House of Hacks

Thursday, December 26, 2013

How to make an air lottery ball machine

Need an air lottery ball machine? In this episode I show how I approached the task of making a homemade lottery machine including what I did and why.

Other homemade lottery machines on YouTube:
Video this lottery machine was built for: Super-Minilypse Utah, USA (iStock drawing)

Playlist of other project overviews.

Music under Creative Commons License.
Intro/Exit: "Hot Swing" by Kevin MacLeod at
Incidental: "Awesome Call" by Kevin MacLeod at


Today at the House of Hacks we're going to look at making a lottery machine.


Hi Makers, Builders and Do-It-Yourselfers. Harley here.

One Thursday a while ago, my buddy Rich gave me a call. He asked if I could build him a lottery machine. I told him, "yeah, I thought we probably could do something." Then he asked if he could have it by Monday. It turns out he was responsible for organizing an event that had a limited number of slots. Of course they had more people interested in attending than they had slots available and he needed to some sort of drawing. He thought a corny, 70s style video would kind of spice it up. Make it a bit more interesting than just pulling names out of a hat and reading them. So I asked for a budget and told him I'd get back to him.

I first went online to search for places where I could rent something like this. That would have been the easiest, most straight-forward thing to do, particularly given the time constraints. But I didn't find anything so the next thing I looked for was something where somebody had done something similar. I did find one YouTube video and that's all I found. It was a pretty simple build and didn't really work too well. Since then I've actually found another one that worked very, very well. It was a little complex probably, particularly for the time frame I had; it looked like it was microprocessor controlled. Links to both of those are in the description below.

So this is what I came up with. I found a couple punch bowls the right size at Walmart; they're just plastic bowls in the party section.

For the output side where the balls come out, I found that the shielding tube that you get for fluorescent tubes that's designed to keep the glass from showering down on top of you if you shatter the glass, those tubes are the perfect diameter for ping pong balls. And so I just cut a hole in the top and hot glued this in.

For causing all the air to blow around inside I decided to use the blower side of my shop vac. Because the shop vac is so loud, we decided we probably didn't want it on set right next to this while we were filming so we got twenty foot piece of dryer duct; the exhaust vent stuff. And that stretches out and like I said I think it's twenty foot long if I recall correctly.

I cut a piece of wood and drilled a hole in it with a piece of screen over it that would fit in the bottom of the punch bowl where we also drilled a hole. And then I attached -- this is a union that's designed to connect two of these together. I just cut slits on one side and folded those tabs down and hot glued it to the wood.

Then on the other side where the vacuum blower connector has to go in I went to the plumbing aisle and found a rubber drain piece. I don't know exactly what it's used for but the inside diameter was perfect for the vacuum hose and the outside diameter perfectly fit inside a three inch PVC coupler. So I got a reducer that's the three inch to four inch reducer thing and hot glued the rubber part inside here. And then this fit perfectly in the four inch dryer duct.

I hooked everything together and all the balls bounced around very nicely. We were really pleased with the way it turned out in the end. We did have to drill some holes in here and also in here to relieve some of the pressure. We found it was over pressurizing this and it tended to want to blow the assembly apart. But once we put enough holes in here it reduced the pressure enough that the balls bounced around perfectly and came out without any problem but we didn't have problems with it wanting to burst apart.

So, I'll put everything together and we'll take a look at how it works.


Thanks for watching. Please "Like" if you enjoyed this episode and here's a playlist of other project overviews like this one. Here at the House of Hacks we cover a wide variety of maker related topics. Subscribe if this interests you. Leave a comment or question below; I'd love to hear from you.

So, until next time, go make something. It doesn't have to be perfect, just have fun!

Tuesday, December 17, 2013

How to operate an old camera

In the follow-up to cleaning an old camera, I show how to operate the Graflex Series B. Then I reveal the results from the first roll of film through it in five decades after processing the film using the negative to digital conversion steps from a previous episode.

More about this camera:

In this episode of the House of Hacks I'm going to show how to operate this old Graflex camera.

Hi Makers, Builders and Photographers. Harley here.

