Aristo-Craft Mallet Vignette

Aristo-Craft’s 2-8-8-2 Mallet Steam Loco Vignette

Ted Doskaris

April 20, 2007
Revision GE-B

July 3, 2015
Revision GE-C  Added Body Mounting Kadee Centerset Couplers & Lowered Vanderbilt Tender

April 6, 2018
Revision GE-C1, Established local Topics links and embedded videos

Aristo's Mallet Packaging
Initial Aristo Mallet Experiences
Body Mounting Kadee Centerset Couplers & Lowered Vanderbilt Tender
Possible Pilot Coupler Installation Methods
Chosen Coupler & Installation Method
Loco Front Pilot & Kadee Coupler Installation
Vandy Tender Modifications
Vandy Tender Lowering Detail & Drawings
Vandy Tender Body Mount Kadee Coupler
Vandy Tender Drawbar Receiver / Anchor
Truck Mounting
Miscellaneous Issues

Aristo’s Mallet packaging

Aristo-Craft appears to have done an excellent job on packaging for the Mallet.
I think this is one the best I have seen Aristo do.

Some time ago I got the new UP Mallet, and I received it with no damage or any of its parts dislodged.

The collective weight of all the empty boxes is 14 lbs from what I measured.
(The big, empty Yellow box for the loco boiler weighed 4 lbs, 9 oz., and the empty Vandy tender Yellow box weighed 1 lb, 12 oz.)

The collective weight of the removed loco with Vandy tender was 20 lbs, 9 oz.
(16 lbs for boiler section and 4 lbs., 9 oz. for the Vandy tender with its 3 axle trucks.)

Thus, the entire large box with all its contents as received weighed 34 lbs, 9 oz and cost me about $31.00 ground shipping from the East Coast to the West Coast.

BTW, the end of the entire large box includes its dimensions and weight listed in KG, which when converted to lbs, turnout out to be nearly identically to what I measured.

Now for the pictures:

Empty Aristo-Craft Boxes for the Union Pacific Mallet with Vanderbilt Tender:

In the following picture, note the empty "dummy" boxes in the foreground that serve to fill out the large box as added packing:

Aristo-Craft Main Box for the Union Pacific Mallet with Vanderbilt Tender.
Note the PMC (Polk's Model Craft Hobbies) and New Jersey, etc. identity on the side of the box:

BTW, compare the Aristo-Craft Union Pacific with "flags and Wings" GE dash 9 outer box as shown below.
This was obtained from the retailer St. Aubins. Note the identity on the side of the box is not PMC.
(Apparently they have been able to get their Aristo products shipped directly without going to Aristo first.):

Initial Aristo Mallet experiences

Overall, I am very pleased with my Union Pacific Mallet with Vanderbilt tender. It runs smooth and only uses about 2 amps max when traversing my under house layout pulling about 40 cars (Aristo 100 ton hoppers with metal wheels. I know the cars are not period correct.) My circuitous layout has mostly curves and "S" bends with one 270 degree 10 foot diameter loop back.

The packaging was excellently done by Aristo-Craft (Boxes for the Union Pacific Mallet with Vanderbilt Tender shown below.):

I was able to mount the front Aristo knuckle coupler whilst retaining the little cow catcher, but the centering spring attachment is still a mystery as to how it should be installed!
(BTW, When I first ran the loco on my layout that round, front smoke box hatch sometimes would open! I never realized it was intended to open until this happened. I had trouble trying to keep it shut.)

I placed an automotive type vacuum nipple on the Vanderbilt tender draw bar pin to prevent unwanted uncoupling - typically when backing up the loco over those Aristo Wide Radius turnouts. I also moved the mounting pin to the provided, second hole to allow for closer spacing of the tender to loco boiler. As such the loco can still go around 8 foot diameter curves in my rail yard.
(BTW, this large loco sure brings out the faults with those Wide Radius turnouts. You can hear the drivers hit those plastic guard rail abrupt ramps with a clunking sound whilst the loco is traversing the diverging path, and when backing up there is a better than 50 - 50 chance the drivers will climb over those guard rails and derail the loco!)
Also, the tender ladder does not vertically align properly. Apparently it is forced to the offset position by the wire railing being seated too deep in its mounting hole locations. A fix for this is near the end of this vignette; see Miscellaneous Issues, Item 7 Vandy Tender Misaligned Ladder Fix.

