How do you plan on using this system in real life? A tripod on each end? In case you leave the middle free all the time I would consider adding an upside down T profile to the camera. The horizontal part would prevent the camera from tipping over in case of an unfortunate encounter. (Even though I assume the entire construction has its center of gravity on top of one of the long beams.
Anyway, I'll come back tomorrow to watch it. Any plans on adding a motor in some way?
I don't plan to use tripods neither as a motor. Sure the speed would remain constant, but I don't want to spend the time it would require to work on that.
Anyway, I just bought that today, to allow more flexibility to the camera on the plate:
I'll post picture later, as I'll have to go to the local hardware store to get a bigger screw in order to use it with the slider, 3/8 instead of 1/4 I think it is...
Is the video rendered and somewhere on the internet? Vimeo?
Damn, it's up for a whole day sure, I just forgot to link it here apparently:Originally Posted by BarteS
Is the video rendered and somewhere on the internet? Vimeo?
Ah, it does seem to slide as easy as you would expect with these bearings, nice. (Can't tell whether it is in fact smooth as the video stutters a bit over here, could be I'm overloading my computer. :P )
Once the rails are adjusted from left to right to fit the slider (not too tight and just enough so it doesn't move so it's perfectly adjusted) it just rolls over the rails and as the rails are perfectly straight, it's smooth enough. For the price I think it's hard to beat. I'll have to calculate the total cost (don't have all prices in mind, but the rails are roughly 15$ each + taxes at the local hardware store).
I'll keep you updated with that soon.
I am so eager to see the footage...
Well, looks good so far. But with the recently bought manfrotto head (which weights 6 pounds itself) the rails are suffering a bit, being aluminium and maybe not "strong enough" at only 1/16 thick. SO I'm thinking of using steel square tubes instead now. Also, I think I'll make the "boggey" a little bigger/longer, as the head is heavy, when I adjust it (as the camera weight can be sent to the front/back or sides depending on the angle) it'll add to the stability.
Here's some other pictures of the setup using the head:
I've tested it with the head on it. Transfering the videos now. I'll post it tomorow.
I suggest you add "rungs" to make it more like a ladder. Not in the way, but they prevent the rails from moving form/towards each other, causing unwanted jiggles in the movement.
That's nice work, Drapes.
The only thing I noticed that might be a concern is that the camera is prone to toppling. It can't shift laterally by itself, but if you happened to elbow it, there's nothing to stop it tipping off the rails.
I'm in the process of making a slider, and I happened to luck into a 3 metre length of aluminium extrusion from a local ladder manufacturer. What I plan to do is to get a solid block of steel cut to size and stick strips of furniture felt to the bottom and sides, and saturate them in liquid silicone so that they slide easily. I've tested the concept and it works beautifully. No wheels or bearings necessary.
Most importantly, I want to add some brackets to the steel base, to act as a safety bar to hold the whole kit on to the tracks. The attached diagram shows what I mean.
Picture #1 shows the cross-section of the extrusion.
Picture #2 shows the carrier block, cut to be just smaller than the channel, so that the squares of felt can be glued to all sides.
Picture #3 shows the extra pieces of metal (in red), that I'll attach and shape so that they permanently lock the carrier block on to the extrusion, ensuring that it can be left safely on the track without any danger of being toppled off (hopefully).
slide1.JPGslide2.JPGslide3.JPG
Obviously, I'll need to add a handle of some sort somewhere to push the whole carrier along the channel. Also, I'll have to stick felt on the touching surfaces of the red pieces, (the diagram incorrectly shows them touching the extrusion), but that will only require that I shape the pieces to allow for the thickness of the felt.
As I said, I've tried it, and it's 99.999% silent, perfectly smooth, and its speed can be controlled very easily by subtle changes in pressure.
But I'm sure there are obvious flaws in the design that I can't see, and I'll be glad to listen to any suggestions to improve it.
Last time I checked Australia seems to be the country in the major league of collecting natural disasters and other dangerous phenomena (such as the evil versions of the animals we can find in Europe, if we're unfortunate, which you can see at your park or the tennis court near your house in case of yet another flood). Amongst those natural disasters is the sandstorm right? Sort of what the United States copied and tried to improve. But also very dry periods? So, basically dust is one of the enemies right? Do you still feel like saturating felt is the best way to guarantee future use, or do you plan on taking the liquid silicone with you all the time?But again, I could be wrong and dust is not that much of an issue, or otherwise it's a good way to continually polish the aluminum bars.
But aside from that, which could work if you are willing to check the liquid silicone every time before you start, I think the real issue is the red pieces of metal to keep the camera at its position. To me it seems harder than necessary. You would have to look at weight, strength and clearance. Or at least the latter two. With all those bends you either have to bolt weld the pieces together or use a piece of thick sheet metal. In the first case you have to be sure, with the moment, it won't snap at the top bend. With the sheet metal you have to be careful with the clearance. Properly bend sheet metal will work (with all those bends it will grip at the corners) but with a hit you can expect it to hit the sides. Furthermore it will be harder to transport. If you would have to transport it, it would rest on the red pieces, not good for the clearances. Especially to the sheet metal this would be an issue.
Hopefully you are not to distracted by my elite paint-skills, but depending on the material you've got ('I-beams' or not), you could go for two (and for sure some more) alternative options to minimize effort. In blue the aluminum bars are illustrated, in black the camera support. The red balls are, no not pills, bearings.
Design A is an alternative to the design of drapeama. (Altough drapeama has the bearings on the outside of the beams.) It illustrates the 'stick' with a horizontal beam I talked about earlier on. That description would be to upgrade the design of drapeama, from scratch I'd look for an I-beam. To be able to provide some rigidity, as Janke suggested, you would have to add a U-beam or U-profiles underneath.
