FA & FB units

[jward]

yes they do. and they all share a similar drive with the spectrum diesels i've seen.

the only newer bachmann diesels i've seen without flywheels are the standard line ft's gp40s and "gp50s".....not sure about the gp38-2, sd40-2 or the smaller ge switchers.

[NuthinDragginOwt]

jbrock27, I now understand, you have an F7A and F7B, not FAs and FBs. The F7As and F7Bs were built by a General Motors division called "Electro-Motive Division", while FAs and FBs were a product of American Locomotive Company or "Alco". Bachmann offered F7As and F7Bs in their Plus line, and have recently reintroduced them in the Standard Line with sound. The FA-2 and FB-2 models were brand new models for the Standard and Sound Value Line. Bachmann never offered FA-2s in Southern Pacific Daylight paint that I am aware of. An F7A and an FA-2 have different Physical Charactoristics on the body. Here are some examples:
F7A: http://rr-fallenflags.org/lv/lv0512pma.jpg
FA-2: http://rr-fallenflags.org/lv/lv590rpa.jpg

Now to answer your original question, If you are trying to fit an F7A shell onto an FA-2 chassis, it probably will not work due to body length and shape. If you are trying to put an old F7A shell on a new F7A drive, it may work, but you would have to compare the shells to see if the tabs that hold the shell to the chassis are identical, and that there are no tabs or anything in the shell that would restrict the engines mechanical performance. As for the motor change out, that I am not 100% sure on. I seem to recall a manufacturer or two in the past, use to skip putting flywheels in their train set engines, to keep the cost down, unsure if Bachmann did this or if it was another manufacturer, without looking at some samples.
I am also not sure if Bachmann had changed motors since then, but I do remember most of the old Plus engines were not DCC friendly by any means, without having to do some milling on the chassis to make room for a decoder. The only way to really know would be to try and see if the new motor is identical, dimension wise, and that there are clearances for the flywheels. The flywheels will make a difference, performance wise, but just keep in mind that if the engine runs good as is, I don't think I would go through the trouble. I enjoy tinkering, and understanding the mechanics of models, but I myself, find that if the engine works fine, I don't both changing things like that.
The main thing that flywheels will do for your engines is they it will make the engine run smoother, the motor will not "jolt" as hard when stopping or starting, and it will assist an engine in getting over dead spots or dirty track.
Ryan

[Jerrys HO]

jb  that is exactly where I got my info from and yes they come in a black box just like the Spectrums. I bought them for the UP shell's for $30.00 and seem to have gotten more than I bargained for.
Now my biggest question is how difficult will it be to swap motors. I have not taken them fully apart yet to research this but a little insight will be better than going in blind. I did notice a bunch of yellow caps on the DCC units motor and none on the DC unit.
I may turn the others into dummy's. One thing I noticed is that the frames for the B unit's are the same as the A unit's.

I will try to post some pics by tomorrow if this will help some one help me.

NDO

The main thing that flywheels will do for your engines is they it will make the engine run smoother, the motor will not "jolt" as hard when stopping or starting, and it will assist an engine in getting over dead spots or dirty track.

That is what I am looking for. I have an SD45 Spectrum that has them and it sure is smooth. If I put the flywheels on the other A unit it will have everything my SD45 has.
Jeff

the only newer bachmann diesels i've seen without flywheels are the standard line ft's gp40s and "gp50s".....not sure about the gp38-2, sd40-2 or the smaller ge switchers.

I have one of the new SD40-2 and it is without flywheels.

Jerry

[Jerrys HO]

OK here is what I have...





the motors look the same except for the thingamabobs on the DCC motor. the motors also look to be reversed as they are both facing the same direction of travel.

Here is the diagrams




One mistake I mentioned they are not black boxes, they are silver.

Jerry

[jward]

interesting that the parts drawings show an ft body for the top one and an f7 body for the bottom. there is no difference that i can see in the two chassis which would preclude the use of a motor with a flywheel in either. if one were indeed an ft that would explain the lack of a flywheel as the fts don't have them. but the chassis for an ft should be slightly shorter than that of an f7.

for a decoder i know nce makes one that is a drop in replacement for the bachmann decoder. i think it is called bach-dsl or something similar. it should work for converting an analog loco to dcc as well.

[jbrock27]

Jeff, thank you for that info on the new locos.

NDO-sorry bro, my bad, I was not clear in my post.  I assumed since the subject was F7s, that when I simply said "F" it would be understood I was making a reference to F7s.  But yes, what I have is an F7A and F7B unit in B+.  And like Jerry, I found that except for the B unit not having a headlight, the two frames/chassis were identical.

And thanks for the input on my older question about changing the shells.   As it turns out, I was able to take a new FTA shell and mount it on a B+ F7 frame/chassis.  Turns out the length was an exact match.  The only modification I had to do to the FT shell was to cut out 2 posts that were diagonal from each other, that are for 2 of the 4 screws to hold the shell to the frame.   The Dremel worked nicely for this.
This subject is relevant bc like Jerry, my first thought was to change out the motor, but when I looked at the new chassis/frame it looked just like the one in Jerry's picture and it did not look "deep" enough where the flywheel would be.  So I went with leaving that alone and switching the shell instead to the B+ with the flywheel motor.  But I was not trying to modify anything for DCC, I still just run DC.  And yes, Bachmann sells plenty of price pointed locos now, that do not have flywheeled motors.   As I stated in my first post to Jerry, I always have felt motors with flywheels were better than those w/o.

