# R/C options for live steam?



## Skeeterweazel (Feb 11, 2014)

Hello. Trying to figure out my options for R/C for my first loco, which will probably be a Regner Lumberjack (live steam). 
I'm planning on making an electronic "cruise control" for it. It may not pan out, but i'm assuming i'll get it figured out at some point.
Here are my needs as i see them:
1) control servo for throttle.
2) control servo for fwd/reverse
3) servo for whistle
4) input to adjust cruise control speed (dial?)
5) button/switch to turn cruise control on/off. Maybe can be incorporated into input above, e.g. if cruise input = 0, then cruise is off?

So that's 4-5 channels. TX-4 from RCS looks pretty good. But it mentions "THE TX-2s DOES NOT HAVE SERVO REVERSING OR SERVO TRIM ADJUSTMENT". Not sure what that's about.
http://www.rcs-rc.com/pages/tx-4s .

So, just wanted to throw this out and hopefully someone in-the-know will give me some pointers as to what direction i should be taking.

Thx.
Marty


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## TonyWalsham (Jan 2, 2008)

Hi Marty.

None of the RCS TX's have the servo reversing or trim controls normally found with the bulky stick TX's. They were designed that way to keep the costs down. You may not need them anyway.
If you do, I offer one channel servo reversing modules but they do not adjust the end point trims.
What I now offer is a DSM2-EM(AB) auto binding RX that is programmable on three channels for servo default direction of rotation and servo end point adjustment. Plus it has two directional lighting outputs for LED's.

You will not need the TX-4s for a Regner loco. It is designed for locos that require extra servos for drain cocks, blowers etc.
The TX-3 is perfectly suitable. There is a dedicated channel button to control a whistle servo.
You can either leave the knobs set where you want or turn the TX-3 off to cruise.


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## Skeeterweazel (Feb 11, 2014)

Tony, what is servo reversing? 
I don't see the TX-3 on the web page. Is it there?

Thx for our help.


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## Pete Thornton (Jan 2, 2008)

> 1) control servo for throttle.
> 2) control servo for fwd/reverse
> 3) servo for whistle
> 4) input to adjust cruise control speed (dial?)
> 5) button/switch to turn cruise control on/off. Maybe can be incorporated into input above, e.g. if cruise input = 0, then cruise is off?


Marty,

A couple of observations.
(1) the throttle may be all you need to control on board the loco. There is a strong opinion that you can run a loco using just the throttle - you just have to decide which way you want to run when you start it off! Opening and closing the throttle will get you up and down hills.
(Of course, if you want to switch cars at each end of the run, then you need reversing too.)

In the old days, they used to control the throttle with a mechanical governor. When the driven wheels went too fast, the governor closed the throttle, and vice versa.

Have you considered a mechanical cruise control, instead of electronic?


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## Skeeterweazel (Feb 11, 2014)

Pete, i initially thought to use mechanical governor, but wouldn't know how to do it. I think electronic will be the way to go- easier and more versatile.
Thx.
Balls out!


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## Semper Vaporo (Jan 2, 2008)

Some things to consider:

I don't know the Regner locos so I cannot state specifics about it, but in general:

Is the valve gear "real" or "simulated"? By that I mean how does it "reverse" the engine. 

If it is a slip eccentric then there really is no way to reverse the engine with a servo... you have to manually push the engine in the direction you want it to go to get the valve timing for that direction. You need just a servo on the Throttle to control the speed.

If a valve is used to reverse the flow of steam to the steam chest then there is no way to adjust the timing other than full forward or full reverse, but that Reversing Valve can be used in place of the Throttle to control speed... You open the "Throttle" to max and vary how far the Reversing Valve is engaged to limit the amount of steam that can flow to the steam chests. A mechanical system could control the "Throttle" to limit the max speed available and a single servo could control the speed below that by adjusting how far the Reversing Valve in engaged.

If the engine has "real" valve gear for reversing, then you need a servo for both the Throttle and the Reverser Lever because you "MAY" want to run the engine the way a real locomotive is run... First you put the Reverser into full engagement in the direction you want to go, then you open the throttle to get started and once up to speed, you back off on the Reverser to adjust the timing of the valve gear to limit how much steam is admitted to the cylinders and use the expansion of the steam to move the pistons instead of the full boiler pressure... Called the "Company Notch" because it uses less steam, so you used less water, which means you need less fire, so you save fuel and thus you stop less often to replenish the water and fuel.


