vibration frequency. The problem arises when the machine tool’s vibration frequency becomes un-predictable, as it depends not only on L/D ratios, but also on the machine itself and other parameters.
Normally, reducing the L/D ratio will increase tool rigidity, thereby reducing vibration. However, there are also cases when reducing L/D ratio increases cutting tool vibration because a lower L/D setup may make the cutting tool vibrate at a frequency outside the frequency range where the mass damper is optimized. We often observe this situation when using tools with a diameter smaller than 16mm, where the change of L/D ratio dramatically changes vibration frequency. For example, a 16mm tool can have a vibration frequency of about 700Hz at 5XD and 500Hz at 6XD (a change of 200Hz per unit change of L/D ratio) whereas a 25mm tool has a vibration frequency of about 500Hz at 5XD and 450 Hz at 6XD (a change of 50Hz per unit change of L/D ratio).
Because many variables determine a tool holder’s effectiveness for any given application, it’s best to consult the MAQ team if you have questions about the operation of your tool holder.
How do you keep your tool holder in top working condition?
To maximize the effectiveness of your tool holder, it should never operate at a temperature above 100°C (212°F) because overheating reduces effectiveness and accelerates aging of the tool holder’s internal components.
How do you know when your tool holder needs to be replaced?
Tool holder life depends of frequency of use, environment, and many other factors. Although MAQ tool holders do not have limited tool life or shelf life by design, when your tool holder begins to malfunction under conditions in which it has successfully performed in the past, it’s time for a replacement.