Large Scale Central

Control System for a 250 Ton Crane

Problem Solving
#1

So Another project I have had on my bench for far too long now is a GAL Line 250 Ton Crane Kit. The issue really isn’t in assembling it it is how can I control it. Originally I bought controls and parts for a RC plane to drive the Servo’s.

In the end I really do not want to be carting around a RC plane remote to control this thing. I am using RailPro now for my loco’s but that doesn’t support servo control. I looked into using Tony’s RCS system but I don’t think his system is setup to handle the servo’s running a full 360 degrees unit told to stop. Any idea’s on how to control these as while I do decoders and other things I am really not knowledgeable in the RC world and how to control servo’s. I haven’t finished this crane because I need to get the control system settled and installed before I can finish.

#2

Joseph Lupinski said:

In the end I really do not want to be carting around a RC plane remote to control this thing.

Why? It will be a show piece not a daily runner? Thinking 6 or 8 channel.

#3

Hello Joseph.

I played around with continual rotation servos with the idea of making them bi-directional very small power units for smaller locos.

The concept works just fine using the regular RCS TX-5 which has 4 x Digital Proportional channels. The new much smaller # DU-Tx-5 is exactly the same internally.

I was working with servos from Continual Rotation servos

They all worked very well although the speed control on the smaller units was a bit ON - OFF at very low speed.

#4

Hi Tony, was hoping you would see this. When tried you system hooked up for some reason a few servos just kept turning even though they weren’t being told to and couldnt stop them. Wast sure if your system was looking for the one directions stop point and since I made it 360 continuous it didn’t know what to do. So from your post I assume you tinkered with the idea but never fully produced it?

#5

Hi Joseph.
The continual rotation servos in the link are fully controllable forward and reverse with centre position of the channel knob being off. Just like a Centre OFF ESC such as the VIPER series I sell from the UK.

I may still offer them as small Loco/Rail car drive systems as they run just nicely on 5 volts and are = to an ESC and motor in one package.
All I needed to do was a bit more research into the chain drives and they would be ready to go.
I just haven’t had the time what with supplying R/C packages to Argyle Locos for the Accucraft NA’s plus the new C38 due out soon, and developing the new smaller Tx handpieces.

#6

I helped a friend doing tis with a reviolution.

We used the speed control just for all the motors which get selected via function keys.

I used the 75452 IC chip (dual open collector amp capable of 200ma with less than 10ma {current rating of revo funciton keys}. Just needed to make a 5 volt wource for the 75452.

His crane worked for many years with this setup.

#7

One thing you can do with Digital Proportional R/C that has 4 x knobs, is operate all four channels independently and at the same time.