traindavid posted:The earlier armature can be used with the late brush cap by using spacer washers on the armature, but they have to be small enough diameter to not short out the commutator. I disagree with the observation that the "J" springs are harder to work with than the coils and caps; to hold the spring out of postition for brush install/removal lift them up by the end sticking out of the holder and place them to one side where there is a small V groove that will hold them while you work on the brushes. When you're done, lift them off of the V groove and let them down into the tube.
Dave is right, you can use washers but it isn’t as straight forward as just building up the space at the commutator end to get rid of it. It is a balance of adding washers to both ends proportionally so that you end up with the brush tubes reasonably close to the armature, something like 1mm is OK as you don’t want to have too much of the brush hanging in mid air and don’t want the brush tubes touching the face of the commutator.
I just had a play with an old chassis and it looks like you would need to build up the worm end to about 3mm and the commutator end about 1mm, but these are just for this chassis and as Flyer chassis are not precision made they will vary and you just need to have a number of washers available in different thicknesses.
The other interesting point is that the early armatures are 58mm long and the 11077 is 60mm long and what this means is that once you have installed the new later style brush bracket to the older style armature the older style armature shaft does not use all of the new bearing in the brush bracket, it is just a tad short by a mm or two.
Also, as David mentioned, be careful on how you add washers to the commutator end as you can easily short it out if they are too large in diameter. I know of two different early types of armature which on one you could get away with a washer/shim 10mm outside diameter and another which is nearer to 8mm outside diameter. I enclose a picture of both. All in all it is probably better to upgrade to the later armature if you are looking to change to the later brush bracket, the choice is yours.
