Michael Carter
Veteran
That's just the same old IGUS rail people have been DIYing. Mine, even with a light load, has developed some hang-up spots. I just loosen all the bearings now and it behaves a little better, but a fully-rigged camera (and a decent fluid head if you're not just sliding) isn't that great on it. The camera platform (actually the bearing block) is about 3" x 4" - I've found with rails and matte box, etc., it's just too unstable, all that weight hanging off the narrow tracks.