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Steam Powered Face
Shovel
Excavator
Contents of this website are freeware and/or copyrighted material, and may not be sold
under any circumstances.
Email: dogsbody@steamhobby.com
Home:
https://steamhobby.com
1. Credits & Specs
I made the mistake of performing a Google search entitled "meccano
steam". A bad idea, since it let me find someones build of
a
large & wonderful face
shovel excavator model. Powered by steam. Made of
Meccano. Lots of Meccano. A 100+ year old metal
construction set/system
involving girders, beams, plates, wheels, gears, axles, and huge
numbers of nuts
& bolts.
The design was originally built by Patrick Lewis, England, and
featured in the October 1970 issue of Meccano
Magazine.
John Bader,
England, presented an updated article in the June 2002 issue of Constructor Quarterly.
I would have remained in
blissful ignorance,
if not for Chris'
Meccano Restoration site. Alas, it awoke a childhood
love of Meccano and meshed with my current steam cravings.
Chassis
& Body:
Meccano
Power: Meccano
1929 Vertical Steam Engine
Fuel: Liquid
Methylated Spirits (Denatured Alcohol)
Boiler
Pressure:
15+ PSI
R/C: Not yet.
Runtime: 15-20 minutes
Weight: 20 lbs
(empty)
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face shovel excavator
2. Overview
As on Chris' version of
the face shovel, I used 1970's Meccano yellow,
blue &
zinc. This is a large model & needs lots of not
inexpensive brass parts for the power train, lots of not inexpensive
hinges for the tracks, and lots of not inexpensive girders, wheels,
axles, etc... Fully assembled it weighs just over 20 pounds
-- mostly steel and brass.
To build the FSE, first I tracked down the editor of Constructor
Quarterly and purchased a
reprint of the June 2002 issue (CQ56).
Next I bought a used & abused 1929
Meccano Vertical
Steam engine off eBay. These are rare & don't come up
often, so I wasn't picky. The paint had been stripped from my
find
allowing the frame
to rust quite badly in places.
A tear down, wire brushing,
sanding, cleaning, and repaint with Chevy blue (sometimes called Old
Ford blue)
engine enamel cleaned things up. The paint contains ceramic and
is resistant to heat, fuel & oil, plus it matches the 1970's
Meccano blue very well.
The exhaust pipe from the engine cylinder was cut off at some point,
and vented directly into the firebox. I extended it back to
the top of the boiler. Also, no gears were included so I
purchased a replacement set.
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rear view
1929 Meccano Steam
Engine closeup
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The face shovel has a total of 18 controls. All but the
engine
enable/reverse control (red handle on the steam engine itself) are
visible below. There are 10 primary controls, and seven
sub-controls for braking. This might seem like a lot, but
eventually you realize they're all needed.
left side view of control
Here they are highlighted. The reversing gear
control (A), bucket
door release (B), track steering clutch (C), track drive control (D),
three sets of clutch, ratchet
brake, and friction brake boom controls (EFG, HIJ, KLM), two-to-one
gearbox (N), slewing drive control (O), engine clutch (P),
and superstructure locking brake (Q):
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The
transmission seen from the right side:
right side
Details of the boom and bucket
arms:
boom arms
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3.
Base Mechanics
First I built the track steering gearbox, which makes the tracks either
move in the same
direction (for forward/back), or opposite directions (for
turning).
I ran into problems though, since the newer
parts I bought had slightly different dimensions. In addition, I
found
myself unsatisfied with the clutch mechanism.