Then you need to think about how the R/C system controls the servos. It seems that most systems designed for model trains (as opposed to model cars or airplanes) use a couple of buttons to adjust the servo positions... press one button to move the servo one direction a fixed amount per button press and press the other button to move the servo the other direction a fixed amount per press. This seems to work for some people but I found it too limiting.

If the button presses are set to move the servo in tiny amounts, such as, to produce say, 256 steps to move the servo through its full range; then to move the throttle from Off to full Open you have to press the button 256 times, or to Close the throttle from full Open you have to press the other button 256 times. That is too many times for me to press a button when I want to slow the train in a hurry (and I am good a pressing buttons on my TV remote when PBS is running their annual Beg-a-thon and I am searching the other channels for something worthwhile to view!). Conversely, if it takes only 8 presses of the button to go from Zero to Max, or back, then I find that for in-between settings, 6 presses is sometimes not enough and 7 presses is too much and I am constantly hitting alternate buttons to maintain the setting I want. So what is the "ideal" number of presses to move the servo from one end to the other and still provide fine enough of a step size to meet "my" expectations? Dunno!

I use an analog system with a stick or knob that I can flick from one setting to another and only the speed of the servo limits how fast the Throttle or Reverser or Whistle responds to the change of setting, and I can move the control in tiny increments to do any "fine tuning" I want to the setting of the Throttle or Reverser, or make the Whistle go WooOOOooo-woooOOOOoooo.

I went with a Car R/C controller; the Throttle of the locomotive is controlled with the "trigger"/accelerator control and the Reverser is controlled with the "Wheel"/steering control of the transmitter. I can control both with one hand holding the pistol grip of the controller. My index finger on the trigger to control the steam throttle servo and my thumb on the edge of the wheel to push it in either direction to control the Reverser position. The wheel only turns about 1/8 turn in either direction (really "responsive" steering for a car!) to adjust forward or reverse. And since both controls require constant hand pressure it is a great "dead-man's" switch... Let go of the controls and the throttle closes and the reverser centers to neutral and the engine stops. Emergency stops are just a quick flick of the thumb to throw the reverser in the opposite direction (watch those wheels spin in reverse as the locomotive slows and finally reverses!).

And the R/C transmitter has the ability to alter which direction the servo moves in response to a certain direction of movement of the transmitter control... for my right hand I have the steering wheel rotating Counter-clockwise (pushing my thumb "up") to be Forward and Clockwise (pulling my thumb "down") to be Reverse, but if I want to use my left hand I can reverse that setting on the transmitter so the same thumb movement produces the same result ("up" for Forward, and "Down" for Reverse).


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## TonyWalsham (Jan 2, 2008)

The TX-3 is on the Home page.










The insides are two knob controlled fully proportional channels. Just like a stick radio. The whistle control on the top right is a snap action from one extreme to the other and back again.
Best bit. You can fit it in your pocket.


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## BigRedOne (Dec 13, 2012)

I remember "reverse-rotation" servos being available when I began flying RC. (Not sure if they still are, since computer transmitters pretty much took over the upper end of the market decades ago.)

Servos can also be rewired internally. I'd feel timid to try it, but from your cruise control plan you seem comfortable with fine electronic work.

Last, if all else fails, changing the arrangement of control linkages, or fitting an intermediate mechanical bellcrank will reverse the linkage. It may even be practical to alter the arrangement of the apparatus which moves the valve rods.

In addition to reverse and throttle, wouldn't people want to control the fuel supply, or don't those really need adjusting in operation?


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## Skeeterweazel (Feb 11, 2014)

Semper Vaporo: Thx for your response.
All i know about the Lumberjack is that it has a lever to switch between forward and reverse. See video:




 .
Thx for explaining the Company Notch.
I can appreciate your TX but i don't think i want to have to constantly hold a trigger or wheel to make the loco go. Thats's what appeals to me about the RCS units, at least in theory. Still not totaly clear in how they work. I think, like you, i want the whistle on a servo that isn't just on/off so you can make it "go WooOOOooo-woooOOOOoooo".

Tony: thx to you too. And BigRedOne.
I don't see how the TX-3 fits my needs. I need a 3rd knob to adjust my cruise control, and a 4th for adjustable whistle (at least that's the plan). Doesn't the TX-4 better suit my plans?
I plan to have the RX and the servos connected to my micro controller (Arduino Micro). The controller will use inputs from the RX and signal the servos.
A simple tutorial for learning about the controler and servos has you connect them up and write a "sketch" telling the servo to move between 0 and 180 degress. Pretty simple. I've read that in some cases that a setting needs to be changed for servos to work corrctly, can't remember what it is, maybe pulse width. Servo i'm playing w/ is a little micro unit from Radio Shack. Hoping units i get for loco will work as well.

