Large Scale Central

I feel a bash coming on

Modeling
#41

I looked at that link and am having a hard time telling the, for instance, power usage for these vs a regular motor. Any idea for the watt requirements? I saw 3 amps at 8.4 volts but that seemed to be a maximum and not the normal. And they seem to be on average about 1 rotation/second, or about 50-80 rpm.

I’m wondering what the battery life would be for a servo vs a motor, and also how this fits with existing decoders. Do the current decoders (such as airwire) do pure voltage variation to control speed, or do they do pulse width modulation (which this seems to be.

I’m afraid I’m also a bit confused about why servos take both a VCC (like 5 volts) input and a separate PWM (pulse width modulation) input to control speed. Why do they need both? Anybody know?

Thanks!

#42

I had asked for a 5-6v motor for my bash, that was all the battery I have room for.(https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-laughing.gif)

I don’t know why Tony didn’t start a side thread for the Servos he sells.

#43

Yeah, sorry to help sidetrack your build thread. I’ll take any other conversation about servos elsewhere. Have fun on your build, John!

#44

John. I don’t sell those continuous rotation servos.

I posted the link to assist others as to where they can find them.

#45

Tony Walsham said:

John. I don’t sell those continuous rotation servos.

I posted the link to assist others as to where they can find them.

I don’t think I’ll be buying Australian Servos … but this thread wasn’t about servos and I was only showing what I had done as part of my build, but go ahead…

#46

…and what??

#47

Sorry Tony, I was in the 5-6 volt frame of mind and your link went else where and I didn’t see the correlation.

#48

Not a problem John.

As I said, I only posted the link in case others were interested in more information on continuous run servos.

I don’t actually sell them.

#49

John

How are you controlling the servo, with the radio system you alluded too, or?

Michael

#50

Michael Glavin said:

John

How are you controlling the servo, with the radio system you alluded too, or?

Michael

Either a magnet waved over the cab or I have a remote that controls small lights and I might steal that…

I only had 2 locos and one of me, I still use those R/C units for them.

Motorizing my truck is an after thought, I still have the ditcher to mount on the back. There won’t be much room for a battery(https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-surprised.gif) On/Off and I think I can make an extension to the pot to change direction manually.

#51

John,

Sounds like you intend to simply power the servo with said ON/OFF and a battery? I didn’t think the servo would function without a control signal (PWM) and or it would simply free wheel without benefit of a command to position control signal.

Michael

#52

Check the Servo thread, Tony and Eric are answering those questions.

I was told I could make a cheap 5-6 volt motor from it. I am learning as I go.

#53

Well Okay then, since my freebie isn’t as robust as envisioned, I’ve found another drive that might be better. Does anybody have an opinion on the Tamiya metal gear box and low power motor?

I like the dual shafts so I can hang chains on both sides. It also has another powered shaft pointing forward for maybe a radiator fan… 6v

The worm and worm gear are metal.

#54

John

Not familiar with the Tamiya gear box, but it looks like a great idea. The Mac’s chain driven rear axle is perfect for this! Spinning a fan with the aux shaft is a neat idea, maybe you can remove the hood sides to show this feature off.

Michael