This view shows the automotive nipple over the draw bar pin (It would be desirable for Aristo to include this as standard equipment with the loco):

No problems with the closer spacing:

However, the tender's rear truck mount coupler helps when pulling a 40 car train connected to a car with a truck mount coupler around my 270 degree 10 foot diameter loop back over those Wide Radius turnouts:

Some more operational pictures:

Aristo-Craft Union Pacific Mallet, road number 3670, right view:

UP Mallet Vanderbilt tender with as received draw bar pin location in outermost hole.

UP Mallet and Vanderbilt tender connected with as received tender draw bar pin location. (Note the greater than desired - or required during operation - space between the boiler and tender.):

UP Mallet with Vanderbilt tender connected to boiler section showing half inch closer more realistic spacing:

UP Mallet Vanderbilt tender recess allows for close connection to the boiler's platform (Operation even on 8 foot diameter curves presents no problems.):

UP Mallet and Vanderbilt tender overall length with draw bar pin in optional location - saving a half inch. This length measures 47 inches - not including coupler projections:

UP Mallet pulling a 43 car freight train on my under house layout:

UP Mallet traversing No 6 crossover
(Note that the round hatch on the face of the boiler sometimes hinges open during train operation!):

UP Mallet pulling train on No 6 crossover headed toward loop back (shown in the background) in a direction opposite than typical:

UP Mallet Vanderbilt tender includes an illuminated rear light when the loco is operated in reverse mode; however, the loco front headlight remains illuminated when in such operation. Both of these lights are incandescent types:

The beginnings of an Aristo-Craft UP Mallet PFE Reefer "fruit block" train:

Since this picture was taken, I obtained many more PFE and other reefer cars for a realistic reefer fruit block train. In this regard, It would seem that Aristo could better leverage their Mallet product sales by offering a similar “prime mover” fruit block train set as they have done with the Dash 9 hopper car sets and Pacific type steam loco heavyweight set.

Suggested Mallet improvements would be to add seats & crew to the boiler section cab. A fire box simulated flame would be neat to see, too.


Body Mounting Kadee Centerset Couplers & Lowered Vanderbilt Tender

It's time to revisit the Aristo Mallet for improvements in the way of appearance and installing centerset type Kadee couplers.

I've had the Aristo-Craft 2-8-8-2 Mallet with Vanderbilt tender (3 axle Commonwealth trucks) for many years now, but have used it very little since it was equipped with Aristo knuckle couplers, and most of my locos and rolling stock had been fitted with body mounted Kadee centerset "G" scale couplers.

Also, the tender did not seem to look correct since it sat too high off its trucks (which is something to consider before body mounting centerset couplers).  Checking with prototype photographs confirmed this.


Shown below is the Mallet Loco with its tender before modifications.


Shown below is how the Mallet looks now with its lowered Vanderbilt tender.
(Note:  The task of installing Kadee centerset couplers and lowering the tender does not require removing the boiler or any body shells, including the tender's.)


As of this writing date, the Mallet is my only steam engine model.  Because my outdoor layout has loops and grades, I got it for pulling ability given its weight and double drivers.  To double head single driver steam locos with tenders takes more space than MUing shorter diesel models.  The steam engine tenders are, also, dead weight.

The Mallet loco itself weight is about 16 lbs. (The picture below is with the loco having a body mount Kadee 907 centerset coupler (buttressed with an unnoticeable metal reinforcing strap) installed on the front, which has minimal affect on the weight.)


The Vanderbilt (aka Vandy) tender weight is almost 5 lbs.  (The picture below is with the tender lowered and having a body mount Kadee 905 centerset coupler (on an unnoticeable metal right-angle bracket) installed on its rear and a body mount draw bar receiving anchor (unnoticeable right-angled "S" shape metal), which has minimal affect on the weight.)



Possible Pilot Coupler Installation Methods

Among methods that I am aware of include using the existing pilot post meant to mount a coupler such as the Aristo knuckle coupler which I had initially done.


