Has anyone tried making their own e-unit? Seems like it would be a good project to try.
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Yeah, I thought the same thing then my sanity returned. Better to try to fix them first. No harm in trying though, give it a shot. I know e units are a pain.
A good starting point:
Stan, that was an impressive document Paul created. When he first did the thread, I saved it simply because it was such a work of art, that reminded me of some of the avionics documentation I did. 
I was interested in the old mechanical e- unit. Not many improvements over its 100 yr old history but I have an idea.
I had a functional e-unit running with an Arduino-type board, 2 relay module, and a super-cap a while back just to see if it could be done. less than $10 in parts, but it was a bit overkill for an e-unit. Also took up a lot of space, so probably need to stuff the electronics in the tender to actually use it.
The idea really became more worth while, however when a 99 cent radio was added as well as a tirac to apply PWM to the motor. From there we can implement something like LionChief functionality, which is pretty neat on a post-war engine.
JGL
Electro-mechanical e-units? ........ Lionel's e-units and their component parts are relatively inexpensive and readily available, unless someone has a need for something with different physical dimensions, I don't see why they would bother.
The cylinder with the brass plates on it and the brass fingers that wipe on them are weak points, I think. Design a barrel like a cam shaft that would operate small contacts instead of the fingers rubbing on the brass. A relatively simple retro fit.
Not to hijack the thread, but I have always wondered why Lionel called this an "e-unit." When was the term first used? I assume it is an abbreviation, but for what?
I can make a lot of guesses, but figured maybe the guys who specialize in old paper would know for sure.
Originally it was an Ives design so it goes back a hundred years, maybe they called it an "e-unit"?? Not sure.
Not to hijack the thread, but I have always wondered why Lionel called this an "e-unit." When was the term first used? I assume it is an abbreviation, but for what?
In the days of prewar, Lionel locomotives with reversing units had an "E" on the end of their number, like "400E". So the reversing unit was the "E" unit.
electric reverse
Hmmm! I guess I knew about the model numbers, but never made the connection!
Thanks again for all your help.
However, late prewar trains dropped the e designation and still had e-units.
It's quite possible to build an electronic reverse board that would be very small, a fraction of the size of the mechanical E-Unit. As for why you'd want to, that's a whole other story. I use 5 amp relays that are very small in some of my projects, add a uP, two SMT transistors, and a couple of power supply parts and you're all set. The whole package could be done in about a 1" x 1" x .7" cube. It would even have the capability of directional lighting if desired.
Here's the footprint of the relay.
Of course, the question is, why would you want to? There are so many choices for reverse units...
Attachments
E = Escapement
However, late prewar trains dropped the e designation and still had e-units.
True, but by then, I don't think they were making any locos without e-units, so there was no longer a need to differentiate.
For fun 
Yes that was the reason, and these e-less plates are challengeing to find, just as much on other end when they were introducing the e-unit I have some locoe. i.e. a 253 and 254 with reverse units with a rubber stamped E on it since that was cheaper than making a new plate. early e-unit were to large for smaller electrics, but pendulum unit was put in the 251 and 254 but 253 had to wait for the "ives" unit to get its reversing unit. Some locos didn't even have a hand reverse: 248, one direction only. Gosh I love this stuff
Adriatic posted:For fun
Why not create something new that hasn't been done a hundred times? There are lots of neat little items that I'm sure would be useful that are not as common as dirt. 
Literal tinkering fun. And a tad bit of learning by experiencing the build.
I.e., hobby overlap.
E.g.- Hot rodding, Ive made pulley pullers when all I needed to do was go into the house and pull one out of a drawer. I did it because I like metal working and could run tap & die all day grinning. Plus there was all those stairs to the basement and removing sunglasses to deal with, taps needed oil anyhow, etc etc
Yep, you only might be able to pull of a cheaper board, and I doubt you could improve on E-units or R-units much let alone price; the fun, pride, and satisfaction from a homebuild are priceless sometimes.
Adriatic posted:Yep, you only might be able to pull of a cheaper board, and I doubt you could improve on E-units or R-units much let alone price; the fun, pride, and satisfaction from a homebuild are priceless sometimes.
No argument, I just figure that while you're doing something home built, might as well shoot for something a bit more unique.
The E-unit design is 100 yrs old and a source of problems with the older locos. A newer,more reliable e-unit would be a boon to mankind. Some of us want a mechanical unit not electronic in our old Lionel iron.
I project a very small market for a "new" mechanical E-Unit. Designing a truly different mechanical E-Unit is not going to be cheap to build unless you have large quantities.
Just curious, since it's totally non-stock, what's the objection to a newer, more reliable electronic E-unit?
No objection, just a personal preference.
I don't find either type of e unit unreliable as a concept really.
I would build more amp overkill into my own board.
Relays might be stacked to form a latching system that would cycle, as sort of an in between. Size is the issue. Occam's razor was taken to the old tech pretty well. Even gravity is used.
Micro motors and super small micro cherry switches might be of interest. (Bust open an autofocus camera , wow they are tiny) So might changing the shape. Something more linear? A circular "return to zero" servo vs linear coil motor?
Why not do something else?
That's next; task at hand!
