Construction?
A
brass spine section carries all of the components in a strong,
rigid structure. A nickel-silver gearbox frame mounts the Mashima
MHK-1015
motor and flywheel, along with 2 brass and one Delrin helical
cut spur gears, to transmit power down to just above axle level.
Then a silver-steel horizontal
lay-shaft runs underneath the brass spine, carrying the steel
worms that provide power to the wheels. The gear ratio of 15:1 provides
a good balance of power and speed range.
Moulded
Delrin gearbox enclosures place the axles in correct mesh with
the worms and align the axles across the assembly. Although Delrin
is an excellent bearing material in itself, each axle has two
brass bearings, one either side of the brass worm gear, to provide
excellent wheel alignment and smooth running. Two phosphor bronze
thrust washers inside the gearbox enclosures take care of thrust
loads along the layshaft.
A
Polystyrene plastic sideframe mount has three fingers on each
side that can
be trimmed off to provide mounting for bogie sideframes at
13.3, 16.5 and 21mm inside spacing. The sideframe mount also carries
two phosphor-bronze pickups, making contact with the inside flanges
of all wheels. The wheels are solid nickel-silver, to RP25
standard, code 88.
A
nickel-silver bolster, attached above the sideframe mount, runs
in a Delrin turntable to provide a swivel mounting for the BullAnt
to the model. A printed circuit board attached to the rear of
the motor features an interference suppression network to make
the BullAnt CE compliant.
Performance?
A
great deal of care has been taken with the design of the BullAnt
to guarantee quiet, reliable running combined with low maintenance.
The prototype BullAnt was run for 650 hours, 24 hours a day to identify wear
points. During that time, it travelled over 370 actual miles,
or 590 kilometres.
Shortly
after we started production, the moulded Delrin spur gears were
found to be unsatisafctory, so we had specially cut gears made
in a mixture of brass and Delrin with a helical tooth form to
improve smoothness and further reduce gear noise. At the same
time, we took the opportunity to add two bearings to the idler
gear as we had noticed wear in this area with the test unit.
If
the Mashima 1015 motor is a tad small for your application, and
you need a little more power, the larger 1020 and 1024 variants
can be supplied to order. The 1020, while providing more power,
also runs slightly slower than the standard 1015 motor, while
the 1024 runs faster.
More
Ratios?
Shortly
after introduction, the BullAnt will be available with a choice
of 3 gear reduction ratios. The standard ratio of 15:1 is best
suited to
larger scale narrow gauge EMU/DMU applications, while optional
ratios of 31:1 and 60:1 will be offered to provide better slow
speed performance.
More Axles?
An
exclusive feature of the BullAnt design is that it provides for
3 or even 4 axles. And the axle spacing does not have to be equal
either, you will be able to individually specify the spacing for
each axle in the assembly. Even with 4 axles, you can still have
power pickup from all wheels too.
However,
a word of caution, the BullAnt design provides a rigid wheelbase,
there is no lateral movement on the centre axles. This can be
a problem with 3 axle configurations where the axle spacing is
large and/or small radius curves are employed. A rigid frame of
any length can de-rail on corners and sharp points. It is not
really possible to advise a minimum radius that the BullAnt will
handle
as it is totally variable according to wheelbase, wheel size and
wheel profile.
We
do offer, on the other hand, an option that provides a lateral
action on the center axle. With this method, the center wheels
have a slightly narrower back to back measurement and employ a
nickel
silver wheel housing and thinned down wheel bearings. The worm
gear is also slightly thinned as well and this combination means
that there is 1.3mm of lateral movement on the center axle only.
Because of the additional time taken in the assembly of this option,
there is a price premium charged.
Really Short & Extra Long Wheelbases?
With
a minimum wheelbase of 17mm and a maximum in excess of 60mm,
the BullAnt will provide a much needed power source for trams,
multiple
unit railcars, small industrial tractors and the like. If
you are prepared to delete the pickups, sideframe mount and bolster,
the BullAnt can be supplied with a tiny 11.5mm wheelbase!
How big is the BullAnt, will it fit my model?
View the
Spec Sheet in PDF format, showing typical BullAnt dimensions: Spec
Sheet
To save it, right click on the link and choose 'Save
Target as....'
Ordering Options?
- Wheelbase:
From 11.5mm upwards in increments of 0.25mm. 17mm upwards
can be fitted with pickups and bolster.
- Gauges:
16.5mm (HO) - 14.2mm (British 3mm Fine Scale - 12mm (HOm or
HOn3 1/2) - 10.5mm (HOn3) - 9mm (HOe or HOn30")
- Wheels:
All disc - 11.6, 10.5, 9.6 & 8mm (other wheel types will
be added in the future)
- Motors:
Standard, MHK1015 - Optional, MHK1020 or MHK1024
- Matching
dummy BullAnt (non-powered)
Price?
A
two axle BullAnt will retail at $85.00, and a dummy at $25.00
in Australian Dollars. There will be small extra charges for additional
axles or other motor combinations.
How Quickly Can I Get a BullAnt?
We have invested in specialised CNC
machinery to make the assembly of the BullAnt as quick as possible.
All orders go into a queue and are processed in sequence. We aim
to have a maximum of 7 working days from receipt of order to despatch
of that order. In any event, provided we can contact you, we will
advise you when your order is to be shipped.
Note about Dummy BullAnt Please
note that the dummy BullAnt has exactly the same construction as
the powered BullAnt, including brass wheel bearings and these, along
with the power pickups that are fitted, mean that the dummy is not
particularly free-rolling. These features add a certain amount of
friction to the axle, and this is un-avoidable.
About Running In
A number of customers have noticed that their BullAnt is a bit
jerky in its movement when they receive it. The motor can also run
a bit warm as well. This is an indication that the BullAnt needs
to be run in.
Although every BullAnt is tested and run before shipping, we strongly
recommend that you run it in when you receive it. Some manufactuers
build their mechanisms with loose tolerances in the bearings, usually
referred to as 'slop'. We do not do this, all our bearings are made
to close tolerances and need to bed themselves in to provide optimum
performance. Unfortunately we cannot afford the time to do this
with each BullAnt at the factory, or it would increase the cost,
so we ask you to do this yourselves.
Hobby Shops, Distributors & Manufacturers?
Retail
hobby shops and distributors are welcome. Manufacturers looking
for powertrain solutions for their models are most welcome.
Please
contact us at sales@hollywoodfoundry.com or
telephone us on (03) 5629 1100, International +61 3 5629 1100.
Wholesale and dealer prices can be provided to legitimate businesses.
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