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Build The Roamabout
18 Foot Family Vacation Trailer
Although 18 feet is considered the most
practical vacation trailer size for the average family, plans for building
this trailer in 14 and 16 foot lengths are included.
The original Roamabout as it appears after being
road tested over 20,000 miles by Mr. and Mrs. Gartner and their three daughters
on two transcontinental trips.
Roamabout An 18 foot Family Vacation Trailer
By John Gartner
You'll save money in two ways by building your own vacation
trailer. First, because you can build it yourself for one half the cost
of a comparably built and equipped new factory trailer. Second, because
the two largest vacation expenses, lodging and meals, for you and your
family will not be much more than if you stayed at home.
The plus feature of having a vacation trailer is that
even summer week ends can become short trip, fun packed vacation days.
You'll find real comfort in Roamabout too, because it provides sleeping,
cooking and eating
Two beds at the rear of the trailer provide sleeping
accomodations for three members of the family. Dinette table and seats
at the front fold away to make a bed for two other people.
accommodations for a family of five (Fig. 1), yet is small
and light enough to be towed by a modest family car through the mountain
Repeated checks in towing with Chevrolet station wagons
(1950 to 1955 six cylinder models with manual shift) show a mileage average
of slightly over 15 miles to the gallon of gasoline. Fully equipped but
without supplies, Roamabout has a certified weight of 2160 lbs. Actual
weight on the road with supplies (and we carried plenty) is about 3000
Due to the step down design and use of torsion spring
axle, it has an extremely low center of gravity and tows remarkably well.
This step gives 6 ft. 2 in. of headroom in the work area and an overall
height of 7 ft. 2 in. which permits off-season storage in many existing
garages. Tires can be deflated or removed for winter storage in garages
having 7 ft. high doors.
Although it is difficult to make an accurate estimate
of the cost of building due to the variances in prices of materials and
parts, my actual cost was $900, but this included complete fabrication
of the chassis at a local weld shop, six-ply truck-type tires, deluxe fittings,
air foam cushions, apartment-size oven stove, vinyl floor covering, bird's
eye maple hardwood lining and other special equipment. I believe Roamabout
can be built for as little as $600 providing the builder does his own chassis
welding and shops around for materials. Cost of building the 14 or 16 ft.
models will be a little less, but not as much as one might think, since
the same axle assembly, hitch-jack and interior equipment would be required.
Floor plans for all three models are shown in Fig. 13.
Completed chassis frame. Torsion spring-type trailer
axle and combination trailer jack and hitch are purchased parts.
Home trailer construction has been simplified in recent years
by the availability through trailer supply houses of the same parts and
equipment used by trailer manufacturers.
Before beginning construction, it is extremely important
that all materials and parts be on hand so that each part can be fitted
in its place as the trailer is assembled. Make the chassis frame (Fig.
2) first. The distance from the underside of the hitch to the ground should
be approximately 18 in. If you intend to make the 14 or 16 ft. model, shorten
the length of the 3 in. channels to the front and rear of the axle as noted
in Fig. 3, but use the same number of angle iron cross pieces. If you are
not an experienced arc welder, have the frame made up at your local weld
shop: If you do the welding yourself, cut and fit all of the channel and
angle iron first, then assemble with C-clamps and tack welds before running
any continuous welds around joints.
Forward bolt hole lug on axle mounting block (shown
in dotted lines) has been cut off so that the axle can be placed closer
to step in chassis frame.
By following this procedure, much of the distortion due to
welding will be eliminated. Before welding the 2 in. channel iron tie bars
(Figs. 3 and 4) to the frame, cut off the forward mounting lugs from the
axle assembly so that the axle can be fastened 2 in. closer to the frame
step. Place the frame on the axle mounting blocks, align the axle so that
it is exactly at right angles with the 3 in. channel iron members and weld
the mounting blocks to the frame. Before welding, however, be sure that
the axle torsion spring is compressed slightly to give the spindle arm
free up and down play. Then fit the 2 in. channel iron tie bar to the frame
and weld in place. Clean the frame to remove any grease or oil, wire brush
the welds and give it a coat of zinc chromate paint followed with a coat
of aluminum paint. When dry, cut four wooden stringers and bolt two to
each side of the frame at the ends of the
Fitting side piece of wheel housing in position.
angle iron cross pieces. Notch the stringers so that they
will be flush with the top of the three intermediate angle iron cross pieces
and under the end angle irons.
