# esc questions



## D-n-H - Kirkville Branch (Jan 14, 2008)

@import url(http://www.mylargescale.com/Provide...ad.ashx?type=style&file=SyntaxHighlighter.css);@import url(/providers/htmleditorproviders/cehtmleditorprovider/dnngeneral.css); I have several of these ESC's ordered for critters and Bachman xmas 10 wheelers was wondering if there is another way to reverse the motor other then a servo hooked to a switch. http://www.hobbyking.com/hobbyking/...D_ESC.html and another question for probably Tony, if 2 ecs are turned on at the same time with one tx then the tx would control both (MU)ing them correct?? if that is true if one esc is in channel 3 and the other in say 1-2 or 4, why couldn't the two trains then be controlled at the same time in different directions?? or does both ESC's have to be plugged into channel 3??


----------



## Brandon (Jul 6, 2011)

Look at boat and car ESC's, some of those will support the same linear power in both directions.


----------



## Michael Glavin (Jan 2, 2009)

If you want a reverse function why not buy an ESC with reverse as used for cars and boats? Or yes you could complicate it all with a switch and servo with the associated cost thereof. 

Yes, you can use a single transmitter with multiple receivers either on the same receiver channel or any other proportional channel you have available. 

Michael


----------



## D-n-H - Kirkville Branch (Jan 14, 2008)

turnigy doesn't make a 20a brushed esc with reverse, kinda stupid, but for $5 I think it's still worth it for critters that can be put on a reverse loop dogbone.

as for the rx/tx question I may not have been entirely clear

i have 2 different locos that have 2 different esc's was wondering if putting one on channel 1 with channel 2 reverse, then have the other loco on channel 3 with reverse on 4, I could then run 2 locos at the same time with a 4 channel tx

@import url(http://www.mylargescale.com/Provide...ad.ashx?type=style&file=SyntaxHighlighter.css);@import url(/providers/htmleditorproviders/cehtmleditorprovider/dnngeneral.css);


----------



## Michael Glavin (Jan 2, 2009)

Yes, you can operate multiple RX's with a single TX. You can use the same RX channels for control of individually rigged loco's simultaneously, or as you suggest use different channels for independent operation of each loco. 

Michael


----------



## D-n-H - Kirkville Branch (Jan 14, 2008)

thanks wasn't sure if the esc HAD to be in slot/channel 3, if not then i should be able to take the spring out and make a second throttle and run 2 trains at a time.


----------



## TonyWalsham (Jan 2, 2008)

The problem with controlling reverse separately is that there will be no direction lockout, meaning you could reverse at full speed with disastrous results for the loco gears. 
Believe me, if it is possible to do it, it WILL happen and especially if you let children run the locos. 
There are very few car, boat or airplane brushed motor ESC's available that have reversing built in.


----------



## Michael Glavin (Jan 2, 2009)

Hi Tony,

There are actually many sources for brushed reversing motor ESC's out there, see the link below. That said the market share for brushless ESC's is much greater NOW than for brushed ESC's with REV.... And the cost for same supports my assertion. Your comment on INSTANT reverse with an ESC is spot on and a viable concern IMO too. again with the "that said" it would be no different than an operator throwing the REV switch on a powered track layout, seen this done many a time by children and adults too! 
REV ESC's


Michael


----------



## TonyWalsham (Jan 2, 2008)

Hello Michael. 

I guess I should have been more specific with my comment. 
Yes I agree there are quite a few brushed reversing ESC's available. 
What I meant was, there are not many that are suitable for most Large Scale locos. Especially the bigger locos made by AC and USAT. They typically need at least 14.4 volts. There are some LS locos that will operate satisfactorily with just 12 volts available. The Bachmann "Thomas and Friends" series are fast enough even on 9.6 volts. 
Most of the ESC's are limited to a lowish voltage, typically up to 9.6 volt max, and many of them do not have equal speed output in both directions. 
I know of none that offer directional constant brightness lighting outputs or sound trigger functions built in. 

One other point worth considering is when an ESC is a reversing type, they use just half the stick movement either side of neutral for both speed and direction. That gives much less precise control of speed when compared to an ESC that uses the full stick movement for controlling just speed.


----------



## D-n-H - Kirkville Branch (Jan 14, 2008)

the majority of the links in michaels post are actually for brushless esc's, the rest are bad links, lol 

if brushless motors better for car/boat/plane/helis how much longer until the railroad manufactures catch on and follow suit.. I see Aristo eventually alienating themselves with proprietary crap (units without the option of THEIR sound system and THEIR Rx?TX which will drive the average cost per loco up hundreds of dollars) 

Tony i have considered the fail safes with esc use, my sons engines won't have reverse for a while to alleviate any issues with him destroying his engines, and will allow me to run the same time without worrying too much about him changing directions when I'm running. 

As for me, I'm looking at having a mainline train doing laps on the roundy round and the second doing switch operations at slow speeds so accidentally switching directions sin't too big of a worry on my TX


----------



## Brandon (Jul 6, 2011)

I don't know why I didn't think of this before. Pololu makes speed controllers that can be operated from usb (what I'm doing), serial, or RC control. A 18v7 simple controller provides up to 30v (24v max recommended) and 7 amps continuous (30A peak for short periods with no heat sink installed) and for only $33. 

A list of all their simple controllers (no need for feedback or other specialized controllers) is here: http://www.pololu.com/catalog/category/94 

For comparison, the revolution has 8A max current and if you were really worried you could get a higher amp or voltage controller but there's no need. I've run a SD-45 off the 18v7 with no problems. 