What kind of output comes from your RXs? Is it a linear Digital signal that i can use in my controler "sketch" to control things? This is probably my biggest concern- making sure i have useful signal out of the RX. 
R/C is all new to me so it's difficult to ask the right questions.

If servo is connected to RX it will only more 90 degrees? And this must be OK for most live steam applications? 

And still not clear on servo reversing. What is it? Do i need to worry about it?
Just thought to google it. All it is is a servo that works backwards? Don't see where this is an issue for me.

Thx so much for educating me. Please let me know if i'm seeing something wrong, or if anyone has any opinions. Don't be shy.

Marty.


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## Semper Vaporo (Jan 2, 2008)

That looks like the Reverser is controlling direction by causing the steam flow to reverse to the steam chests and not controlling the phase of the steam valves in the chests. As a matter of fact, there are NO steam valves in the steam chest! It is a matter of aligning one hole with the input to the cylinder to admit steam and another hole to allow used steam to exhaust from the cylinder, and on the other end of the cylinder the opposite is true. To reverse the engine, you swap which holes are aligned to either the steam supply or exhaust. And there is a point in-between where no holes are aligned and the engine doesn't run.

It is possible to get the holes only partially aligned and thus pinch off the flow of steam just like a throttle does and thus control the speed using this steam switching system as a throttle.... but the amount of movement of the lever to cut the steam, say just 1/2 off is very slight and would require very fine adjustment capability and very little slop in the linkages from the servo to the valve lever.



Servo reversing, as I understand it, is to be able to control which direction the servo moves in relation to a particular movement of the control on the transmitter.

Pushing the Tx lever forward, or turning the knob clockwise, might move the servo clockwise and that might "pull" on the controlled valve if the linkage comes to one end of the servo arm. You could connect the controlled valve to the other end of the servo arm (assuming the servo pivots in the center of the arm... top goes right, bottom goes left for clockwise movement)... or you could turn the servo over and still connect to the same end of the arm to get a reversal of the action on the valve. You could also insert a lever pivoted in the middle between the servo and the valve control such that pulling the top of that lever pushes the bottom in the other direction (bell crank action).

You can also rewire the servo to reverse the thing but that can be tedious to do and not damage something (don't ask!)

But it is possible that you cannot have the servo arm extend out the other direction due to obstructions, and no room to mount the servo on the other side, and no room for a bell crank in the middle, and you don't want to do rewiring inside the servo, so the transmitter can be re-programmed such that the servo will move in the opposite direction for the original movement of the control on the transmitter. (Which is what I do on my transmitter if I want to use my other hand to control the engine.)

As for not wanting to keep my hand on the control... well, you can defeat the spring returns on the transmitter controls and then they are a "set and forget" control... but "for ME" that defeats my reason for running Live Steam.

Electric trains are for "roundy-round" unattended running whilst you sip your tea.

"Live Steam" is for BEING the Engineer and HAVING control of the Locomotive.

You DO need to watch the level of water in the boiler and open or close the axle pump bypass valve (if so equipped) as needed, or stop and pump water into the boiler when the level gets low (or run an engine that definitely runs out of fuel before it runs low on water!)


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## TonyWalsham (Jan 2, 2008)

Hi Marty.
You can adjust the cruise control on the big knob. Just set the speed you want and let it go. You don't need an extra channel.
There is no need to feed the RX output into an Arduino. The knobs adjust everything.
Yes you could use a third knob to "play" the whistle, although most steam whistles I have seen are basically ON and OFF. So the TX-4s may be best.
Most servos are set for the correct rotation, although they are usually adjustable from the stick radios via a normal or reverse switch. My TX's do not have that feature to keep the cost down. My "Auto Bind" RX's do have that feature.


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## Skeeterweazel (Feb 11, 2014)

Tony, i'm guessing your CC doesn't work like i intend mine to. Mine will have a wheel sensor to measure speed, so when train goes up a grade, the Arduino will sense it is slowing down and add more throttle.
I intend to program it so i can run in CC mode, as well as in regular "manual" R/C mode. I'm sure i'll start out w/o R/C to learn how to run loco, then more to R/C, and then figure out the whole thing using Arduino and CC.
Thx.
Marty
P.S.: i'm really having fun communicating w/ you all. I love learning about all this steam loco stuff!


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## TonyWalsham (Jan 2, 2008)

All I can say is the knob outputs on my TX's are 300º movement of the knob to control 90º servo movement. Resulting in much finer control of a servo than a stick radio can provide. ......and you can fit the handpiece in your pocket.
They are not intended to be interfaced with any other type of control such as an Arduino.
Good luck with your search.