Make the wheel housings (Fig. 5) next. Since tires and
wheel sizes vary and clearance above the wheel must be at least 5 in.,
first measure the distance from the top of the tire to the bottom edge
of the channel iron frame and add 5 in. If you use the same axle assembly
and tires we did, this distance will be 16 in. above the step and 22 in.
below the step (Fig. 5). Measure and cut a piece of 1/4 in. waterproof
plywood to size as in Fig. 6 and bolt to the channel iron with 10-32 machine
screws spaced 5 in. apart. Cut the 1/4 in. plywood front and rear end pieces
and bolt to angle-iron cross pieces.
Coat contacting surfaces with Hunts elastic caulking compound
before bolting plywood in place to make a dust tight seam. With the three
pieces of plywood in position, rip 1 x 1 5/8 in. pieces from 2 x 4 in.
stock for wheel housing frame members (Fig. 5). Carefully cut and fit each
frame piece in place and fasten to plywood with waterproof glue and #6
x 3/4 in. fh screws (Fig. 7).
Make the floor from four sheets 1/2 in. exterior plywood.
One 4 in. and one 6 in. strip ripped from the second from the rear floor
panel (Fig. 8) will provide the vertical piece needed at the step and the
batten that is glued and screwed to the underside of the rear and next
to the rear floor panels to join them (Fig. 3). With a portable electric
saw cut a 3/16 x 2 in. rabbet on the undersides of the front and rear floor
panels to clear the angle iron cross pieces. Bolt the floor to the chassis
frame with 1/4 x 1 1/4 fh machine screws, countersunk and spaced about
1 ft. apart. Use #8 x 11/2 fh screws along the wooden stringers. Make sure
floor fits tightly against angle irons where stringer bolt heads protrude
by chiseling a clearance hole on underside of floor panels. Do not fit
shaped wooden sills to front and rear of floor until side walls are erected.
Fasten 1/4 in. plywood to wheel housing frame
with glue and screws.
If underfloor insulation is desired, now is the time to install
it. Back the chassis up against a solid object and lift the front until
the rear floor edge is against the ground. Remove the caster wheel and
place jack end on top of a strong box. Then crawl under the chassis and
cover all exposed underside sections of the floor with 1/2 in. waterproof
Celotex fastened every 12 in. with 7/8 in. galv. roofing nails. Then lower
the front of the chassis to raise the rear area and repeat the insulating
process on the back section. Coat the entire underside with asphalt aluminum
Your next step is the construction of the two side walls.
Lay four sheets of 4 x 8 ft. exterior plywood 1/4 in. thick on the garage
floor to form a large rectangle 8 x 16 ft. Measure and draw 1 ft. squares
over the entire area and lightly sketch in the wall outline as in Fig.
9. A 1/2 x 1/2 in. strip of wood to bend and scribe against will aid you
in drawing a smooth curve. If you care to increase the head room in the
trailer, layout the roof line higher than shown. Dotted lines indicate
outlines for 14 and 16 ft. models. Because all trailer window frames are
flat, be sure to make the outline perfectly straight where the windows
in the front and rear ends will be located.
Locate and cut the three 1 x 1 5/8 in. studs (marked X
in Fig. 9) 2 in. longer than the plans call for at their lower ends. The
center stud straddles the vertical plywood seam. With the studs held in
their exact position, drill small guide holes for nails through the studs
and plywood at each end of the studs and the center where the four sheets
join. Now, turn the entire large 8 x 16 ft. rectangle over so that the
studs are on bottom. Separate the front and rear panels at the center and
coat the center stud with waterproof glue.
Cut floor panels to clear wheel housings and bolt
floor to chassis frame.
Reassemble the panels on the center stud using nails in the
small guide holes to align the panels to their original position and fasten
to the stud with 1 in. oval head aluminum drive screws spaced 2 in. apart.
Then slide out the two end studs, coat with glue and replace using nails
in guide holes to relocate. Fasten with same size drive screws as you did
the center stud. After blocking up the chassis level and solidly, get at
least two helpers to raise and hold the wall panel temporarily on the right
side of the chassis facing front.
