General Information

The Jiffy-Drill is designed specifically to drill both small holes and large holes in a variety of materials. The size of hole and the material determines the power and RPM required to perform the task. On most applications a single motor is not capable of doing a wide range of holes or materials. In these cases, the motor can be changed to achieve the best power and RPM needed. Although, you can normally sacrifice drilling cycle times to reduce the number of different motor sizes needed.

Mounting the Jiffy-Drill

The unit can be mounted in any position, but if mounted to drill upward, a chip cover should be used to keep coolant and chips out of the electrical switch compartment or use coolant resistant limit switches. There are four, 1/2"-13, tapped holes in the base of the Jiffy-Drill body which can be used for mounting. Caution! The two front mounting bolts must not penetrate more than 1/2" to avoid damage to the feed piston barrel. Although, on most tapping jobs, usually less than 50 lbs. feed force is required, on drilling applications the structure supporting the Jiffy-Drill may have to take up to 2500 lbs. thrust.

When using the Jiffy-Drill unit, we always recommend using a fixed hardened bushing. The design of the Jiffy-Drill allows for smooth extension and retraction, using soft seals and wear rings. The unit can not sustain accuracy if the drill bit is subjected to a side load or drilling on a curved or uneven surface without a hardened bushing. We recommend installing a bushing in a fixture as close to the part as possible. In some cases this fixture and the Jiffy-Drill can be mounted on a slide and becomes an integral part of clamping the part to be drilled.

Hydraulic Setup

A hydraulic power unit to operate a Jiffy-Drill is not part of the Jiffy-Drill but may be ordered as auxiliary equipment, or perhaps a standard hydraulic power unit already on hand can be used. Hydraulic hoses should be ordered locally after the distance between the power unit and the drilling unit is established. Several Jiffy-Drill units, which are powered with hydraulic motors can be run from one hydraulic power supply.

Hydraulic to Rotate Spindle

Flow for spindle motor will be determined by desired RPM on each Jiffy-Drill. Several power arrangements may be used: two (or more) pumps driven from the same or from opposite ends of a double shaft electric motor; a two-section (or more) hydraulic pump; two (or more) separate hydraulic power units. A pressure compensated pump may be used for both the main motor drive and the spindle advance. Spindle rotation is determined by which port is connected to the hydraulic pump. During setup, verify tool rotation.

Choose a hydraulic motor from these tables that will deliver the required torque and RPM. If you will be using an existing power unit, you will be limited by the pressure and flow available from your existing power unit. On new applications try to keep operating pressures around 600 - 800 PSI and GPM at 25% to 75% of maximum GPM the motor can operate at.

On jobs where several Jiffy-Drill units are to be used, one large power unit can serve all the units by having one or more large pumps and with pressure compensated flow control valves installed in each Jiffy-Drill motor circuit and feed circuit.

Hydraulic to Advance Jiffy-Drill Spindle

A flow of 2 GPM is usually sufficient for piston advancement. Hydraulic pressure of 100-800 PSI is needed to advance and retract the spindle when drilling holes. A hydraulic pressure of 200 PSI, for example, working on the internal piston area of 3.14 square inches, will give a thrust of about 600 lbs. on the drill bit. With hydraulic feed pressure up to a maximum of 800 PSI, a thrust of about 2500 lbs. can be produced. It is important to use a pressure reducer and gauge in the feed circuit. (extend area: 3.14 sq.in., retract area: 1.37 sq.in.)

To maximize drill feed control, a counter balance valve should be installed in the outgoing flow line of the Jiffy-Drill. This valve tends to hold the drill back when it strokes forward by resisting sudden high surges in the flow. It should be adjusted to the minimum setting which gives adequate control, as it places an extra load on the hydraulic power source. The counter balance valve should contain a check valve for free flow on drill retraction.

The system compensator setting should not be used to regulate chip thickness. It should be set and locked at a pressure high enough to take care of moderately dull drills, but no higher than necessary because surplus oil from the hydraulic power supply must discharge across it. The higher its setting, the greater the heat generated in the oil.

The 2-way solenoid valve is optional, and used only when a rapid advance up to the work is desired. It should be energized for rapid advance, then de-energized just before the drill bit touches the work. It may be wired to operate from the deceleration switch located on the Jiffy-Drill unit.