Another method is to use the existing pilot post to mount a Kadee coupler or the coupler with its box; however, to mount the Kadee coupler its shank hole and / or coupler box hole requires either reducing the diameter size of the pilot post or enlarging (drilling out) the hole in the coupler shank and coupler box.  But removing material in this manner would appear to weaken the coupler with risk of failure if the loco were being doubled headed pulling a heavy load, or more significantly, pulling a heavy load in the reverse direction.

That said, there is another very important load consideration with respect to how the greater front pilot assembly is constructed and attached to the Loco.  
As can be seen in the following illustration there are only two small screws that attach the Pilot Mount to the Front Platform in respective slits!  Thus, if one were to ignore this deficiency, mounting any kind of coupler would at best be for cosmetic purposes.

In regards to mitigating the pilot mount attachment deficiency, a method employed by some folks was to glue a plastic spacer block to the underside of the front platform and attached the Kadee coupler box with a screw or drill a hole through the top of the front platform and underside spacer block for attaching the box.  However, since the greater plastic front pilot assembly is attached near the bottom front of the motor block, load forces are via the platform where it attaches at a right angle to the part that ultimately fastens to the motor block, thus, leverage forces are at play, too.

Chosen Coupler & Installation Method

While I could use one of my custom made Datum Precision metal coupler boxes to house a Kadee centerset coupler, I decided to try out the standard Kadee 907 coupler assembly, albeit with modified coupler box shank.  To install this box, minimal trimming of the Loco's pilot mount (while not affecting its post) is required, along with using a fabricated steel bracket ("pilot strap") to reinforce the plastic pilot.
CAUTION:  Loco Component Breakage Risk

During handling of the nearly 16 pound loco boiler section, it's easy to inadvertently break away the "Power Reverser Actuator" arm component on the right side of the boiler just above the rear driver assembly front cylinder.  That's because the rear driver assembly cylinder can interfere if not held straight when the driver assembly is rotated.  Illustrated below is how a repair can be done using tubing and CA glue.



To transport the Mallet loco boiler section, it's advisable to keep the rear driver straight and not rotate it toward the Power Reverser Actuator arm whilst carefully placing the loco on a fairly rigid surface - like a 2 foot track section.  The Loco and track section can then be carefully  picked up as a single entity and moved.  To work on the Loco pilot area, I carefully turned the loco on its side whilst placing it on a thick double folded towel with the pilot slightly overhanging the edge of the work bench.


Loco Front Pilot & Kadee Coupler Installation

Removing the pilot components:

As shown below the Mallet pilot area is held in place with 2 tiny screws for the "cowcatcher" and 2 slightly larger screws for the pilot mount.  With reference to the image, remove the coupler pilot "cowcatcher" and then the Aristo knuckle coupler (if so equipped) and finally the pilot mount.


With the underside of the greater pilot area now exposed, the modified coupler box and pilot strap is now poised for installation.  Before installing these parts, the following information describes what is to be done to them first.

Modifying the Kadee 907 Box:

Shown below are the modifications to the Kadee 907 coupler box.  The box appears to be made of a hard nylon material so the trimming done would not seem to compromise it.



Notching the Front Pilot Mount:

Show below are the minor modification to the pilot mount so it will accept an inverted 907 coupler box.



Fabricating the Pilot Strap:

This is the most difficult part of the project to do as it must made fairly precise so it fits as intended.
The strap I made was from a 1 inch wide stainless steel piece of metal; however, the strap only needs to be 0.90 inch wide.  Also, though very strong, the hard stainless steel is difficult to work with; however, I believe mild steel will still have the needed strength and be easer to work with.  That said, even when using stainless steel, I was able to form the strap using a machinist hammer, hobby vise and small rectangular steel blocks positioned against the metal held in the vise  to strike with the hammer to make the bends.

Shown below is a dimensional drawing of the pilot strap shaped like an inverted "U" with offset wings.



Installing Coupler assembly & Pilot Strap:

Shown below is how the pilot strap is to fit with the modified coupler box.

