HOn30 Davenport 0-6-0 conversion

[JeffB]

Hello all,

  I figured I'd share some photos of the HOn30 conversion I did a while back...

  The model started out as an HOn3 West Side Models D&RGW #50.  The prototype, as many will know, was a 30ton Davenport 0-4-0.  I converted the brass locomotive to an HOn30 0-6-0.  The new mechanism consists of 3D prints from Shapeways, that I designed and finished.  It uses a 12V Maxon 1217 coreless motor and drives the rear axle through a 108:1 gear ratio, using custom made gears from NWSL.  I purchased 0.3Mod worm stock and gear "sticks" for 0.3Mod worm gear, reverse worm gear and spur gears.  From these "sticks", I parted off (using my lathe) the specific thickness gears I needed, then bored out the holes for gear and axle shafts as needed.

  Wheels are NWSL nickel silver HO scale 88 contour wheels, that had the flanges narrowed to fit the HOn30 turnout frogs I use (built from Fast Tracks HOn30 fixtures).  The flanges were turned off the middle drivers to replicate how the prototypes were built.  The wheels are mounted on 2mm axles, with laser cut, 1mm thick brass counterweights.  In between the counterweights and wheels are 1.5mm thick square brass axle bearings. 

  The mechanism is also equalized, in that it can adjust to track irregularities, so that all six wheels are on the rails all the time.  The rear axle is fixed/rigid, but the middle and front axles can float up and down and adjust side to side as well.  This is done through the use of an equalizing beam between the two axles, which bears down on a bearing in the middle of each axle. 

  This gives excellent electrical pick-up, which helps to eliminate the fact that I didn't use a flywheel.  Due to the equalized axles, I had to hinge the coupling rods so that it would allow the axles to move vertically without binding.  To do this, I made forked ends on the end of one rod on each side.  A hinge pin soldered through the holes in both parts creates the hinge and allows the rods to "flex". 

  All the metal parts other than the gears, gear shafts, axles and crankpins were laser cut from either steel, brass or phosphor bronze (I work in an industrial laser R&D Lab).  The coupling rods are made from 0.025" thick steel, with the hinge plates cut from 0.005" thick steel.  The brass frame plates that the axle bearings move up and down in, are laser cut from 0.025" thick brass.

  The mechanism is controlled by an ESU "Lokpilot" V4 Micro decoder.  I prefer these for coreless motors because they have 4 CV's that allow you adjust for the type of coreless motor, as well as some of a particular motor's operating characteristics.

  The combination of the coreless motor, 108:1 gear ratio and equalization gives exceptional operating characteristics.  Minimum continuous speed is about 0.3smph, with a continuous (safe and still quiet) top speed of about 15-18smph.

  Here's some photos...

IMG_5825 by jeffB, on Flickr

IMG_5822 by jeffB, on Flickr

The converted body, with the Shapeways frame.  This was printed in the old "FXD" and is held in place by 3 screws that were used to attach the original frame.

IMG_5823 by jeffB, on Flickr

Front/side view...  I filled in the large coupler openings in the end beams with some brass.  I also swapped out the original D&RGW caboose steps for laser cut steel steps that are closer to the Davenport design.  The air cylinders on each end, that were used to raise/lower the couplers for adjusting the coupler height between std gauge and narrow gauge were also removed.

The body shell was primed with Krylon black primer.  The top color of the body is a dark green by Vallejo, applied with an airbrush.  Some weathering has been started, but more needs to be done, as well as the addition of some shading/highlights to lighten up some of the features.

The frame print was painted with a Vallejo red, then "weathered" with artist oil black.

I'm not 100% happy with all the paint...  I'll try to fix/adjust it, but if I'm still not happy, I'll strip everything and start over.

Here's a photo of three mechanisms that were designed for this project...  Two were originally geared 75:1, but I wanted a higher compounding ratio, as well as a higher overall ratio.

IMG_5810 by jeffB, on Flickr

Here's the locomotive with the mechanism installed.  The rods and counterweights were painted, but need stripping so I can get a better finish on them.

Untitled by jeffB, on Flickr

Untitled by jeffB, on Flickr

Untitled by jeffB, on Flickr

Side on view.

Untitled by jeffB, on Flickr

Side on view of the mechanism, painted up and ready for the decoder and installation.

Just in case you think that this is a bit extreme, here's a few photos of a mechanism built for HOn2/7mm gauge...

Untitled by jeffB, on Flickr

Untitled by jeffB, on Flickr

Untitled by jeffB, on Flickr

I have to have Shapeways print a narrowed frame for this mechanism, but it will fit into the West Side Models brass body the same way that the HOn30 version does.  The HOn2 mechanism has the same final gear ratio/gears as the HOn30 version, but I used a smaller (8mm x 16mm) coreless motor in it.  Because that motor has double shafts, I was able to mount a flywheel.

[Chris333]

Welcome to the Railwire! 

[JeffB]

Welcome to the Railwire! 

Thanks man...

Edit:  Doesn't seem to be a lot of interest in narrow gauge subject matter on this Forum!  No biggie. 