Have the lower ends of the studs resting on the chassis floor
and wheel housing as in Fig. 10. Trim off the lower ends of the studs (3/4
in. maximum) until the wall is in the correct position in relation to the
chassis. Check the marked curves at each end and around the wheel housing.
With side wall temporarily held in position on
trailer chassis, check curved outline for head room and where it joins
Check also for headroom, length, etc. Be sure to allow space
for front and rear sills when drawing the curved side lines. Mark a pencil
line on the wall at the floor line and along the lower edge of the stringers.
Since the outside of the wall becomes the trailer exterior, you will want
to keep it free from scratches. Place about six lengths of 2 x 4 in. stock
on the garage floor and, with the aid of two helpers, remove the wall and
place it on the 2 x 4's, stud side up. Check the pencil mark along the
floor line to make sure the bottom line of the wall or skirt extends at
least 3 1/2 in. below the floor line at the forward or step down end. Then
saw off the lower ends of the two rear studs 15/8 in. above the floor
line and wheel housing line for the 1 x 1 5/8 in. wall sills.
If you are using the same size windows we used, measure
and layout the side wall for the window and door openings, and the rest
of the 1 x 1 5/8 in. studding as in Fig. 9. Cut and fit all the vertical
and horizontal studs.
To locate the exact position of where to drive the screws
through the 1/4 in. plywood into the studs from the outside, drill 1/16
in. holes through the plywood at the center and ends of each stud. Then,
when the side wall is turned over later, connect the 1/16 in. holes with
a pencil line which will indicate the location of the center of the studs.
Coat the studs with waterproof glue and fasten with two 11/4 in. nails
in each stud to hold them in place while you turn the side over. Have the
studs resting directly on the concrete floor and fasten the plywood to
the studs with 1 in. oval head aluminum drive screws spaced 2 in. apart
where studs join and 6 in. apart at other places.
Now, again turn the side over and fasten studs where they
join with metal corrugated fasteners. Prop the side up above the floor
and saw out the window openings flush with the studding. To keep the side
rigid for future handling, do not cut out the door opening until later.
Cardboard pattern shown in black is used to layout
curved plywood stud shown with notches cut for roof rafters.
Installing roof and end-wall rafters.
The curved studding around the edges of the sides is your
next job. First mark and cut out 2 in. wide curved patterns of cardboard
to fit between each vertical and horizontal stud above the floor line (Fig.
11). Make similar patterns 1 in. wide for the edge below the floor line.
Place the 2 in. wide patterns on a 4 x 6 ft. piece of
1 in. thick plywood. Properly laid out, the 4 x 6 ft. sheet
will be enough for both side walls. Do not worry about direction of grain
because the plywood has sufficient strength in any direction. Mark the
1 in. wide patterns for the edge below the floorline on scrap pieces of
1/2 in. plywood left from the floor. Cut with a band
or jigsaw and glue and nail the 1/2 in. pieces only along
the lower edge clinching the nails on the plywood strip side. Temporarily
place the 2 in. wide plywood pieces in position on the side (do not glue
at this time) and mark the position of each 1 x 1 5/8 in. rafter (Fig.
9) for notching. Space every fourth rafter 4 ft. on centers so that 4 ft.
wide plywood can be used for the roof without cutting. After cutting rafter
notches in the curved studs (Fig. 11), glue and drive screw the curved
studs to the plywood sides. Drive the screws through from
the 1/4 in. plywood side about 1 in. from the edge because
the edge is to be rounded off later. Trim the edges with a block plane
and sander, and temporarily set the wall on the chassis to see that it
fits properly. Now, using the right wall as a pattern, make the left side
wall (Fig. 9). It is identical with the exception that it has a center
window instead of a door. Be sure to put the studs on the right side of
the plywood to make the sides pairs. Drill 1/4 in. holes spaced about every
12 in. through the sills as in Fig. 9. To permanently assemble the sides
to the chassis, first coat the sides of the stringers and about 1 in. of
the top of the floor along the side edges
Rounding off corners of roof and side wall with
with caulking compound. Set the walls up on the chassis square
with the floor of the chassis and brace solidly. Fasten the walls to the
stringers with #10 x 1 in. fh screws driven through from the outside of
the plywood and spaced 6 in. apart. Fasten the sills to the floor with
#14 x 2 1/2 fh screws through the 1/4 in. drilled holes.