In this previous episode I first showed this new-to-me camera that explained how the light travels through it and did a little cleaning on it. I mentioned in that video that I was going to be taking it out, run some film through it and report back on how it turned out.

I tried taking video out in the field but it didn't work out too well logistically so I'm going to do this episode here in the workshop.

Today I'm going to talk about the actual operation of this camera. I'm going to talk about how to load the film, how to set the exposure, both the aperture and shutter speed, how to take a picture and finally take a look at some of the first images out of this camera in over fifty years. If at any time you want to skip to a specific portion of this video, just click the appropriate menu item over here.

This camera model had available to it different backs. Each back took a different type of film which allowed you to change film types from one image to the next. You could also have multiple backs of the same type and put different types of film in them. This allowed you to shoot the same type of film but different varieties. Like black and white and color or different film speeds. Mine came with a carrier for 120 film which is really nice because 120 film is still made and manufactured. It's readily available. Amazon carries it. You can get it at your local camera store.

To start loading the film you move this little bar which frees up the carrier, the back to come off. This is what a 120 back looks like. To open this up you pinch these silver bars together and it just opens up like this. Inside here there's a film carrier, like so. There's a place for the supply reel. The film comes around here, this is what faces the shutter, rolls around and goes onto a take-up reel. The take-up reel, when a roll of film is finished, just free-rolls forever, like this. When you want to put in a new roll of film, you just manually click this over to the "S" position, you can hear that click, and now you're ready to load a roll of film.

So, we'll take this film out of the box. It comes in air-tight, light-tight packaging to keep the film fresh. There's a piece of tape here, you just break the seal across here. Sometimes it's easier said than done. Oh, this one just peel off, that's kind of nice. Different brands of film will do that a little differently.

The film goes in here, and it's just spring loaded, so you just put it in like so. You want to make sure this is in such that the film emulsion, the black part, is coming out from the bottom like this. This is so when it wraps around like this it's facing into the camera. It then rolls around and you put this little piece of flap in the slot like so and you just wrap it up. See how that slipped out? I've had that happen before. You want to make sure that when you start rolling this that it's actually engaged. There's nothing more frustrating than to think you've shot a whole roll of film only to open this up and find it's still at the start. There we go. Once we have it loaded on about one roll like that we want to put it back in here like so. And then we want to roll this around until it gets to "1." It stops when it gets to "1" and this is now -- put it right back on the back of the camera. The camera is now loaded with film and ready to shoot.

Exposure is made up of three things: film speed, aperture and shutter speed. This is commonly called the exposure triangle. We're going to talk about how to set this on the Graflex.

First, film is measured in ISO units that typically have values of 100, 200, 400 and so forth. Kind of powers of two. In digital cameras you can change this on the fly from one image to the next and you can also have partial settings on the ISO numbers between those power of two numbers. With film, each roll of film has a specific value and so once you put a roll of film in the camera that's what you have to work with until you take that film out. On the Graflex this is a little bit different because the backs are interchangeable so if you have multiple backs you can put different film in each back and change the backs from one image to the next, if you so desire.

The second leg of the exposure triangle is the aperture. This controls how much light comes through the lens and is measured in units called f/stops. Each f/stop either doubles or halves the amount of light coming through the lens. The larger the number, the smaller the hole and the less light that comes through but the greater the depth of field. On the other hand, the smaller the number, you get a larger hole that lets more light through but you have a shallower depth of field. The aperture blocks off this light with vanes that are controlled by either rings or levers that outside around the lens. Different lenses have different ranges. This particular lens opens up to f/5.2 and closes down to f/22.

The last leg of the exposure triangle is the shutter speed. This controls how much of the light that's going through the aperture actually makes it through to hit the film. In most cameras, there's a dial that you turn to set the shutter speed to what you want it to be and the camera just takes care of the rest. The Graflex however is quite different. It has a long piece of fabric in it with four different slits in it of different sizes. This fabric is rolled up on rollers that are then attached to some springs. The spring can have variable tensions set on them. So to set the shutter speed, you look on the side of the camera on a chart that has all the different shutter speeds on it. You find the shutter speed you want and read across to the left side to find the slit to use and read up the column to find the tension to use. There's then two controls on the camera that you set to these two values. To set the slits value, first of all make sure this lever is in the down position. That puts the mirror down and also engages the latch for the winding mechanism. Next, wind this knob until the value that's indicated by the chart shows up in this little window. If you find you've gone too far, you can use this release lever to back up to previous settings. To set the tension value, simply turn this knob on the bottom of the camera. If you find you've gone too far, you can back up by pressing this little release knob.

