Archive for mini dolly

Home Built MicroTrack

Posted in DSLR Video with tags , , , , , , on February 7, 2010 by evanbutson

OK, So after playing with the IndiSlider for a few days I was pretty happy with it, however there were a few points that kept me from being 100% happy. Namely, it was noisy, VERY noisy, there is no way you could use it whilst recording sound, it was short, whilst making it very portable, I found that I really would have liked it to be just a little bit longer, maybe another 10cm or so. And finally, it was not as smooth as I would like, especially when doing ultra slow tracks. That being said I am very happy with it, and due to the fact that it is very portable and very easy to setup, I will definitely be using it on shoots from time to time.

After having a look on the web for what is available that would fill my needs, ie longer, smoother and quieter, I found several options, all costing upwards of $500 US. Now, I could probably justify this purchase but I also felt the need to start a little pet project, and building my own seemed like it would be a bit of fun. So off to the local Bunnings hardware store to see what I could find. Now I didnt really have a plan on exactly how I was going to build this, it seems most of the higher end microtracks use some kind of pipe and circular ball bearing housing, not something that sits on the shelves of your local hardware store by default. So I wandered around the hardware store isles for a while (one of my favourite pastimes) until I came across an isle that had replacement parts for sliding doors and windows. Here I found a wide selection of small ball bearing based wheels all begging to be made into a dolly. After picking up literally every single pack I ended up with 4 or these.

I then picked up some square aluminium tube with a lip that would hold a small aluminium tubing perfectly straight for rollers to run along.

I then picked up some corners to join the track together and a piece of make your own bracket metal plate, this stuff is awesome, it is super lightweight, comes precut with holes and is infinitly bendable and configurable, perfect as a base for the camerato sit on (or so I figured).

So with all the bits ready I decided to have a go at mocking up the rig, using some self tapping screws that I got with some computer fans I mounted the four rollers at the corners of the metal plate, sticky taped the metal tubing to the aluminium tubing, using the lip as a guide and whammo, all was good.

I mounted my camera onto the plate and had a few shots at tracking back and forth, and straightaway noticed a problem, with the cameras centre of gravity to high, it had a tendency to tip over, added to that, as the camera was mounted onto the metal plate there was no way to adjust the cameras position, doing dutch tilts or even tilting up or down. This was not going to work, but the good news was the wheels resulted in a super smooth track, I just needed to lower the centre of gravity. So off to Bunnings it was again, and once again after a wander around I came across these metal post hold things, made of extremely thick metal I figured they would not only allow me to lower the centre of gravity of the camera, but the additional weight would guarantee the wheels stayed on the track. Anyway, cut a long story short, I really dont have half the tools I really need, I barely have an area to work in as it is, and that awesome thick metal, well I had no way of bending it within the tolerance I needed for this project which realistically are about .5 of a mm give or take. Observe my pathetic first and only attempt.

Im’ sure given enough time and or the right tools, I would have gotten this to work, but after an hour or so of trying to gently coax both sides to be perfectly the same height and shape, I knew it was a losing battle. SO back to my old friend the do it yourself bracket plate, that and some right angle aluminium and I had a very similar setup within half an hour, with the added benefit of using bolts to attach the side ‘wings’ meant I could adjust the relative height of each corner to get a perfect mate with the track.

And here it is with my D200 (for testing purposes) and a ball joint tripod head as well.

Now this worked pretty well, and I could have called it finished and started cleaning up the build, but I still had the problem with tipping, not as bad as before, but enough to warrant some more work, so I decided to make a wider track, I would sacrifice some travel distance but that would be made up for with a super stable platform for the camera, that would allow me to place the camera any way I wanted with a tripod head and not have to worry about instability. Here is the Mark III tray with my D200 in its final form before I pulled it apart, filed down all the sharp edges, trimmed all the bolts and prepped it for paint.

Next up was the track itself, basically this was a pretty simple affair to put together, after carefully measuring the final width of the carriage, I cut the two pieces of aluminium tube to mae a rectangle, then after going to bed and sleeping on it, I actually pulled it apart went and bought some new three prong connectors and added legs to the corners, this was for two reasons, one I wanted to be able to pop the track on a table etc with a guarantee that the carriage would get caught on anything, and additionally I needed a small amount of clearance on the base to make room for my other addition, some guide rollers to guarantee the carriage wouldnt lift off the track for any reason. In this photo you can see the metal tube for the track being glued to the metal lip, you can also see on the right hand side a small section of pipe I attached to both sides, this is so if I need to mount the track higher I can just use two C-Stands and use SuperClamps to grab onto the tubes to mount the track at any height I want.

And finally the guide runners, I picked up a set of smaller wheels similar to the ones use for the main carriage, but added small washes to them,

then using the same style of do it yourself bracket metal, but this time a single strip, I made a small bracket that would hold them underneath the carriage, attached with a bolt and a butterfly nut for easy removal when I need to take the carriage off the track. These runners only barely touch the base of the track, they dont really add any smoothness to the carriage but they do come into play if for some reason the carriage decides to want to come off. I attached them with a small self tapping screw and some super glue for good measure.

So that’s it, the glue on the track is setting as we speak (I have to wait another 24 hours). Then I will post some completed shots. In the meantime here is a few shots of it using the IndiSlider
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All in all if you were to buy only the parts I finally used rather then 3 of everything that I did 🙂 Your looking at about $80 Australian to build this, and all you need tool wise is a hack saw, a good vice and the ability to cut and measure parts very carefully, I interestingly do not have the final part and so I end up cutting, getting it wrong, cutting again, and so on until dump luck gives me the part at the correct length.