Factors to Consider When Retrofitting a Spindle
If your current spindle isn’t right for your application anymore, whether it’s due to higher performance requirements or new regulations/standards, it could be more cost-effective for you to retrofit/upgrade your spindle rather than buy a replacement. Retrofitting is usually less expensive, and it also reduces waste and downtime because you can still use your existing setups after your spindle has been upgraded.
The only downside to retrofitting is that spindles sometimes aren’t eligible. Some situations that would make your spindle ineligible for a retrofit are if it has severe structural damage, its design doesn’t allow for newer, modern components, or if your manufacturing process has evolved far beyond what the original spindle is designed to handle.
We recommend having your spindle evaluated before you make this decision. A specialist can help you understand what your options are and point you in the most cost-effective direction.
If your spindle is eligible for an upgrade, keep reading to learn more about some of the factors to consider.
RPM/Speed Requirements
Increasing the RPM of your spindle can be great for accommodating higher production rates, machining harder materials, and reducing the need for secondary processing requirements.
There are several ways a spindle can be retrofitted to increase its RPM:
- Upgrading its motor and drive system: Switching from standard AC motors to high-speed AC or DC motors can sometimes help the spindle’s drive system handle increased power.
- Changing bearings: Installing angular contact bearings or ceramic bearings that can tolerate increased thermal and mechanical stresses.
- Performing dynamic balancing: Dynamic balancing helps adjust the weight distribution within the spindle, which helps to minimize vibrations and maintain accuracy.
- Improving cooling systems: Higher RPM means more heat, so your spindle may need a better cooling system, such as forced air or liquid cooling.
Load-Carrying Capacity
If you need your spindle to handle heavier loads, you need to increase its load-carrying capacity. The best way to handle this during retrofitting is to upgrade the bearings, which are essential in supporting the spindle’s rotational movements while bearing the load of the machining process.
Angular contact ball bearings or roller bearings are often the better choices for increasing load-carrying capacity because they both can handle radial and axial loads effectively. The material the bearing is made from will also impact the spindle’s capacity. Ceramic bearings are often ideal for high-load applications because they are harder and more wear-resistant than steel. How the bearings are arranged in the spindle will also affect its capacity. A duplex or triplex set of bearings, configured in back-to-back or face-to-face arrangements, can increase the spindle’s ability to manage heavier loads.
Another factor to consider is that as loads increase, so does the need for lubrication. You may need to upgrade the lubrication system, too, to ensure your bearings don’t wear out quickly. Also, the spindle housing and mount may need reinforcement to handle the increased loads.
Exposure to Potential Contaminants
The environment that your spindle is in will significantly influence its performance and lifespan. If you have a newer environment that could potentially expose your spindle to dust, debris, and/or coolant, you may want to add an air purge system or upgrade to sealed bearings.
Air purge systems use a continuous flow of clean air to create positive pressure inside the spindle housing, which prevents contaminants, like metal shavings or woodworking dust, from entering the spindle. The continuous airflow can also help eliminate any heat that’s generated during machining. They’re generally recommended for high-debris environments or in high-precision manufacturing operations where even the smallest particles can compromise machining accuracy.
Sealed bearings also help prevent contamination for spindles in in dusty, abrasive, and high-moisture environments. As the name suggests, sealed bearings have seals that help both prevent contamination and retain lubricant. Since these seals help retain lubrication, they also need less maintenance.
Exposure to Moisture
If humidity levels have increased in your environment or if your operations now involve using coolants or fluids, you may want to implement sealed bearings or an air purge system, as discussed in the section above, and consider encapsulating your spindle’s motor windings.
Encapsulation involves applying a protective layer to the windings. This coating helps prevent corrosion on the metal components of the motor windings and reduces electrical hazards by blocking potential water and moisture.
Maintenance Preferences
You could also transition your spindle from a traditional grease-packed lubrication system to a more advanced oil-mist lubrication system to reduce maintenance requirements.
Over time, grease can harden or become contaminated, so it must be removed and reapplied. However, an oil-mist system will constantly provide a fine mist of oil to the spindle’s parts and is especially essential for spindles in high-speed applications. Keep in mind that, depending on your spindle’s design, an oil-mist system might not be compatible. If you’re not eligible for an oil-mist system, you could still reduce maintenance requirements by upgrading to sealed bearings or upgrading the spindle’s shafts, collars, and housing to higher-quality, wear-resistant materials.
Mounting Configuration
Whether you need to upgrade your spindle’s mounting configuration to improve accuracy and reduce vibration, or to adapt to new machinery or processes, there are several retrofitting solutions you could consider:
- Customizing the flange to fit the machine’s interface or creating interface adapters.
- Upgrading your spindle’s brackets and housing materials to improve its structural integrity.
- Adding vibration dampers or isolators between the spindle and the mounting surface.
- Applying specialty coatings to mounting components to reduce corrosion or abrasion.
Get More Recommendations Today
If you’re interested in upgrading your spindle, contact our team at Superior Spindle. We specialize in repairing, rebuilding, testing, and retrofitting CNC spindles from many manufacturers, including Kessler, Chiron, DMG Mori, and Mazak, and take pride in providing industry-leading engineering recommendations. Our experts can help you understand which upgrades might be best based on your new application requirements.
Complete our online form today to get started.