In the above picture, observe how the modified Kadee 907 coupler assembly is sandwiched by the Pilot Strap over the mounting post.  It's important that the strap be below the top surface of the post so when all is held together by the washer and screws it will keep the overall greater plastic pilot from pulling apart and flexing under heavy loads.

Shown below is how the installed coupler aligns with the Kadee 980 gauge with the "Cowcatcher" reinstalled.



The thin white shims provided with the Kadee 907 kit can be used to "fine tune" the coupler alignment as I did here.


A small piece of plastic glued atop the installed box should be done for appearance sake.


Shown below is the completed Mallet Boiler section on an 8 foot diameter track curve.



Vandy Tender Modifications

The Vanderbilt (Vandy) tender described pertains to the version equipped with 3 axle Commonwealth trucks.

Three things are to be done to the as delivered factory Vandy tender:

(1) Lowering the Vandy tender to be more like a  prototype tender as seen when examining several prototype photographs.  Since a Kadee centerset coupler assembly is going to be body mounted, the tender must be lowered first in order to establish proper coupler height from the railhead.  Lowering is done by removing the truck sideframes from the truck bolster, making a slight modification to it, and then inverting it with side frames reattached.  


Other details to be explain are involved in lowering the tender; however, lowering the tender is a surprisingly easy task to accomplish.

(2) Attaching a body mount Kadee 905 centerset coupler assembly to the rear of the tender using a fabricated steel right angle bracket.


The results of which are shown below.


Other details and a drawing are to follow.

(3) Attaching a body mount draw bar receiver to the loco end of the tender using a fabricated steel right angled "S"strap.


The results of which are shown below.

Other details and a drawing are to follow.

Vandy Tender Lowering Detail & Drawing

Tender Preparation:

The tender's front truck can be removed by unscrewing it from the chassis mounting post.  So can the rear truck, but this truck includes two captive wires for electric pickup purposes.  My example had a great deal of wire relief so I was still able to work on it (and do coupler body mounting) by moving it away from its chassis post and placing it on a towel between it and the chassis.  This avoided having to cut and later reattach the wires.

With the trucks now poised to work on, the tender is lowered by removing the trucks' bolster from the side frames, inverting (flipping over) the bolster, beveling the "H" legs so wheel flanges clear, and then reinstalling it (using no. 2 screws, washers & nuts) to the  underside of the side frame ears.  In so doing the bolster with pocket that now would face upward needs a spacer so as to obtain the desired lowered height of the tender.

Spacer &  drawing:

In conjunction with the inverted truck bolster, the spacer thickness determines the amount that the tender is lowered (overall height from railhead) by reducing the excessive gap between the top of the trucks and the chassis underframe.


Shown below is the truck with inverted bolster and spacer installed.  What was the truck coupler mount tang must be trimmed or completely removed.
Coupler Tang Trimming:

If the truck tang is not removed (or trimmed as shown below) the rear truck will interfere with the body mounted coupler bracket and the front truck will interfere with body mounted drawbar receiver.



Truck with Modifications:

Shown below is what's involved with the truck for lowering the Vandy tender.


So as to have working room for body mounting coupler and drawbar receiver, the trucks should not be remounted at this time.  That said, the illustration below depicts the steps involved for removing and then reinstalling a truck once the modifications had been done to the bolster.



Vandy Tender Body Mount Kadee Coupler

The Kadee 905 coupler assembly is body mounted on the rear of the tender using a right angle bracket .

Fabricating Mounting Bracket:

In the example shown below, the mounting bracket was made from a hardware store purchased metal wood framing construction plate having multiple holes.  The not needed holes were offset from the required holes so as not to be a problem.



Drawing - Coupler Assy. Mounting Bracket:

The pictures below, also, depict how the bracket is to fit onto the chassis underframe with only requiring the existing "Long Bolt" to secure it.  That's all that was needed to make for rigid installation.


Both the fabricated bracket & Kadee 905 assembly have vertical slots.  This affords the greatest possible vertical adjustment tolerance when installing the coupler assembly to align with the Kadee 980 track height gauge.  As to the bracket, you could just drill the 4 holes at their target centers for mounting the coupler assembly and see if that will suffice; if not, then elongate the holes in the vertical plane to the as shown specified dimensions.

