Crescent Industries, Inc. C-250 Schematic

Crescent Industries, Inc. C-250

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Product Information:
Model:C-250
Manufacturer:Crescent Industries, Inc.

Schematics Content

Page 1:

FIGURE 1.

RECORD PLAYER, TOP VIEW

1. SETTING FOR SIZE OF RECORD

The size of record for which the record changer is set to play is indicated by the number (on the top of the cover assembly) nearest the turntable.
To change the setting, grasp the record support and cover assembly and rotate it a half turn until it snaps into place with the correct record size toward the turn table. In changing the setting from 10 - inch to 12 inch, rotate the assembly counterclockwise only; in changing from the 12 - inch to the 10 - inch setting, rotate the assembly clockwise only.

2. STARTING FOR AUTOMATIC PLAY
Load the record changer with a maximum of ten twelve-inch or twelve ten-inch records, and set the hold down pad so that it rests on the top record. Move the control knob to the auto-on position which will set your record changer for automatic play and start the turn table rotating.
Press down on the reject button which is located on top of the arm rest or push down on the pickup arm momentarily if it is setting on the arm rest. The entire stack of record will be played automatically.

3. MANUAL PLAY
Set record support and cover assembly for size record you intend to play and place record on turntable. Move control knob setting to manual-on position and press down on reject button or push down on pickup arm momentarily if it is setting on the arm rest. If you desire to play the record for the second time in succession press down on reject button and the record will be played again. After record has been played manually grasp pickup arm and place on arm rest and remove record.
Reject button may be used during manual play only when playing standard ten or twelve inch records otherwise it must be done manually.

4. REJECTING A RECORD
To reject a record at any time and start playing the next one, merely press down on the reject button. This may be done while playing manually also.

5. UNLOADING RECORDS
To remove the records it is advisable to have the changer mechanism out of cycle. However, it is possible to unload the changer while it is in cycle so long as the pickup arm is clear of the records.
Move the control knob to the off position before lifting pickup arm to arm rest and remove records.
When removing records, hold them lightly and lift straight up.

CAUTIONS

1. Do not place your unit on a radiator or other source of heat. The pickup may be damaged by heat.
2. Never use force to stop the motor or turntable.
3. Do not leave records on the supports as they are liable to warp. To protect your records, keep them in a record file, album or cabinet when not in use.
4. Records which have become warped or damaged will slide on one another when playing, resulting in unsatisfactory operation.

5. Never leave the pickup arm with the needle resting on a record or the turntable.
6. Do not let the pickup arm drop off of the arm rest.
7. When setting for size of records, be careful not to break the hold down pad.

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THE CHANGE CYCLE

6. DESCRIPTION OF CHANGE CYCLE.
(See Figures 2, 5, and 6.) While a record is playing and as the pickup arm moves toward the center of the record, the arm control pin (28A) on the arm control assembly (28) moves along the portion of the arm control track (33B) as indicated at " P figure 2. As the record reaches the pickup or trip point, the pin reaches point " T " on the track. As it moves into the recessed position in which it is shown in the illustration, it permits the trip spring (32) to pull the arm control plate (33) forward towards the centerpost (37). As the arm control plate is drawn forward, the stop tab (33A) on the arm control plate (33) is withdrawn from behind the reject catch (51) on the eccentric cam (53). The cam, which no longer is held in place by the stop tab (33A), is pulled over by the eccentric cam spring (54) until the rubber tire makes contact with the knurled roller (46) on the turntable shaft (38A). This knurled roller, which rotates with the turntable shaft, rotates the eccentric cam. In turn, this forces the riser plate assembly (34) back along its guide rods (42A) away from the centerpost (37). As soon as the riser plate begins to move, the push-off cam and shaft assembly (36) rides along the inclined track (34C) of the riser plate (34). This action causes the push-off cam and shaft assembly (36) to be drawn downward; as a result the pickup arm lift (21) presses down on the arm lift bearing pin (15), causing the pickup arm to be raised clear of the record. Then the riser plate tab (34B) contacts and moves the arm control assembly (28) which, since it is coupled to the pickup arm support assembly (23) carries the pickup arm away from the centerpost and clear of the edge of the turntable. As the riser plate (34) continues to travel further along the guide rods (42A), the riser plate motion bracket (34A) contacts and rotates the push-off cam and shaft assembly (36); as a result, the push-off arm (5), which is coupled to the push-off cam and shaft assembly (36) causes the push plate (7B) to drop a record to the turntable.
During the second half of the change cycle, the pressure of the push plate spring starts to return the push plate (7B) and push-off arm (5) back to their normal position. At the same time, the motion of the eccentric cam (53) and the guide rod recoil spring (35) propel the riser plate (34) toward the centerpost. The arm control assembly (28), and hence the pickup arm, are drawn back by the tension in the set-down spring (27). After the arm reaches this point directly above the set-down
the riser plate (34) has moved far enough back towards the centerpost (37) to allow the push-off cam and shaft assembly (36) to ride down the inclined track (34C) of the riser plate (34). This lowers the pickup arm onto the record. As the eccentric cam (53) aided by the eccentric cam spring (54) completes its revolution, the rubber tire of the cam moves away from the knurled roller (46) on the turntable shaft and the reject catch (51) to rest against the stop tab (33A) of the arm control plate (33). The change cycle is completed.

