Fitting 2.4 ghz RC to a lgb stainz loco

[a98087]

As this been a few threads, I thought I'd post my advice about fitting RC to a lgb stainz loco

disclaimer

This isn't the best way to do things just a way I've found that works!!

It's a the same method as published by gregh on the sandstone and termite

Here's greghs link


http://www.members.optusnet.com.au/satr/2point4GHz.htm

1. choose your battery technology - a chose lipo due to size and weight

2. acquire all the parts you need:
Transmitter (tx). Mode 2 if possible, this puts the left stick normal position at the bottom not centralised
Receiver (Rx)
Electronic speed controller (esc)
Battery and charger
Servo
Dpdt toggle switch
Fuse
Lipo voltage monitor
On off switch

3. Dismantle loco and remove the following
Skates
Pick up bullets
If it's a 4 pin block the 2 pins that are the track pick ups, this is to improve the running of the chassis, and insulate from the track

4. Either solder a wire to each motor terminal, or use some female pin crimps, but you need about 6-8 inches of trailing wire leaving the motor block

That's the motor block finished

 

[a98087]

The next stage is to assemble and test the wiring loom

In the photo you can see:

White lump is a 3s 11.1v lipo battery

Black item is a brushed electronic speed controller (esc) that only does forward

Dark grey item with a white plasticard cam is a servo with a dpdt switch glued to the side

The small white box is the receiver

 

[a98087]

The purpose of the dpst switch is to swap the polarity over as the speed controller is very cheap about £4, but it only does one direction.

The cost of this system is
Esc £4
Servo £4
Dpdt switch £2
Receiver - depends on your chosen system

Prices are all from hobbyking

This makes it a bit cheaper than other systems, but it does take a bit more space than others.

dpdt switch

All this does is swap the esc output polarity over, by using the servo to operate the switch,


This set up feels nice in your hands as the left stick does the throttle and the right stick does the direction.

 

[a98087]

With regards of fitting the stainz here`s what I found

The transmitter fits perfectly in the roof mounted speaker moulding, just a small groove is needed to ease running the wires

You have to remove and discard the cab boiler moulding and the driver to fit everything in

You also need to remove the groves that are around the drivers feet, this is so that you can glue the servo down


The wires from the Rx to the servo and esc need to be run down the front of the cab where the firebox moulding was

The picture shows otherwise, but I found I had to reverse them after the picture was taken!!

Also in the finished model the battery and servo have swapped sides as its the only way it would fit



I hope this post helps a few people and any questions please ask

Dan

 

[Zerogee]

Very interesting thread, thanks for posting it.... just one question: Is there a particular reason that you didn't use a speed controller with forward and reverse, and thus not need the reversing switch and servo?

Is it that fwd/rev contriollers are significantly more expensive or difficult to get?

Oh, just one more: did you use a safety/control board for the LiPo battery, or is it the type with the circuitry built into the pack?

Jon.

 

[a98087]

With regards to speed controllers they can be divided into 3 types


Train, car and boat

Boat ones tend to all have full speed forwards, half speed reverse

Car ones have full speed forwards, half speed reverse and also a brake feature that can sometimes be turnt off

Train ones are full speed in each direction

Also trying to find an esc for brushed motors limits the choices, as car and planes are using more and more brushless motors as there more powerful

The only train ones I found was the Peter spoerer supplied ones that range from 24 to 35 pounds.
These work but the other method is cheaper.

And at £4 for a dc brushed 20 amp speed controller, it's a very good price

http://hobbyking.com/hobbyking/store/__9090__Turnigy_20A_BRUSHED_ESC.html

Dan

 

[Tony Walsham]

Dan.
Train ESC's fall into two types:
1. Centre off which uses just one channel for both speed and direction. Usually the elevator channel. Most ESC's are like that.
2. Low off where the direction is set with one channel and speed with another channel. Like as described above using a servo but way more sophisticated and more expensive. I make the Low OFF RCS OMEGA-3v7. The Deltang ESC's can be programmed for Low OFF as well.

Better quality ESC's usually come with directional constant brightness lighting and at least one sound trigger. Plus they will handle much higher voltages than the inexpensive one way ESC's.

 

[gregh]

You've done an amazing job fitting the servo/DPDT switch into a Stainz. (I'm pleased that someone has found my el-cheapo method useful.)

To answer Zerogee's question about voltage protection of the LiPO - the Hobbyking ESC has an undervoltage protector selected by a little plug. When volts get too low, it stops the motor!

You don't need overvoltage protection on the loco - you should use a charger that has that feature.

RE: the voltage rating of the Hobbyking ESC - it's supposedly only rated for 3S LiPo ie a max 12.6V. I have been using 4S (17V) and also 12, NiMH cells (16V) on two locos, for quite a while without problem.

 

[a98087]

Good points there Tony, I hadn't considered the sound or light outputs, I was more concerned about just easily converting trains to battery

And to answer the lipo question,

My experience with lipos is they have two sets of leads from the battery, a thick heavy gauge set that does the power, and a second set that is 4 wires if a 3s lipo that you connect to a lipo charger.

The battery can either be removed for charging or charged in situ, using a lipo charger extension lead, I use a 800ma charger so as not to cook the battery

Dan

 

[PhilP]

Slight thread drift..
There is a MyLocoSound ESC100/B listed on EvilBay at the moment (also known as an Electron 12).. Supposedly 0-24V at up to 12A. - Is this suitable for a loco, and does anyone know whether it is centre off, or low off please?

I can't find any instructions for this, so assume it is an older model??

 

[GAP]

Good points there Tony, I hadn't considered the sound or light outputs, I was more concerned about just easily converting trains to battery

And to answer the lipo question,

My experience with lipos is they have two sets of leads from the battery, a thick heavy gauge set that does the power, and a second set that is 4 wires if a 3s lipo that you connect to a lipo charger.

The battery can either be removed for charging or charged in situ, using a lipo charger extension lead, I use a 800ma charger so as not to cook the battery

Dan

All but one of my locos use this method and for a simple light solution I connected a white LED across the ESC output. I have 2 Stainz crying out for conversion so this will be very helpful, my other Stainz uses a trailing car(tender).

I have actually converted my transmitters so that I have throttle and direction control on the one stick.

Greg has the conversion on his site as well, it take less than 5 minutes to do the conversion and all that is required is a small piece of springy material to make a wiper.

I am very wary of LiPo after all the bad publicity they get, but after talking to 2 model plane fliers I am now going to use them.
I was told that the rule of thumb for charging them is at a rate of 50% of their capacity max ie 5000mAH charge at no more than 2500mA.
I was also told that LiFePO batteries are more stable so that will probably what I will go for.
Evidently a balancing charger is the way to go (it uses the smaller wires to monitor cell charge, more cells more wires)
One of the fliers has had LiFePO batteries installed in model jets and has been using them for a few years with no trouble and he charges them in-situ.

The loco that uses a different ESC (a robotics one, capable of powering 3 motors in parallel and has a higher input voltage level) it has the function of sensing the throttle stick position at switch on and making that the off.
So if I do not need reverse I can put the stick fully down and with the transmitter turned on I turn on the loco and the throttle is set in that configuration till I switch off the loco, reposition the stick and turn the loco back on.
I find that this gives me more flexibility for slow speed control.