# AF 302 boiler differences



## BrokeCurmudgeon (Feb 8, 2016)

I seem to recall a conversation about this issue but I can't find it. So, please bear with me. I have two AF302's They are both die cast shells but one has coil brush springs and the other lever brush springs. I am trying to find more about why the same number engine didn't have the same motor. I assume that in the middle of the production run, AF ran out of one type motor and started to use the more modern coil brush spring motors. Comments?


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## AmFlyer (Mar 16, 2012)

Short answer is I do not know when the change was made in the production runs from slotted to shouldered brushes and their related brush springs. There was a change made to the brush bracket in 10/49 to add the oil slinger to the commutator assembly. The new shoulder brush design with coiled springs was easier to assemble, it saved money.
There are one piece die cast Atlantic shells (no wire handrails) and 4 piece Atlantic shells (wire handrails.) There are 4 distinct types of 4 piece shells, I am curious what type shell has the slotted brush springs and what type of coupler is on the tender.
Type I, reverse unit slot in boiler, channel type crosshead guides. Type II, similar to I, but L shaped crosshead guides. Type III, no slot in boiler, channel type crosshead guides. Type IV, no slot in boiler, L shaped crosshead guides. There are other casting differences, some only visible when the shell is disassembled. I left those out for identification simplicity.


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## AmFlyer (Mar 16, 2012)

In the amusing but not helpful category the 1947 and 1949 manuals both show the slotted brushes in the maintenance section. In the 1952 manual that illustration is updated to show the shoulder brushes with coil springs. Since I have many 1948 and 1949 engines with the newer coil brush springs it only means Gilbert was slow in updating their Consumer Manuals.
Additionally Gilbert changed the armature construction in early (but not at the beginning) 1947. The part number was not changed. If this coincided with the brush design change there would be no engines with boiler mounted smoke/choo choo units and slotted brush springs.


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## mopac (Feb 24, 2011)

I have a K5 (as I remember a 312) smoke and choo choo in boiler and it has slotted
brushes. Its dead on the track and I have not gone through it yet. Someday I will
change it to shoulder brushes. I guess it will need a new brush cap and maybe armature.
It is the only engine I have with slotted brushes. I will look for a date stamp when I take it apart.
I am thinking it is a 47 or 48. I still need to pull a wheel on it. It has a broken square stud
on one wheel. I started pulling the wheel and the axle started coming out of the wrong wheel and I stopped.
I either need to get me a wheel puller or a small punch.


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## AmFlyer (Mar 16, 2012)

I also have a 1948 312 with slotted brushes. That is part of my basis for concluding the early 1947 armature design change was unrelated to the brushes.


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## cramden (Oct 13, 2015)

I wouldn't worry too much about it as long as it's running. Sometime in its long life parts may have been swapped to repair it. One piece die cast boilers don't appear until late 49-50. I have always thought that slotted brushes were fazed out late 48 or early 49. My 302 is a 4 piece boiler with a brass weighted link coupler and it has the coil spring brushes, as well as my 48 322AC (SIB) and my 48 Royal Blue. The only lever spring brush engine I have is a 47 322 ( Sit). I think Gilbert used up existing inventory during production runs and it's not all that uncommon to have items that have early and later parts depending on what was available during a particular run. As Tom stated, it was easier to assemble the later style brushes and springs on the assembly line. There are a lot of strange Flyer items out there that don't follow conventional norms, that can be fun in itself finding oddities.


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## BrokeCurmudgeon (Feb 8, 2016)

AmFlyer said:


> Short answer is I do not know when the change was made in the production runs from slotted to shouldered brushes and their related brush springs. There was a change made to the brush bracket in 10/49 to add the oil slinger to the commutator assembly. The new shoulder brush design with coiled springs was easier to assemble, it saved money.
> There are one piece die cast Atlantic shells (no wire handrails) and 4 piece Atlantic shells (wire handrails.) There are 4 distinct types of 4 piece shells, I am curious what type shell has the slotted brush springs and what type of coupler is on the tender.
> Type I, reverse unit slot in boiler, channel type crosshead guides. Type II, similar to I, but L shaped crosshead guides. Type III, no slot in boiler, channel type crosshead guides. Type IV, no slot in boiler, L shaped crosshead guides. There are other casting differences, some only visible when the shell is disassembled. I left those out for identification simplicity.


My two must be Type IV. However one has slotted springs and the other coil. Other differences I have noticed is the coil spring boiler has a sheet metal tender with a cast metal tender weight and brass link coupler. The slotted also has a sheet metal tender but has a composite plastic/metal weight with a dark metal weight on the link coupler. 
Of course, I bought these on EBay so who's to say that they are original? Both run and smoke just fine. The only problems were with the e unit.


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## mopac (Feb 24, 2011)

I read somewhere the brass coupler weight is 48 and the black weight is 49.
Its that way on my 350 Royal Blue. Mine has brass weight.


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