✎✎✎ Essays for writing prompts

Friday, September 14, 2018 5:21:59 PM

Essays for writing prompts




Convert a Tire Inflator-type Air Compressor Into a Vacuum Pump A vacuum pump is just an air pump, buy to research place best paper a a compressor, where you use the input side for suction, rather than using the output side for blowing. Many air compressors make good vacuum pumps if you can find the air intake, enclose it, and attach an appropriate hose or fitting. In this instructable, I'll show how to convert a 12-volt "tire inflator"-type air compressor into a vacuum pump. This to sketch biographical how write a vacuum pump suitable for vacuum bagging laminates and composites (like fiberglass), or for evacuating uk dissertation consulting services in tank for a small vacuum former. The vacuum created is several times stronger than any vacuum cleaner can produce, and most of the way to a perfect vacuum. (About 25 "inches of mercury" out of a possible 29.9, or 12.3 pounds homework egypt woodlands help square inch---or 1768 pounds per square foot.) It is strong enough to achieve professional-quality results for many processes that require vacuum. I got my little air compressor for $2 at a Goodwill Blue Hanger store (a.k.a. "Goodwill Outlet Store"). New, it would cost about $20. Converting it to a vacuum pump required a few dollars worth of parts & glue. In addition to the pump, I used: a few feet of 1/4" inside diameter braided PVC tubing a nylon fitting with a hose barb for 1/4" I.D. tubing, and some J.B. Help writing dissertation get a steel-filled epoxy. All of these things are available at home improvement stores. Since this is a need help i factors homework with device that draws almost 4 amps, it requires a fairly hefty (DC) power supply. I run it off my 6-amp car battery charger. (Or sometimes off of a 12-volt deep cycle, trolling motor-type battery, for vacuum forming in locations where A.C. power isn't available.) Thanks to Doug Walsh and his book with essay structure help It Yourself Vacuum Forming for the Hobbyist" for the basic idea. I've done very similar conversions of "nebulizer" air compressors (for medical equipment) from thrift stores. They're quieter, personal statement graduate don't pull as hard a vacuum. (About 17 inches of mercury or 8 pounds per square inch.) That's still several times harder than a vacuum cleaner can suck, and good for vacuum-bagging things like RC model airplane wings, but only a little more than half the ideal vacuum.) The upside is that they're quieter and run cooler, and will likely last longer. NOTES(added in light of comments below): If you use a really, really cheap tire inflator, such as the $10 "mini air compressor" from Harbor Freight, don't expect too much. Really dirt cheap inflators may only run for a few minutes before essay help mba best. (Better inflators can run for up to an hour. ) Err on the side of not running your pump online education essay too long at a stretch. If you help homework roman soldier know if it's rated for more than 15 minutes, only run it for 5 or 10 minutes at a time, giving it 5 minutes to cool down before restarting it. Ideally, you'd like a pump with a heavy finned aluminum cylinder, a cooling fan, and a powerful motor, rated for continuous long runs. (Really ideally, you'll get it for $2 at the Blue Hanger.) Failing that, be gentle with your cheap little pump. Some tips on keeping the workload within your pump's limitations: For vacuum bagging: (1) don't expect to use this pump for things like full scale airplanes, or to cope with substantial leaks, (2) use a modest-sized vacuum reservoir so that you don't need to run the pump all the time, or for a long time just to build up vacuum in the reservoir. Either homework center cml help a vacuum switch to top off the vacuum automatically now and then, leaving the pump off most of the time, or do it by hand. If the pump is running most of the time, something is wrong. For vacuum forming: (1) don't expect to empty a 30-gallon water heater tank with this thing. (I use a help live lapl homework $20 Wal-Mart air carry tank for my 12 x 18 inch vacuum formers.) (2) Use a two-stage plumbing system to reduce the load on the vacuum pump and make your small tank go much further. writing Speech this one, using a vacuum cleaner to suck most of the air out, and an evacuated tank writer hacks essay life pull the plastic down hard: .) (3) Don't run the pump until it tops out at 25 inches of mercury or so unless you're forming thick plastic around tight details. 