DCC Turn Out Help

[rrinker]

 Unless they greatly changed, the Athearn 6-wheels trucks ALWAYS rolled better than the 4 wheel ones. Doesn't make much sense because there are more gears in the 6 axle, but they did. Quiet and smooth, every old BB with 6 wheel trucks (with the plastic sideframes - the older metal ones with outside bearings, forget it). I had a BB S-12 switcher, I MADE it run smooth and quiet by one, replacing the gears with an Ernst slow speed set - top speed maybe 30smph after that), second, lapped the gears in by runnign toothpaste in the gearbox in both directions, the thoroughly washing it all out and repalcing with proper plastic-compatible gear lube, and third, repalcing the wheels with NWSL nickle-silver wheels. Oh and I got rid of the metal strap across the top and sodlered a wire from each truck tower to the motor. The gearboxes were so smooth that I could set the thign on a piece of track with the worms pulled out and tilt it and it would roll, not slide. No gear noise, but since the motor ran relatively faster it wasn't exactly quiet under power. I did a pulling test at the club layout, piling on as much weight as I could get to sit on top of the body without falling off - I forgot how many cars anymore on the grade but it wa a lot, but I never could get it weighted down enough to stall the motor, it ALWAYS slipped. So if you are getting BB locos to actually stapp out where th motor stops turning - something's wrong. Mine slipped even with stacks of lead squares balanced on the top of the hood and cab roof - ie more weight they you could possibly add in a 'normal' fashion. Stock weight, forget it. - besides the weights on top I had already packed the inside of the shell with as much weight as would clear the motor and gears.

                                                    --Randy

 

[cudaken]

modelmaker51

As a rule of thumb, a 4 axle engine should pull 10 -12 cars for best efficiency, a six axle engine about 15 cars

 

 Jay, that part I do not get. From what I have seen in the parts list, a 4 axle engine will use the same motor as a 6 axel engine. So why would the same motor run easier with more traction effect? In fact the 4 wheel axel should run cooler do to less friction from the extra gears in the trucks. Then there is the extra weight of the engine.

       Cuda Ken

[modelmaker51]

cudaken

 These are RTR Athearns, not old Blue Boxes. My Athearns RTR's are maybe 1 year old if that. I tested the SD 50 that I replaced the motor (used a used motor of same type) with DC Chip and a with MRC 2500 and stall was hight at 2.0 Amps, but! With a 20 car drag it only pulled .4 amps, DH 123 range is 1.5 amp to high of 2 amps.

 Today's Athearn motors should draw about .75 to 1.0 amps at startup and cruise at about 0.3 to 0.5 amps pulling a good size train.(15 cars).

As a rule of thumb, a 4 axle engine should pull 10 -12 cars for best efficiency, a six axle engine about 15 cars, if you pulling more per engine, you're definitely over working the locos. The harder you work them the hotter the motor gets, the less efficient it gets, (more amps). Over 12-15 cars, double the engines for better efficiency and lower current draw.

A 1.5 amp decoder should be fine with Athearn's RTR and late BB engines, if you go by the Rule Of Thumb above.

[cudaken]

davidmbedard

No, Athearn RTR locos draw more current over time.  Eventually you will be beyond your decoder's capability.   This sounds like what is happening.

 Dave not sure what the No was about?

davidmbedard

You have a few choices, but the one I would go for would be to remotor your Athearn units.  With a can motor you can go from a 1 amp draw to a .1 amp draw.

 These are RTR Athearns, not old Blue Boxes. My Athearns RTR's are maybe 1 year old if that. I tested the SD 50 that I replaced the motor (used a used motor of same type) with DC Chip and a with MRC 2500 and stall was hight at 2.0 Amps, but! With a 20 car drag it only pulled .4 amps, DH 123 range is 1.5 amp to high of 2 amps.

 Thanks for the answer but little uncleared to what it was about.

                Cuda Ken 

 

[cudaken]

 Most of the engines that have had there decoders go bad are Athearn RTR where all I had to do was plug in the decoder, so the motors are not grounded.

 I all so tested the volts at the rails and I am at 14.5 volts.

 I will add, the decoders do not go bad fast. Many of them have lasted 100 of hours before they go out. Only 2 engines that ate there decoder sort of fast was the SP RTR SD 50 by Athearn, it took a lot throttle to get it started, I have replaced the motor and board and seem fine. It's decoder lasted around 40 hours. Second one is the old PK BL 2 that started this post, it ate it first decoder in under 2 hours, that is the one that sparkerd. Replaced the cracked center gears and thought it was fine, ate a second decoder in about the same time frame. I thinking it's the old steel wheels, will test it stall stall power later.