Design B could be modified in such a way you could still use the liquid silicon. Depending on the length of the horizontal aluminum bars you could join the two aluminum on the bottom and cut them on inner sides on the top. Otherwise you could add a little beam in between. If you wish to use the liquid silicon (or good old soap) you could put a little sheet of metal in the beam, right where I positioned the bottom bearings. If you can get your hands on I beams I'd go for the second one.
And now I've got to get back to my class 'drawing the Mona Lisa with Paint'. Good luck!
Last edited by BarteS; 2011 July 8th at 07:41.
1) Thanks Krute!
2) No, it's pretty stable and doesn't really move, unless I put the weight too much in front or back,
3) As for shifting laterally, it can't happen because of the bearings on the sides: once the rails are properlly adjusted (tight enough between the bearings) it just can't move and the bearings rolls smoothly on it.
4) Of course I could desing someting with bearings on top, side and bottom but it would be hell of a job to install/remove it on the rails!
As I said, once the rails are properlly set, it just rolls on it, no need to put extra pieces under it: so I can always have something to "hold" the rails or prevent them to move/displace.
I'll try to improve my design, draw and scan it. Then I'll post it here.
It's not about the rolling part, just about the tipping. That's the sole reason to possibly put an upside down T profile underneath the base. And this is just a suggestion to those that are a bit concerned about the tipping, possibly because they know they (or their environment) can be a bit careless. If you don't need it, it's great, saves costs, weight and building time. All better to actually start using this one to make more movies.
Lol, we're not quite that bad for dust, BarteS!
I live on the east coast, and the so-called "Red Centre" is a world away. Occasionally, when there's a dust storm out west, we might get a red haze over the coastal cities for a few days, but normally we're as dust-free as a tropical rain forest.
I like your design. But I've already got the aluminium at a very good price and I'd be unlikely to score that well again. Also, I want to avoid bearings because I imagine they'd require precise alignment so as not to foul on the track and cause noise.
I'm happy with using silicone, because it dries out eventually, and can be wiped off easily, along with any dust it might have attracted. Oil, even fine machine oil, would have to removed after use with solvents, and that would hasten the oxidisation of the aluminum.
But thanks a lot for your suggestion and your diagrams. I'll keep them, because sometimes my projects end up being totally different than they way they started out to be.
Yes, that's what I'm thinking.
And even if you're the most thorough and cautious camera operator in the world, there's always the crew member who'll bump into something. If eevrything is lashed down and secure, that's won't be a problem.And this is just a suggestion to those that are a bit concerned about the tipping, possibly because they know they (or their environment) can be a bit careless. If you don't need it, it's great, saves costs, weight and building time. All better to actually start using this one to make more movies.
What kind of silicone is that? AFAIK, silicone is designed not to dry out...
If you want a noiseless slider without any grease or fluid, use Teflon pads. They are dry and slippery, and stay so forever.
(I've used Teflon for bearings in my locomotives, and they work beautifully, needing no lubrication.)
I definitely agree that there should be a way of securing the slider to the beam(s). Otherwise, one little accident, and the camera is a has-been.
That just gave me the thought: why not using a piece of LGB track and mount the tripod head onto an LGB flatcar (maybe shorten it)? Can't get any more fluid than that.
"It is dark the other side. Very dark!" - "Oh, shut up and eat your toast!"
LGB track in only 45 mm gauge - a bit too narrow for stability. Put two parallel tracks, say, 200 mm apart, and it gets better...
It's a spray can of silicone lubricant from the local hardware. I just checked the tracks where I had sprayed it yesterday and you're right, there is a very thin film of silicone still on it, even though I wiped it down with a paper towel. It seemed to come off very easily the other day, and I assumed that was because it was drying out. But looking at it this cold morning, it's still there.
I might not have shaken the can enough, and wound up with more propellant than silicone. Anyway, it's good to know that it won't dry out after all. I expected that, being a lubricant, it would more or less remain in a more or less "dry greasy" state, the way nylon bushes feel. But it's actually still quite fluid, as you say.
I used silicone because I already had a can of it. Never thought of buying teflon pads, although that is a better idea. I'm a bit of a tightwad, so I try to make do and go the very cheapest route with everything I make, (that's my modus operandi when making stage props). Hence the shameless scrounging of the aluminium from the ladder place.
Indeed. I've been trying to think of all the different possible ways of adding that feature at the lowest cost, but I may have to end up getting a piece of aluminium machined to fit just right.I definitely agree that there should be a way of securing the slider to the beam(s). Otherwise, one little accident, and the camera is a has-been.
As for durability, I think the felt pads/silicone setup would last virtually forever. Those pads are made to go under heavy furniture for easy shifting, and with silicone in them, and only the weight of a HV40 or T2i plus steel mounting block, they'd never need replacing.
Last edited by Jim E; 2011 July 8th at 17:44.
I actually thought of using model railway track at first. But the cost put me off. Even for kids' toy track, it's not super cheap. Besides, rolling wheels make noise.
I've thought about another interesting concept, for the bearings, but I'm not quite sure about the rails and how to make them more sturdy. I'll keep thinking about that and I'll update it when I'll have something that really worth discussing!
Janke's suggestion of "rungs" at intervals along the length of the rails would help a lot.
Of course, but I'm thinking to add bearing like that "[" top-bottom and side to prevent anything else than rolling on it. I'll think of something else, maybe the boggey with adjustable lenght instead of the rails.
Somehow it makes me feel the designs will approach a DIY truss to be be rigid, solid and provide a wide and smooth rail
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