736 power draw vs other PW engines?

[runtime]

Hi folks,

Tried running my 736 with 8-9 freights around my 40' plus loop, which contains numerous block sections and power connections, which I know do not provide equal power around the layout.

It seems this is my only engine for which my transformer cannot supply sufficient power.

I can run PW F3's, Geeps,  a 636, MPC Geeps, with power to spare. The 736 will barely crawl around the sections of the layout most distant from the power source. Although all other engines slow down some at the far sections, it is far more pronounced for the 736.

My transformer is a non-train specific, of unknown origin multi-tap which i am using at the 20V tap (max is 24V). 

I am assuming the transformer is not capable of supplying sufficient current to satisfy the 736.??

Is this a correct analysis, does the 736 draw more current than almost any other PW engine?

Thanks, 

runtime

[jwse30]

I would think your postwar F3 would draw more current than a 736 if it is a two motored one. Do you know what watt or VA rating your transformer is? If the spot where it slows down is a curve section, perhaps there's some binding occurring. If that's the case, it should slow down at the same spot without the load of the cars too.

It sounds like it slows down at the same spot every time and the other engines do not, or not as much. If that's true, perhaps that section(s) of track need cleaned and maybe the wheels and rollers on the 736 do as well. While you're at it, you might as well clean all the track, and all your engine's wheels and rollers. If your layout is anything like most, it probably needs it.

Sorry I don't have a definite answer for you, hopefully this helps a bit though.

J White

[ADCX Rob]

runtime

My transformer is a non-train specific, of unknown origin multi-tap which i am using at the 20V tap (max is 24V). 

I am assuming the transformer is not capable of supplying sufficient current to satisfy the 736.??

How do you regulate speed?

[Frank53]

While I don't have a 736, I do have a 726 and it is my finest PW runner by a wide margin. It is my very best "crawler" capable of low speed with a larger load. I am currently pulling ten PW Sunoco tankers with an illuminated caboose and it will crawl around at surprisingly low speed. It strikes me the models of the early post war years 45-49 were very smooth runners compared to the 50's and 60' issues.

[rtraincollector]

My first question would be when was the last time your 736 was properly cleaned and oiled/grease as my 736 runs fine with no trouble at all. I even had it pulling 7 MTH NYC 17" passenger cars and I only have one tap at the moment and my layout is a loop 14' x 16' and it pulled with no problem

[runtime]

Thanks to all for replying.
I regulate speed with a large reostat.
I'll try sending a pic tomorrow.
Sounds like engine needs clean and lube.;
Could be s!me binding on curve, but much slower than dual motor F3 at same throttle.
Being brief using phone.
Thx.
Runtime

[ADCX Rob]

runtime

I regulate speed with a large reostat.

I thought so.  Between the the rheostat and the track, you have too much resistance in the circuit between the transformer and the engine.  If you are running the twin-motored diesel at "full throttle", there isn't as much resistance in the rheostat.

[runtime]

ADCX Rob

Thx.

So how do I reduce the resistance?

runtime

[ADCX Rob]

Use a conventional transformer with a continuous multi-tap secondary - rollers or wipers - (ZW, KW, R, etc.)or a newer electronic transformer(ZW-C or ZW-L).

OR, select a tap on your old transformer that will allow full speed setting on your rheostat.

With any power supply, the track and connections need to be clean and tight.  Feeder connections should be made to additional lockons every 6 to 10 feet.

[runtime]

Thanks again Rob.

But I'm puzzled:

Does a how does a 'conventional' transformer providing power differ from my setup? (I do have a ZW I bought at auction which need a new power cord, at a minimum, - have never used it)

Changing the tap on my transformer form 20v to 24v will make other engines run too fast, even at min rheostat settings in some cases, which is why I run at 20v. 

Only my 736 is underpowered. I was just running a 646 with the same 9 car consist and it runs fine at less than full throttle, similar to my F3s, Geeps, Budds, etc.

WHY DOES ONLY THE 736 REQUIRE SO MUCH MORE POWER?

Thx again,

runtime

[Hudson#685]

Runtime,

I have a 736 and it runs great at all speeds. I agree with RT. Give it a good cleaning and lube it sparingly. There was a recent article in CTT on how to do it.

Good Luck,

John

[Hudson#685]

Runtime,

 

I think your transformer will be able to power it.

John

[ADCX Rob]

runtime

Changing the tap on my transformer form 20v to 24v will make other engines run too fast, even at min rheostat settings in some cases, which is why I run at 20v. 

Only my 736 is underpowered. I was just running a 646 with the same 9 car consist and it runs fine at less than full throttle, similar to my F3s, Geeps, Budds, etc.

Using a rheostat is unpredictable.  It varies the resistance in the circuit, not the voltage, like a transformer does.

With the 736, I was thinking to go to a lower tap, less than 20, actually, not more than.  You want to eliminate the rheostat as one of the factors.  The nearly identical appearing 646 has a completely different drive mechanism, and depending on the state of tune, there could be a wide variance in operation between the two. 

A full cleaning and lubing the 736 is in order, oiling the side rods too, as they are functional on this model, not just for show like on the 646.

[MRTerry]

Runtime,

My article on how to clean/tune/lube your locomotive is in the September 2012 CTT. I use a Turbine in the story, but the mechanisms are basically the same. You can order it by calling 1-800-533-6644.

Thanks for reading CTT,

Terry

[musicman37]

Would it be possible to try running the 736 on a different layout? I think that trying your ZW is a good idea too.

[Hudson#685]

Runtime:

Remove the brush plate and clean the armature real good. Clean all of the dirt out of the grooves. I think that may be your problem. I use CRC QD Electronic Cleaner, a toothbrush and if I have to a toothpick, but be careful with it. Reaasemble and lube. It may make a difference.

John

[TRAINCAT]

Just get your ZW serviced and rid of that hokey contraption you are using.

Roger

[rtraincollector]

I just put a new cord in one of my zw's about 2 months ago I went to wal-mart and they had a heavy duty cord with a 2 prong plug. It was a little bit of a job as never doing it before but it wasn't that hard really. I agree it would be your best bet to use the ZW for better regulating the out put. While in there look at the rollers and the core to ensure all is working fine. I'm not that much of electrical minded but I was able to do it.