Special Note: All of the technical modifications presented here are intended to enhance the performance of the RC model and in no way are any modifications required for operation. Likewise information presented here is not guaranteed and is offered as suggestion only.
Infra Red Battle Unit Emitter LED Installation - This Page - Discussion and test results of a gun barrel/muzzle brake mounted TBU emitter LED. Diode-Speed-Control
Turret Rotation for Tamiya 1/16 tanks - Page 2 - Turret traverse problems and the theory and a tested solution to correct this.
1/16 Tiger I and Tiger II bracing for use with metal tracks - Page 2 - Design upgrades for use with Metal tracks to improve operation.
Bandai Type IV performance run Out of the Box - Page 2 - Test results of running performance and comparative ability with Tamiya tanks.
Pershing MF unit combined with Sherman DMD unit - Page 2 - Test and operation results combining the Pershing Multi-function with the Sherman DMD controller.
Relative Scale Chart - Page 2 - Train scale reference for dioromas and accessories
King Tiger Idler Tension Conversion - Page 3 - New track tension system for the King Tiger idler that is reliable and cost effective.
Charging Switch - Page 4 - Install a charging switch and never have to take apart the tank again to get at the batteries.
Method for Steel Wheel conversion for Tiger I - Page 5 - Convert the Tiger I to a late production Steel Wheel version.
Tamiya Battle System Operational Bsics - Page 6 - Answers questions on how the electronic system works.
Infra Red Battle Unit Emitter LED Installation
The Tamiya IR emitter LED is mounted at the gun tip to better simulate firing. The flash unit is preserved in the muzzle brake. The LED is enclosed in an 1/8" mono phone plug available at any electronics store with the miniature phone jack mounted in the 1/8" end of the muzzle brake opening.
Installed on Tiger I Infrared LED installed in plug
Initial testing shows this to be a viable method of controlling dispersion and provides shielding from IR noise (daylight).
Pros: 1. Better beam control and slightly increased range; 2. more realistic source for firing than the mantlet; 3. Reduces friendly fire casualties when in close formations or crossfire conditions; 4. Removable for display or servicing/replacement of LED; 5. Co-exists with flash unit well; 6. Eliminates the blind spot created by the gun barrel when mounted in the mantlet.
Cons: 1. Aiming is more directional to gun elevation and traverse making hits more difficult; 2. It is visible and not hidden in the tank; 3. Wiring the gun barrel after construction can be difficult
Test Results: 1. Maximum range 110 feet 2. Maximum angle of dispersion off-axis 14 degrees (28 degree total spread) 3. No hits greater than 10 feet off-axis at any distance
The graph below demonstrates the hit area of the IR beam at various ranges and off-axis distances using the optional LED gun barrel mounted. The horizontal measurement is range in feet and the vertical is off-axis in feet.
x = Both score hit; T = Tiger scores hit; KT = King Tiger scores hit
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FEET |
0 |
5 |
10 |
15 |
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5 |
x |
--- |
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10 |
x |
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15 |
x |
--- |
--- |
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20 |
x |
KT |
--- |
--- |
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25 |
x |
x |
--- |
--- |
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30 |
x |
x |
--- |
--- |
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35 |
x |
x |
--- |
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40 |
x |
x |
--- |
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45 |
x |
x |
x |
--- |
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50 |
x |
x |
x |
--- |
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55 |
x |
x |
x |
--- |
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60 |
x |
x |
x |
--- |
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65 |
x |
x |
x |
--- |
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70 |
x |
x |
x |
--- |
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75 |
x |
x |
x |
--- |
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80 |
x |
x |
KT |
--- |
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85 |
x |
x |
--- |
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90 |
x |
x |
--- |
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95 |
x |
KT |
--- |
--- |
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100 |
T |
--- |
--- |
--- |
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105 |
T |
--- |
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110 |
T |
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115 |
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Test parameters: The test was performed with the Tiger I (56010) and Tiger II (56018) each armed with a Tamiya battle unit with the LED emitter mounted at the end of the gun barrel as shown above. Both subjects were fully charged with two 2400mah batteries each. Tests were performed outdoors on level grass not more than 2 inches in height and with no obstructions within 10 feet of the test range (to avoid absorption/reflection of IR signals) on a partly cloudy day (no direct sunlight). Measurements were made at 5 foot square intervals and interpolated between points.
