Wednesday, March 7, 2012

Tutorial: DIY - Small basic dolly for smooth camera motion

Good day!  Today I decided that I wanted to do a photo project that would mimic a 'car rig shot' but on a much smaller scale.  Specifically metal die-cast cars.  Given that there is a lot of different pieces needed for the full scale rig, a complete redesign and slightly different methodology would be needed given that a scaled down rig would not support my camera!

The theory is this:  If you move your car and camera at the same speed and orientation and drag the shutter, it will appear that the car is moving really fast.  Now, because I like to have a bit of fun I thought that it would be interesting to make a scale model car appear to be moving very quickly.

I decided that I would need to get a smooth rolling camera dolly to mount my camera on and devise a way to attach a car to it.  A quick internet search showed a few, but I was convinced that I could do this for less than $25.  I designed something in my head and went about getting the parts for it.  The most important part of this rig is the wheels.  They need to roll smoothly.  I decided that inline skate wheels would fit the bill.  Fortunately there is a Thrift Store pretty close to me.  Found a pair of donor skates for $7.99.  I figured that $1 a wheel was pretty good, and since I only needed 4 of them, that would leave me 4 extra for another project.

Here is my parts list:
4 - inline skate wheels ($8)
1 - 12"x1"x4' pine board ($6)
1 - 3/8"x1 1/2" hex head bolt ($.22) [this is specific to the size of the thread of your ball head - check first and buy the correct size.  If you are unsure, get both a 3/8" and a 1/4")
4 - #10-24x2 1/2" machine screws and 12 - #10-24 nuts ($3.54)
8 - 1 5/8" Sheetrock screws ($.??  I had them in the garage and they are like $5 a pound - so maybe $.10)

Tools needed:
Table saw, Drill, Drill Bits, Counter Sink Bit, Screw Driver or Driver bit for your drill, Tape Measure

How To:
* Cut 2 parts of the board to be 12"x12".  Save the remainder of the board for another project.

* Rip one of the newly cut boards into 2 "strips", 3" wide.  The remainder of this piece can be saved for another project.

* On each of the 3" strips, drill and counter sink 4 holes along the long bottom of each.

* Secure each of the 3" strips to opposite sides of the 12"x12" platform.

* Mark a line to determine how "high" to drill the holes for the wheels, and mark on the line how far in from the edge to make those holes.  I am being non-specific dimentionally here as there may be different size wheels.  Mine were 5/8" up and 1 1/2" in from the edge.  Measure for the placement of the wheels.

* Drill your holes for your screws.  Accuracy is important here as you need to insure that all 4 of your wheels touch the "ground" together.

* If you have not already done so, remove 4 wheels from the donor skates. This will likely require hex wrenches.  Discard all of the hardware and nekkid boot.  You just want the wheels.

* Thread one of the nuts on the screw.  I intentionally got screws that were too long so I could adjust them on the inside.  The distance that you will put this down depends on the length of screw, thickness of board and the thickness of the wheel. Thread this screw into the hole and secure another nut down on the screw.  This should lock the screw down. I only tightened mine finger tight, you can use a wrench of your so choose.  Then put the wheel on the screw and now the final nut to secure the wheel.  So your 'sandwich' should be: Screw->nut->board->nut->wheel->nut.  The middle nut is important as you need to hold the wheel off of the board so that it spins.  The size of the nut is important as you only want to tighten down on the bearing so that the wheel spins.

*Now repeat this on the other 3 corners.

* Drill a hole 'somewhere' on the platform for the 3/8" bolt to go through to secure down your ball head.  The hole I drilled was a little large, but not too bad (I didn't have a correct sized bit).  If you find that you have drilled your hole too large, move to another spot and drill another hole just slightly larger than the shaft of the bolt, or you could use a fender washer between the bolt and the platform.

* Thread the bolt through the hole from the bottom and screw on your ball head.  This one you might want to tighten more than by hand, but please don't tork the heck out of it.

I do have to put a little note here - if your ball head pans, make sure you have it tightened so that you can give it a little twist if need be, but not so loose that it will go all rotatey...  On my head, the knob to tighten the pan is right at the board.  When mounted, it cannot tighten.  I learned...

* Mount your camera to the ball head and viola!  You have a very basic camera dolly.  iPhone photo warning, I left my other body at the camera shop.

You can stop here if this dolly will suit your needs.  But remember me telling you that my project was to move a scale model car and the camera at the same speed and orientation?  Joan Crawford was wrong - I *DO* need a wire coat hanger.  They are great DIY staples to have around!  Cut off the hook part and straighten it out.  On one end, bend a loop in it so that you can screw it into the dolly.  You will need to decide where you want your car to be to determine where you want your bends on it.  Also, depending on the scale of the scale model, may dictate the length.  The last bit of stuff needed is how to secure this to the car.  Because some of these cars can be pretty expensive, I wanted to use something that was non harmful to the car.  My daughter has to use these silicone-wax ear plugs to take a shower.  She cannot get water in her ears.  She also can't seem to get them into the trash after she uses them.  I have stepped on a few.  They are sticky.  IF you go this route, use a fresh one.

This is my first try, straight out of camera.  Alignment is crucial here!

I obviously did not get it dead straight...

This is after a little post processing magic! Not too bad.  About what I expected for my first go.  I have a lot of ideas and tweaks for this.

I think I will end this tutorial here since the name of this is "DIY - Small basic dolly for smooth camera motion ".  I will make a part 2 that will show what I did to create the "Scale Model / Die Cast Rolling Rig Shot".  You can view that by clicking "HERE"!  I will have more and better images to show you there, along with a how to on the removal of the rig.

If you enjoyed this, please let your photographer friends know by sharing it to them.  If you have any questions, I will do my best to answer them, just leave a comment below.


  1. Ha! Well written and actually pretty cool. The final result was perfect.

  2. Looks pretty good. I imagine using an image stabilized lens would help a good bit too. Now, figure out a way to make this work for my car, would ya?