The F-7 & F-7a (DCC) shell, what other models can be swapped with this engine?

[Ralph S]

The F-7 & F-7a  normally numbered 307 I want to swap the shells with some other diesel shell.
Or would it be easier to sell the F-7 and F-7A DCC and buy different models. The reason is- these engines ( I have four of them) work so very well, I'm not good at re-painting, and they are getting confusing as to which one I'm working with. Also buying the shells would be cheaper than replacing the entire engine. Any suggestion would be greatly appreciated.

[jward]

F7a chassis should also fit FTa, FTb and F9a. What locomotives are you interested in?

[Ralph S]

I'm more of a freight type engine guy.  The F-7 and F-7a really look like the Superman stopping train,  (from the 1960's TV show) and I really have low interest in this model engine.  Bachmann's engines in this model perform very well on my layout, I've had friends use their AHM and Ahearn models and they didn't do very well on my layout. I'm looking to buy a different Bachmann diesel, DCC of course, but I believe that the length of the engine, it's wheel carriage, is the factor that reduces the performance of the engine on my layout.

[jward]

Just a point of clarification: the F7 and its close relatives like the FT, F3 and F9 were primarily freight engines. I assume you are more interested in the hood type of freight engine rather than the streamlined type?

If you're looking for something that ran from the mid 1960s on the GP40, GP38-2 or SD40-2 are good choices. the latter two were the de facto standard locomotives in the 1970s and 1980s. Examples of all 3 are still running on major railroads, and the latter two are fairly common on most lines.

[Ralph S]

Let me get this straight, are you saying that the F-7 and F-7A frame and motor (not the shell) will fit in the shell of the GP40, GP38-2 or SD40-2?  When I measure the wheel carriage of the two, the GP40, GP38-2  wheel(carriage) base is longer than the F-7 wheel base.
And Yes, I'd prefer the more common freight trains, I'm trying to look more modern, up-to date, on my layout and in this case the engines too.

P.S.  Thanks for replying so rapidly, I really appreciate this.

[jward]

No the GP and SD units will not fit the F7 chassis. As you surmised, they are longer. The GP units would be good for 18" curves, while the SD would work best on 22" or larger curves. In the Bachmann catalog, The SD70ACe and ES44AC are the most modern, examples of both have been built within the past couple of years. But those are BIG locomotives, and they require at least 22" radius curves. The other ones i mentioned before are still running in large numbers, in fact the GP38-2 and SD40-2 were some of the most reliable and numerous locomotives ever built.

[Ralph S]

Wow! I don't know why Bachmann doesn't emphasize the difference in the curve radius.  You 've got me thinking that the reason that the F-7's I have work so much better is because I have the 18 inch or shorter curves.  This may be why the AHM and the Ahearn's I tried didn't work so well on my layout. 
Now that I believe the reason for the better F-7 operation on my layout, I'm convinced that there is no changeability with other diesel shells for the F-7's. Therefore, on the second note, I'll rid myself of the F-7's and change the curve radius on my layout to support the larger engines that I really like much better.  Maybe I'll keep one or two for switching yard.
I'll keep you posted on my changes...  I'm still in the process of trying to retire...so these changes won't be immediate...     Happy Holidays to ya, and Thanks!

[jward]

I live along the Norfolk Southern mainline just east of Pittsburgh. Up until last year they maintained a set of F7s for the executive's train but those were sold off. Previous to that the last F7s on the system ran on what was then Conrail in 1980 in local freight service.

The GP38-2s and SD40-2s currently work the local freights along with the GP40s. These also work in the yards as needed.  The ES44ACs and SD70ACes run the through freights along with the AC4400CWs and C40-9Ws and ES40DCs. Models of the first two of those are made by Athearn, The ES40DC is very similar in appearance to the ES44AC the main difference being the lack of the AC traction motors and associated electrical equipment to run them.

