Master Instruments
Halda Tripmaster Full Size Photo
Halda Twinmaster Full Size Photo
For this purpose you will require a few X-gear wheels and possibly - but unlikely - one Z-gear wheel. The number of different X-wheels you will need depends on within what percentage range you want to be able to adjust up or down.
The table below shows the range of X-wheels available. Against each of them you will find a percentage figure. This figure is the percentage with which the odometer reading changes per tooth deviation from that very wheel.
Example: If your instrument is fitted with X-wheel 141, a change to X-wheel 140 increases your odometer reading by 0.709%. In the same way a change from 141 to, for instance, 137 increases your odometer reading by 2.836% (4 teeth x 0.709% = 2.836%).
|
|
|
From this table you will be able to decide which X-wheels you may need around the one fitted in your instrument.
Example: Your instrument is on delivery fitted with X-wheel 141. Suppose your instrument shows 9.72 miles when the Rally Master says 10 miles. You consequently show 28/100 of a mile or 2.8% less, so you want to change to an X-wheel giving you a 2.8% increased reading or as near as makes no difference. Each tooth deducted from 141 changes your odometer reading by 0.709%. You consequently need 2.8/0.709 = approximately 4 teeth less than 141, or 137 teeth. Fitting 137 will give you an increased odometer reading of 4 x 0.709% = 2.836%. Your readings will in other words be 0.036% fast compared to the Rally-Master's, which is of course only 0.36/1000 miles per mile or less than 2 feet per mile!!
On receipt of wheels ordered, we suggest that - for easy reference - you mark them with the percentage, PLUS or MINUS, that each wheel means to your instrument, thus avoiding mathematics during the rally.
A special storage unit, shown in the brochure, permits complete protection for your extra gear wheels and keeps them in neat order readily available for use.
A spare gear holder is another useful accessory for fast adjustment during a rally. You then also need a spare Z-wheel with the same number of teeth that you have in your instrument. When you know what X-wheel to use to equal the "Rally-Master's mile", you fit this and the Z-wheel to your spare gear holder and you then have a complete unit ready for inserting in the instrument, thereby further reducing the short time it takes to change gears.
We suggest that you order the parts you require from the same company that delivered your instrument.
HALDA MASTER is connected to the speedometer as shown in figure 1. The speedometer cable 4 is detached from the speedometer 1 and screwed instead on to the T-gear 3, which in turn is screwed direct on to the speedometer. In special cases where space is lacking, it may be necessary to insert an extension cable 2 between the speedometer and the T-gear. The drive cable 5 joints the T-gear to the MASTER 8. MASTERS are supplied as standard with the connection for the drive cable direct from the rear as shown on figure 1, alternative 1. If the connection is required at a right angle as shown in alternative 2, it is necessary to order as an extra, an L-gear part No. 705512. When several instruments are joined in series as alternative 3, a special T-gear with through drive, part No. 705508, must be ordered as additional equipment.
|
1. Speedometer 2. Extension cable 3. T-gear, ratio 8:1 4. Speedometer cable 5. Drive cable to MASTER 6. L-gear, ratio 1:1 7. T-gear, ratio 1:1 8. HALDA MASTER |
| Check that driving cable from
T-gear 3 enters gear 7 in direction of arrow, as indicated in figure 1, alternative 3. |
The drive cable is supplied with standard length of 24" (600 mm). Other lengths from table 1 are available if requested at the time of ordering.
T-gear for connection to the speedometer is supplied with screw connection and driving pin appropriate to the car for which it is required. Part numbers are shown in table 2.
Extension cables are supplied as extra accessories. Part numbers are shown in table 2 with details of connection thread types and driving pin dimensions.
|
|
||||||||||||||||||||||||||
The MASTER is provided with an adjustment gearing, by means of which the instrument can easily be accommodated
to every existing make of car - that is to say, to the number of revolutions made by the
speedometer drive to each mile or kilometer.
Looking at MASTER from the front, the gearing is found inside the left hand end plate, which can be lifted off after loosening the retaining screw. The position of the two change wheels X and Z is shown on fig. 2. The relation between the number of teeth on these wheels and the number of turns R per mile (km) of the speedometer cable is given in table 3.
MASTERS are delivered from the Works set for approximately 1000 revs of the speedo cable per mile (km).
When calibrating, the MASTER is zeroised and a trial run is made over an exact measured distance of 1 mile (km). The figure shown on the MASTER at the end of this test is multiplied by 10 and the resultant figure is sought in the table. This then shows the correct number of teeth required on the X- and Z-wheels.
Example: Suppose after the test that the 1/100 mile (km) figure wheel has stopped exactly between 3 and 4 and the 1/10 mile (km) figure wheel on 6 - then the total registered would be 63.5. Multiplying by 10 gives 635. Checking this value for R in the table shows that for this figure Z = 48 and X = 134. The X- and Z-wheels so determined must be fitted in the MASTER for this to show the correct distance.
| N° 145863 | N° 101508 | N° 145864 | |||||||
|---|---|---|---|---|---|---|---|---|---|
| X | Z | ||||||||
| 70 | 58 | 48 | 39 | 32 | 27 | 22 | 18 | 16 | |
| R | R | R | R | R | R | R | R | R | |
|
118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 |
383 387 390 393 396 400 403 406 409 412 416 419 422 425 429 432 435 438 442 445 448 451 455 458 461 464 468 471 474 477 481 484 487 |
463 466 470 474 478 482 486 490 493 498 502 506 510 514 517 521 525 529 553 537 541 545 549 553 557 561 565 568 572 576 580 584 588 |
559 564 568 573 578 583 587 592 597 602 606 611 616 621 625 630 635 639 644 649 654 658 663 668 673 677 682 687 692 696 701 706 711 |
688 694 700 705 711 717 723 729 735 740 746 752 758 764 770 775 781 787 793 799 805 810 816 822 828 834 840 845 851 857 863 869 874 |
838 846 853 860 867 874 881 888 895 902 909 917 924 931 938 945 952 959 966 973 981 988 995 1002 1009 1016 1023 1030 1037 1044 1052 1059 1066 |
994 1002 1011 1019 1027 1036 1044 1053 1061 1069 1078 1086 1095 1103 1112 1120 1128 1137 1145 1154 1162 1171 1179 1187 1196 1204 1213 1221 1229 1238 1246 1255 1263 |
1220 1230 1240 1251 1261 1271 1282 1292 1302 1313 1323 1333 1344 1354 1364 1375 1385 1395 1406 1416 1426 1437 1447 1457 1468 1478 1488 1499 1509 1519 1530 1540 1550 |
1491 1503 1516 1528 1541 1554 1566 1579 1592 1604 1617 1629 1642 1655 1667 1680 1693 1705 1718 1731 1743 1756 1768 1781 1794 1806 1819 1832 1844 1857 1869 1882 1895 |
1677 1691 1705 1719 1734 1748 1762 1776 1791 1805 1819 1833 1847 1862 1876 1890 1904 1918 1933 1947 1961 1975 1989 2004 2018 2032 2046 2061 2075 2089 2103 2117 2132 |
Manufactured by
HALDEX AB, HALMSTAD, SWEDEN
Cables: Haldex - Telex: 3584 - Telephones: 035/118560
CITY-TRYCK, HALMSTAD 118369
U.S. Distributor: Vilém B. Haan, Inc.
Los Angeles, California 90025
September 1969