7. DESCRIPTION OF DETERMINATION OF 10 - INCH AND 12 - INCH SET - DOWN POINTS.
During the early part of the change cycle, the arm control plate (33) has traveled (in a direction away from the centerpost) until the size change stop (33C) reaches the cam (36B) of the push-off cam and shaft assembly. The distance traveled by the arm control plate (33) will depend on the size of the record being played; the distance is less for a 12 - inch setting than for a 10 - inch setting. (This is true because the push-off

cam (36B) presents its short radius to the size stop [ 33C ] for the 10 - inch setting and presents its long radius to the size.change stop for a 12 - inch setting.) This variation in distance traveled means that the arm control track (33B) will be in a position closer to the centerpost for the 12 - inch setting than for the 10 - inch setting. This in turn means that during the change cycle the arm control pin (28A) whose path is determined by the motion of the arm control assembly (28) will leave its recessed position, and will ride along the " S " portion of the arm control track for the 12 - inch setting and along the L portion for the 10 - inch setting. (See Figure 2.)
As the pickup arm moves back towards the record during the second half of the change cycle, it will be stopped when the bracket (28C) reaches the adjusting screw (29). How far the arm returns before being stopped depends on whether the arm control pin (28A) has been riding in the " S " or " L " portion of the arm control track. If the pin has been riding in the " S " or 12 - inch portion of the track, the arm will be stopped at a point directly above the 12 - inch set-down point; if the pin has been riding in the " L " or 10 - inch por tion, the arm will be stopped at a point directly above the 10 - inch set-down point.

8. REJECTING A RECORD. (See Figures 3 and 6.)
The reject button (59A) is located on the top of the arm rest (59). The parts used to provide push button rejection are shown in Figures 3 and 6.
Figure 3 shows the changer going thru cycle, that is, in the process of rejecting a record. When the changer is out of cycle the reject catch (51) engages both the stop tab on the arm control plate and the reject arm (44A). If the changer is allowed to finish playing the record, the stop tab on the arm control plate is with drawn from behind the reject catch (51); the eccentric cam (53) is then pulled against the knurled roller (46) and the change cycle begins. However, when the reject button (59A) is pressed the reject trigger wire (64) pulls the reject arm (44A) from behind the reject catch (51); the eccentric cam (53) is then pulled against the knurled roller (46) and the change cycle begins.

9. MANUAL PLAY.
The control knob (60) is located on top of the motorboard (72). The parts used to provide manual play are shown in figures 5 and 6.
To play manually, move the control knob (60) to the left. This will shift switch mounting to the left and cause manual control bracket (44B) to be engaged, so that size change stop (33C) is prevented from com ing forward and completing change cycle.
The reject button may still be used as explained in Paragraph 8 even though the control knob is set for manual play.

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ADJUSTMENTS
CAUTIONS

1. See that the drive pulley and the rubber tire on the motor (61) and the rubber tire on the eccentric cam (53) are kept clean and free from oil, grease, dirt, or any foreign material. Carbona or carbon tetrachloride may be used for cleaning these parts.

2. If replacement of any parts requires the removal of the lift adjusting collar (10), pickup arm support assembly (23), or the push-off arm (5), be sure the re-position or replace these parts as directed in paragraphs 11, 12, and 14 respectively.

TOOLS REQUIRED

# 6 Bristol Set Screw Wrench
# 6 Allen Sct Screw Wrench
# 8 Bristol Set Screw Wrench
# 8 Allen Set Screw Wrench
Lift Out Tool (2 Required)
Can be obtained as Kit.

10. REMOVING CHANGER FROM CABINET FOR ADJUSTMENT.
When it is necessary to remove changer from cabinet for adjustment this can easily be done with the aid of the lift out tool furnished as specified above. Wires must be disconnected first.
The changer is mounted on four rubber shock mounts (73), their location can be quickly identified by the location of the four phillips head screws (76) on the motorboard (72). Hold lift out tools by long handle, one in each hand and pry up under bulb of rubber mount, two at a time. Pry up on two that are located on the same side of motorboard. When one side is free of cabinet, wedge something under motorboard so the free mounts do not fall back into the hole. Use the same procedure on the other two mounts and the changer is free of cabinet.
To install changer back in cabinet line up rubber mounts with holes in cabinet and push down on motor board. The changer is automatically locked in cabinet, connect wires and changer is ready for operation.