JB

[sd80mac]

Hi JB,

I'm actually more interested in your method of development and construction. The laser-cut metal and 3D printed hybrid frame/chassis displays excellent  engineering!

[Hawghead]

Jeff,

Welcome to The Railwire.  Most of the folks here are N scalers but there are a few of us here that try to keep the narrow gauge flame alive.  However everyone here appreciates good modeling no matter what gauge or scale so I'm sure you'll fit right in.

Scott

[JeffB]

Jeff,

Welcome to The Railwire.  Most of the folks here are N scalers but there are a few of us here that try to keep the narrow gauge flame alive.  However everyone here appreciates good modeling no matter what gauge or scale so I'm sure you'll fit right in.

Scott

Thanks Scott...  I wasn't upset or surprised.  When you do the sort of esoteric stuff I generally do, you have to expect that you don't get much interest in it!


Jeff

[Chris333]

Well the gauge is the same or even narrower with his HOn2 version.

You should see his 3D artwork to plan these drives out. 

[peteski]

This is some amazing $hit Jeff!  I'm not into H0 or narrow gauge, but like others have said, I enjoy seeing creative scratchbuilding, and good documentation (excellent photography!).  Your stuff looks more like factory-made items, not some home-brewed project.  But you also have the CAD skills, and access to some serious industrial tools, to pull this stuff off.

A lot of us modelers are sill in dark ages when it comes to model deigns and building skills.  Great to see what can be accomplished with more modern techinques.

[JeffB]

This is some amazing $hit Jeff!  I'm not into H0 or narrow gauge, but like others have said, I enjoy seeing creative scratchbuilding, and good documentation (excellent photography!).  Your stuff looks more like factory-made items, not some home-brewed project.  But you also have the CAD skills, and access to some serious industrial tools, to pull this stuff off.

A lot of us modelers are sill in dark ages when it comes to model deigns and building skills.  Great to see what can be accomplished with more modern techinques.

Thanks Pete!

Here's a few screen shots of the solid model design for the HOn2 version of the Davenport conversion.

HOn2_DM_2 by jeffB, on Flickr

HOn2_DM_3 by jeffB, on Flickr

The two screenshots below show the gear layout and equalizing beam between the inner and one of the outer axles.  It will give you an idea of how I equalized the mechanism and how you get a 108:1 gear ratio into a 7mm gauge mechanism.

HOn2_DM_4 by jeffB, on Flickr

HOn2_DM_1 by jeffB, on Flickr

The two screenshots below show the solid model for a 6.5mm to 7mm gauge HO scale 8-10 ton Davenport 0-6-0 diesel mechanical.  Same basic principles as the larger mechanism above, but further condensed to fit the smaller model  The gear ratio on this design is 70:1, but I have a new design for it that ups that to 84:1.  Drive wheels are a scale 24" in diameter, with a 62" wheelbase.  Davenport actually built a locomotive like this for a sugar plantation railway in the Caribbean, it was an 8 ton unit, powered by a CAT D318 engine.  I back dated the design (different hood/exposed CAT radiator) to better fit with what I intended to model

8T_HOn2_DDM_1 by jeffB, on Flickr

Here's the mechanism and frame...

8T_HOn2_DDM_2 by jeffB, on Flickr

Jeff

[peteski]

Nice!
Like I said, what I see you do I would expect to see in the design engineering department of Rapido Trains, Scale Trains, Atlas, Kato, or any other model manufacturer.  You have skills and talent to do such quality designs.  Not many average modelers are that lucky.

[JeffB]

Nice!
 You have skills and talent to do such quality designs.  Not many average modelers are that lucky.

Thanks...  I have a lot of advantages over most modelers.  A combination of equipment (at home), work experience and access to tools that nearly every else doesn't have access to.  I think of it as the "Perfect Storm" for a modeler.

Jeff

[Cajonpassfan]

Well, that, and a helluva skill set!
Welcome to the Railwire, Jeff.
Otto K.

[timwatson]

@JeffB this is AMAZING work dude!


There are so many things to love here. No wonder you want to get the SM4k working again. Excited to keep track of this.

[JeffB]

Well, that, and a helluva skill set!
Welcome to the Railwire, Jeff.
Otto K.

Thanks Otto...   That skill set is a lifetime in the making!

@JeffB this is AMAZING work dude!


There are so many things to love here. No wonder you want to get the SM4k working again. Excited to keep track of this.

Thanks Tim...  Oddly enough, most of the stuff above doesn't require a home 3D printer.  All the mechanism blocks/gearboxes and the new frame for the WSM D&RGW #50 were done by Shapeways.  The 12-15ton Davenport will require the use of the SM4k, or at least the Photon for the body parts, but I still need to use Shapeways for all the gearboxes I make.  Home 3D printers can't print gearboxes in the way I design them.  Holes for gear shafts fill in.  Axle slots droop or sag.  Drilling or filing them out tends to move the hole or slot, which you can't have in a gearbox and a rod driven mechanism.

Anyway...  I appreciate the kind comments/praise guys.  It's taken a long time to get to where I'm at, and a lot of it wouldn't be possible or practical if I didn't have the machines I have access to.

Jeff