The Rotobore® Rotating Spindle System can be used on any vertical ram type EDM machine. The spindle is designed around class 7 bearings to provide a rotational accuracy of .0001 " or less over 4 inches. This allows the EDMing of both perfectly round and straight holes to extremely tight tolerances. Accurate centering and alignment of the electrode is provided by the unique Centri-Tilt® system attached to the spindle head. The Centri-Tilt® allows both tilt and centering alignment to eliminate electrode runout even with the smallest wire electrodes.
Pressure or suction flushing can be performed directly thru the spindle to the electrode. The spindle head is powered by a closed loop feed back motor to produce high torque and constant speed (from 0-500 RPM), thru a flexible drive shaft.
The benefits received from rotating your electrodes with the Rotobore® besides the obvious accuracy, include the reduction of cutting time, uniform electrode wear, and improved flushing.
SYSTEM DESCRIPTION
Your Rotobore® system includes the following items:
DRIVE UNIT
The drive unit contains a DC Motor-Generator, an AC-DC power supply, control circuitry and system controls.
The motor speed is controlled by the power transistor on the heat sink at the rear of the drive unit. The tach-Generator motor produces a DC voltage proportionally to the motor speed. This voltage is compared to the reference voltage set by the pot location on the front panel. The internal controls then automatically regulate the voltage to the motor via the power transistor to maintain the selected speed. The control circuitry is all solid-state to assure dependable performance and reliability. The motor is protected against overload by a circuit breaker located on the rear and a fuse located on the front panel.
Included on the drive unit is a coiled cord on the front with a push button to jog the spindle to assist during electrode alignment.
Spindle Head
The Rotobore® spindle head is a delicate precision tool and should be handled appropriately. The spindle has been designed to be splash proof. The Spindle Head is not submersible. The spindle is designed to be used vertically, however can be mounted to be used horizontally if special care is taken to prevent oil from entering the housing.
The spindle uses class 7 bearings on an insulated stationary shaft with a rotating housing. The bearings are grease loaded for the life of the unit. The current bypasses the bearings (which are insulated) via a slip ring and brush assy., which allows a maximum cutting current of 35 AMPS max (standard).
The spindle is set up to accept a 1/8 x 27 pipe fitting to allow for pressure or suction flushing of up to 75 PSI MAX thru the center of the spindle to the electrode. There are a number of seals and 0-rings which prevent the EDM fluid from getting into the bearings or spindle housing.
The spindle drive is created by the pinion assembly. The pinion gear is on an eccentric to allow for adjustments for proper gear meshing.
The spindle design and material selections have been carefully chosen and tested to assure dependable operation and low maintenance for a long life.
Centri-Tilt® System
Centri-Tilt® (CTC-1®) System comes pre-installed on the spindle head. The CTC-1® features a two axis tilt system mechanically suspended by means of an inverted ball swivel from a two way shift centering system. This allows for accurate alignment to eliminate electrode runout. Both systems use fine pitched thumb screws to allow for fine adjustments. Both systems operate independently but yet are cross-linked to prevent any rotary motion. Positive mechanical locking of both systems creates high rigidity. A balanced system allows for vibration free rotation at any speed. As long as the electrode is also balanced and does not exceed 20 Lbs. A variety of electrode holding systems are available which will slip right into the CTC-1® Nose Piece for most any application.
The drive shaft is available in (2) lengths, either 36" or 52". The drive shaft is composed of a metallic casing covered with plastic, and terminated with stainless steel swivel fittings. The drive shaft contains a special wound flexible core. The core is removable for periodic lubrication, with any medium density general purpose grease.
ALIGNMENT BAR
The system comes with an alignment bar to be used to set and test the head. See CTC-1® operations.
COOLANT HOSE KIT
The Coolant Hose Kit contains plastic tubing and fittings to be able to adapt to most systems to allow pressure or suction flushing thru the spindle head and electrode.
SPARE PARTS KIT
The spare parts kit includes alien wrenches, extra screws and spare seals.
SPINDLE HEAD MOUNTING ADAPTERS
There is a full line of mounting adapters which are available to fit any application which may be required.
It is important to determine if the platen or mounting surface on the RAM of your machine is insulated from the machine control voltage. Some machines are not and therefore require special insulated adapters for proper machine operation.
For accurate performance of the Rotobore® Spindle, it is essential that the RAM or Quill of the EDM Machine moves perfectly perpendicular to the machine table surface and that the spindle axis be perfectly parallel with such motion. Out of squareness can result in oval holes or apparent hole location shifts. Check squareness of your machine and Ram (or any tooling system installed) by indicating a cylindrical square placed on the machine table.
The spindle assembly is ground while revolving on the internal bearings to produce a parallel spindle (Top to Bottom). The spindle is installed into the housing and the mounting surface on the housing is ground on the bearings to maintain this parallel condition and perfect squareness to the spindle axis.
All mounting adapters must be installed and trued in a similar way to maintain these conditions. (Note: if a mounting adapter was supplied by the manufacturer on your spindle, it has been trued to maintain these conditions.)
If you choose to make your own adapter, the hole pattern on the top of the spindle housing is (4) equally spaced 10-32 tapped holes on a 1.125" bolt circle. Make sure your adapter is flat and parallel as described above. You also need to provide a 5/8" diameter hole in the center of your adapter to provide access to the spindle screw (the pan head screw on top of the spindle housing.) You also need to provide enough space to prevent the drive cable from bending to sharply.
INSTALLING THE Rotobore® SYSTEM
Install the Rotobore® Head with CTC® onto the machine or tooling system as required. Orient in such a way to make access for the flushing port and drive cable as needed.