Saw out the door opening and save the pieces to make the
door. Cut 18 rafters 6 ft. 11 1/2 in. long and fit into the notches cut
in the curved studs as in Fig. 12. Fasten with glue and two #8 x 1 3/4
in. fh screws at each end (Fig. 14).
Make the front and rear end sills (Fig. 3) from 2 x 2
in. stock. Bevel to conform with curve of sides and bolt to front and rear
angle iron cross pieces. Mark the width dimensions of the front and rear
windows on the rafters at each end so that the windows will be centered,
and fasten two pieces of stud stock vertically between the roof rafters.
Make a similar frame for the roof vent above the spot where the cooking
stove will be located. With all the frame pieces in place, bevel the edges
of the rafters so that the plywood ceiling and ends will fit snugly. Use
1/4 in. exterior plywood for the roof and end walls. Cut the plywood pieces
slightly over 7 ft. long and trim ends after installation. If you have
trouble bending the rear panel, wrap it in a blanket and soak with hot
water until pliable. Use #6 x 1 in. fh screws spaced 2 in. apart at the
end sills and where the panels are joined, and 6 in. apart elsewhere. Use
4d (1 in.) cement coated nails to fasten the roof plywood to the curved
studs. Place the nails about 3/4 in. from the edge to allow for rounding
off corner with a plane or draw knife as in Fig. 15. Sand rounded corner
with a disc sander to make it smooth and uniform. Leave the corners below
lower window line square because they are later covered with aluminum corner
molding. Electrical wiring, insulating and completing the exterior and
interior of Roamabout to get it ready for that vacation will be described
in Part 2 appearing in the next issue.
Roamabout, the lastest of 14 trailers designed especially
for the backyard builder by John Gartner,
author of the book "All About Trailers".
(publisher Henry Holt & Co.)
Roamabout An 18 foot Family Vacation Trailer
By John Gartner
With the roof and end-wall panels in place, and the corners
rounded off as described in Part 1, installation of the electrical wiring
is your next step. Brake, stop, tail and clearance lights are wired to
a common connector at the tongue under the trailer (Fig. 16). Run the wires,
which are plastic covered to avoid deterioration, under the trailer and
up through holes drilled through the floor and sills. Fasten the stop,
tail and clearance lights to the walls and connect to wires extending through
holes drilled through the walls in back of light fittings. Staple the wires
to the trailer underside and wall studs with insulated staples.
For the 110-volt interior lighting circuit, use #12 two-wire
Romex cable again run under the trailer and up the side walls through holes
drilled through the floor and walls sills. Carry the cables up to about
6 in. above the tops of the windows for connecting to wall light fixtures
later (Fig. 17) when interior wall covering is applied. Use standard junction
boxes fastened to the underside of the trailer floor where branch lines
Connect the outside end of the cable to a standard male
connector for hookup with an extension cord to power supply. If an electric
refrigerator is to be installed, provide an additional branch line to a
convenience outlet located in the trailer wall near the refrigerator.
The tank shown at forward end of the trailerin Fig. 18 is
the butane storage tank containing fuel for the cooking stove and an interior
emergency light. Purchase the tank and mount on its 1/2 x 1 in. steel support
bars as in Fig. 6, Part 1. Temporarily place the stove in position in the
trailer and run a 3 in. copper tubing under the trailer, and up through
a hole in the floor from the stove fitting to the regulator on the butane
tank. Coil the tubing at the fitting ends as in Fig. 18 to absorb vibration.
Be sure to make all connections gas tight to prevent leakage, particularly
inside the trailer. If a gas light is to be installed use 1/4 in. copper
tubing from a tee-fitting on the stove line to the light.
Completed front end of trailer. All parts shown
are exposed to weather. (A) Butane tank; (B) Regulator; (C) Copper tubing;
(D) 110v line cord from lights in the trailer; (E) 6-Way connector for
brakes and clearance, stop and tail lights; (F) Safety chain: (G) Trailer
hitch; (H) Jack.