In a nutshell, with the weeding out of several older models in the past year, the 5 models Bachmann makes, plus the two Athearn makes, make a very good representation of what's actually currently in use.


To answer your comments regarding curve radius, nay locomotive is going to run well on larger radii. But the 4 axle units like the F series or the GP series is going to be fine on 18" curves. The larger 6 axle locomotives like the modern ones might be able to negotiate sharp curves by themselves, but due to the overhang on the ends that swings wide on sharp curves, they will probably derail cars coupled to them. The shorter the car, the greater likelihood of this happening. coupling coal hoppers to these locomotives and trying to run them on sharp curves is asking for trouble, but longer cars may work. Naturally the larger the curve the less likely this is to happen. You should be fine with 22" curves or the larger 24" curves.

Model railroading to be honest is a big trade off between what you'd like and what you have room for. I think that you can run the larger locomotives you want  if you have a reasonable amount of space, say the size of a ping pong table or larger. It is possible to put 22" curves on a 4x8 sheet of plywood but you won't have much room for anything else. using a larger size like 5x9 or 5x10 will increase your options dramatically. Most HO layouts plans designed for a 4x8 area can be modified to work with 22" curves in a 5x9 or 5x10 space.

[Ralph S]

Great, my curves are less than optimum.  I don't remember if I told you that I was using old flex track from my 40 year old train collection, and working on moving to the E-Z track.  What I learned is that there are two versions of the E-Z track 18" and 21".  If there are other radius, I haven't heard of it.  I'm glad that you responded, since the information you gave provides me with reduced investment in continuing with the F-7 versions. That is, trying to swap shells, that's out now.  I'll work with my budget and in the process increase the radius of the current curve radius of my current and present plans. 

I believe I have sufficient room to increase my layout.  After this pandemic is behind us, my wife has agreed that our bonus room (13 by 20 ft) is mine to do with.  With 40 years of models in 3 boxes, the new models just purchased, the kids (soon to be gone), myself soon to be retired, the layout will definitely be one that will support both DC, DCC and my battery operated models.  All HO scale, and the only thing in the way moving forward is priorities from other than the train set.

[Terry Toenges]

There is a lot of different E-Z Track available.
------------------------------------------------------------------------
E-Z TRACK
E-Z Track Dimensions - 5/16" High x 1 15/16" Wide

Bachmann EZ Track straight pieces
Nickel Silver with gray roadbed                                              Ties are 1/4" on center
Part #         Length inches         Length millimeters     Number of ties
44510......................9" rerail power...............228.6..................33 ties = 22.86 cm
44511......................9".....................................228.6..................33 ties  = 22.86 cm
44512......................3".......................................76.2..................10 ties = 7.63 cm
44513......................2 ¼.....................................57.15.................9 ties = 5.715 cm
44514......................4 ½".................................114.3.................18 ties = 11.43 cm
44528......................9" rerail no power.........228.6...................33 ties = 22.86 cm
44548......................9" auto-reverse..............228.6...................33 ties = 22.86 cm
44579......................9" dual crossing gate......228.6..................33 ties =  22.86 cm
44581......................9" bulk 50 pieces...........228.6...................33 ties
44584.....................36" bulk 25 pieces..........914.4
44591......................2 ¾"   Hayes bumper......69.9....................9 ties = 6.985 cm
44592......................Assortment (592 1-5)
44592-1...................¾"....................................19.05..................3 ties = 1.905 cm
44592-2...................1".....................................25.4....................4 ties = 2.54 cm
44592-3...................1 ¼".................................31.75..................5 ties = 4.445 cm
44592-4...................1 ½".................................38.1....................6 ties = 2.54 cm
44592-5...................2".....................................50.8....................8 ties = 5.08 cm
44597......................9" power insulated gap.228.6....................33 ties = 22.86 cm
Steel with black roadbed
Part #         Length inches         Length millimeters     Number of ties
44410......................9" rerail power...............228.6.................33 ties = 22.86 cm
44411......................9".....................................228.6................33 ties = 22.86 cm
44412......................3".......................................76.2.................10 ties = 7.63 cm
44428......................9" rerail no power..........228.6.................33 ties = 22.86 cm
44481......................9" bulk 50 pieces...........228.6..................33 ties = 22.86 cm
44486.....................36" bulk 25 pieces..........914.4..................           = 91.44 cm
44491......................2 ¾"   Hayes bumper.......69.9...................9 ties  = 6.985 cm

