This was my first project working with MDF and I was pleasantly surprised. It has a few draw backs compared to solid wood or plywood. It is very heavy compared to its strength and the dust is very fine. All the dust has taken residence on absolutely every square inch in my garage.
Step 1: Specs/Features of this Fully Loaded Truck
Step 2: Tools/Safety and Bill of Materials
Circular saw, router, reciprocating saw, belt sander, hand sander, drill, paint brush/roller
Table saw, chop saw, nail gun, paint sprayer
Always were a dust mask or preferable a respirator when cutting MDF
Were your safety glasses
2 sheets of ¾” laminated particle board 75lb each
2 sheets of ½” MDF 60lb each
3.5 sheets of ¾” MDF 90lb each
2 Sheets 5/8” MDF 75lb each
2 sets handicap hinges
24 14-20 T nuts
2 ½” diameter aluminum rod
8 3” ¼-20 wood bolts
16 1” ¼=20 wood bolts
4 1 ½” ¼=20 wood bolts
1 box 1” wood screws
1 box 1 1/2 “ wood screws
1 gallon safety yellow paint
1 quart black paint
1 quart silver paint
1 gallon primmer
2 spray cans primmer
2 spray cans black tool dip
Lights, switches, wire, power supply
Step 3: Getting Started
The base is comprised of 6 large pieces. The top and bottom pieces are the same size. See picture. The mattress will rest on the top piece and the bottom piece will be the floor in the storage area. The top and bottom pieces are 3/4” laminated particle board for easy cleanup and a slick sliding surface. These pieces should be cut 2 inches larger than your mattress. Make sure you measure the actual mattress. I measured the showroom floor mattress thinking it would be the same but it was 1 ¼” different in the width. Based on this dimension you can determine the sides and ends. The 5/8” MDF side pieces overlap the ¾” MDF ends. The back end piece will need an opening to access the storage area. The top and bottom pieces rest on 1 ½” strips ¾” MDF attached to the ends and sides with glue and 1” screws. The side height dimension is controlled by the needed storage height and 2/3 the mattress height. I choose the height of a Rubbermaid container plus 3” for the storage height. Screw pieces together with 1 ½” wood screws dry fitting and disassemble for facade fitting.
Dump Truck Sides
The cab left and right sides are mirror images with the exception of a routered groove for wiring if wanted. They are made of 2 layers of ¾” MDF. Where the sides attach to the base they are only one layer thick. The fender attaches in the single layer area to provide extra strength. The fender is two layers of 5/8” MDF. The fender shape is sculpted with a belt sander. I cut the strait edges of the windows out with a circular saw and finished the radius cut with a reciprocating saw. I cut the door out with a 1/16” blade on my reciprocating saw. This gap plus sanding was plenty for door operation and alignment. Going back to wiring, router a ½” by ½” groove on the inside panel so the wire will lay between the panels. Lay the wire in before gluing, brad nailing and screwing them together. Use a ½” radius router bit on all outside edges. Use a 3/8” router bit on all inside edges including the door and window areas.
The dumper is ½” MDF with the exterior corrugated ribs two 5/8” X 3” layers MDF. There is a single interior corrugated layer of 5/8” MDF. The corrugated pitch is 6”. The top rail is two ¾” X 3” layers exterior and a single layer of ¾” MDF interior. This top rail thickness is perfect for hot wheel cars. The different layer thickness adds depth and interest to the façade. My wife said to write that, I think it just looks cooler.
For the dimensions, the lower portion of the dumper is 8” above the top of the mattress. I am not sure if there are any codes on a bed rail height recommendation but this looked good to me. If you are concerned you may want to check. The dumper is 2/3 of the entire bed length. It is best to lay the pieces out on the base side pieces as shown in the pictures to confirm fitting. Proportion is everything when you are making a simplified copy of a real thing. If the proportions are off to much it will look goofy.