 I am 95% sure what is happing is there is a small short out there that does not happen all the time, it is slowly eating away at the decoders till they go bad. Booster breaker is not killing the power when the short happens. Case in point, last year my Athearn Dash 9 stalled in a tunnel on the C line. It some how melted the wires from the trucks to the board, and damgaed the board (funny thing is the decoder made it?) and track power never shut down. It was not till I saw smoke coming out of the tunnel that I knew there was a problem, I was watching the A and B line. 

 I am calling Tony's today to find out about a breaker system for my layout.

 Thanks for all the help and I will up date after I talk to Tony's today.

                        Cuda Ken 

[maxman]

retsignalmtr

another thing that i see is that it could be caused by a high inrush voltage not current. this would occur when the short happens and the voltage drops. then when the short clears the voltage spike could damage the decoder. the way i see this problem resolving is just to cure the shorting situation.

The inrush voltage idea has merit, except that what has been described as happening is that the decoder fries at the moment of the short.  There has been no indication (as yet) that the booster breaker is tripping and resetting continously.  Resolving the short situation also has merit, except that he seems to have a bunch of different shorts occurring.

I believe that he has also described some decoder failures with the engines running along apparently normally.

Again my opinion would be that he would have nothing to lose by adding the protection of a breaker.

[retsignalmtr]

maxman: electricity always takes the path of least resistance. unless there is a defect with the decoder it will only draw the current it needs to run the motor, light the lights or make the sound work. it may be that the motor is not properly isolated from the frame. having been an electrical worker all my life i am familiar with inrush currents that could get to 10 to 20 times the current rating of a circuit breaker for only a millisecond or so and have seen circuit breakers that are very sensitive to this. another thing that i see is that it could be caused by a high inrush voltage not current. this would occur when the short happens and the voltage drops. then when the short clears the voltage spike could damage the decoder. the way i see this problem resolving is just to cure the shorting situation.

[maxman]

retsignalmtr

if a wheel on a loco bridges two rails of different polarity it will cause a short. the current will rise to the level that will trip the comand stations internal circuit breaker. this over current will never get to the decoder itself as it passes through the wheel only.

I have thought about this, and you might be correct.  I can see that the current passes through the wheel, but not being electrically minded I don't completely understand why the current will know not to bypass the locomotive/decoder.  Is there not still a circuit through through the engine as long as it is still sitting on the rails?  Is not the engine in parallel with the wheel?  Inquiring minds want to know!

Anyhow, I still think a circuit breaker of some sort is required, especially if there is 8 amps or so capable of being applied.  What seems to work well for most people is the DCC Specialities PSX1.  See http://www.tonystrains.com/products/dccspecialties.htm.  This breaker has some sensitivity adjustment that comes in handy if you have sound engines that have a high inrush current at powerup.  The breaker somehow can differentiate between the inrush and a short.  But that's another subject.

So far as measuring stall current goes, yes that is good to know if you are sizing decoders.  But from what is being described the decoders are being cooked following a short circuit iteration.  Assuming a correct decoder installation, the only way I see so many decoder failures happening is too much current flow from somewhere.  While there may be some other problem, I still see the breaker as a requirement.  There is the issue of cost, but when you eat 2 or 3 decoders at a sitting you don't have too much to lose trying the breaker.

My opinion anyway.

Regards

[retsignalmtr]

if a wheel on a loco bridges two rails of different polarity it will cause a short. the current will rise to the level that will trip the comand stations internal circuit breaker. this over current will never get to the decoder itself as it passes through the wheel only. i have a digitrax empire builder system. the circuit breaker trips in 1/8th of a second. i have had many shorts at frogs of insulfrog peco switches and have used nail polish on the frogs which has cut down on the shorts. another thing is i have changed the speed that the system reacts to a short to 1/2 second. changing this react time allows the loco to keep moving and get past the spot where the wheel is creating the short before the system reacts to the short and stops the loco. also just because a wheel bridges two rails does not mean that the circuit protection will react if the current does not rise to the level it is set for. i have had a loco derail and the system didn't react to a short but the heat from the high current melted the plastic frog that the wheel was on and the only way i knew something was wrong is when i smelt burning plastic. the truck sideframe was also damaged but the decoder wasn't affected at all. after i removed the loco i tested the area with a quarted and the system did react to it. 