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## Garratt (Sep 15, 2012)

Marty, you need to divide and conquer for such a project. OK to do a quick tour of what is around but things need to evolve from what is functional into a cohesive system. All you have to do at this stage is to create a Picaxe (or whatever) set-up that reads the wheel speed and devise an algorithm that will control the regulator to keep the locomotive running at a consistent desired speed without it stalling, lagging, lunging or hunting. Once that is done then devise an interface to RC and the way it is controlled. There are many completely separate problems and possible solutions here before getting too ahead of yourself with how you think things should be.

Andrew


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## Garratt (Sep 15, 2012)

Tony, the details are in the devil. Ha ha!

Andrew


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## Skeeterweazel (Feb 11, 2014)

Garratt, i've done a fair amount of messing around w/ the Arduino and have a rough "sketch" of how it will work. I'm sure it will need tweaking.

If anyone knows what the output is from a modern RX please chime in. I would guess that whatever it is it will work for me; the Arduino is fairly adaptable.

Have a good weekend.

Marty


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## Semper Vaporo (Jan 2, 2008)

Tony -- Your systems just keep getting better and better... too bad I have already spent my money on what I am using (long before you came out with your 1st ones!).

But I have a question for you. I have always had the desire to build a mock-up of a Loco cab big enough to actually sit in. Maybe just 3 walls and a roof but with the looks on the inside of a Steam Locomotive cab. And then disassemble one of my car controllers/Tx units to mount the control elements in the mock-up such as I could have a full sized Throttle lever and a "Johnson bar" on the floor with a latching quadrant to control my Mike(s).

I realize one of the selling points is that your Tx controllers can fit in your pocket (and that IS a good point, compared to the monster pistol grip controllers I have), but what kinds of problems would I likely run into if I wanted to put the variable potentiometers (that the controller knobs are on) on the ends of some long wires to get one up on the front wall and the other down on the floor to be moved by my faux levers in the cab mock-up? Is there some practical limit to how long the wires could be? What kind of shielding would be necessary?

Yeah, I know, silly pipe dream, but I am still contemplating it!


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## TonyWalsham (Jan 2, 2008)

Hi Semper.
The short answer is, I have no idea.
I am not being deliberately evasive, but such an idea had not crossed this aging mind. You might be better off asking David Theunissen at Deltang.
It is he that provides me with the highly programmable TX2 modules he makes in the UK. David is very helpful.


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## BigRedOne (Dec 13, 2012)

Semper, why not keep the transmitter nearly intact and use fishing line or similar to connect the replica controls to the transmitter?

If you can avoid permanent modifications to the transmitter, you'll also have a better likelihood of selling it if you eventually wish to.


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## Gary Woolard (Jan 2, 2008)

Tony, I may have missed this -- but what receivers can your TX talk to? Do you have your own?

thanx,


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## TonyWalsham (Jan 2, 2008)

Hi Gary.
Any that are DSM2/DSMX compatible. eg Spektrum and Orange.
Or I can supply super smart RX's that are programmable.


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## Garratt (Sep 15, 2012)

Skeeterweazel said:


> Garratt, i've done a fair amount of messing around w/ the Arduino and have a rough "sketch" of how it will work. I'm sure it will need tweaking.
> 
> If anyone knows what the output is from a modern RX please chime in. I would guess that whatever it is it will work for me; the Arduino is fairly adaptable.
> 
> ...


Servo pulses... You will need to do a lot more than just twerking.

Andrew


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## Skeeterweazel (Feb 11, 2014)

According to Wikipedia.
http://en.wikipedia.org/wiki/Servo_(radio_control)

Radio control servos are connected through a standard three-wire connection: two wires for a DC power supply and one for control, carrying a PWM (pulse-width modulation) signal. Each servo has a separate connection and PWM signal from the radio control receiver. This signal is easily generated by simple electronics, or by microcontrollers such as the Arduino. This, together with their low-cost, has led to their wide adoption for robotics and physical computing.

The control signal is a digital PWM signal with a 50 Hz frame rate. Within each 20 ms timeframe, an active-high digital pulse controls the position. The pulse nominally ranges from 1.0 ms to 2.0 ms with 1.5 ms always being center of range. Pulse widths outside this range can be used for "overtravel" -moving the servo beyond its normal range.

A servo pulse of 1.5 ms width will typically set the servo to its "neutral" position or 45°, a pulse of 1.25 ms could set it to 0° and a pulse of 1.75 ms to 90°. The physical limits and timings of the servo hardware varies between brands and models, but a general servo's angular motion will travel somewhere in the range of 90° - 120° and the neutral position is almost always at 1.5 ms. This is the "standard pulse servo mode" used by all hobby analog servos.

