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DelTang 2.4GHz receivers - pt.I
 Moderated by: W C Greene Page:  First Page Previous Page  1  2  3  4  5  6  7  ...  Next Page Last Page  
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 Posted: Mon Oct 1st, 2012 04:29 pm
   
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W C Greene
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VIVA LA BATTERIES!

Woodie



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 Posted: Tue Oct 2nd, 2012 07:40 am
   
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Bernd
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David,

I'm very interested in your minuature recievers. Here's the reason why. I have a thread going on motorizing a crane and it would be great if I could R/C the next one that I want to motorize.

The nice thing about a crane is that it has a crane tender car with it and one could hide the batteries in that to make it function without needing any kind of track power.

Still have to take some time to peruse your web site.

Bernd



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 Posted: Tue Oct 2nd, 2012 08:25 am
   
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DavidT
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Hi Bernd,
Nice build thread and some great engineering. Yes, my Rx43d-x-v5 receivers are intended for that kind of thing. They can have up to 3 integrated forward/reverse ESCs and a 4th external one. They can drive servos as well if those are more appropriate. And if you have spare channels on your transmitter (up to 7) you can switch lights on and off, have a flashing light, etc.

To do this kind of stuff the outputs have to be configured the right way. They all have a default that hopefully suits some people. But they are also intended to be customised. You can do that yourself or I can set up for you.
Regards, David.

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 Posted: Tue Oct 2nd, 2012 11:09 am
   
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Herb Kephart
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David--I was going to ask how much amperage those little boards will handle--doesn't look like there is enough there to dissipate much heat--but then I realized that you designed them for aircraft where the motors aren't bashful about how much current they consume.

Do you have gnats attached that cool things by flapping their wings?

Herb 



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 Posted: Tue Oct 2nd, 2012 11:30 am
   
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mwiz64
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Aircraft generally have lots of cooling provided by the prop so they can get away with a little more heat generated in the power system. That said, the current trend is to up the voltage and lower the current draw to get the same wattage to the drive shaft. That provides two benefits. One, everything runs cooler. Two, the whole system is more efficient thereby increasing run times. Of course, the down side is more cells in the battery pack. The trick is to strike a balance whereby the increased voltage allows the use of smaller (lower capacity) cells and still have the desired battery duration in a package that fits in the model.

There is another downside to higher voltage power systems in models and that's the threat of electrocution. I don't believe we'll be running any over 40 volt DC power systems in our little model trains. I did have a 3Kw power system in a helicopter that utilized a 10S lipo battery. Ive since sold the heli but not because of the power system. When that thing spooled up the sound of the rotor blades came close to the sound of the real thing. That was intimidating. And you should have seen and heard the spark the arming plug created... Yowza!

Mike

Last edited on Tue Oct 2nd, 2012 11:35 am by mwiz64



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 Posted: Tue Oct 2nd, 2012 12:27 pm
   
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DavidT
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Herb,
The gnats were retired after early tests :-) I've had almost no hardware failures over the past two years. My emphasis on surface vehicles is new but I've been using the 2-way motor driver chips for driving actuators in planes all that time.

Heat comes from current and resistance so from testing with a few trains of my own, reading about battery life on this forum and asking a few customers, I don't think trains normally draw high currents. So I'm not expecting heat issues. I've been told that 1:87 RC scale modellers use very small lipos that last a long time so again they seem to be a low average current application.

One of my test vehicles is a tank. This has 2 track motors and the traction to drive over obstacles/work hard. It also has a rotating turret. I found the receiver got a little warm while using up the whole capacity of the battery in energetic sessions. No concern from my side.

Technically the 2-way ESCs in my receivers are rated between 400mA and 800mA. So they should be used in appropriate vehicles. They have thermal protection so in extreme cases they will shut down. But I'd be very surprised if people experience this. But good question!
Regards, dt.

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 Posted: Tue Oct 2nd, 2012 01:03 pm
   
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Bernd
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Thanks for the compliments David.

What I'm looking at is 3 motors, possibly 4 to operate the crane. Those motors all work in the 4.8 volt range and miliamps for current. I was thinking of using a crane tender car to carry the battery and wire it to the crane.

You say that the Rx43d-x-v5 reciver will do all that I want?

It'll give me speed control and forward/reverse of all 3 or 4 motors independentley?

 If that's the case, great. I'll have to look into purchasing a reciever and play around with it. I'll be intouch via PM on this later.

Bernd



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 Posted: Tue Oct 2nd, 2012 02:48 pm
   
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DavidT
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Bernd,
You have two choices but Rx43d-4-v5 is the easiest way to control 4 motors. This has 3 separate on-board 2-way ESCs. It comes with an 'addon board' to create the 4th.

4 nicads or 1 lipo are the main battery options.

You will need a DSM2 transmitter. I can suggest some obvious options if you don't have one.

Feel free to ask if you have more questions.
Regards, David.

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 Posted: Tue Oct 2nd, 2012 03:11 pm
   
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DavidT
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A single lipo in case you don't know is nominally 3.7v but is charged to 4.2v. Voltage falls under load and as capacity is used. The receiver will cut power to the motors when it falls to 3v.

4 nicads or nimhs are nominally 4.8v but can be around 6v hot off charge and are very flat at around 3.6v. My receivers only have the 3v sensing but nicads and nimhs are usually OK with being discharged quite deeply.

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 Posted: Wed Oct 3rd, 2012 02:24 am
   
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35er
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Hi Guys

am a professional model builder who recently started using David's RC system in our 1:35 scale locomotives. I am delighted to say that these receiver/transmitters work very well with efficient motor/gearhead combinations (mostly 6 or 3v) and single cell LiPo's

simple installation with a built-in battery charge terminal on the underside of the model allows recharge without battery removal. this requires a simple isolation switch on the battery to motor connection to isolate the motor & receiver circuit whilst charging.

a single 380mAh LiPo provides in excess of 60minutes running time using a efficient can motor with 160:1 gearhead.

the installation meets our key criteria e.g. simple, fully concealed installation, basic control system without gimmicks, operation on rough track as is characteristic for narrow gauge industrial lines, all at a very low cost.

No connection with David's company except as a very satisfied customer.

have fun & stay cool
BernardS

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