Step 4: Components
The hinges on the door took me a while to figure out what I wanted to do. The door is the only moving part and I wanted it to be as kid friendly as possible. I would feel really bad if my son hurt himself on something I made if I could have made it better. I finally decided on handicap hinges with one of the hinge sides flipped. See pictures. This way in the closed position the hinge forms a 15 degree gap. This gap minimizes pinch fingers by allowing a space but the outside is not noticeable. If finger pinching becomes a problem I will install webbing in this gap to end it once and for all. For the center screw on each side of the hinge I installed a ¼-20 screw and T-nut to guarantee the screws do not strip out if a neighbor kid pulls down or hangs on the door. My kid would never do this. A plunger stop is used to hold the door in the closed position. The door stops against the base portion of the bed. I limit the amount the door opens to help climbing into the truck with 1” webbing under the hinge screws. The door handle is a 6” SS drawer pull recessed half way into the surface of the door. A small pocket was routered 1” depth into the door for your fingers.
In the interest of saving time I designed the tires so standard 16” hub caps would fit. This way I didn’t have to make wheels too. The tires are three ¾” MDF and one 5/8” MDF layers of 24” diameter circles. The top layer I cut the ID to the outermost diameter of the hubcap using a circle cutter attachment to my router. The next layer I cut the same diameter ¼” depth. This is so the hubcap is recessed into the tire for a more natural look. I then cut the holding hubcap diameter the remaining thickness through the 2nd layer. I cut the 3rd layer same holding tab diameter to the depth of the holding tabs. The 4th layer is not cut. For the 20 lugs I drilled two ½” holes at the base of each lug corner and used a reciprocating saw to cut them out on the 4th layer. Then I glued the 3rd layer to the 4th layer. I used a tracing bit on my router to cut the lugs into the 3rd layer. You could use the reciprocating saw for all layers but the router cut surface will require less prep for painting. I then repeated this for the 2nd and 1st layers. And finally I used a belt sander to shape the side wall of the tire. If the bed is going up against the wall like mine you will only need 2 tires.
I used tool dip paint for the tires over standard rattle can primmer. The rubber texture makes the tires more realistic. It took 1 can of primmer per tire. That’s MDF for ya.
The cab roof is two layers of ¾” MDF. To make things as save as possible I added two ½” diameter Aluminum rods between the layers. I drilled and taped the rods ¼-20 thread at both ends. I drilled a hole and placed a nail through the rod so it will not spin. I used wood bolts to attach the cab top to the cab sides into the rods. This way if someone somehow breaks the 1 ½” of MDF by sitting on it they will not fall though into the cab. Say like the neighbor kid again. The aluminum rods will bend but it will not be a catastrophic failure. I added two handles with a router. The wiring is added between the MDF layers so there is no wiring visible for little fingers to get to. Notice the extra area for the connector. Once connected the connector gets pushed into this area so it is not smashed. For all hidden wires I used 16 gauge wires just in case.
Cab Front and Dash
The front of the cab is a single layer of ¾” MDF. The grill is glued to this piece and it is two layer ¾”MDF. It has 7 slots cut with a router only one layer deep. The dash is two layers of ¾” MDF. I made a small box for gauges. The gauges and switches were bought off ebay for 40 dollars. They are for a boat and came on a plastic dash which I modified to look more like a truck dash. The wiring travels down to the electronic compartment via a routered ½” by 1” slot behind the grill. I needed 21 wires.
The cabin floor is ½” MDF with scrape strips glued to it to reduce noise. The floor surface is ½” below the door opening to minimize tripping while exiting the vehicle. I used a dado cut to secure the floor to the cab sides but you could use ¾” MDF strips. The steering column I used bolted though the floor. I used a custom hot rod steering column to minimize design time. It has telescoping, tilting and angle adjustment so I can easily change it based on the size of the cab. I could have bolted the steering wheel to the dash but that would not be as cool, plus I get blinkers, flashers and horn all in one.
The compartment under the floor is used for the electronics.
