Did anyone ever manufacture a low profile motorized 3 rail motor block?

Lionel & K-Line diesels were both made with completely self contained motor truck blocks with either AAR type or Blomberg "B" type sideframes starting in ~ 1982 in starter & low-end sets..

What do you mean by low? Ghr had some small blocks for corgi pcc cars. Those were small and low profile.

This is a G-scale Aristo Craft would like something like this in 3 rail "O" gauge. (see picture below).
The only thing close would be the motor block and wheels from a new Lionel hand car

Go 2-rail.  All that stuff is available in one form or another.  The smaller the motor, the fewer cars you can pull, all other things being equal.  I believe the smallest is the NWSL Magic Carpet.  3-rail scratch building components have an extremely thin market - that's why you don't see them.

The closest thing to what you pictured in 3-rail would probably be the  truck block assembly from a K-Line speeder. I don't believe it's available as a retail part, but RMT markets the speeders now, and for the moment, O-Line Reproductions is selling repackaged K-Line pieces stranded by the Aristo-Craft shutdown when they were in a partnership with RMT.

The latter option would be more cost effective since you only intend to use the power truck, but quantities are probably limited to stock already in the retail pipeline owing to the nature of the venture.

There was also a member here who was attempting to develop a 3-rail power truck using a 3D-printed block and gears from HO diesels (or NWSL components?), but haven't heard anything since he showed a video of it running with a 9V battery perched atop it.

---PCJ

Here is a typical K-Line diesel motor truck(Lionel's is nearly identical) :

These can easily be completely self-contained / self-powered with just the addition of a small rectifier.

Look no farther than the Williams 44-ton locomotive.  It has two very small motorized trucks.

gunrunnerjohn posted:

...the Williams 44-ton locomotive.

A little steeply priced at ~ $140 per truck!

Do note the trucks pictured above have no flywheels.  When power is cut, they STOP!  Fast!

RJR posted:

Do note the trucks pictured above have no flywheels.  When power is cut, they STOP!  Fast!

The worm drive ones, yes. The spur drive trucks coast.

ADCX Rob posted:

gunrunnerjohn posted:

...the Williams 44-ton locomotive.

A little steeply priced at ~ $140 per truck!

No argument, but there was some discussion about Williams making them available for separate sale.  That could be interesting for many little projects.

FWIW Rob, my Wienermobile is running on that K-Line truck you posted.

The spur drive trucks coast.

Not the old cheap Lionel RS-3 I have stored away somewhere.

RJR posted:

The spur drive trucks coast.

Not the old cheap Lionel RS-3 I have stored away somewhere.

Well, then you need to clean out the carpet fibers, hair strands, tinsel, and fur from long-dead family pets from the gears, motor shaft, and axles of gears and wheels, and then lubricate them appropriately.

These designs are notorious for picking up all of this stuff and winding it up tight.

I have a couple of those K line trucks Rob has pictured. These are NOS. The ones I have are P/N K-2100-2. Let me know if you could use them.

I was working on one.....   had the housing 3-d printed,  but I didn't have a good spacing between gears and ate up gears......   I should contact nwsl for their help....