To determine the proper exposure values to use, you usually use a light meter. This is an older model that's very simple. It has a photosensor and a meter in it. The meter has a little red indicator on it. To use it, simply point it at the scene and rotate this dial to line up a green indicator to match the red indicator. You then set the film speed to match what you have in your camera and then directly read out on the chart here that tells you what shutter speed to use for which aperture you want to use. Very simple to use. Never fails. No batteries required. This is a newer version of the same thing. It's bigger. Requires batteries. But it also has a few new features. It does have a manual mode on it though so you can set the ISO on the film and find out what aperture and shutter speed to use to get a proper exposure. However, when I'm out in the field taking pictures, I'm always going to have my SLR with me and it has a built in meter so I just use it. I set it to manual mode, set the ISO to match the film I have loaded in the camera, and then center the needle on the meter by changing the f/stop and the shutter speed to be what I want it to be. I can then take a picture to make sure I have the correct exposure that I want in the camera and then I can just take those three values and apply them on the Graflex and be ready to go.

Once you have your exposure values, you're ready to make your image. The first thing of course to do is to frame and focus. I find it's best to do this with your aperture wide open so you can actually see what you're doing. Focus is controlled by this knob on the side which all it does is move the lens closer or further away from the film plane. To do both your framing and focusing, you use the viewfinder here on top and just look down through here, adjust your frame and then do your focus. Once all that's done, then you can dial in your aperture to what's appropriate for this particular image. Once all your exposure values are set, your shutter speed and aperture, you already have your film in there, you're ready to take your image. I find this works best as a four step dance. You just do each step right in sequence after the other without interruption. Step one is remove this plate from the film. This exposes the film to the inside of the camera. Two is to press the shutter release that's over on this side. Three is to put the plate back in. And four is to advance the film. I find that if I don't do this each and every time that I'll forget a [step] -- usually to either take this plate out, which results in no image, or I'll forget to advance the film, which results in double exposure, neither of which you really want. Once all the film has been used, it'll all be on the take-up reel; none will be left on the supply reel. Unlike 35 mm cameras where you reverse the film back into the canister, you just leave it on the take-up reel in this one. Take the back off to a darkish location, just like you used to load the film, open up the back, and on the end of the film will be a moisture sensitive adhesive. Lick that and stick it to the film. That'll keep it from unwinding, coming off the roll and ruining your film. Keep it in a dark location as you take it to your film processor for developing. And finally, take what used to be the supply reel that's now empty, take it off, put it in the take-up reel position and put in a new roll of film and you're ready to go again.

I ran a roll of film through the camera and took it to a local lab for processing and scanning. I had no idea what to expect since this is the first film that had been through the camera in over fifty years. I didn't know if it might have light leaks or some other problem with the camera that had caused it to fall into disuse. I received the scans via e-mail and opened them up and found them to all be identical. This was pretty surprising since I'd done exposure bracketing from one frame to the next and expected to have different exposures. I picked up the film in person a couple days later and sure enough they did have different exposures from one frame to the next. So the camera was working just perfectly. As it turned out, the scanner was in auto mode and it had adjusted the exposure on each frame to be what it thought it should be, negating the exposure bracketing I'd done. So, lesson learned is next time I need to have them turn off auto mode, if I've done exposure bracketing, in order to get the proper exposures on each frame.

I used the negative to digital conversion process I described in this video to get digital images that had the correct aspect ratio and exposure values. I'm very pleased with the way these images turned out.


I'll probably be doing more with this camera in the future. I may even do some developing if I do a lot with it.

If you have any questions or comments, leave them in the comments section below. And subscribe if you're interested in maker related videos. And here's a play list of other photography related videos that I've made.

Until next time, go make something. It doesn't have to be perfect, just have fun!