Bachmann EZ Track curved pieces
Nickel Silver with gray roadbed
Part #               Radius inches                   Track length   Radius millimeters  Number of ties
44505......................15" (12 pieces for circle).................7 27/32" track.........381........................31 ties
44501......................18" (12 pieces for circle) ....................9 7/16" track.........457.2............... 34 ties
44580......................18" bulk 50 pieces....................................................................457.2....................34 ties
44549......................18" auto-reverse.......................................................................457.2...............34 ties
44529......................18" rerail no power..................................................................457.2................34 ties
44502......................18" rerail power.......................................................................457.2................34 ties
44503......................22" (16 pieces for circle).................8 5/8" track........... ..558.8...............30 ties
44583......................22" bulk 50 pieces....................................................................558.8...............30 ties
44519......................26" (20 pieces for circle)................ 8 5/32" track..............660.4...............33 ties
44506......................28" 18 deg (20 pieces for circle).... ....8 25/32" track...........711.2...............35 ties
44509......................33.25" 12 deg (30 pieces for circle). ...6 31/32" track...........844.55..................28 ties
44504......................33.25" 18 deg (20 pieces for circle). ...10 7/16" track...........844.55.............42 ties
44508......................33.25" 6 deg (60 pieces for circle)........3 15/32"....................844.55..................14 ties
44507......................35.50" 18 deg (20 pieces for circle).....11 5/32" track..........901.7....................45 ties
44532......................½ 22" (32 pieces for circle)....................4 5/16" track............558.8....................17 ties
44531......................½ 18" (24 pieces for circle)   .................4 23/32" track..........457.2................17 ties
44530......................1/3 18" (36 pieces for circle)................. 3 5/32" track...........457.2................11 ties
Steel with black roadbed
Part #               Radius inches                Track length     Radius millimeters    Number of ties

44401......................18" (12 pieces for circle) ....9 7/16" track.....457.2......................34 ties
44480......................18" bulk 50 pieces............................................457.2..............................34 ties
44429......................18" rerail no power...........................................457.2......................34 ties
44402......................18" rerail power................................................457.2......................34 ties
44403......................22" (16 pieces for circle) ...8 5/8" track.........558.8......................30 ties
44483......................22" bulk 50 pieces............................................558.8.......................30 ties

Bachmann EZ Track turnouts (switches)
Nickel Silver with gray roadbed
Numbered turnouts diverge one part per number in their name. A #4 turnout diverges 1 part for every 4 parts in run.
Part #               Size                  Straight Length     Number of ties
44557......................left #4   with 2 ¼" str........10" long..................41 ties str.
44558......................right #4  with 2 ¼" str..........10" long..................41 ties str.
44561......................left stndrd/w 18"rad cur.......9" long....................33 ties str    
44562......................right stndrd/w 18"rad cur.....9" long ...................33 ties str
44565......................left #5....................................11 1/2" long...........47 ties str. 46 ties div.
44566......................right #5..................................11 1/2" long...........47 ties str. 46 ties div.
44569......................wye #5 w 2 ¼" str.................11 3/8" long............45 ties   
44559......................left #6....................................15 1/2"....................62 ties
44560......................right #6..................................15 1/2"....................62 ties
*44575.....................left crossover #6..................21 1/4" long ...........85 ties
*44576.....................right crossover #6...............21 1/4" long ............85 ties
44139......................left #4 DCC..........................10" long..................41 ties str.
44140......................right #4 DCC........................10" long..................41 ties str.
44130......................left std/w 18"r cur DCC.......9" long....................33 ties str    
44131......................right std/w 18"r cur DCC.....9" long ...................33 ties str
44132......................left #5 DCC..........................11 1/2" long...........47 ties str. 46 ties div.
44133......................right #5 DCC........................11 1/2" long...........47 ties str. 46 ties div.
44134......................wye #5 DCC.........................11 3/8" long...........45 ties
44135......................left #6 DCC..........................15 1/2" long............62 ties
44136......................right #6 DCC........................15 1/2" long............62 ties
*44137....................left crossover #6 DCC.........21 1/4" long............85 ties
*44138....................right crossover #6 DCC.....21 1/4" long.............85 ties
*#6 Crossovers are 2 3/8" between track center lines.