[cudaken]

maxman

This question was asked by someone before in another thread started by Cudaken.  As far as I can tell it has not been answered, but maybe I'm mistaken.  My impression is that the 8 amp thing is connected without any current protection other than any internal breaker it might have.  If this is really the case, then every time he has a short the current will flow up to the internal breaker setting, or at least to the point where a decoder fries and breaks the circuit.  The way his railroad eats decoders, I'm wondering if this is the case.

 Maxman and Martin, only circuit breaker is in the booster it self, and I will add it is slow. Could you post links about add on circuit breakers. On a ideal bench, there should be no shorts to protect the decoders from.

 I will post pictures of the turnout later, I am worn out and just got home from my LHS, open till 10 PM on Thursdays. From what I got from the club members tonight it is installed right. Only power is coming from the heal, both toes have plastic rail joiners on both sides of the rails. I picked up a new Atlas 6 to be on the safe side. God it must be longer than I thought when I bought the last number 6, I was set back a little when I saw $12.95, last ones I bought where $8.95. Turnout that sparked is old, you can see the rivets that hold the blades.

 On the nail polish trick, I used that when I ran DC on the Peaco turnouts I have. I have not used it for a year, before I could see the arch, but only happen with my PK E-6's. They have not seen any duty for 2 years after I went DCC. Tonight I was told again power to the heel and insulted joiners on the toes where find, is that right? 

 OK, out of gage wheels could cause the arch. What is the wheel is to wide? With the older PK BL 2's they could be a older style, how do you check the withe? I would think the newer Athearn RTR SD 50 there wheels should be fine.

 Today at work I did use the multimeter and tested the stall amps. SD 50 #1 using a MRC 2500 stalled at 1.66 amps. Test the motor from the problems SD 50 #2 that had a high stall speed (Remember I have 2 SD 50 RTR by Athearn, one that went bad last night was never a problem till last night) stalled at 1.26 amps out of the engine. Tested a new RTR motor I was going to replaces it with and it all so stalled at 1.26 to 1.30 amps. Hum # 2 motor seems fine.

 While I was at K-10 Model Trains tonight one of the so call experts (he still know more than me for now) said I should stall at 1amp? Using the DC line with a MRC 9500 with meters (I sure wished I kept mine) it stalled at 2 amps. He then told me that was the problem and he has a A B F7's by Proto ran by one decoder and both engines at the same time would stall at 1 amp? Put them on the track and held them down while I started giving them power, Hum, at 1/3 they peg the meter at 3 amps! So much for local experts.

Then we ran my SD 50 # 1 with a 20 car drag, at a good clip say 50 sMPH it only pulled .4 amps. So it is with in range of the DH 123 power handling and nothing wrong with the engine.

 I want to thank all the kind folks that are trying to help. If you are willing to talk with me on the phone PM me with your number and time I could call. I type real slow, this has taken me over a hour to misspell.

 Stock tip, if Digitrax is publicly trade and I stay with DCC! You will make a killing!

       Dazes Confused Crap

                   Cuda Ken

[mfm37]

 First make sure that all of the track including turnouts passes the quarter test. Short the track everywhere and see if the booster's internal circuit breaker trips immediately. By immediately. I mean start counting as you short the rails. If you get to two before the breaker trips, that's too long. Add feeders or increase bus size until the test works everywhere,

Next, invest in a DCC circuit breaker that can be set to a lower trip current than the 8amp booster. 8 amps is really too much to be throwing at HO or N scale power districts. Passing the quarter test should keep you from frying decoders ut those boosters will automatically reset and make the whole 8 amps available each time it tries to reset.

 Martin Myers

 

[maxman]

rrinker

Do you have just that 8 amp MRC booster hooked to teh track or do you have some directly powered by the Bachmann and the rest powered by the MRC?

This question was asked by someone before in another thread started by Cudaken.  As far as I can tell it has not been answered, but maybe I'm mistaken.  My impression is that the 8 amp thing is connected without any current protection other than any internal breaker it might have.  If this is really the case, then every time he has a short the current will flow up to the internal breaker setting, or at least to the point where a decoder fries and breaks the circuit.  The way his railroad eats decoders, I'm wondering if this is the case.

So, how about it?  Is there or is there not a breaker? 

[DigitalGriffin]

Sorry Ken.

Could you please post photos of said turnout?  And where your feeders are?

Do you have a volt-meter?

 

[jeffrey-wimberly]

 The only time I lost a decoder to a short at a turnout it was on an electrofrog turnout (something I no longer have on my layout). The front truck of a P2K GP30 derailed on a kink and shorted the frog causing the decoder (MRC) to blow.

[Trainman Sam]

cudaken

 All so any links to a diagrams of turnout parts so I wont sound so stupid?