11. SET - DOWN POINTS AND PICKUP OR TRIP POINT.
(If the pickup arm support assembly [ 23 ] has been removed or if its sct screws are loose, it must be re positioned as described in paragraph 13 before adjusting the set-down points and pickup or trip point.)
This changer is designed so that the 10 - inch set-down point, the 12 - inch set-down point, and the pickup or trip point are simultaneously adjusted in a single operation. It is recommended that you make the adjustment at either of the set-down points. This adjustment is made by means of the adjusting screw (29) shown in Fig. 3. Turning this screw counter-clockwise will cause the arm to set down closer to the centerpost; turning it clockwise will cause the arm to set down further

Away from the centerpost. One turn on the screw will move the arm about 14 inch.
If the adjusting screw (29) will not change the set ing sufficiently, the pickup arm support assembly (23) may be out of position (see paragraph 13)
The set-down point when using a straight-shank needle will differ slightly than when using an offset shank needle. If
you do not know which type of needle is to be used by the customer, we suggest the following settings when tested with a straight needle: measuring from the side of the centerpost, 45/8 " for the 10 - inch set-down point, 55/8 " for the 12 - inch set-down point, and 1-19 / 32 " for the pickup or trip point.
If you know which type of needle will be used by the customer, and test with that type of needle, the following settings are recommended:
Measuring from the side of the centerpost, 4-21 / 32 " for the 10 - inch set-down point, 5-21 / 32 " for the 12 inch set-down point, and 15 / " for the pickup or trip point.
When using an offset-shank needle, slight variations in set-down point can often be corrected by loosening the needle screw and rotating the needle slightly.

12. PICKUP ARM HEIGHT.
When properly adjusted, the pickup arm height should be such that, without a needle and with a single record on the turntable, the arm should be about 1/32 " above the record. The arm height depends on the location of the lift adjusting collar (10). As the collar is moved down, the arm is raised, and vice versa. When necessary, the pickup arm height may be adjusted by re-positioning the lift adjusting collar (10) as follows:

Page 4:

SERVICING AND REPAIR

(a) The changer should be out of cycle.
(b) Lift the pickup arm and check to see that the pickup arm lift (21) is positioned properly over arm lift bearing pin (15). (See Fig. 4.)
(c) Remove needle and place pickup arm on turn table close to its edge.
(d) Loosen set screw in lift adjusting collar (10).
(e) Remove slack by pushing up on push-off cam and shaft assembly (36). Do not compress the arm lift shaft spring (36C).
(f) Using a # 6-32 Bristol wrench, place it in the set screw and slide the lift adjusting collar (10) down until it is snug against the pickup arm lift (21).
(8) Tighten set screw in the lift adjusting collar.
(h) Check height.

13. RE - POSITIONING PICKUP ARM SUPPORT ASSEMBLY (23).
To assure proper set-down adjustment, this must be done carefully as follows if set screws are loose or if pickup arm support assembly (23) has been removed.
(a) Turn adjusting screw (29) (see paragraph 11) clockwise 2 full turns.
(b) Place a 12 " record on the turntable.
(c) With the changer out of cycle, manually move the arm control assembly (28) outwards as far as it moves freely. In this position, the arm control pin (28A) will be located as indicated at " A " in Figure 2.
(d) Place pickup arm so that needle rests in first playing groove on the 12 " record.
(e) Tighten the two set screws in pickup arm sup port assembly (23).
(f) Make the final set-down adjustment as described in paragraph 11.

14. REMOVING COVER (3) FROM HEAD ASSEMBLY
(7). (a) To remove cover (3) from head, squeeze cover at ends and lift up enough for cover to come free of rotating plate (70).

(b) Remove hairpin spring from hold down plate (4) and slide hold down plate (4) out of rotating plate (70).

15. RE - POSITIONING PUSH OFF ARM (5).
This must be carefully done if set screws are loose or push off arm (5) has been removed.
(a) Rotate the record support to the 10 - inch posi tion. Remove push off arm (5).
(b) Line up push off cam (36C) with push off arm (5) so they are parallel. If the push off is still faulty set push off cam (36C) slightly back of push off arm (5), this will give a little less push off on 10 - inch side and little more on 12 - inch side. Reverse this procedure for more push off on 10 - inch side.
(c) Put push off arm (5) in position leaving push off arm about 1/32 " above top of arm lift shaft.
(d) Tighten set screws in push off arm.

16. CHANGER REPEATEDLY GOES THROUGH CHANGE CYCLE WITHOUT PLAYING RECORD.
(a) Mounting screw on eccentric cam (53) may be loose. Tighten.
(b) Cushion spring (31) has slipped out of position and is on wrong side of riser plate tab (34B). Re position spring. (See Figure 5.)
(c) In normal operation, the trip spring (32) holds the arm control plate (33) against the riser plate (34). If the trip spring is faulty, it permits the arm control plate to rise too high above the riser plate. This causes the reject catch (51) to pass underneath the stop tab (33A). To correct, bend the legs of the trip spring closer together. If necessary replace trip spring.
(d) Eccentric cam (53) is bent so that reject catch (51) passes underneath stop tab (33A) on the arm control plate (33). To correct, straighten cam by put ting changer out of cycle and pressing upward on cam near reject catch.

17. NEEDLE SLIDES ACROSS PORTION OF RECORD AFTER SET - DOWN ON 12 - INCH RECORD.
Cushion spring (31) has slipped out of position and is on wrong side of riser plate tab (34B). Re-position spring. (See Figure 5.)

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FIGURE 6

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See Exploded View, Figure 6, for Identification of Parts.