Forkardt f operating instructions

Forkardt f Operating and Mounting Instructions for Forkardt Type F Chucks

The item numbers indicated in connection with single parts refer to page 3/4 of the spare parts list, as far as not otherwise specified.

1. Operation
1.1 Turn the key counterclockwise until the limit stop. Observe indicator pin 15 (Page 18/Fig. 1). Then press the push button for the jaw safety device (located behind every base jaw) — the base jaw is now ready for removal or repositioning. Pull out any one of the jaws, then turn the key clockwise and observe wedge block 5 and the indicator pin. The pin disappears as soon as the rack toothing engages with the jaws on ⅔ of their width. Therefore: "When the pin is projecting, the chuck is not to be tightened and run, because the jaws are not in mesh."

1.2 Turn further clockwise. The pin appears shortly before the limit stop. Hence: Do not chuck in this area, because no retightening effect is available.

1.3 Turn the key again completely counterclockwise. Press the push button, shift jaws to the other diameter. Jaw holders 16 (latch pins 16a) must snap in.

1.4 If this should not be clearly perceptible (when jaws are going tight), first one jaw only is to be repositioned, key is cautiously to be turned clockwise, probably jaw is slightly to be knocked until teeth mesh — never continue turning by force. Then turn back, reposition the next jaw in the same way, etc.

1.5 Insert jaws the other way around because they can be used in both directions! Always remember: Jaw No. 1 in guideway No. 1, etc. Insert jaws at least up to the outer check circle to ensure that all wedge block teeth bear.

2. Mounting the Chuck
2.1 First, check the machine spindle nose for true running, both round and axially and without slip, with a dial gauge alternately at the front end and rear end. Remove probable damages of the spindle nose accommodation surfaces. Check mating surface on the flanged spindle by straightedge.

2.2 Check the finished flange first for true running, both round and axially, with a dial gauge alternately at the front end and rear end! Only then bolt on the chuck!

2.3 On fastening with intermediate flange, never have the outer chuck edge bear against a shoulder (Page 18/Fig. 1). The flange must bear on the entire surface (Page 18/Fig. 2).

2.4 Ready-to-mount Forkardt chucks are available for spindle noses with short taper. Chuck, design J, for bayonet mounting (Page 18/Fig. 5), design K for spindle nose with threaded holes for through bolts, design D for Camlock mounting. If we are informed of the origin of the machine before supply, we can grind the centering taper so that it fits without remachining.

2.5 Before putting the chuck onto the spindle nose, carefully clean the mating surfaces of both parts and rub them with some oil. With the chuck held under light pressure, no perceptible backlash should exist in the taper, and maximum 0.02 mm play should be between the plane faces (feeler gauge), otherwise, the chuck back plate has to be remachined (either to be forwarded to our works or request for instructions).

3. Checking the Chuck
3.1 Only in a duly mounted state (Page 18/Fig. 3), check surfaces c and d must run true. Otherwise, every further checking would be useless.
3.2 It must be possible to shift the jaws as easily as before mounting, compare to 1.1. Stiff movement reveals distortion of chuck body due to wrong mounting! Concerning checking of centering accuracy see chart page 17.
3.3 For checking concentricity of a type F chuck:
- Test mandrels are clamped in position "high jaw step inside"
- Test rings are clamped in position "high jaw step outside"
in the duly accommodated chuck. Concerning torque on the key during concentricity check, see chart page 17. Forkardt-F type chucks have a repeat accuracy better than the class 1 requirement of DIN 6386 applied to scroll chucks. If the permissible concentricity error should be exceeded, please check the following:
- Initiated key torque according to chart page 17
- Accurate accommodation of the chuck
- Test mandrels and test rings (diameters different from DIN 6386).

4. Care of the Chuck
In order to ensure reliable chucking of the component given the high loading capacity of a type F Forkardt chuck, the use of high-duty lubricant is absolutely necessary. We recommend cleaning our chucks at regular intervals and lubricating them with our special lubricants. In such a way, an optimum output and a long service life are achieved.
4.1 Lubricate the power transmission surfaces of the spline shafts, drive ring, and thread of the spindle with PF 20 or PF 5. The spherical cap and pressure ring at the spindle as well as the jaw securing elements shall be greased with PF 4.
4.2 The cap of the chucking spindle is to be lubricated through the funnel-type lubricating nipple in the spindle square by using rush-type hand guns or high-pressure lever-type hand guns, which can be supplied by us, at least once per month. Lubrication nipple in the square of the operating screw on F 250 and larger, and opposite the square on F 160 and F 200.
4.3 If the clamping force nevertheless diminishes, the inner part of the chuck may be contaminated or coolant has washed out or decomposed the grease. Then the chuck is to be dismantled, every part is to be thoroughly cleaned with paraffin or washing petrol, all inner parts are to be lubricated, the chuck is to be reassembled. Depending on the load of the chuck, this thorough cleaning and lubrication should generally be effected after every 200 operating hours.
4.4 Cleaning and greasing of those inner parts, which can be taken out without dismantling the chuck (e.g., base jaws), is recommended then when no lubricating film is available.
4.5 Dirt and fine chips easily penetrate into the chuck when the jaws are in their outermost position. This is prevented by placing our shaped rubber plugs into the clean jaw guides, whereby the heat-resistant protection plate must lie towards the bore (Page 18/Fig. 4). Collected dirt is to be pushed away towards the chuck bore.

5. Please Note:

1. The chuck is never to be checked on a mandrel between centers!
2. The chuck is never to be tightened before it has been properly flanged on!
3. The chuck is never to be mounted against the outer edge (Page 18/Fig. 1)!
4. The base jaws have never to extend over the check circles!
5. An extension tube is never to be fitted to the tightening key!
6. Tight sitting jaws are never to be struck with a hammer! The chuck is to be cleaned!
7. Top jaws are not to be unscrewed from the base jaws for accurate gripping! Accuracy would be lost! Another set of jaws is to be used!
8. Hard top jaws or solid jaws subsequently supplied are to be ground in the chuck for accurate concentricity.
9. The chuck is never to be left unattended while the wedge blocks are disengaged from the jaws! If anyone starts the spindle, the jaws could fly out (F 80-125).
10. The normal chuck cover No. 2 is to be removed on using a centering cover when the cylindrical mounting is retooled to short taper flange!
11. When a larger number of identical components is processed on one clamping diameter, above all at a very tightly adjusted opening stroke of the jaws, only very few movements take place in the chuck gear. This results in a squeezing out of the lubricating grease between the loaded surfaces and thereby the efficiency factor of the chuck is decreased. In such cases, the chuck should be operated several times without inserted component at the full stroke after a definite number of clamping cycles (indicative value 200 to 400). The lubricating grease in the inside of the chuck is then again distributed on the sliding surfaces of the inner parts of the chuck and favorable clamping force values of the chuck are re-established. The requirement for regular relubrication of the chuck is, of course, not abolished by this measure.
12. Please specify chuck size, manufacturing number, and spare parts number from page 3/4 on placing orders for spare parts.