The dog clutches (formed from gears & screws) only engaged
coarsely. Applying too much force to the steering control
could
easily stall the steam engine. Thus I
redesigned things using 26T bevel gears instead, making the operation
very smooth. The bevel gears mesh nicely when pushed
together, and the upgrade is highly recommended.
bottom view of
track steering gearbox
Finishing the base naturally involved making... the
tracks. This part of the assembly is a mind
numbing experience. There are 168 hinges, each attached
with two screws, two
washers, four nuts, and lots of Loctite. Fun, fun,
fun... Or not. :-)
closeup of track
A picture of the fully assembled tracks attached to the base. Can
also see the linkage I devised for controlling the engine clutch here:
rear view of
tracks
Finally, a closeup of the bearing ring sitting between the base &
crane platform. The fixtures hanging from the platform and hooked
under the bearing ring are free running pulleys that stabilize the
platform to prevent rocking.
side view of
tracks and bearing ring
Overall, base assembly is straightforward. The text and
pictures provided in Constructor Quarterly are more than
adequate. My
only recommendation is to use new axles everywhere. Used
axles typically have small bends or buildup that inhibits smooth
operation, which I learned the hard way.
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4. Platform Mechanics
The crane platform assembly is somewhat more involved, but most
elements can be figured out with thought, and careful reading of
the magazine.
view of platform
assembly
Naturally the first step was putting together the platform
superstructure, A-frame, and side plates.
I approached the transmission opportunistically using the
provided photos. Whatever was obvious I made
first. Some elements must be inferred, and certain areas
are only covered by the text. Ultimately I went through
numerous cycles of disassembly & reassembly
when working on areas with tight access. I can't emphasis
enough the
importance of using new clean straight axles.
One area not well
described in the magazine is the track &
slewing
drive controls. These transfer engine power to the track
steering gearbox, and platform slewing gear (within the bearing ring)
respectfully.
The vertical clutches are described, but not
how they're articulated. See right for my approach here.
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drive clutch
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4.1
Design Changes
As with the track steering
gearbox, I upgraded most clutches to use
bevel gears. The original dog-clutches used a collar grubscrew to
engage a #171 standard socket coupling. They only engage in
one position, when grubscrew & coupling slot
align.
The bevel gears work much better, engaging at any position and
requiring less movement. They are longer however, requiring
more axle space. Minor shuffling of elements in places is
necessary.
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old &
new dog clutchs
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The two-speed reduction gearbox with bevel gears. It wouldn't fit
in the original position, so I turned it 90 degrees. As a
small bonus, the new position makes
hooking up the engine easier.
two speed
reduction gearbox
The updated boom drum
drive. The boom drum raises & lowers the
entire boom (crane assembly). Plenty of axle room here, so
an
easy refit.
Also visible is the superstructure locking brake control -- the 38t
gear connected through a trunnion. Somewhat close to the
boiler, so don't burn your hand!
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boom drum
drive
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The updated reversing gears. These support reversing engine
power to the tracks, slewing gear, and bucket arm crowd
drum. The reversing gear axle was overfull once
fitted with bevel gears, so I switched to #171a Short Socket
Couplings. I also removed the stack of wheel discs forming a
center bearing (not really needed anyway). The gear
selectors I made from strips of 3/8" by 1/16" aluminum.
reversing gears
The revised bucket arm
drum drive and bucket arm crowd
drum drive. These control lifting the bucket arm up/down,
and pushing/pulling the bucket arm in/out within the boom.
Plenty of room for the bevel gear upgrade in both cases.
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buck arm drum
drive |
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5. Materials List
& Vendors
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Contact
Address:
Constructor Quarterly
17 Ryegate Road
Crosspool, Sheffield
S10 5FA
England
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- Meccanoman
Online Superstore. Great selection, often offering both
new & used parts. Accepts new web orders infrequently
though,
so
check back often.
- Meccanoshop.
Prices tend to be a little higher, but they're always open.
Discounts on bulk purchases of smaller items like
screws/washers/etc... Copies of Constructor
Quarterly are sold there also (scroll to bottom of page).
- Joel Perlin
Erector Sets
& Meccano. Large inventory of Meccano
parts. In particular, stocks the hard to find #27S
replacement gear/pinion set for the 1929 Meccano Steam
Engine. The pitch of the 27S gears differs from standard
Meccano gear pitch, matching the original steam engine gears.
- eBay.co.uk
Large number of Meccano vendors to be found on the UK
eBay. Keep an eye on shipping costs.
- Other Supplies (Home Depot, Kragen, etc...)
- 3-in-1 oil
- Loctite Thread Locker
- Chevy Blue Engine Enamel
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