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Discussion Boards => HO => Topic started by: Sturm88 on December 07, 2010, 10:01:03 PM

Title: New to hobby- quick question for engine purchase
Post by: Sturm88 on December 07, 2010, 10:01:03 PM
Hello all.  I am ne to the hobby and am still not 100% with terms when it comes purchasing engines.

I am looking at the Spectrum EMD SD-45.  The flywheel description does not specifially say it has "Dual Flywheels".  It just says flywheels, indicating multiple.  Am I right to assumethis engine does NOT have dual-flywheels?

Thanks in advance.
Title: Re: New to hobby- quick question for engine purchase
Post by: jward on December 07, 2010, 10:27:09 PM
this locomotive has two flywheels, one on each side of the motor.

the sd45 is a personal favourite of mine, from back in the 1970s when they ruled the rails around here. it is nice to have good running models of them available.

Title: Re: New to hobby- quick question for engine purchase
Post by: ebtbob on December 09, 2010, 09:02:51 AM
I do not belive anyone makes a diesel model with just one flywheel,  do they?
Title: Re: New to hobby- quick question for engine purchase
Post by: jward on December 09, 2010, 09:34:02 AM
i have seen one flywheel in small diesels. i can't remember which one but it wasn't a common one. i think it may have been brass. as i recall there wasn't enough room to fit two flywheels.
Title: Re: New to hobby- quick question for engine purchase
Post by: NMWTRR on December 09, 2010, 09:43:32 PM
The old Model Dicasting Boxcab locomotives only had one flywheel. They also had climax that used the same chassis and it had one flywheel.

Trying to convert one to DCC so have it apart on my work bench right now!
Title: Re: New to hobby- quick question for engine purchase
Post by: Nigel on December 09, 2010, 09:58:13 PM
The dual flywheels thing is a bunch of marketing BS with no basis in engineering.  The flywheel(s) add rotating inertia to the system; which can be done with one or more flywheels, or flywheel like features. 

The Roco made Atlas diesels (GP40, GP38, SD24, SD35, FP7) and Roco made Model Power diesels (E7, E9, Shark, FA) from the 1980's all had single flywheels.  The E7/9 model had huge can motors with a single very large diameter flywheel with its own bearings.  These models all run extremely well, though a bit on the noisy side.