The Pololu simple controllers also have a BEC port though they recommend you don't use it if your receiver has servos connected as it's limited to something like 500ma which can only really power a receiver. No soldering or anything needed, just plug a servo extension wire into both a receiver and the pololu, set the BEC jumper to either 3.3v or 5v and connect your battery and motor(s) wires to the screw tight ports and you're done. 

The pololu also does useful things like auto-range calibration for channel throw range, auto-cut off if motor problems are detected and you can also plug the controller into the usb port of a computer and configure acceleration and braking curves, voltage cut off, starting voltage, max voltage, max amps, 3000 speed steps in each direction, and all sorts of other cool and useful stuff.


----------



## D-n-H - Kirkville Branch (Jan 14, 2008)

interesting esc, thanks for adding it here, added to favorites to look it over again later


----------



## TonyWalsham (Jan 2, 2008)

US$33 certainly is a very impressively low price. 
However, the ESC does not have directional constant brightness lighting outputs, the speed control is over a 50% less stick throw, meaning the control is actually a lot touchier than using the full throw of a throttle stick and there are no sound trigger outputs. 
How much extra will you have to spend to get those features?


----------



## Brandon (Jul 6, 2011)

If comparing apples to apples, the pololu speed controller is in the same category as a car or boat esc but provides higher input and output voltages and amp ratings than car and boat esc's. Comparing apples to oranges a car/boat/pololu speed controller has different pros and cons than the train ESC's you sell at rcs, it's just preferences. 

For touchiness, that potentially could be a mute point as most transmitters now days have proportional control, but I believe the acceleration method used on the RCS does give a more precise control of a locomotive if you want to ignore laws of physics for trains and quick start or stop or vary momentum curves each time you start/stop a train, but that wasn't part of the conversation here (yet, as it's a good point to discuss, though the OP might not care about this for his particular situation). I should note that the pololu has 2 rc channel inputs so the second can be used for various functions including a speed limiter or quick kill (think e-stop) so if you want to have a train keep with constant momentum you can set the accel and decel speeds on the pololu and have an rc channel to e-stop if wanted or use the second channel to adjust the momentum curves in real time, similar (but obviously not the same method) as the RCS. 

Yes, a con of car/boat/pololu esc's is that you wouldn't have aux triggers or directional lights if locomotive isn't moving (ie:, the loco would behave as it would using track power) but the OP didn't ask about that either (yet?). However with a $4 picaxe someone could read the stats of a pololu via the serial link and do directional lighting like the rcs (say >= 0001 forward and


----------



## ralphbrades (Jan 3, 2008)

The real problem is -that there are very few manufacturers of dedicated ESCs for locomotives... I can think of only about four or five that I would recommend. I have used Electronize and they are very simple and rugged -but very low in functionality. Their FR15TVR is about as simple as it gets! I have lots of friends using the Brian Jones Mach5 for their Gauge 1, and 16mm locos. Although his blurb says you could use it for a Gauge '3' loco -I would not recommend it for G3 work as (personally) I do not think it has enough current capacity at only 7 Amperes. Cliff Barker makes his own and it is *very* nice! Again I would say that it is a good choice for Gauge 1 and 16mm (or smaller) but I again would say that it is underpowered for G3 work. His key fob device works on 433Mhz (which is legal in the EU). The Australian sourced system(!) gets a thumbs up from me for G1 and 16mm but Tony I think you have to look at some method of bus slaving of devices for the builders of DMU and EMU setups. (I do know that there are a couple of BELL-5 units being built). I do recommend the ESCs from "Dimension Engineering" for use with a Gauge '3' loco. These were originally designed for use with Battle Robots!!! Considering the size and weight of your typical G3 loco (circa 12 Kg) it is not too far out. They have the ability to interface with external control systems (such as PIC or STAMP) and are regenerative (useful in a large loco). 

regards 

ralph


----------



## TonyWalsham (Jan 2, 2008)

Hi Ralph. 
There are two ways to "slave" an RCS ESC. 
1). I offer a plug in slave unit for the 6 amp ESC but to operate with a degree of uniformity they MUST use the same voltage supply. Meant for one high curent loco only although you could have an ESC in one loco and a slave in the second loco powered by the 1st loco. 
2). If both locos are high current you can easily bind two different units to one TX. If it is necessary to compensate for any performance differences due to different battery voltages, each ESC (including any slave) can be speed matched for compatibility. 

In practice, speed matching is rarely required if both locos and battery voltages are of the same specifications.


----------



## Amber (Jul 29, 2011)

Tony, that system of slaving a second engine to the first engine while using the same batteries would probably work really well with a 3 unit setup such as an F7 A-B-A consist, using the B unit as the battery car. You could use a fairly large battery that way and have plenty of power for 2 powered engines.


----------



## D-n-H - Kirkville Branch (Jan 14, 2008)

Experimenting with the esc's that arrived Monday, Today i was running 3 locos independently with 1 tx, make the tx Mode 3 tonight so that I can run 4 at a time tomorrow, 

on the HobbyKing 2.4Ghz 6Ch Tx & Rx V2 (Mode 1)(THROTTLE ON RIGHT) - I took off the spring on the left stick and added a brass stick to match the right side. 

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9041 

channels 5 and 6 operate the 2 turn dials in the top left and right corners, granted the 2 esc's cannot be reversed by the tx, manual switches can be added to the locos to reverse them. 

channels 1-2 operate the throttle and a servo to change loco direction on the left stick 
channels 3-4 do the same on the right side


----------

