How can you convert a 2 position eunit to run a Lionel DC motor in the 8007?

Why not put the DCRU in the tender?  There are plenty of tethers you could adapt to fit the purpose.

The tender has a post war whistle.

A Dallee 2 or 4 amp reverse unit should fit in the tender, you can get AC from the center rail off the whistle, and ground the Dallee through the tender, and use a two wire tender tether to connect the Dallee to the motor. I don't know if you could use a diode and a small DPDT switch on the loco if space is as limited as you implied. 

You should be able to fit an electronic reverse board in that locomotive.

Another option would be a mini reverse unit, it is about 3/4 size of a standard reverse unit. 610-8733-106.

lionel used to sell the boards for that engine ,i have one but never put it in yet

Problem with the 2 position e-unit you are asking about it is only a Single Pole Double Throw contact, you need a Double throw Double throw contacts to do what you are talking about.......  to do that you need a 3-Pos E-unit and a bridge rectifier.....  I believe I still have the wiring diagram the TCA & Williams sent out with their e-unit kit for the Silver GG1 Set the TCA did for their 25th aniv. set

I had no problem installing the Lionel electronic 103 reverse unit in that engine.

Mike Slater posted:

Problem with the 2 position e-unit you are asking about it is only a Single Pole Double Throw contact, you need a Double throw Double throw contacts to do what you are talking about.......  to do that you need a 3-Pos E-unit and a bridge rectifier.....  I believe I still have the wiring diagram the TCA & Williams sent out with their e-unit kit for the Silver GG1 Set the TCA did for their 25th aniv. set

 

Mike, I cant find that info can you send it along?  Thank you.

Johnsgg1 posted:

I had no problem installing the Lionel electronic 103 reverse unit in that engine.

John,

I looked 3 ways from sun up to install that 103 in the 8007 and I dont see how there is any room. Its too wide and the electronics are too high.

Chuck Sartor posted:

Another option would be a mini reverse unit, it is about 3/4 size of a standard reverse unit. 610-8733-106.

By standard reverse do you mean a mechanical e unit or its smaller than a 103 electronic e unit?

The one I am referring to is electronic. about 3/4 size of the 103 version.

I cant find the paperwork, however I looked at a e-unit......

ok lets see if i can explane this......

first you will run a wire from the pick up rollers an the frame to a bridge rectifier,

DC power out (+power and -power) will go to 3 post e-unit as shown,

Motor + and motor - will go to motor

also don't forget to run ac power to the coil that operates the e-unit

Rich D posted:

Johnsgg1 posted:

I had no problem installing the Lionel electronic 103 reverse unit in that engine.

John,

I looked 3 ways from sun up to install that 103 in the 8007 and I dont see how there is any room. Its too wide and the electronics are too high.

Rich, I am visiting in Williamsburg right now.  I can't access my 8007 until Tuesday.  If still interested I can send pictures then.

The 103 I have is approx 1 1/2 inches square and 3/4 inches high.  I put one in the same engine as yours.  It will fit in the boiler - as I recall I put it on edge and wrapped it in electrical tape to make sure it didn't short out on anything.  It lays loose pretty much kept in place by the wiring.  I didn't add the lock switch - just left those wires tied.

If you really want to use the two position unit w/ no neutral, it's very simple with two diodes. It will be half-wave DC.

Connect the  anode of one diode and the cathode of the other to one motor terminal. Connect the remaining anode & cathode each to one of the two switched terminals on the 101 type 2 position reverse.

Connect the remaining motor leg to center rail power.

Now in each position of the reverse unit, only one of the diodes is powered, providing either forward or reverse.

Wow Rob, how about a diagram?

SWANKO, please don't use the crappy electrical tape for this!  Heatshrink tubing of the correct size won't turn into a gooey mess after a few months!

I don't think that will work.

There are many undesired current paths through that arrangement. The bottom two rectifiers of each bridge are connected in anti-parallel. The "southwest" rectifier of the upper bridge is in parallel with and opposite polarity to the "southeast" rectifier of the lower bridge, for example.