DCC?

[full maxx]

does DCC give better low speed control or does that depend on the quality of the engine or the quality of the decoder , also will it change the top speed of the engine...not that I want it any faster cause I don't and if it does, is the top speed controllable as far as setting a lower max

[ABC]

What DCC system do you have? If it is an E-Z Command then you can't program CVs like max speed, acceleration & momentum. But buying a quality decoder along with a more advanced DCC system will do wonders, but some locos running ability is not as improvable as others.

[BestSnowman]

In my experience low speed control varies greatly based on the decoder. I have some locomotives with cheaper decoders that don't move well at crawling speeds on DCC but do with DC. I have some with nicer decoders do operate much better at low speeds.

[lmackattack]

the DCC system does not really give you better motor control but certain decoders will allow you to address this issue. For instance you can get a standard "cheep" decoder that will just do basic F-R motor control and F-R light control. this cheep decoder will run locos basicly the same as DC did. Now some slightly upgraded decoders will allow you to adjust the BEMF control  and Voltage start control (AKA.. Vstart.) these can greatly help low speed motor RPM and tame a jerky motor. I have taken a cheep decoder out of a sluggish engine and put in a $25 decoder with BEMF control and it was like a complete new engine. Its amazing what DCC will do for you!

Trent

[full maxx]

sorry ...what does CV's stand for, and I don't have a dcc system yet but considering the train has ran most of the day and being the favorite present , I might as well get one , that is why I'm asking questions before hand...I learned by my question tonight that you have more control with different systems and I'm sure "you get what you pay for" as far as cost and functionality ...so what would be a good system that won't break the bank that will give more control with speed control lights and sounds

[lmackattack]

Configuration Variables = CV

CVs adjust the decoders action when that CV is in use with the loco. you change its value depending on its use. Its how we tune our engine to do things we may want. it can be used in lighting,motor control,sounds etc....

this may help explain(for now dont worry about bits and that talk)
http://www.nmra.org/standards/DCC/standards_rps/RP-9.2.2%202007%20July.pdf

[jward]

the short answer is that yes, you can slow locomotives down with most dcc decoders. you can also set the acceleration and deceleration rates. you can speed match all your locomotives if you want. i have successfully speed matched a stock athearn (12:1 gear ratio) with an ernst geared athearn (32:1 gear ratio, the motor and drive being otherwise identical) so that they would run together.

that said, there seems to be some question as to whether dcc onboard locomotives support all of the necessary cv's to take advantage of these features. in particular, max voltage (vmax) doesn't seem to be able to be adjusted.....

[rich1998]

a poor running loco will usually not be improved by a dcc decoder.
i have found the tsunami, loksound and digitrax decoders do better than inexpensive decoders with some bargain dcc equipped locos. the ones I have all have bemf.

search the internet for decoder bemf if you do not understand what it means.

i had a spectrum 4-4-0 i bought two years ago with the basic factory installed  lenz decoder that was so so.
a roundhouse 4-4-0 with factory installed mrc sound decoder was about the same.
others i have read have experienced similar mediocre operation with entry level decoders.
the new spectrum's and roundhouse with tsunami should work really well.
lex

[Jim Banner]

A while back, I tried a decoder with BEMF speed control in an old Tyco locomotive from the 1960's.  When new, it took about 1/2 throttle to start, and then leaped forward at40 or 50 scale miles per hour.  Forty years on, it still does the same thing.  Adding the decoder improved things somewhat.  The locomotive still took off with a leap, but a much smaller one - about 15 mph.  I could get the starting speed even slower, but the decoder hunted excessively, making the running very rough.  So, improved, yes.  Spectrum performance, no, no, no.  You just can't make a silk purse out of a sow's ear.

[lmackattack]

I think it really comes down to the loco in question. a really old or poor engine with a cheep motor may not improve like a newer engine will.

When new My Bachman DCC 2-8-4 standard line did not run well at low speed out of the box. It took 1/2 throttle to get it to move with 20 cars. as soon as it started to move it took off to 60MPH. I could not use the momentem because of this. I took the bachman decoder out and put a $30 Lokpilot decoder with BEMF and now it would walk away with 40 cars at 2 scale mph. Amazing!

this is what DCC can do for you. the hard part of BEMF is that some decoders need lots of CV settings to adjust the BEMF.

Trent