Recommended Jiffy-Drill Hydraulic Circuit

Electric Control of the Jiffy-Drill

Three built-in limit switches (part number J-318) should provide adequate switching for design of circuits for fast forward, skip feed, normal feed, dwell, reverse, and reverse stop. Each switch is actuated by an adjustable cam. The forward limit switch has a fine thread adjustment for drill depth. After setting its cam for approximate depth, loosen lock screw and adjust screw for fine adjustment. Turn adjusting screw clockwise for a depth increase of 0.0357" per turn. Tighten lock screw to secure adjustment screw.

Limit switches are rated up to 4 amps at 125 volts A-C or 1/2 amp at 125 volts D-C. Use relays, if necessary, to control higher current or voltage.

On standard Jiffy-Drill units these switches are not wired, and the external wiring is brought through the conduit hole in the rear of the switch cover. For factory wired units see option EP.

Sample Electric Circuit Operations

The following samples only consider the electrical controls needed to control the extension and retraction of the feed cylinder for various types of drilling operations. The control of the spindle rotation may be incorporated into the feed circuit. Although for most applications the spindle rotation control is independent of the feed. These circuits serve only as a guideline in assisting you in setting up the Jiffy-Drill. We currently use several of these circuits in our manufacturing facility, but caution is urged to limit possible damage during the initial setup and testing of your control circuit. In some cases, customers have incorporated a reverse spindle rotation option during the initial design of their machining center.

Standard Drilling

The two limit switches are those in the Jiffy-Drill. Solenoids A and B are those on a 4-way hydraulic valve. Other components include two relays, a start push-button, and a panic button. The rear limit switch is held in its open position when the quill is retracted. To start a drilling cycle the operator momentarily presses the start push-button. Solenoid A and Relay 1CR become energized and the quill starts forward. The relay locks in electrically through its own contacts and the N.C. (normally closed) contacts of Relay 2CR. This keeps Solenoid A energized throughout the forward stroke. When the forward (depth) limit switch is actuated, Solenoid B and Relay 2CR become energized. The relay locks in electrically through its own contacts. It also breaks the locking circuit to Relay 1CR and releases Solenoid A. The quill retracts until the rear limit switch is actuated. This breaks the circuit to Solenoid B and Relay 2CR. The 4-way valve spool goes to neutral position and unloads the pump.

Hole Reaming

Spot Facing

The Jiffy-Drill can be used to spot face an existing hole or used with a step drill. In these applications the hydraulic feed circuit must be carefully designed to reduce the possibility of chatter on the spot face surface. The control circuit is designed with a short dwell time when the depth limit switch is triggered. This allows the spot face to be cleaned up before the drill retracts. (Timer is not included with the Jiffy-Drill.) The drill must be installed so that at full stroke of the unit (cylinder is bottomed out), the desired depth of the spot face is achieved. The unit can be mounted on a locking slide to allow for periodic adjustment of the spot face depth. (The location of the drill determines spot face depth.) To reduce the full length stroke, an internal stop tube can be used. The electric timer used for dwell timing is the re-set type: its contacts do not close until the end of the time period. When the coils de-energize, the contacts re-set to zero time. The operator momentarily presses the start push-button. Solenoid A becomes energized and causes the quill to advance. When the forward limit switch is actuated, this energizes the coil of the electric timer. The quill remains stalled at full stroke until the timer contacts close. This energizes Solenoid B to retract the quill.