Step 5: Electronics
The electronics compartment has a key latch so no little ones can access the wiring. The electronics are 12 volt so I could buy automotive lights and have a very large selection. I chose a 12 volt power supply from superbrightleds.com as well as two pulse width modulators (PWM) to dim the lights. The LED lights a far too bright to run at 12 volts and reducing the voltage or adding a resistor does not really work that well with leds. I used two PWMs so I could selectively dim two circuits. If you do this make sure you separate the grounds too. I ran 12 volts through the fuse panel, to the key switch, to the blinks/flashers and to the two PWMs. The flasher must have a 12 volts input to work properly but the lights can run off of a different voltage and ground. All the running lights and head lights are on one circuit with the dome and cargo light on the other PWM circuit.
Step 6: Paint and Book Self
You should use the safest child safe paint you can find. Do some research your child is worth it. I chose Behr premium latex paint. I chose high gloss and have some regrets. I knew that I would be bolting painted panels together and I wanted them to be able to be disassembling without sticking together. This is not what latex paint is known for and especially not full gloss. I searched for a paint that would dry without being tacky but they were either toxic or had a complex prepping process (similar to painting a car). I asked at more than one home improvement store and they all said that latex will dry and would not stick together within a week. Wrong. I waited 4 weeks and still tacky. Apparently, if you are a paint expert please correct me but drying and surface cross linking or non-tacky agents in the paint reduce the gloss. So a flat latex paint will dry fast and the surface will not be tacky. If you get high gloss latex paint it will never dry, well not for a very long time. The paint I purchased said it would dry in 4 weeks. A few components are at 2 months and the paint is still a little tacky. It is not that tacky to touch but if you place a small Lego on the paint it will stick after an hour or so. To get around this because high gloss was a must for my son’s truck I masked all mating surfaces from high gloss paint. I also placed drawer liner between surfaces just in case the primmer sticks together. I used blue tape for small ¾” mating surfaces.
With that said choose your paint wisely it can make or ruin your project. Epoxy and oil base paint may be better but they are more toxic than the latex. They will also require significant sanding, prepping and you may not be able to touch up like latex. Again I am not a paint expert so please do your own research. I just wanted to add emphasis on the importance of paint choice.
Front loader mural with book shelf
Although the front loader is not a wood project it is an integral part of the functional wood book shelf. Painting a mural is fairly simple if you cheat a little like finding someone to help that has painted a mural, my dad in my case. This is my first mural or painting for that matter and it turned out better than expected. First I went down to my local Caterpillar dealer to take a few pictures and then I borrowed a projector from a friend. I figured out the best place for the mural where it was not blocked by the truck. My son’s room is very small so I had only a few options. I initially wanted the bucket over the dumper but I thought my son might bonk his head on the bucket. So I placed it over the cab as if the truck is rolling forward and the loader is waiting to dump the dirt into the dumper. Not dump on the cab. My dad did a little photo shop to get things looking right then its paint by number. You can trace the projected image then paint or paint with the projector on. We used left over latex paint from the dump truck. This way I could paint it over if I can ever afford another house.
The book shelf is very straight forward. I made a bucket tooth out of scrap wood then patterned it onto the book shelf with the router tracing bit. The bottom piece and side leading edges are ¾” MDF. The rest is left over ½” MDF.
Step 7: Mission accomplished
My son loves the dump truck. He tells everyone he talks to about his very own dump truck. It is absolutely priceless. He turns on various lights at night to keep the room from getting to dark. He has not once asked why his sister is sleeping in his crib. Mission accomplished.
The bed cost was $430 dollars without the electronics and steering column /wheel. This is a little pricey but worth every penny. With everything it was around $1020 dollars. Ok I went way over budget but in the interest of keep schedule and coolness factor I had no choice. I guess I will need to eat a bag lunch for the next six months. I did reduce a few options because of the accumulating cost like: Humidifier smoke stacks, rotating tires, shaker motors, dumping dumper, etc. The time to produce this truck was 2.5 months.
I hope you are inspired to create something.