First, might I say, you shouldn't say you sound stupid...  You are searching for help and gave the best description you could, and I was able to follow it, so that says something for your descriptive abilities!!!

Here is a link that I believe will help you become a little more familiar with the terminology!

http://en.wikipedia.org/wiki/Railroad_switch

Please note: the second paragraph (on the link page) is INCORRECT, unless it is a SPRING switch...  On a standard switch, even if it is "unlocked", if a train trails through the switch it can cause severe damage to the mechanism and the points... 

Sam

[retsignalmtr]

you could try the nail polish trick. paint on some nail polish or paint on the rails just beyond the point of the frog to extend the insulation a little farther so the wheel will not bridge both rails causing the short. i have had this happen quite often but it has never blown a decoder. it has not happened since i started using the nail polish. i have atlas and peco on my n scale layout and i have only had this problem with the peco insulfrogs. my club has it happen on both atlas and peco switches  i have had this happen several times with my ho sound equiped locos that had to have the address reset to factory defaults of 03 then reprogramed to the 4 digit cab number but it never destroyed the decoders.

[cudaken]

 The MRC booster is the only power supply, the Bachmann feeds into the MRC. I did make it by Harbor Freight and picked up Cen-Tech Digital Multimeter item 92020 and will test the amps the Athearn RTR SD 50 will pull at stall. I have two of the SD 50's and this one had never been a problem to last night. I have not checked the wheel gage on the it yet, but I will.

 When the SD 50 bought the farm, it was pulling 21 cars and was going down grade, at 50% throttle.

 I have seen articles about cutting rails by the frog, is that to stop arching?

 All so any links to a diagrams of turnout parts so I wont sound so stupid?

 Randy, thanks for being so kind and not throwing in the towel on me.

       B Line passing spur is now closed.

                    Cuda Ken

[rrinker]

 This should NOT be killing decoders. Do you have just that 8 amp MRC booster hooked to teh track or do you have some directly powered by the Bachmann and the rest powered by the MRC? If so, is this turnout where the two systems come together as far as track power? Atlas turnouts are fairly short-proof since the insulated section of the frog tends to be rather large. Based on some older Atlas ads, they did at one ppoint make a variation of their turnouts that actually had contacts and pwoered the frog, but I've never actually seen one in person. You could check this by testing continuity between the outside rails and the frog with the turnout in either position (and track power OFF! don't blow up your meter). With a powered frog there might be a smaller insulated section that wheels could bridge. Or if it has missing pieces - like the guard rails. There could eb contact with the back of a wheel. Check all wheels for proper gauge. Few if any of the locos you have have 'fixed' wheelsets - they are all split axle types that press into the gears from each side. They can easily get out of gauge over time, especially with a lot of running which it seems you do. I would check them all now, and then periodically after they've been run for a while. Too toght is jsut as bad as too loose.

                                                 --Randy

[cudaken]

 Few of you folks that follow my tell of woes know my bench loves to eat decoders. Last week I started to add decoders to my old PK 2 BL 2's. Ran the first converted BL 2 (call it # 1) on the A line and was pretty happy with the results. Made the thumping sound go up the grade like a cracked center gear, well that is normal and would have to wait till I got new gears.

  Moved it to the B line and still ran great, for a while. On the B line it is running in to a turnout from the Toe end (long time I was told to think of a turn out like a two toe foot, where the turn out is straight, that's the heel, toes is where the track separates) it is heading into the heel. Other words and sure lacking for better terms, if it is a right handed turnout, the engine is heading left.

 Few times but not often, when it was going through the turnout, it stalled and then kept going. Then it stopped and decoder was bad. I was thinking with the possible cracked gear, it was coming out of gage and caused a short. BL 2 # 1 has steel wheels.

  BL 2 (#2) has ran around 15 hours on this line with no problems, it looks to have worn out Nickel wheels, I can see a cooper color, but is not all steel like the first BL 2.

 I installed new gear's in #1 and ran it on the A Line and again was happy with it and there was no thumping sound, problem fixed. Moved it to the B line (where it ate it's first decoder)  and happened to be where I could see it running into the turnout, and I saw a SPARK!   

 What do I do to fix this problem?

 Son of a %^&*, as I was typing this I just lost another decoder in my SD 50 on the same line! (I was hoping it was just the steel wheels on the old BL 2 #1.

 It is a old Atlas turnout that has been on the layout for 3 years and came off E Bay so I do not know what kind of Atlas turn out it is. 

 How do I make or buy a Cude Ken proof turnout! I am turly getting sick of this *&%$!!!!!!!!!!!

 PO again, Cuda Ken