Peck Drilling

The Jiffy-Drill can be used to stroke in and out to perform a peck drilling operation. In these applications the hydraulic feed circuit must be carefully designed to allow the timing of each stroke. When the quill is in retracted position, the rear limit switch is mechanically held in the actuated position. When the operator momentarily presses the start push-button, Solenoid A becomes energized and the quill starts forward. When the rear limit switch is released, the timer coil is energized and starts a timing period, but its contacts do not close until the timing period is completed. Relay 1CR coil becomes energized and locks closed through a set of its own contacts. During the drilling period, and after the timer has completed the timing period, its contacts close. This energizes Solenoid B and causes the quill to retract, pulling the drill bit out of the hole to clear the chips. The quill returns to its home position and actuates the rear limit switch. One set of contacts breaks the timer coil circuit allowing it to re-set to zero time. The other set of contacts energizes Solenoid A and starts the quill forward again. As the quill moves forward, the timer coil again becomes energized and starts another timing period. This “pecking” action may occur several times before final drill depth has been reached. When, finally, the depth limit switch has been actuated, one set of contacts energizes Solenoid B to retract the quill. The other set of contacts breaks the holding circuit and releases 1CR relay. This makes it impossible, when the quill has retracted to home position, for it to start forward again until the operator presses the start push-button for another drilling operation. The flow control valves in the feed circuit should be adjusted to limit free travel speed to a safe value, one which will not break the drill bit when it contacts the work. Feed force for the drilling should be adjusted with a pressure regulator in the line to the feed circuit. It should be adjusted to a feed pressure which will not overload the drill. The time period should be short enough so the drill bit does not load up with chips.

Rapid Advance Spindle, Then Slow Feed Drill

Using a 2-way, normally closed solenoid valve to bypass the slow feed control, the Jiffy-Drill can be advanced at two separate feed rates. This allows the drill to be placed farther away from the work piece to facilitate part loading and unloading, yet still not greatly affect production cycle time by rapidly advancing the drill. The three limit switches are those in the Jiffy-Drill. Solenoids A and B are the coils on the hydraulic valve controlling the feed cylinder, and Solenoid C is the 2-way, normally closed valve that allows the bypasses of the slow feed control valve. To start a drilling cycle, the operator momentarily presses the start push-button. Solenoid A is energized and starts the quill forward. Relay 1CR and Solenoid C are also energized for rapid advance feed, the slow feed control is bypassed. Relay 1CR locks in electrically through a set of its own contacts, and keeps the quill advancing after the start push-button has been released. When the feed switch is actuated, Relay 3CR is energized and locks in electrically through its own contacts. Another set of contacts de-energizes Solenoid C, causing the quill to slow down to feed speed for the remainder of its forward travel. When the forward (depth) switch actuates, Solenoid B and Relay 2CR become energized. The relay locks in electrically through its own contacts. Another set of contacts de-energizes Solenoid A, causing the 4-way valve to shift into retract position. When the quill has fully retracted, actuating the rear limit switch, Relay 2CR is released, causing Solenoid B to become de-energized and allowing the 4-way valve spool to go to center neutral, unloading the pump. The quill remains retracted until the operator presses the start push-button for another cycle.

Skip Drilling

The Jiffy-Drill can be made to shift from fast forward into feed several times during forward stroke of the quill by replacing the standard deceleration cam with a special cam made by the user on a lathe, having peaks and valleys to energize and de-energize Solenoid C at the proper distance intervals. Similar to the “Rapid Advance Feed Circuit”, skip drilling uses a 2-way, normally closed solenoid valve to bypass the slow feed control. The major difference between the skip drilling circuit and the rapid advance circuit, is the rapid advance switch is used to turn “On” the bypass of the slow feed valve in the skip drilling circuit. In the rapid advance circuit this switch is used to turn “Off” the bypass valve. When the operator momentarily depresses the start push-button, Solenoid A is energized and starts the quill forward. Depending upon the location and design of the skip drilling cam, the Jiffy-Drill will advance at one of two feed rates. The rapid advance switch is “On” during the high spots of the skip drilling cam and “Off” during the low spots. When the advance switch is “On”, Coil 3CR is activated causing Solenoid C to energize and allow the feed cycle to bypass the slow feed control valve therefore rapidly advancing the feed cylinder. When the advance switch is “Off”, the feed cycle resumes to normal slow feed.

Parts Drawings and Information

For parts and dimensional drawings please use the Product Selector to get information about your specific model.

Routine Maintenance Items

Spline Drive Lubrication: The spindle drive spline should be wiped generously with a high film strength grease. To reach the spline, unscrew the bearing retainer. This is a left-hand thread. Pull out the spindle for access to the spline.
Wipe a light film of the same grease on the switch cam rods where they go through the torque plate.