Conclusions: The range is very good for outdoors on cloudy days being within 10 feet of Tamiya's published range similar to the pattern of control. The range difference of the two specimens may be due to the sun being at the back of the Tiger I and in the face of the King Tiger (although test conditions were cloudy, IR radiations from the sun are not fully diffused or attenuated). As seen on the graphs the directivety has a maximum 14 degree spread off-axis or total 28 degree total spread.
Install details: As for materials, a standard mono 1/8 plug and a miniature 1/8 jack will be all you need (both available at Radio Shack). As for wiring if this is done during the construction phase any small gauge wire fed through the barrel along side the flash unit should work. Because this was installed after construction, solid wire was used for custom inductor winding construction (26 gauge perhaps smaller, not sure) which had an enamel finish for insulation which is very thin. The extra thickness of rubber insulation would prohibit installation so an enamel insulation finish was the way to go.
For the LED and phone jack make sure the Anode is connected to the positive (Tamiya Red wire) voltage and the cathode to the negative (Black or Tamiya White wire) voltage. You can tell this from looking at the LED by the leads: On some manufacturers the longer lead is the Anode. Or you can tell this from looking at the dielectric layout in the LED: The small pin will be the Anode and the large bowl or dish shaped pin will be the Cathode. A third method you can check from a DMM (Digital Multi Meter) set to the Diode test function and verify polarity.
All this said, if the LED is wired in reverse there is a good possibility the LED may be damaged since it acts as a short for current flow and damages (burns up) the dielectric material.
As for soldering, this should not be a problem as any low wattage iron will be safe as long as contact is less than a few seconds on the leads.
The most critical element will be the fitting of the 1/8 in. jack in the muzzle brake opening. The Tiger I, Pershing and King Tiger have large enough brakes to accomodate the device. The Sherman 76mm may be a smaller fit requiring a bit of reaming or perhaps using the subminiature phono jacks commonly used with cell phones.
Test the fit first. The installation is much easier while the two halves of the muzzle brake are not assembled but if the 76mm brake is a one piece resin - there may be some added installation difficulty, requiring some cutting, Ouch!..
Replacement LED: Had an opportunity to test a Radio-Shack replacement IR LED for the Tamiya Battle System and the results are compareable.
Both the Tamiya LED and the Radio-Shack [part no. 276-143 (high intensity)] LED have the same wavelength emission and similar range
(up to 30m). So as a local (and cheap) replacement LED, this is a good alternative to the Tamiya LED.
Actually any IR LED at 940nm will work also.
Diode-Speed-Control
Electrical Representation:
This configuration reduces voltage at the motor by about 0.45 Volt to 0.9 Volt depending on current demand.
Physical Representation:
Successive pairs may be added in series to reduce speed even further. There is no direct correlation between number of diode pairs required for speed performance, but one pair may be sufficient for a scale 2-3mph speed reduction.
The diode size should be capable of full motor load. The motors are estimated based on resistive load testing to draw no more than 2 amperes which translates to a 15 Watt motor load.
The diode rating should be capable of a 3 ampere current of the rectifier type, continuous rating. These diodes are commonly available at Radio-Shack #276-1143 and other parts suppliers for 6-30 cents each.
The diode is better than a resistive load in that demand current will not be reduced. The disadvantage is reduced torque as the voltage (pressure) available is reduced.
This solution is also very well applied to reducing turret rotation speed as well, each pair affecting roughly 1-2 seconds in 360 degrees of rotation.
