Wednesday, February 15, 2012

Building a Skate Wheel Dolly for Film and Video

Last week I pulled the Kessler Crane that a friend gave me after a shoot out from the garage.  It got me excited to start shooting again, but I am currently without a dolly, as I sent the one I’d previously been using back to its original owner after the last project.

So time to build a dolly.

There are lots of different styles and methods on the web, but a lot of the how to’s are videos, which I always find incredibly frustrating (I don’t want to have to watch a video).  A lot of the how to’s also don’t have a parts list.  A lot of the how to’s also add a lot of unnecessary steps and parts.

So I thought I’d document my version here.


Parts list for the Dolly:

Thrift Store:

  • 16 - in-line skate wheels (that’s two pairs of Rollerblades… I paid $2.50 a pair for a total of $5 at the local Habitat for Humanity ReStore)
  • If you don’t want to use used wheels, you can also order new wheels on E-bay.  There are consistent offerings of wheels for around $10 for four wheels.  You can probably find even better deals (as I type this there is a lot of 44 brand-new 84mm wheels with abec-5 bearings going for $9.99).

Lowe’s or Home Depot:

  • 16 - 1/4” x 2” zinc plated hex bolts (I paid $.24 each)
  • 64 - 1/4” zinc plated flat washers (I paid $.11 each)
  • 32 - 1/4” zinc plated cut washers (I paid $.15 each)
  • 32 - 1/4” zinc plated hex nuts (I paid $.09 each)
  • 02 - 1-1/2 in. x 48 in. zinc plated slotted angle rail (I paid $.11 each)
  • 01 - 48” x 28” 3/4” plywood platform
  • 02 - 48” 2x4’s (these aren’t absolutely necessary)
  • drywall or wood screws

NOTE: At Home Depot, the hardware packs of 100 pieces cost considerably more than buying pieces individually; stupid but true.


Parts List for the Track (modify liberally with whatever you might have available):

Lowe’s or Home Depot:

  • 02 – 8’ lengths of Galvanized or aluminum 1 5/8” diameter fence post (used for chain link fence)
  • 01 - 60” 2x4
  • 08 - 2 5/8” 16 penny nails



You will be fastening the skate wheels to a piece of angle steel as shown here.  There will be four clusters of four wheels, that will glide on two steel pipes (galvanized chain link fence posts) for track.



Here is one of the Rollerblades I stole the wheels from. You simply unscrew the bolts with an hex (Allen) wrench and remove each wheel.



Here is the hardware (bolt, wheel, nuts, and washers) laid out in the order you will assemble them. It goes: bolt, flat washer, cut washer, wheel, cut washer, flat washer, nut, flat washer, rail (not shown), flat washer, nut.  The cut washers fit up against the wheel bearings and allow the wheel to spin.  This is critical.  If you don’t use the cut washers, the flat washers will press against the wheel and the bearing and the wheel won’t be able to turn.  If you want, you can use a stand-off (a metal tube) instead of a cut washer, but the cut washer is the cheapest route and works great.



The perils of using used skate wheels. As you can see in the photo, the previous owner failed to rotate her wheels on a regular basis, thus the wheel is lopsided. To avoid this problem, you can either buy wheels new, or simply install the wheel with the worn side out (so the unworn side hits the track). The wheel in the photo below will thus need to be flipped on the bolt axel.

The perils of used skate wheels


Here are all sixteen wheels, assembled and ready to attach to the rails.

16 wheels all in a row


Here is a detail of how the wheels are attached to the rail.

How they're attached (detail)


You can space your wheels however you see fit.  I’m a little OCD, so I set mine on the holes lined up with the imprinted diamond mark on the rail.  Just make sure if you are using a slot that allows the bolt to move up and down or back and forth, that you’re setting everything in the same position.



Next comes the dolly platform.  You will be tempted to make the platform as wide as possible to accommodate wide-spread tripods, but I highly recommend making your platform less than 30” wide, so it will fit through most doors.  Some doors are only 28” wide, but most are either 30”, 32”, or 36”.

The thicker the wood for your platform, the sturdier the dolly will be, but this also means it will be heavier and harder to lug around.  I had some 1/2” plywood lying around, so that’s what I used.  It’s got some flex to it, so I ran 2x4’s all the way around the edge (the two steel rails (to which the wheels are bolted) running the length of the platform pretty much take care of the longitudinal flex, so the cross pieces are all that’s really necessary.  However, I did the whole perimeter so there would be something to grab when carrying it around (the 2x4’s act as a handle).  If you want, you could also glue a top layer of thinner MDF directly to the plywood to make it really strong and prevent flex, but this will contribute greatly to the total weight.



You will almost certainly find that you need to raise the wheels a bit off the platform (they will likely rub against the underside of the dolly).  You can use longer bolts and extra nuts to address this, but I feel that longer bolts run the risk of bending or at least flexing.  I chose to put a small strip of wood under each steel rail.  You will want to do this before/while setting the width of the rails (next step).



Finally you need to make the track on which the dolly will ride.  The standard width for dolly track is 24.5 inches (62.23cm), so it makes sense to set your track at this width.  Flip the entire set up over and set your wheel rails on the bottom of your dolly platform.  Place your track on the wheels.  Again, you should now have your dolly and track laid out on the floor upside down.  Measure 24.5” on center from pipe to pipe, and then screw your wheel rails down to the dolly platform.  You can also just measure the peak of the steel rails if your wheels are evenly spaced on either side of said rails.





Ideally you would also have crossties (supports every 2 feet or so) to keep the dolly track from flexing. An easy solution for crossties is sandbags. You can permanently affix your crossties to the track by drilling a hole in the center of the pipe and screwing it down to the cross ties, but it makes it more difficult to transport the track.  I have also found that even when riding my dolly there is little to no flex in 1 5/8” galvanized steel pipes, so I don’t use cross ties.

You can join lengths of track together for a longer track run, but you will almost certainly get a “bump” in your footage when you roll over the seem where two pieces of track meet. If you do join pieces, you will want a tight fitting tube or solid cylinder fit inside the two pieces of track to keep the two pieces fit snugly together.

Some people would suggest it’s just as easy (though definitely not as cheap) to buy track, and build your dolly.  When you purchase track, you’ll also have better luck with joining lengths together (if you need a run longer than 8ft.).  You can also buy curved sections (bending pipe requires special tools, and is beyond the scope of most DIY-ers).

At this point, you may also want to make a “hi-hat.”  This can be simply a piece of plywood with a bolt in the middle of it (on which to mount your camera).  A hi-hat is just a sturdy way to set your camera on a flat surface (like a dolly).  Obviously you’ll want to recess the hole for the bolt on the bottom of the hi-hat, so the board rests flush on a flat surface.  I drilled a hole then glued the bolt in place with Gorilla Glue.

p.s. Don’t store your dolly on the rails or leave it sitting for a long time or you’ll create flat spots on the wheels that will cause bumps when you roll.

1 comment:

heavy duty castors said...

Some companies produce wheels with a hard core and softer outside so the bearing won't get crushed. While this doesn't happen very often, it is a design feature you should consider when buying softer wheels.