Air Powered Car

in the comment section of last week's air-powered car video you guys explained to me that having parallel steering geometry will cause tires coming when turning as an aerospace engineer and having never designed a car before this was completely new to me but luckily it was an easy fix for the rear axle I chose to use the same 608 ceramic hybrid bearings as used in the air engine now because the inside diameter of these bearings are about seven point nine five millimeters I struggled to find a suitable rear axle so I chose to use a brass tube with an outside diameter of six millimeters and 3d printed some spacers to fit inside the bearings but first I must mount the driven gear the driven gear is 80 millimeters in diameter and has 100 teeth which required to be printed on my coastal mini Delta 3d printer with a naught point two millimeter nozzle to get the required tooth definition a 3d printed the wheels from regular PLA filament supplied from my sponsor 3d prints UK I chose this over using regular radio-controlled car wheels to keep the weight and rolling resistance low the engine was mounted using slots so the gear ratio could be adjusted as well as the gear tooth mesh the drive gear had 25 teeth giving an engine to rear axle gear ratio of four-to-one but it wasn't that simple I did run into some issues when printing the gears even using the naught point 2 millimeter nozzle as you can see here the tooth definition is pretty terrible despite the design following a correct tooth shape not only that but the larger driven gear didn't have a consert radius causing issues with the teeth meshing so I swapped out the five spoke gear for a solid gear design with a low infill and deeper tooth pattern this design had a better mesh but it also had some warping issues which I fix with the heat gun and some patience and then clamped it to the rear axle using two bolts because PLA is a relatively hard plastic it doesn't offer enough grip required for a tire so using an old bike inner tube I attached a strip of rubber to the rim using some glue whilst the Glee was drying it was time to mount the front wheels because the front wheels weren't driven the bearings could be mounted inside the hubs and then bolted straight into the steering mechanism and then mounted the rear wheels using the same clamping technique as the large gear reattached the engine and then headed out for a quick test because I hadn't mounted all of the radio control gear I decided to test it only 30 psi and it looked pretty promising it was time to build a throttle and I realized I could simply squeeze the hose to restrict the air flow which removes the need for a complex diaphragm valve as I designed in a previous video so using a very basic level mechanism I was able to reduce a cross-sectional area of the tube and therefore adjust the RPM and engine then a radio-controlled servo was added and using a very basic push rod I was able to control the throttle it was then just a case of shortening the tubing and mounting the plastic bottle I gave it a small kick just to test the steering and then proceeded to pump it up to 50 psi and nothing and again pretty terrible okay a bit better but I could still have pushed it further so what's really happening here basically the car won't run at high pressures and this test shows it pretty well the first few pushes go nowhere and then it suddenly gets going for just ignore the fact that I scrubbed off all the speed in the corner this time I bumped it up to only 35 psi and it worked a lot better [Applause] so what's really happening here well it's all to do with the gear ratio and the air inlet valve inside of the engine it seems as though the engine is lacking in talk so the obvious thing to do is to increase the gear ratio by either decreasing the diameter of the drive gear or increasing the diameter of the driven gear the only issue with this is that in order to open the inlet valve inside of the engine a torque is produced by the engine in the opposite direction and it is a job of the flywheel to overcome this and open the valve now because the wheels and essentially the forward momentum of the car are the flywheel in this case increase in the gear ratio reduces the effectiveness of the flywheel therefore only allowing the engine to run at even lower pressures so let's try to sum this up for the car to run at higher pressures the engine requires more energy from the flywheel to open the inlet valve this can be done by either adding more mass to the flywheel or spinning it faster to achieve this that engine needs to produce more talk which can be done by increasing the gear ratio however this reduces a talk in the other direction from the flywheel to the engine basically reducing the flywheel effectiveness so the gear ratio must be reduced to increase the effectiveness of the flywheel but the problem with this is it decreases the torque produced at the rear wheels by the engine so the only other way to increase a torque output from the engine is to increase the pressure and we're back to square one so that's the conundrum that I've run into when testing this air powered car I think the only way to fix this car is to completely redesign the engine either by increasing the volume of the cylinder inside the engine so that the energy transfer to the flywheel is greater than the energy required back to open the ball valve or to completely change the valve system and move to a rotary valve or a valve that will spin and let it air in and out the only issue with that is that I'll probably run into issues of trying to see it it properly because it's quite hard to have something spin smoothly without air leaking out sides so that pretty much does it for this week's video if you do the video please give a thumbs up if you're new to my channel please please subscribe and a huge huge thanks to all my patrons for supporting me you guys seriously make these weekly videos possible and if you supposed to be on patreon and he wished to or you want to see any behind-the-scenes information bonus footage etc then check out my patreon link down in the description below next week I have a pretty cool piece of manufacturing equipment to add to my workshop and I'm really excited to get it working and show you guys so thanks again for watching and I'll see you next week goodbye

Channel: Tom Stanton

Views: 1,463,311

Rating: 4.8260212 out of 5

Keywords: 3D printer, 3D printing, 3D printed, 3d Print, tutorial, engine, air engine, compressed air, compressor, pump, engineering, engineer, CAD, PLA, pneumatic, pneumatic engine, pneumatic actuator, exhaust, diy, homemade, how to, build, 4 stroke, 2 stroke, gas, motor, how it works, air, do it yourself, stl files, free, thingiverse, design, o ring, propeller, piston, cylinder, crank, crankcase, crankshaft, conrod, bushing, make, made, idea, pvc, power, single cylinder, steam engine, steam, trains, car, powered

Id: nyPc82mW2BA

Length: 10min 6sec (606 seconds)

Published: Fri Jun 15 2018