Hydraulic Drive Motor: This motor is lubricated by the hydraulic oil and needs no other lubrication. Should the shaft seal ever need replacing, seal kits are available, complete with instructions.

Removing Drill Bits: With Morse taper spindles, drill bits should be removed from the spindle by inserting a lever-type drill knock-out in the slot provided. Caution! Do not hammer on the knock-out or spindle; this may damage the spindle bearing.

Quill: Keep dirt wiped off the quill, and lubricate it once every 12,000 cycles or once a month, whichever is sooner, with a few drops of oil.

Limit Switches: Routinely inspect limit switches for loose contacts, damaged trigger levers, broken or worn mechanisms, and general structural rigidity.

Seals: Visually inspect unit for hydraulic leakage which could indicate the need for seal replacement. (Seal leakage is a very rare occurrence.)

Removing Spindle Bearing

First remove spindle as described under spline drive lubrication. The spindle and drive shaft are locked together by a tapered pin. Punch the taper pin out by striking it from the side labeled X-X. To remove the bearing, the two parts of the spindle must be unscrewed from each other. These are standard right hand threads.

Interchanging Hydraulic Motors

In setting up for a different job, the hydraulic motor can be interchanged with a different model which may have a more favorable ratio of torque and RPM for the new job. See our motor quick change option on page 12 for alternative options.

Remove four socket head nuts. Pull out the motor with spline sleeve still attached. The spline sleeve set screws are swedged in place and removal might be difficult. It is recommended when using interchangeable motors, that you keep the spline sleeve attached and not swap sleeves between motors. If removal of sleeve is necessary, the swedge must be removed by deburring or use a small end mill to remove swedge. Loosen set screw, and pull spline sleeve off motor shaft. Transfer motor ring, if used, to new motor shaft. Replace spindle sleeve and re-swedge tightened set screw. Unscrew four studs from the old motor and mount them on the new motor. Place the spline sleeve on new motor shaft and tighten set screw. Plug the new motor assembly into the Jiffy-Drill body, engaging the spline sleeve with the spline on the spindle. Reinstall and tighten the four socket head cap nuts.

Recommended Spare Parts

At least one spare limit switch (part number J-318) should be kept on hand. In an emergency, the deceleration limit switch, if not used, can be substituted as a replacement for one of the other switches.

When replacing a limit switch, transfer one wire at a time from the old to the new switch, to avoid the possibility of getting the new switch wired incorrectly.

Locating Unit Serial Number

The unit serial number is located on the right side of the unit when looking at the spindle end. Be aware that the covers between units are interchangeable. Therefore, the part number on the cover may not be the correct part number of the unit. Consult the factory for determining the exact part number of your unit or locating the serial number. Serial number may be required when ordering replacement parts.

Seal Kits

Seal kits are available from your local distributor or the factory. Be prepared to supply unit serial number to determine proper seal kit number.

• RKJD-1: Complete soft seal kit for serial numbers up to 577Ql. (Units purchased prior March, 1986.)
• RKJD-2: Complete soft seal kit for serial numbers starting with 578Q3.

Drill Cylinder Seal Kit Installation

1. Remove bearing retainer nut (left hand thread). Pull drive shaft out.
2. If there is an adapter ring, remove by first removing the two loc-tited set screws in face. Use a torch to break the loc-tite bond. Remove the adapter ring (left hand thread).
3. To remove stop rod mounting plate, loosen socket head cap screw at bottom. Use a flat head screw driver to slightly spread stop rod mounting plate and slide mounting plate off of the quill. You will need to remove the switch cams to completely remove stop rod mounting assembly.
4. To remove torque plate, remove 4 mounting screws. Pull torque plate up to the threads on quill. It is easier to remove plate by unscrewing seal around thread (left hand thread).
5. To remove cylinder rod end, rotate rod end 45 degrees, slide off rod end using the corners to grab hold of. Remove bronze bearing and seal from the rod end. Remove quill from the barrel. Remove seals, being careful not to damage quill surface. Clean and dry surface of all parts before re-assembly. Lubricate using high film strength grease.
6. Replace seals using a small screw driver, being careful not to damage seal or quill surface. Using a thin film of grease on the seals will improve installation and sealing.
7. Re-assemble in reverse order.