RC servos are usually powered by the receiver which in turn is powered by battery packs or an electronic speed controller (ESC) with an integrated or a separate battery eliminator circuit (BEC). Common battery packs are either NiCd, NiMH or lithium-ion polymer battery (LiPo) type. Voltage ratings vary, but most receivers are operated at 5 V or 6 V.


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## Skeeterweazel (Feb 11, 2014)

pretty slick solution to control fwd/rvrs on Lumberjack:
http://www.buntbahn.de/modellbau/viewtopic.php?t=11642


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## Pete Thornton (Jan 2, 2008)

Skeeterweazel said:


> pretty slick solution to control fwd/rvrs on Lumberjack:
> http://www.buntbahn.de/modellbau/viewtopic.php?t=11642


The Mamod uses a similar reversing lever, so if you search for Mamod r/c you might get some ideas. I've seen (photos of) it done using levers back to the servo.


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## Skeeterweazel (Feb 11, 2014)

Tony, i see Tx-5 on website. How is that different than the TX-4?

thx.


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## TonyWalsham (Jan 2, 2008)

It isn't. I had to change the numbering system for the TX's so the name reflects the number of functions. The TX-4s actually has 5 x functions so it has become TX-5.
There is a new simplified TX-3 and soon there will be a TX-7 with 4 x discreet sound trigger functions.
All three will have a Ch # 5 button for a steam whistle.
The TX-2s and TX-20 will be phased out.


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## Skeeterweazel (Feb 11, 2014)

thx.


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## Cooke (Aug 26, 2012)

Tony, 

That's great to hear that you'll have 4 sound triggers. The more I learn about your system the more I like it. When might the TX-7 be ready for sale?

Patrick


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## Semper Vaporo (Jan 2, 2008)

BigRedOne said:


> Semper, why not keep the transmitter nearly intact and use fishing line or similar to connect the replica controls to the transmitter?
> 
> If you can avoid permanent modifications to the transmitter, you'll also have a better likelihood of selling it if you eventually wish to.


You'd be surprised at the Rube Goldberg contraptions I have come up with just to avoid taking a controller apart. Clamping the Johnson bar to the steering wheel of the controller is the simple part... Then a wire over multiple pulleys to push/pull the trigger from a bar mounted on the roof (roof throttle) or on the "Backhead", and a spring loaded rope to work the 3rd channel to blow the whistle. (One configuration was 12 pulleys!)


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## TonyWalsham (Jan 2, 2008)

Hi Patrick.
I need to get a small pcb made for mounting the 4 x push-buttons and associated resistors. That is going to take about a month. Inside the case it will be much neater and easier for me to assemble.
I will announce it 1st of April for delivery 1st of May. Deliveries will be in order date.
I have hand built a couple of working sample and they function just fine.


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## Batsco (Mar 30, 2011)

Skeeterweazel said:


> Hello. Trying to figure out my options for R/C for my first loco, which will probably be a Regner Lumberjack (live steam).
> I'm planning on making an electronic "cruise control" for it. It may not pan out, but i'm assuming i'll get it figured out at some point.
> Here are my needs as i see them:
> 1) control servo for throttle.
> ...


 You could try talking to this guy he has done something like you are after albeit with Picaxe.

Maybe you could just adapt his method to Arduino.

http://www.santacruzlumberco.com/MLS_PDFs/CruiseControlLiveSteam.pdf

This is a kit I bought for my Ruby it controls both Throttle and Reverser (Johnson Bar) works well of an elcheapo 2.4GHz Transmitter Receiver combo.

http://www.rc-steamers.com/rubykit.htm


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## Skeeterweazel (Feb 11, 2014)

Thx. Batsco. I have seen Dave's rig. Mine will be similar, but better. Ha!

My biggest issue is deciding on a TX. Leaning toward the RCS because i like the knobs. Don't think i've come across any negative stuff, but haven't see a lot of positive. Not that that's bad, just that users aren't posting reviews on it. I know Tony is on this board and i don't want it to seem i'm talking behind is back. I just want to try and educate myself about this stuff so what i do buy will work for me.

Marty


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## TonyWalsham (Jan 2, 2008)

Hi Marty.
Talk away.
You will not see many reviews of my TX's yet because they are only new to the market.
You are right to be cautious.
Perhaps you could ask for opinions on the Live Steam forum. Whilst some of the live steamers also run battery R/C not all do and therefore do not read this forum.


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