Steel with black roadbed
Part #         Size                                                         Number of ties
44461......................left stndrd/w 18"rad cur......9" long.......................33 ties str
44462......................right stndrd/w 18"rad cur...9" long ......................33 ties str
       
Bachmann EZ Track crossings
Nickel Silver with gray roadbed
Part #         Size                                         Length                      Number of ties
44540.........................30 deg. Crossing long...........11 59/64" long...........................41 ties
44543.........................45 deg. Crossing short...........3" long.......................................8 + 3 center.ties
*44542.......................60 deg. Crossing short...........3" long......................................12 ties
*44542.......................60 deg. Crossing long (old)......................................................41 ties
*44541.......................90 deg. Crossing short ........2" long with 4p 2" straights....8 ties
*44541.......................90 deg. Crossing long (old)......................................................23 ties (?)
*Long and short 60 and 90 crossings are both being sold under their same respective part numbers.
Steel with black roadbed
Part #         Size                                         Length                        Number of ties
44440........................30 deg. Crossing long........ 11 15/16" or 11 ¼"......................41 ties
44441........................90 deg. Crossing short........2" with 4p 2" straights.................8 ties

Bachmann EZ Track special packs
Nickel Silver with gray roadbed
Part #         Package            Pieces
44596..........First Railroad Track Pack - World's Greatest Hobby
...............................................................Building Your First Model Railroad DVD
...............................................................9p 9" straights
...............................................................1p 9" rerailer power
...............................................................1p 9" rerailer no power  
...............................................................20p 18" radius curves
...............................................................2p 3" straights
...............................................................2p standard turnout - left
...............................................................2p standard turnout - right
...............................................................2p Hayes bumpers
...............................................................4p switch wires (green)
...............................................................1p terminal wire (red)
                                                                            
44594..........Expander set            
...............................................................4p 9" straight
...............................................................4p 18"radius curve
...............................................................1 left manual turnout
...............................................................1 right manual turnout
...............................................................2 Hayes bumpers
                                                                            
44547..........Reversing System         
...............................................................4p 9" straight reversing
...............................................................4p 18"radius curve reversing
...............................................................2p 9" straight
...............................................................2 Hayes bumpers
...............................................................Power pack and variable speed controller
...............................................................Illustrated instructions
                                                                                  
Steel  with black roadbed
Part #         Package            Pieces
44487..........Figure 8 Track Pack - 76" x 39"   
...............................................................21p 18"radius curve
...............................................................1p 18" curve rerailer
...............................................................30 degree crossing
                                                                            
44475..........Over-Under Fig 8 Track Pack - 78" x 36"   
...............................................................19p 18"radius curve
...............................................................1p 18" curve rerailer
...............................................................4p 9" straight
...............................................................14p graduated pier set
...............................................................power wire
                                       
44494..........Expander set            
...............................................................4p 9" straight
...............................................................4 18"radius curve
...............................................................1 left manual turnout
...............................................................1 right manual turnout
...............................................................2 Hayes bumpers
                                       