Make the sink frame as shown in Fig. 19; this also includes
an enclosed space for the refrigerator or ice box and an open-at-the-top
storage cabinet. Only major dimensions are given. Determine other dimensions
from size of purchased sink basin and ice box. You can rip saw all 1 x
2 in. framing members from 2 x 4 in. stock. Or lumberyard 1 x 2 in. stock
(which actually measures 13/16 x 1 5/8 in.) may be used. Cut out the sink
top for the trailer-size sink basins before cementing the linoleum in place.
Place the sink in position on the top, and mark for drilling a hole through
the floor to run a 3/8 in. copper tube from a hose connection under the
floor, just inside the sill to the faucet (Fig. 17).
Waste water goes through the sink drains into a Y-fitting
and then by garden hose to another hose connection under the floor. If
a trailer-type toilet is to be installed, place it as shown in Fig. 13
(Part 1). Follow the plumbing installation instructions received with the
Once you have completed the plumbing and wiring, the interior
insulation can be applied. Staple 1 in. thick insulating material with
vapor barrier, or reflective aluminum, to the entire side walls between
the studs and to the end walls from the floor to bottom of the windows.
Cover the insulated walls with 1/8 in. plywood and fasten
with 1 in. oval-head aluminum drive screws. Carefully mark and cut the
plywood sheets to coincide with the curved end walls and around the wheel
housing but do not cut the window openings until after plywood is in place.
Remember to drill holes in the plywood for all wiring leads and the butane
light tubing if it is to be included.
Also remember that the roof insulation will be on the
outside and that the ceiling rafters remain exposed. Interior cabinet work
should be completed before the roof is insulated because a number of fastenings
will have to be made into the roof plywood.
Although several interior arrangements are shown in Fig.
13 (Part 1), you can change these to suit your own individual needs. Remember,
however, to keep heavy equipment such as the stove or refrigerator as close
to the axle as possible, and be sure to bolt them to the floor.
Also check the window and vent placement. The vent should
be placed above the stove.
Starting at the rear of the trailer, make the two bed frames
(Figs. 20 and 21). The bed frames on the original Roamabout were made to
fit the 26 and 41 in. mattresses we had custom made at a local mattress
shop. You can, however, install one wider bed extending across the width
of the trailer (see Fig. 13, Part 1) and then use a standard 48 in. wide
For the clothes closet, which extends from the floor to
the ceiling, make the frame of 1 x 2 in. and 3/4 x 3/4 in. stock (Fig.
22). Fasten the 1 x 4 in. top framing member to the 1/4 in. roof plywood
with screws driven through from the outside. Fasten the vertical frame
pieces against the wall to the horizontal wall studs and the bottom frame
pieces to the floor. Cover the two closet ends and front of the shoe storage
compartment with 1/4 in. plywood and install the 1/4 in. plywood shelf.
Take the dimensions for the 1 x 2 in. cabinet door frame
directly from the door openings so the frames will fit inside the openings
when the doors are closed. Cover the frames with 1/4 in. plywood, allowing
it to extend 1/4 in. beyond the frames all around. Hang the doors with
standard kitchen cabinet hinges and door latches.
Determine the drawer size from the closet frame and assemble
as is detailed in Fig. 22.
The dinette seat and table arrangement, which is used
for eating during the day (Fig. 23), converts to a bed at night (Fig. 24)
. Make up four seat frames (Fig. 25) and have your local upholstery shop
make the cushions hinging two together as in Figs. 24 and 25. To support
the seats, install a seat base into each forward corner of the trailer
(Fig. 25). Make the dinette table as in Fig. 26 and fasten to the front
trailer wall with a continuous hinge so that the table can be raised and
lowered. For the ceiling cabinet and shelves (Fig. 17) use 1 x 2 in. stock
for the framing and 1/4 in. plywood for shelves and cabinets.
The long piece of 1 x 2 in. stock marked X in Fig.
17 forms a ledge on the edges of the shelves to prevent small articles
from rolling off. After the interior cabinets are finished start covering
the outside of the roof. First place a 1 in. thick layer of cotton or wool
Interior view showing dinette cushions and table
in positon for eating.