Select a suitable location for the drive unit. The drive unit must be set horizontally to allow proper ventilation and air flow across the heat sink on the rear of the unit.
Check the unit to make sure the switch is OFF. Connect the power cord on the drive unit to a grounded outlet, (The light will be out.)
Caution: the drive cable does carry machine gap voltage so make sure your machine tool power supply is turned off. At this point install the drive cable into the drive unit and then into the spindle head. Verify that the red alignment marks on the pinion assembly and housing, (where the cable attached to the housing) are still aligned. If the marks have moved, loosen the two set screws directly below the pinion assembly and re-align the red marks, and then re-tighten the set screws while holding the pinion assembly into the housing.
Make sure the cable is out of the way and there is appropriate access to both drive unit control and EDM Machine control panel. Adjust drive unit location to provide straight or gentle bends in the drive cable thru the full travel of the EDM machine ram.
Using the supplied coolant hose and fittings, connect the spindle (1/8 x 27 N.P.T. port) to the machine flushing manifold as required. Remember, do not exceed 75 PSI. Use Teflon tape as required to prevent leakage.
Caution: Do not use metallic tubing as this could carry machine voltage. The plastic tubing supplied will inhibit the chances of accidental shock.
For first alignment or rough system alignment use alignment bar provided with system.
PERPINDICULARITY ALIGNMENT (refer to figure above)
Loosen both small tilt lock screws. Place an indicator on the electrode in line with the tilt adjust screw. Move the machine ram up and down adjusting the tilt adjust screw until the proper alignment is realized. Lightly snug the tilt lock screws and re-adjust as required. Rotate the CTC-1®, 90 degrees and repeat to obtain required alignment for both axis of the Rotobore.
CENTERING (refer to figure above)
After perpendicularity alignment is completed, loosen all (4) of the centering screws, which are radially mounted. Using an indicator located at the top of the electrode, (closest to the CTC-1®) (Rotate the spindle by hand, or use the jog cable at a slow speed setting), check for runout and adjust the centering screws until the desired concentricity is obtained. Snug each screw down to lock the centering and re-check and adjust as required.
Locate your indicator at the bottom of the electrode and check for runout. If runout is observed, use the tilt adjust screws as required. Then move the indicator to the top of the electrode and adjust concentricity using the centering screws as above. Now move the indicator to the bottom of the electrode, recheck, and repeat these steps as necessary.
OPERATION
Once the CTC® has been adjusted for proper electrode alignment, the spindle is ready to be used.
Set potentiometer on the front panel of drive unit to desired speed setting and turn spindle on.
DO NOT IMMERSE SPINDLE INTO EDM COOLANT. The Rotobore® Head is splash proof only.
DO NOT EXCEED 35 AMPS MAXIMUM OR 75 PSI COOLANT PRESSURE.
DETERMINING THE PROPER SPEED SETTING
There is no clear cut relation of speed versus electrode diameter, hole depth, cutting current, etc., currently known. Just as with any EDM job, experimentation is required to find the optimum speed setting for each application and to determine your own general rules of thumb.
MAINTENANCE
DRIVE UNIT
Keep the heat sink in the rear clean and maintain good airflow around the unit during operation.
DRIVE CABLE
Periodically, lightly lubricate inner core with any general purpose medium density grease.
SPINDLE HEAD
If oil leakage is discovered replace lipped seals as follows:
Remove the drive cable from the spindle head. Depress the black detent pin under the pinion assembly and rotate the spindle by hand until the detent pin drops in. Using the black ball pins on the CTC®, (Do not use the adjusting screws, as they will bend) and while keeping the detent pin depressed, unscrew the CTC® from the spindle head. On the Spindle face plate remove the (4) 5-40 screws holding the nose piece on and remove the threaded nose piece, remove the inner seal (part # R10-1 130) located around the shaft and replace. Be careful not to damage the carbide sleeve on the shaft. Then replace the seal in the nose piece. (part # R10-1140) Re-assemble making sure to replace the 0-ring between the CTC® and spindle. Make sure the CTC® is seated tightly against the spindle face plate for proper operation.
CTC®
Do not immerse in EDM Fluid. Do not remove red retainer ring or do not adjust set screws in the face of the red retainer ring, as this will void the warranty.
SYSTEM TROUBLE SHOOTING
Drive unit is non-operational (no motor rotation):
Drive unit functions but continually trips circuit breaker or repeatedly blows fuse:
Spindle has no speed control (Run-away spindle):
Jerky spindle at slow speeds:
Spindle heats up:
Unable to adjust electrode alignment:
Spindle does not repeat, electrode alignment impossible:
Coolant leakage:
Elipitical holes or apparent hole location shift:
FACTORY SERVICE, MAINTENANCE AND ASSISTANCE:
Call Everest Industries for any assistance solving problems you may have as we are happy to help you however we can, with advice, parts or service when required. (714) 847-6062
Fast and dependable factory service and maintenance available on all products.
Note: The spindle, Drive unit and CTC® all have serial number which are tracked. The drive unit serial number is stamped on the back of the drive unit. The spindle and CTC® serial numbers are located on the face plates of each item internally.
Please include written, specific detailed information with all requests for service or maintenance on any problems you are experiencing with the Rotobore® System.
All items will be evaluated and a quote given before work is started.
Ship all service or maintenance requirements, postage prepaid, to:
®
16402 Gothard St. #E
E-Mail: Info@Rotobore.com
© 1998 Everest Industries Corporation®
Huntington Beach, CA 92647
Phone: (714) 847-6062
FAX: (714) 847-6251