Thank you! That''''s a very compact solution indeed! I have a suggestion: why don''''t you cut (or build) and mount over the servo arm an elevation wheel like the one used in the standard elevation unit, minus the geared border? If the stock wheel is too big, you can cut your own profile (it''''s just a triangle) and fit it to your needs. That would allow for a smoother movement, without sudden returns of the gun to the starting position. But maybe you already thought about that and simply there is not room enough. I hope the picture helps to make myself clear. Another question: which is the rated voltage for the servo you used? I just found max 5V ones.
In the while, I can post a couple more pictures. After cutting, bending and fitting the aluminium support, I finally found a solution for the "power plant".
The fake motor will cover the two main switches (single pole each) and act as a big pushbutton. I thought that opening the motor hatches and pressing the motor itself to start the tank will be cool. Since the battery is split, and I want a recharge plug too, the power supply circuit was a bit complicated to design and fit. The batteries must be connected in series, then the supply Y-split, then both wires intercepted by the switches to protect the electronics while charging. After the switches I had also to foresee the additional power supply to the turret for the gun sound card. Last night I connected everything and tested the circuit, and everything run.
Still to do: - the whole front and rear lights circuit, which I want to be switchable on and off, and plan to hide the switch under a crate of the stowage. - the hull Mg gun - hiding the volume knob under one of the front spare wheels transported in front of the hull - turret rotation and connections
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I see what you mean. I have a spare unit and will look at that solution. And yes, it is a tight fit. As for voltage I don''t know. I has to cut the wires from the servo and solder them directly to the servo drive motor. So I guess voltage restriction is no longer a problem
If the original wheel is still too large, you can cut your own profile from a tube or something cylindrical which fits the servo arm lenght as its base radius.
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Joined: 5/1/2007 From: Escondido,
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quote:
ORIGINAL: borealis
In the while, I can post a couple more pictures. After cutting, bending and fitting the aluminium support, I finally found a solution for the "power plant".
The fake motor will cover the two main switches (single pole each) and act as a big pushbutton. I thought that opening the motor hatches and pressing the motor itself to start the tank will be cool. Since the battery is split, and I want a recharge plug too, the power supply circuit was a bit complicated to design and fit. The batteries must be connected in series, then the supply Y-split, then both wires intercepted by the switches to protect the electronics while charging. After the switches I had also to foresee the additional power supply to the turret for the gun sound card. Last night I connected everything and tested the circuit, and everything run.
Still to do: - the whole front and rear lights circuit, which I want to be switchable on and off, and plan to hide the switch under a crate of the stowage. - the hull Mg gun - hiding the volume knob under one of the front spare wheels transported in front of the hull - turret rotation and connections
Awesome Borealis,
Man this is coming together sweet, I fricken think that idea of pushing on the motor to start is very cool! Looking forward to you next progress report!
The lower hull has finally found its (hopefully) final layout. - The 2nd speaker has been mounted on a vertical styrene wall between the motor vane and the electronics. - The receiver board is mounted upside down over the gearboxes on the left (its back is covered in black insulating tape to avoid shortening issues) - the wire antenna is next to the control board - the volume knob is disguised and will be operated through one of the front spare wheels. - the engine compartment and the engine itself (which operates as the main switch pushbutton) have been painted and weathered.
I had a problem with two of the AA batteries (maybe during a test charge): they leaked some sort of white acid on the aluminium supports. I had to clean the most of it using the dremel and was lucky it didn't pour over the electronics!
Now the upper hull and the "mysteries of the leds".
I put two ultra-bright white leds on the front and two red leds on the rear lights, as well as an MG led. I wanted the lights to be switchable on and off because in daylight there's no need to have the lights on, (apart from using them as a feedback that the main board is powered).
The lights switch is disguised under a wooden crate, and is operated by sliding the crate itself back and forth.
After connecting the front and rear leds in parallel, I found that I wasnt' able to keep the four of them switched on at the same time. If the 4 where connected, only the rear ones would turn on, and as I removed the wires for them the front lights turned on. I tried different connections, adding wires etc, but my only ipothesis is that pins 1 and 3 do not supply enough power for the leds I used. But that goes beyond the basic knowledge of simple circuits I have, therefore I accepted it as an act of faith and changed the connections in an (acceptable) working way: now only the rear lights blink when I press the engine-button (so I can check it both the red buttons hidden under the engine have been correctly pressed) and when I push the ingnition button on the transmitter, they stay lit. If I want to run the tank in the dark or at night, I slide the wooden crate and the two front lights turn on (while the rear ones turn off), and they are quite bright.
After the final check, all of the wires have been secured (and the connections insulated( using a hot glue gun.
Now it seems that next one will be a painting session.
If anyone has drawings of a VHSS M4A3 105 Sherman, please post them: I might choose a different camouflage (well, the markings mostly, since it's all olive drab).
< Message edited by borealis -- 4/24/2008 10:16:07 AM >
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All Forums >> RC Cars, Buggies, Trucks, Tanks and more >> RC Tanks >> RE: 1/18 RC Sherman 
RE: 1/18 RC Sherman - 
Borealis, the toyish sherman tank is totally transformed under your skillful hand. 
I'm very impressed. Wish I've got half your skills... 