CNC spindle maintenance is treated as a dirty, boring and often overlooked job. A clean spindle is essential for proper taper contact between the spindle and V-flange toolholder. Build-up of chips, dust, and oil in the spindle can jeopardize taper contact and result in premature wear, repair downtime and even CNC machine breakdown.
Ultimately, breakdowns cause production to stop and the ensuing costs are high since no parts are being produced. The most cost-effective way to increase your daily CNC machine productivity is through proper maintenance−ensuring optimal toolholder to spindle contact. A breakdown’s true cost can conservatively be projected from five to 15 times simple maintenance costs.
It’s important to note that all V-Flange tooling is designed to fit the spindle taper within tolerances of 0.0001”. Any debris, in the form of dust, grease, chips or other contaminant left on the spindle, taper or flange can cause poor TIR, poor tool life and poor tolerances.
Recognizing that a clean, smooth spindle surface is essential for proper taper contact between the spindle and v-flange toolholder, JM Performance Products Inc. has developed its advanced Spindle Cleaner Kit and Spindle Restoration Kit.
The spindle cleaners and spindle restoration tapers are made from anodized aluminum that will not collapse in the spindle during use. They also come with removable handles that can be used with all cleaning and resurfacing head tapers.
Designed to remove loose oil, debris, and other contaminants from CAT and BT spindles in 30, 40, 45, 50 or 60 taper sizes, JMPP’s Spindle Cleaner Kit includes:
▪ 1 or 2 AT3 precision tapers
▪ Removable Handle(s)
▪ 16 oz. Bottle Degreaser
▪ Fabric Cleaning Strips
▪ Lint Free towels
▪ Carrying Case
JMPP’s Spindle Restoration Kit (pictured), designed to remove high spots attributed to debris and rust that has galled to the surface of the spindle and cannot be removed through cleaning, includes:
▪ 2 Precision Taper Restoration Heads
▪ 2 Spindle Restoration Handles
▪ 16 oz. All-purpose Cleaner
▪ 4 different micron finishes of material strips
▪ Carrying case
Note: Both kits include complete instructions and there are JMPP “how to” videos for both processes on their web site.
S&S Tool Inc., Conneaut, Ohio, an established specialty CNC machining operation since 1985, had been experiencing ongoing crashes on its five CNC machines. President Paul Sedmak noticed there were high spots in the spindle, which caused the taper to sit unevenly. Seeking a swift solution to avoid repeated shutdowns, which could cost approximately $6,000 per machine, Sedmak contacted JMPP President John Stoneback, who made an onsite visit and demonstrated the Spindle Cleaning Kit’s simple process.
According to John Stoneback, the tool ran out 0.005” at 5" from the spindle face. When he inspected it, he noticed a notch at the large end, the result of a tool that had broken loose and gouged the spindle. Stoneback began by cleaning the spindle, which was heavily coated with baked on coolant, perhaps 0.005” thick. The spindle hadn’t been cleaned in 4 or 5 years. He then began resurfacing the spindle using the taper fitted with 40-micron aluminum oxide strips.
When he initially began the process, it was extremely difficult to maintain the pressure of the taper in the spindle because every time the tapered fin of the head hit the gouged area, the resurfacing head would jump and push out against Stoneback’s hand. He had to use the all-purpose cleaner to remove debris, including metal fragments, off the strips, but after about half an hour, he finally got smooth rotations. At that point, he used new strips to really shine the surface. A final cleaning with the cleaning head and towels left the spindle looking like new.
Sedmak then used a master test bar and checked the TIR, which was within 0.0001” out 10". When you consider that it would have taken a day to pull the spindle, one or two weeks to regrind it, and yet another day to reinstall the spindle, a few hours of time saved S&S Tool a considerable amount of money in terms of down time and lost production.
According to Sedmak, “The results were readily apparent and we implemented the kit into our maintenance schedule immediately. We’ve been using it for over three years and won’t go back. For a small investment, all of our machines run more efficiently, the tools run truer, and we’re saving on cutter wear.”
According to Stoneback, “The main purpose of regular spindle maintenance is to ensure that all equipment required for production is operating at 100 percent efficiency at all times. Therefore, it’s essential to implement a frequent spindle cleaning and restoration maintenance system that operators should conduct at least once per week.”
Related Glossary Terms
- aluminum oxide
Aluminum oxide, also known as corundum, is used in grinding wheels. The chemical formula is Al2O3. Aluminum oxide is the base for ceramics, which are used in cutting tools for high-speed machining with light chip removal. Aluminum oxide is widely used as coating material applied to carbide substrates by chemical vapor deposition. Coated carbide inserts with Al2O3 layers withstand high cutting speeds, as well as abrasive and crater wear.
Enlarging a hole that already has been drilled or cored. Generally, it is an operation of truing the previously drilled hole with a single-point, lathe-type tool. Boring is essentially internal turning, in that usually a single-point cutting tool forms the internal shape. Some tools are available with two cutting edges to balance cutting forces.
- computer numerical control ( CNC)
computer numerical control ( CNC)
Microprocessor-based controller dedicated to a machine tool that permits the creation or modification of parts. Programmed numerical control activates the machine’s servos and spindle drives and controls the various machining operations. See DNC, direct numerical control; NC, numerical control.
Fluid that reduces temperature buildup at the tool/workpiece interface during machining. Normally takes the form of a liquid such as soluble or chemical mixtures (semisynthetic, synthetic) but can be pressurized air or other gas. Because of water’s ability to absorb great quantities of heat, it is widely used as a coolant and vehicle for various cutting compounds, with the water-to-compound ratio varying with the machining task. See cutting fluid; semisynthetic cutting fluid; soluble-oil cutting fluid; synthetic cutting fluid.
Measure of length that is equal to one-millionth of a meter.
Secures a cutting tool during a machining operation. Basic types include block, cartridge, chuck, collet, fixed, modular, quick-change and rotating.
- total indicator runout ( TIR)
total indicator runout ( TIR)
Combined variations of all dimensions of a workpiece, measured with an indicator, determined by rotating the part 360°.
On a rotating tool, the portion of the tool body that joins the lands. Web is thicker at the shank end, relative to the point end, providing maximum torsional strength.