You don't have to take the tender apart to install the bracket, or any other parts.  But the illustration below will show the interior where the long bolt is fastened.  Viewing this may be helpful when  attempting to align and thread-in the long bolt that now will, also, serve to secure the bracket.


Vandy Tender Drawbar Receiver / Anchor

The factory truck mount drawbar receiver is to be replaced with a body mount drawbar receiver fabricated from a hardware store purchased metal strap.  This is done for the same reason as for replacing the tender's rear truck mount coupler; that is, not only for cosmetic appearance, but to eliminate the torsional loads and stresses that can twist the truck off the rails when operating heavy or long trains, especially in the reverse direction.

Drawing - Body Mount Drawbar Receiver:


The fabricated strap utilizes a two point mount:
One using an existing screw location on the chassis underframe
The other using a small screw centered through a recess located at the end of the tender

Shown below is how the right angle portion of the strap is to be fastened to the end of the tender.


Shown below is what's involved as to mounting the fabricated Drawbar Receiver.



Truck Mounting

After the coupler and drawbar receiver are mounted, the trucks as modified can now be remounted.
Before mounting and fastening down the rear truck with its wires, be sure push the excess wire length back into the tender chassis hole.

A short length bushing must be installed to extend the chassis mount post to make up for the geometry change for the inverted bolster with spacer.  Shown below are the measured dimensions for locating stock or for making one.  I used an Aristo bushing salvaged from a freight truck and cut it to the needed length (height).  


Note the original factory truck mount screws are too short and must be replaced with longer ones as shown above.  The screw length should be about 0.8 inch long; longer than this runs the risk of bottoming out against the tender's internal metal weights.

With the completed modifications, the Vanderbilt will operate OK on an 8 foot diameter track circle.



Miscellaneous Issues

(1) Mallet Component Breakage & Repair:

During handling of the nearly 16 pound loco boiler section, it's easy to inadvertently break away the "Power Reverser Actuator" arm on the right side of the boiler just above the rear driver assembly front cylinder.  That's because the rear driver assembly cylinder can interfere with this component if not held straight when the driver assembly is rotated.

If need be, illustrated below is how the component repair can be done using tubing and CA glue.



(2) Mallet Smoke Box Door:

The front face of the loco's boiler has a hinged door that opens and is a very nice feature; however, during Loco operation on a layout the door will tend to flap open and close.  A simple solution is to use an adhesive that does not make a strong bond yet still is sufficient to keep the door closed as shown below.



(3) Mallet "Grain of Wheat" Bulb:

The small bulb can come out from its lamp housing, usually during handling and transport of the Loco.
Just push it back into the housing.



(4) Mallet Drawbar Problem:

The factory drawbar receiver used on the Vandy tender includes a smooth finish anchor pin. During layout operation, the loco with periodic slack action or going from forward to reverse, etc. can result in the loco's drawbar to ride up off the anchor pin - becoming detached.  A solution is illustrated below.



(5) Vandy Tender Rear Panel:

The rear of the tender's chassis is factory made with an inverted "U" slot apparently to provide room for the truck mount coupler to swing within as the truck rotates.  With a body mount coupler the slot can be filled in on either side of the coupler to look more prototypical.  Shown below is an example where a small rectangular piece of plastic is CA glued in place.



(6) Vandy Tender Coal Bunker Removal:

Note: It is not necessary to remove the coal bunker shell to lower the tender or body mount coupler and drawbar receiver.

To access the tender's interior circuit board, speaker ,etc. parts, the bunker can be removed as illustrated in the following example:


Shown below is an interior view within the cylinder portion of the tender.


If desiring to separated the cylinder portion, it can be seen how the long screw and little plastic snap clips retain the cylinder to the chassis underframe.

(7) Vandy Tender Misaligned Ladder Fix:

The factory installed handrails on the Vandy tender can be done so as to misalign both platform and ladders.  In the example shown below handrails on both sides, top and bottom areas, had to be fixed so they were not bound up against the ladder.  The coal bunker shell was removed to facilitate the fix.





Mallet Kadee Coupler Test Operation on Layout



Mallet Kadee Coupler Test Operating in Reverse on Layout






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