44597..........First Railroad Track Pack - World's Greatest Hobby
...............................................................Building Your First Model Railroad DVD
...............................................................9p 9" straights
...............................................................1p 9" rerailer power
...............................................................1p 9" rerailer no power  
...............................................................20p 18" radius curves
...............................................................2p 3" straights
...............................................................2 standard turnout - left
...............................................................2 standard turnout - right
...............................................................2 Hayes bumpers
...............................................................4p switch wires (green)
...............................................................1p terminal wire (red)

***
The standard switch is 18r 30 degrees. It was intended to be a drop in replacement for both a 9" straight and a full 18r section. However, the points are inset 1.5" from the end, so if you want to complete a circle using the curved route, you'll need to insert a 1.5" straight 180 degrees opposite the switch.
The #4 is roughly 15 degrees.
The #5 is 12 degrees.
The #6 is roughly 10 degrees.
****
Track - 1 3/8" open flat uderneath.
Use the Lowe's foam -1/2" wide x 1/4" thick
Walmart foam - 3/8" wide x 3/16"

[jward]

EZ track comes in 15", 18", 22", 26", 28", 33 1/4" and 35 1/2" radii. Atlas comes in 15", 18", 22", and 24" radii.

YOu can bend your flex track to any radius you want. If you're using cork roadbed here's what  i would do. First lay out your curves using a simple trammel made from a yardstick with holes drilled at the 1" mark, plus whatever radii you wish to use plus 1". For 22" radius that would be 23". Find the centerpoint of your curve, temporarily nail the trammel to that point by inserting a nail through the hole at the 1" mark. Your trammel should swivel on that nail. Insert a pencil in the hole for your radius, and rotate the trammel through your curve. The pencil will mark the centerline of the curve. Carefully lay out your cork strips along the centerline, using it as a guide for each half. When you lay your flex track, the crack between the cork halves will be the centerline of your curve. if you line up the nails of your flex track with that centerline you should have a nice constant curve with no kinks in it.

[Len]

A quick check with a search engine will find a number of sites on "tuning" old Athearn locos to get them to run better. The main issue is the power pickup system. Replacing the sliding 'clips' with a hardwired arrangement improves things a lot.

Also, if they are the old open frame style motors, A-Line offers can motor replacements, along with other upgrade parts, for a number of older Athearn locos. These are already electrically isolated from the fram, making DCC upgrades a lot simpler.
https://ppw-aline.com/collections/diesel-re-powering-kits

Len

[jward]

My experience the old Athearn  blue box units to DCC has been that isolating the motor from the frame is the easy part. No need to replace the motor, all you do is swap the copper clips from the top to the bottom and vice versa. You'll have to remove the clips anyway to solder the decoder leads to them. The bottom clip has two small tabs that are bent down to contact the chassis, the top one doesn't. By moving the clip with the tabs to the top of the motor where they can't contact the chassis you solve that problem. Just for good measure cover the new bottom clip with electrical tape so it can't possibly contact the chassis and you've got the motor isolated.

There are two design flaws that negatively impact performance on DCC. These are not an issue on DC but DCC is much more reliant on good contact to operate correctly.

The first flaw is the Sintered metal wheels which are difficult to keep clean enough for DCC. Athearn sells replacement wheelsets with Nickle silver wheels, and NWSL sells the wheels themselves if you wish to reuse the axle gears.

The second flaw is a bit harder to correct. Athearn relied on the weight of the locomotive sitting on the trucks to conduct  electricity from the trucks to the chassis through the bolster pin. The best thing to do here is to solder a wire directly to the metal plate the axle bearings fit into, feed the wire up through the chassis and solder it directly to the decoder leads. You can do this for both sides of the trucks if you wish, but i found it easier to just solder the leads to the metal tabs that hover above the gear towers on the trucks. Finally, you'll want to replace the Athearn headlight and clip with something soldered directly to the decoder. Failure to remove the original headlight can short out the decoder.