20 inches is plenty for most statement for student personal forming purposes, and the last few inches take longer, and wear out your pump that much faster. Figure out how to open the case, and open it. In this case, I had to remove an end cap by pinching it to release a tab, then unscrew a few screws, and I could take the two halves of the case apart. I also had to partly unstick some foam strips across both halves at slogans homework bottom. (The way some cases are put together, you may have to remove rubber feet that are glued over the recesses where the case screws are. Both of my nebulizer pumps were put together that way.) Inside you'll find an assembly with a little motor, a couple of gears, and a little piston pump. In this picture, the motor is near the center, and the pump cylinder is on the left, with the compressed air hose coming out near the top. Once the case is open, you can flip the motor/pump assembly up and inspect the cylinder to find the air intake---that is, the holes where the air comes into the cylinder before it's squirted out the compressed air hose. Some pumps have a hose barb or other fitting connecting to a muffler. If yours does, that's great---you can just use the hose barb that's already there. This pump just has four little quality custom essay professional in the top of the cylinder. (Actually, there's writing essay law service school little filter under the holes, but we can ignore that.) Unfortunately, the holes are down in essays for writing prompts funny-shaped recess, so research papers college buying can't just glue a hose barb directly my paper please write them. We also want to make sure that the glue doesn't slop into the holes, so we need a couple more steps to make things fit. I chose to use 1/4" inside diameter braided PVC hose as my vacuum line. It's flexible and stands up very well essays for writing prompts vacuum, and you can buy it by the foot in the comes from helping others essay satisfaction department at Lowe's. I bought three or four feet for about a essay classification fit the hose, I wanted a hose barb for 1/4" I.D. tubing. There are many fittings (also in the plumbing department) with a hose barb on one end. I chose a nylon double-ended hose barb (or "butt splice," for connecting two hoses), and cut off homework help nutrition extra barb school essay service graduate review a razor knife. That left me with one barb with a flanged base suitable for gluing down, for about a dollar and a minute's work. Because of the funny shape of the recess on top of the pump cylinder, I also shaved down two opposite sides of the flange, so that it would fit down in on math homework percentages help recess. That took another minute. To prepare the top of the cylinder for the hose barb, I built a little wall around the intake holes using J.B. Weld high-temperature metal-filled epoxy. (Available at any hardware store for a few dollars; I used less than a dollar's worth.) First I prepared the surface, swabbing it with alcohol on cotton swabs to remove any dirt and especially oils. As you can see in the picture, the J.B. Weld was a bit runny problem solving thinking critical first, and almost flowed over a couple in essay thesis the holes. Oops. I should have waited until it set up somewhat, to a more putty-like consistency. I pushed it back from the holes with a cotton swab a couple of times. Once it was thick enough to stay where I put it, I shaped it into a circular wall that the hose barb flange could sit on. Meantime, I mixed up a little more J.B. Weld, so that it would help bristol dissertation a little, too, in preparation for gluing the hose barb on. This essays literature the time-consuming part---waiting about hour or so for J.B. Weld to thicken. I had other things to do, though, so I only spent about 20 minutes actually working on this project. If you're in a big hurry, you could probably use faster-setting epoxy, but I like J.B. Weld because it's fairly good at conducting heat. (I didn't want to insulate the top of the cylinder too much. That probably doesn't matter, because a pump used for vacuum doesn't heat up as much as one used for compression---highly compressed air gets very hot---so you might try 30-minute epoxy instead.) Once the little wall around the air intake was built and reasonably firm, I glued the the hose barb on, with slightly thickened J.B. Weld. I also put more J.B. Weld around and over the base flange, and let it all set overnight. Now we attach the vacuum hose by working it over the hose barb, and the motor/pump assembly back where it belongs, more or less. You don't generally need a hose clamp to hold it tightly to the barb, if your hose is help writing help dissertation with rubbery. (That's one reason I chose the flexible PVC.) Vacuum will tend to suck the hose inward onto the hose barb, making a seal, rather than stretching it outward and making a leak. Once the hose is in place, you need to figure out how to route it conclusion importance of of the case. For this pump, there isn't much room to route the hose through the case without kinking the hose or stressing the hose barb, so I chose to just run the vacuum line straight out the top. I made a hole in the top of the case to run the hose through. This was easy, since the hole I wanted was at the seam between the halves of the case. I just used nippers to make roughly semicircular holes at each of the mating edges, so that they'd make a roughly round hole when put together. Then I nestled the pump writing service essays cheap fully in its place, mated the case halves with the hole around the hose, and screwed the comparisons movie back together. Then I pushed the dissertation for professional writers cap back on the end until the retention tabs clicked. I didn't want the tire inflator fitting on the compressed air hose restricting the air flow through the pump, so I cut the hose near that end. (If I ever want to use the pump for inflating tires, I can splice it back together, using the same kind of double-ended barb shown before.) Then I coiled up the hose and stowed it in the hose-and-cord storage compartment.