0-8-8-0 Kitbash

Good idea, especially for those who can't afford $$$$$$ for Mallets. How will you build the boiler (not to get ahead of your present work).

I'm going to cut one boiler just ahead of the cab, and scab it on to the front of the second boiler somehow. Most likely a combination of JB Weld and brass strips for bracing inside.

 

It'll probably be a little short, just because of the massive swing the boiler is going to have.

 

Two main challenges will be getting smoke to come out of the correct place, and dealing with the motor on the lead driver set.

 

The new hinge system is working almost perfectly. I just need to trim down that plate a bit more, and come up with a better roller for inside the slot.

 

Not to be a kill-joy, but I doubt you'll be able to mount a motor to the lead frame and still be able to negotiate any type of curve.

 

As for the smoke, you'll just need to devise a way to mount the smoke unit to the inside of the front of the boiler instead of to the chassis.  It should be possible to rig up an extension to the piston actuator arm from the rear (fixed) frame.  Might need to fuss with the mounting point to adjust the amount of movement in the arm.  Just making the arm longer would be way too much motion.

Wowak,

 

You're thinking the motor won't clear the boiler, right?

 

I've got a plan for that. My idea is to cut a slot in the boiler for the motor to pass through as the locomotive articulates. I'll attach the cutout pieces of the boiler to the sides of the motor to disguise it when the locomotive is running straight.

 

Skipping the motor would make the project much easier, and I may end up doing that. It runs pretty well just pushing the lead frame around the track, even through most of my O-27!

 

The hinge bracket still needs to be shaved down a little more, and it needs a better roller in the slot. Right now I have a piece of soft wire insulation as a roller, which acts as a bit of a shock absorber.

The motor is at the rear of the chasis and should not present a problem unless you have real tight curves.  For a smoke unit you could mount a fan driven Lionel/MTH smoke unit directly inside the shell.  If you are good at modifing you might be able to take one of the motor leads through a micro-switch to creat the puff.  I don't know if this would cause the smoke unit to over heat, you would have to watch it close for a while. 
I hope this helps
Ron

For smoke, I may just find a fan-driven unit.

 

I picked up an MTH Keystone Express 2-8-0 set yesterday. I've never experienced fan-driven smoke before. Holy moly!

Fan driven smoke is the way to go, I've put a few of them into puffers and the results are well worth it.

 

Looking forward to seeing this proceed, cool idea.

Update:

 

My "Mini Mallet" took its first steps under full power on Saturday evening. Both motors are wired to the E-board on the trailing frame, in parallel. The pickup rollers are removed from the lead frame to improve tractive effort, and the neutral from the lead frame was tied into the system to prevent "liftoff" stalls on non-derailing switches.

 

I was expecting disaster when I first applied power. I should've bought a lottery ticket. Not only did the locomotove start smoothly, it completed several circuits of my O-42 section without a single derailment! On the first try! It even navigates the O-27 curves!

 

Even in its unfinished state, this thing is too cool for school. The lead drivers have this neat little touch of wheelslip when starting out with a consist, like you see in the movies of the Big Boys and Challengers. Just a quick "chug-chug" then all 16 drivers start pulling in unison.

 

Dang! I thought I had a video of it in action on my phone, but all I have is a single still shot. I'll remedy that later today, for sure.

That looks good.   I've never seen that done with two Lionel engines before.

 

Back in the 70's when the AHM 0-8-0 plastic engine kits came out in O-scale, I took two of those and made a 2-6-6-4 articulated out of them.