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How small can an apple be?
Posted: Thu Feb 11, 2016 8:04 pm
by wibblywobbly
I was a bit bored, so spent a couple of hours experimenting with designs to see how compact and inconspicuous I could make an apple with 4 sensors and 4 led's. This was the final design, shown against a scalpel blade for reference.
Re: How small can an apple be?
Posted: Thu Feb 11, 2016 8:52 pm
by Rad_Schuhart
Wow looks good! Can you give me a list of what I need to buy to make one?
For the price of one tamiya unit we may be able to do 120 custom ones like yours with aliexpress!
Re: How small can an apple be?
Posted: Thu Feb 11, 2016 9:15 pm
by wibblywobbly
It's just 4 x VISHAY TSOP4838 sensors and 4x 5v superbright led's, though any led's will do. The moulding is simply a 3D printed one that I did. The led's clip into the top and the sensors slot into the base. Just needs a 5 pin plug to go to the main board eg IBU/Clark. It will also work on an Elmod board, easier really as they don't have a seperate IR emitter plug, their emitter is wired into the 5 pin.
Re: How small can an apple be?
Posted: Thu Feb 11, 2016 9:20 pm
by Rad_Schuhart
Thanks! I'll search for the components in aliexpress and I will try to do a couple for my tanks. For the emiter (the cannon) what do you use?
Re: How small can an apple be?
Posted: Thu Feb 11, 2016 9:34 pm
by wibblywobbly
Sensors
http://uk.farnell.com/vishay/tsop4838/i ... dp/4913190
Emitter
http://www.maplin.co.uk/p/940nm-infrare ... iode-yh70m
You'll also need the Molex plugs, preferably pre-wired, otherwise you will also need a crimping tool, they are tiny !
Re: How small can an apple be?
Posted: Fri Feb 12, 2016 7:25 am
by Rad_Schuhart
Thanks for your links. I took a look to them and searched them in aliexpress too. Also I found this receivers that are cheaper,
http://www.aliexpress.com/item/10pcs-Un ... e67c816224
Do you think they would work?
EDIT: This couple looks very cheap for being true
http://www.aliexpress.com/item/10pair-5 ... 764252f0a4
Re: How small can an apple be?
Posted: Fri Feb 12, 2016 8:19 am
by wibblywobbly
Without the specification for the sensors or the IR emitters, its not easy to tell whether they would work.
The Vishay sensors are a reputable brand, and known to suit RC tanks. If you can get hold of the spec for the AliExpress ones, and compare it to the Vishay ones, you will be able to see whether they are the same.
The emitters come in various specs, various ones have been used/tested over the years to see how they perform. As a 'very' general guide, the blue ones are higher power but shorter range, the white ones are pretty much an equivalent for the Tamiya emitter. The key is the 38khz frequency for Tamiya compatibility.
The acid test is whether an emitter will hit a sensor at 30 meters, and whether a sensor will detect an emitter at 30 meters.
I am going to see if I can shrink the sensor mount even further so that a tank commander will fit over it, I can mount the led's anywhere on the tank, but a plug in commander that is also an IR apple would be handy. If I can find a torso online that I can 3D print, I can create holes in it for the sensors.
Re: How small can an apple be?
Posted: Fri Feb 12, 2016 8:45 am
by Rad_Schuhart
I've seen some people that managed to put the IR sensors inside the heng long's tank commanders. Some of them even put the sensors inside of the small windows of panzer's cuppola and seemed to work.
Hope it helps.
Re: How small can an apple be?
Posted: Fri Feb 12, 2016 9:01 am
by Tankbear
Like Rob says the Vishay sensors are a quality brand and not expensive, so I wouldn’t even bother looking elsewhere to save a couple of pennies.
The IR emitter, there are millions available out there. But look at the data sheets and go for the narrow beam version because all the energy is going forward towards the target, a wider beam will have same energy but because wider won’t go as far.
Ian
Re: How small can an apple be?
Posted: Fri Feb 12, 2016 10:52 am
by Rad_Schuhart
Tankbear wrote:Like Rob says the Vishay sensors are a quality brand and not expensive, so I wouldn’t even bother looking elsewhere to save a couple of pennies.
The IR emitter, there are millions available out there. But look at the data sheets and go for the narrow beam version because all the energy is going forward towards the target, a wider beam will have same energy but because wider won’t go as far.
Ian
Then Ill buy that ones
I assume that I wont need any resistor, righ? Just the 4 IR Sensors, the 4 leds and the plug.