Interior view showing dinette table folded up
and one set of seat cushions folded down to make up bed.
outside of the entire roof and down the end walls alongside
the front and rear windows. Use about a 2 in. spot of linoleum cement every
square foot to temporarily hold the batting in place and trim the edges
of the batting so that the corners will be nice and rounded after the canvas
covering is in place. If 8 ft. wide canvas is unavailable, sew together
two 30 ft. lengths of 48 in. wide canvas with a double seam. Coat the outside
of the rear end wall below the window with waterproof linoleum cement.
Now, with the canvas draped over the top and end walls, carefully position
the canvas over the cement and smooth out by rubbing with your hands to
eliminate wrinkles. Tack the canvas along the bottom and lower edge of
the rear window with copper tacks. Now, going to the front of the trailer,
pull the canvas gently but tightly over the top and tack along the top
edge of the front window (Fig. 30). Trim the canvas along the sides of
the roof allowing enough material to extend about 1 1/2 in. beyond the
rounded edge of the sides. Tack the canvas to the sides every 2 in. (Fig.
30). Do not tack on the roof proper, only along sides and window and vent
When completely tacked, cut out canvas around windows
and vents, leaving about 1 in. of canvas to wrap and tack around openings.
Before fitting windows and vent in place, give the canvas top two coats
of oil-base mastic aluminum top sealer. This is a heavy, paste-like
material that is waterproof and always retains some degree of elasticity.
Do not use asphalt base aluminum mastic because it has a tendency to rot
After sealer has dried, coat the edges of the window and
vent openings with plenty of caulking compound and fasten the window and
vent frames with #8 x 3/4 rh aluminum screws spaced 3 to 4 in. apart.
Make the door as detailed in Fig. 27. Use the pieces of
plywood left after cutting out the door opening as covering material on
the door frame. The removable panel is optional. You may prefer to make
the lower part of the door solid. However, we found that by removing the
panel on hot summer nights the ventilation was greatly improved which made
sleeping much more comfortable. As shown in Fig. 28 the panel area is screened.
Use a continuous hinge to hang the door and fit with a trailer door lock.
The interior door trim can be rip sawed from leftover stock
or stock-size house window and doorstop material, which measures about
3/8 x 1 1/2 in., may be used. When installing, allow door trim to project
1/4 in. beyond the door opening to serve as both door trim and stop. Your
local lumber or paint store dealer can furnish you with information for
interior finishing, according to the type plywood you use. I used Cabot's
wax stain in a silver gray color. You merely brush or wipe it on the plywood,
allow to set for 5 to 10 minutes, then wipe off the excess. Rubbing with
a cloth later gives it a satin finish.
Lower part of door has screened opening for ventilation.
Opening cover panel removed and shown at right.
For the outside finish, paint an exterior enamel could be
used. Or use (as I did) 1 coat of Firzite tinted with colors-in-oil, followed
by two coats of spar varnish. I used orange colors-in-oil to tint the Firzite
used on the area on each side above the top window trim; lemon yellow between
the upper and lower window trims; burnt sienna from the lower win-dow trim
to the bottom. The canvas on the front and rear end walls was finished
with a matching brown enamel. If the trailer is kept outdoors all year
around it should be varnished each year.
Outside molding (Fig. 29) is applied last. Use 1 in. strips
of aluminum between and in line with the upper and lower edges of the windows.
Cut the flared ends of this molding (Fig. 31) from sheet aluminum. Use
1/2 in. aluminum corner molding along the side bottoms and up the ends
to the lower edges of the end wall windows. To cover the tacked ends of
the canvas along the top and ends of the sides, use a 1/4 x 3/8 in. strip
of oak. Fasten with 1 in. brads but be sure to drill holes for brads to
avoid splitting oak strip. Give oak strip two coats of spar varnish.
Stretch canvas across top of roof and tack to
rafter at top of window.
Front corner of trailer showing junction of various
With the trailer completed, install the electric trailer-brake-kit
parts on your car and hitch the trailer to the car. Hookup the trailer
wiring connector, install safety chains from car to trailer and test the
operation of the brakes and lights. Before making a trial run on the highway,
however, fit long arm, sideview mirrors to your car and order your trailer
license plates. And that completes this project, which should give you
many happy hours of low cost vacations.
This modern chassis makes an excellent base for your
teardrop trailer project, lightweight camping trailer, or vintage travel