CamRoller | Notion

This is one of those projects where internet advertising got to me, just not in the way they intended…and yes, I am implying this is not a unique occurrence, what can I say, I’m impressionable.

This particular instance started when I kept seeing ads for camera rollers like this one. And hey, to complete the inception, here’s an affiliate’s link to it…the internet, gotta love it!

And I’m sure I kept seeing these ads because I kept clicking on em and ogling the things. But, what these advertisers fail to understand, is that I’m just a tad unemployed at present, and I have a 3d printer (and a bunch of random parts). So I have the option of trading my time and some filament so I can both keep my $50 and have my toy :)

And this is what I came up with. The wheels are TPU on the rims, and PETG for the hubs, and that green worm visible up front allows me to set the steering between +/- 45 degrees.

Those PETG hubs on the wheels have a snug fit on some roller skate bearings.

To hold those bearings in place, I made some PETG ‘retainers’ that the M4 BHCS fasteners secure against. And those M4 fasteners are threading into some of their M4 heat set buddies.

These retainers are the same basic design that I’ve used on almost all of my builds that use skate board bearings for a while. I find the 8mm bore on them a bit of an awkward size for 3d printing. By the time you get any reasonably sized fastener through them, there’s just no room left. Ideally, my preference would be to have an extrusion coming from the ‘rigid body’ that the bearing is being attached to (the roller’s chassis, in this case). What I’d really love, is if the heat set in that extrusion extended deep enough to bridge that extrusion to the rest of the body…but now I’m just doing some very specific day dreamin, sorry. Anyway, yeah, these retainers do alright :)

I went with relatively large diameter (100 mm) wheels. The largest I saw on most commercial offerings were roller blade wheels, which I think are usually closer to 80mm. But I with the stand-off of the ball head on top, I won’t have any issues with them obstructing the view. I wanted to go a bit larger in hopes of a smoother ride. I don’t have any of the smaller wheeled cousins to compare against, but it’s worked well enough for me!

Now for what those wheels attach to. The main structure of the roller is composed of three printed parts, Rot_top (blue), Rot_bot (green), and Rot_center (grey)…I know, I’ve got a natural knack for catchy naming…it’s a gift.

And inside of that stack is one of my go tos, some v-grooves and a lotta balls. These aren’t the most smooth-running bearings, but they do provide a lot of stiffness against rotation on the axes I don’t want rotating. The heat set up top is a 1/4-20 heat set for attaching my ball head.

I had a Vanguard BH-250 ball head unused on the shelf (ok, I guess I am lucky enough to have more than just the printer on the shelf to ‘save me’ that $50). My ball head has a 3/8-16 female thread, and my roller is going to have a 1/4-20 female thread. But with my camera gear, I have some 1/4-20 to 1/4-20 male adapters. So I designed in a recess that would fit this adapter and still allow the bottom datum of the ball head to make intimate contact with the roller surface, giving the camera the best shot at rigidity. This interface should work with most ball heads. The BH-250 is sort of “middle of the road” in terms of sizes.

To set the angular position of this bearing to set my steering angle, the Rot_top part has an integrated worm gear.