(Login flyer103) HyperScale Forums from IP address 220.127.116.11
I'm building the old Revell 1/32 Corsair and I want to install a small electric motor to turn the prop.
I'm not sure of the specs of the motor but on a single AA cell (1.5v) it turns the kit prop very nicely, and about as fast as I would want it to go. But it would be nice to be able to slow it down. I know this can be done with resistors or rheostats, but's I've never installed these.
If anyone has any suggestions I'd love to hear them.
...often slow to respond to requests by users to do anything (like posting a response). We tend to think the site has frozen up and hit the "post your response" button again (and again) which results in multiple posts. Take you time, and wait for the old technology to catch up to your wishes - it ain't you, it's the system we're on.
For all intents & purposes a rheostat is an adjustable resistor. You can put one in-line with the circuit.... best bet is to look into basic electronics and "do it yourself" sites. It's not that difficult, actually.
You can simply connect an adjustable resistor (a potentiometer, or "pot" in electronics parlance) to vary the current going to the motor. This would be a very crude method, but it would work. One drawback is that inevitably some of the power would be dissipated into heat on the resistor. For a typical 1.5V DC motor that might draw 30-50mA currents; something like a 25 Ohm, 2-3W rheostat should work.
The "right" way to do DC motor speed control in a setting like this is through PWM (pulse width modulation). PWM involves applying "pulses" to the motor, i.e. turning the motor on-and-off many times a second to adjust its effective speed. This is how almost all DC motor speed control is done in real systems, but it requires a dedicated circuit and/or microcontroller.
If this is a quick build to sit on a shelf, and you would only turn on the motor once in a while, anything more complex than a simple potentiometer might be overkill. But if this is a model that you would display in a museum or exhibit setting long-term; I personally would have used a simple Arduino microcontroller board-based solution. It would only cost around $10 (search for "Arduino Mini Pro" on Ebay) and perhaps 15 minutes of programming. It would be a good excuse to get started with simple microcontroller programming projects, too.
This message has been edited by KursadA from IP address 18.104.22.168 on Apr 4, 2012 2:33 PM This message has been edited by KursadA from IP address 22.214.171.124 on Apr 4, 2012 2:25 PM
Your user name and password will give you full posting privileges to all of HyperScale Forums.
Please note the following conditions of posting:
All contributions are welcome but please refrain from political or abusive comments, racially or religiously offensive remarks, swearing (including the thin disguising of swear words with asterisks and other characters), insulting language and crude metaphors. Please do not use Plane Talking as a public platform to complain about retailers or manufacturers (about issues such as broken or missing parts) before you have followed all normal channels to resolve any greivance. Plane Talking is not the place to conduct personal feuds or for posting personal attacks. Please do not post in capital letters only, as this is considered to be shouting and therefore impolite. Also, please do not post in 'texting message' word format. Any posts breaching these guidelines will promptly be removed from the server and the offender may be excluded from further posting to the HyperScale Forums. Off-topic posts may also be removed from the server.
In addition, Plane Talking is not a forum for the public criticism of the models that appear as Galleries or Articles. Please make any suggestions for improvements or criticism direct to the author via the email link at the bottom of the Article.
Finally, please note that this Discussion Group is privately operated and that I reserve the right to delete any post or cancel any registration for any reason whatsoever.