Early version Dash 8-40C

[Catt]

I have a very nice running early pre DCC Dash 8-40C that I would like to convert to DCC.What I need to know is if the motor is isolated from the frame.It looks to me like it is, but I figure this is the place to find out.

Anybody got an answer for me ?

[richg]

Put your ohm meter on resistance and check. If you are going to do DCC installs, you better get and know how to use a multimeter. It could save you from heartburn and smoked decoders.

http://www.trainelectronics.com/Meter_Workshop/index.htm

http://www.trainelectronics.com/Meter_HF/index.htm

I have three of these meters.

Rich

[Catt]

In other words you don't have a clue either.

[richg]

Yours might be completely isolated. No idea. How early?

Go to the below site and look at the diagrams. Open yours up and compare. Do some research on your own.

http://www.hoseeker.net/bachmann.html

Cut the two motor wires and try to run the loco on DC might be a way to go. From what I recall from some old Bachmann diagrams, you have to separate the frames to disconnect the motor wires from the frames. I had to do that with a Plymouth switcher and the motor halves are white plastic. Yours might be the same.
I had a diesel and the motor looked completely isolated but the motor brushes were part of each motor half. I had to isolate the motor from each frame half with Kapton tape and use nylon screws to mount the motor to the frame halves. A test with my ohm meter showed me one brush was still connected to the frame. Right at the spot for the threaded hole, there was a lip in the frame when the hole was tapped which punched though the tape. I had to file down each mounting hole so this would not happen again.
I then checked with the meter again and no continuity so I connected the two decoder wires to the motor.
I have been working with electronics since 1954 and it is automatic to do continuity checks. on almost any projects before powering up.
As cheap as these meters are, no reason to not have at least two.

Rich

[jward]

to provide a definitive answer, the early dash 8s were a standard split frame chassis. as such, the frame halves provided a conduit between the trucks and the motor. the halves are held together by plastic t nuts. so no, they are not dcc ready.


the good news is that this is one of the easier dcc conversions to make. jim banner, who used to be a regular here, posted this excellent pictorial on how to convert an h16-44. the dash 8 is laid out the same way, only longer.

http://members.shaw.ca/sask.rail/dcc/tmaster/tmaster.html