Jerry-I think the motor cradle set up is compatible for both; my concern still is clearance for the flywheels against the frame/chassis.    I agree that was a good price for 2 units.  Were they used or "NIB", "unopened", "unused"....??

**And yest, I have HO Scale Trains Resource saved to my Favorites 

[jbrock27]

...and my bad again, I see all along the talk has been about FAs.  Sorry, when I see "F", my mind automatically pictures an F7. 

[jbrock27]

Here's a question related to Jerry's project: is it possible to even remove the flywheels w/o a flywheel puller?
Bc unlike just sliding flywheels off an Athearn Blue Box motor, I had no luck trying to just pull the flywheels off my B+ GP 35.
Thanks.

[Jerrys HO]

jb27 & jeffw

Were they used or "NIB", "unopened", "unused"....??

jb27 yes new in box,never opened except for the B unit which was lightly weathered.
The top pic w/decoder is an ft which came out of the diesel commander set.
The bottom pic is the Bach Plus which is a f7.
The frames are identical and as you noted had to cut two post in the shell to swap shells.
I had purchased a B unit w/DCC on board. The shell from the Plus unit swapped with no mods.
Here's a pic of the changes.


jb27 the frames have the room to swap to the flywheels but I think I am going to take Jeffs advice and get a nice decoder to put in the Plus frame and maybe sound in the B unit.
I think I am chickening out on the motor swap. Why fix it if it's not broke.
I will keep posted as to when and how I start the decoder project.

Thanks Jeff, JB27,D, NDO
Jerry

[jward]

this is slightly off topic and i relate this only as an example of what can be accomplished with dcc through programming.....

those of you who have been in the hobby for years remember the athearn blue box locomotives, they were simple, rugged and reliable. you may also recall ernst made regear kits which replaced the standard athearn gears with thin profile ones which increased the gear ratio from 12:1 to 32:1 resulting in much improved low speed performance, marginally increased pulling power and a top speed of about 40-45 scale mph. the gear kits were made for almost every locomotive athearn made, except the dd40. i quickly made ernst geared athearns my standard motive power.

fast forward a few years. after years in n scale, i returned to HO with my old fleet of athearns and a brand new dcc system. i had just purchased a dd40 for use as a track testing tool, figuring that of those long wheelbase rigid trucks could negiotiate my track reliably i'd have no problems with my smaller diesels. in the course of installing decoders in my fleet, the dd40 got one. problem was, with its factory gearing and no easy way to convert it to 32:1 it was an orphan, not compatable with any of my other locomotives.

i had read about dcc speed matching, and had even done some of it with my other athearns which all ran at slightly different speeds. i decided to see if i could speed match my dd40 to the rest of the fleet which ran maybe half as fast. guess what? it worked!!!  i found i could accomplish through dcc programming what was impossible to do through gear ratio. the 12:1 unit ran with the 32:1 ones.....

that is an extreme example of what a fully programmable dcc decoder can do for you. you can pretty much speed match anyting  if you tinker around with the settings. the basic speed comtrol settings are in cvs 2 to 6, with more in depth fine tuning available in the 60s 70s and 80s.

[jbrock27]

That sounds like a good decision making process Jerry and makes all the sense to me.

I am very interested in knowing how this turns out for you.  I'm glad to follow along and learn stuff.

[jbrock27]

Jeff, it certainly sounds like DCC is capable of some awesome stuff.  Maybe some day I take that journey...

I wonder how many modelers are in DCC now?  I had a couple of hand me down magazines I was looking through that were from around 2009 and I was surprised to read that even at that time, they said 75% of modelers were still in DC and 25% in DCC.

-Came back a little while ago from the "Big E" Railroad Hobby Show.  Talk about mind blowing overload!

[jward]

jb

that day may come sooner than you think. the price of the decoders keeps dropping, the features f the command stations and decoders keep improving. dcc becomes more affordable every year. i do know i've wired my layouts for dc even though i run dcc in case i ever need to revert to dc because of a command station failure. my first zephyr served me well for 8 years, until replaced by a new model zephyr last summer. the old one still works even after all the abuse my son and i put it through. nwo i won't have to revert to dc because i have a spare in case of problems.

just a few years ago you couldn't have touched a sound equipped locomotive for under $500, or a dcc equipped one for under $200. i now have 3 soudn locomotives all of which i bought for under $100 each. i've bought dcc equipped bachmann gp40s for $25 apiece.

the biggest obstacle you'll face in converting is the cost of the number of decoders you'll need to convert all your locomotives. 

[jbrock27]

You are probably right Jeff and make an excellent point about needing to decide whether to convert locos already in my possession.  And I need to consider that for any future purchases: do I even buy any more analogs?  Buy analogs with the idea of coverting in future and what the possibilities are in being able to do that with that particular loco?  All good things to consider.

Your point is well made about the price coming down making it doable.  Reminds me of LCD and Plasma TV prices coming down making them affordable for a lot of people.

Yea, I would have to start from ground zero with the power supply and go from there.  And here I was thinking I was doing well, recently changing over to a MRC Tech II 1400 power pack !

[Stephen D. Richards]

All, just a little FYI.  You can put flywheels in teh GP40/50/38/etc.  I do it on a regular vasis.  I used to buy the flywheels but now I turn my own "custom" flywheels.  Usually you hace to "remove" material from the frames and a little patience making the drive shafts.  If you have the money and don't have the time, it is easier to put in and hardwire a decoder.  This Winter has been rather light on the railroad but last Winter I assembled/built over 15 DCC locomotives with the custom flywheels, custom motors and drive lines.  If anyone is interested I would be glad to share what I have learned in this process.  Hope that helps!  Stephen