Guest Aaron Posted August 21, 2003 Share Posted August 21, 2003 I think the supercharged nissan pickups may have the likage you are looking for. The Z06 vette uses a trottle by wire setup. I have seen a couple magazine cars using it. Quote Link to comment Share on other sites More sharing options...
JoeinCA Posted August 21, 2003 Share Posted August 21, 2003 Greimann: I think you under estimate the quality of the model airplane electronics. I cant see any good reason not to use them. I'll figure out how to do it, but i need to get the car on the road first... Joe Quote Link to comment Share on other sites More sharing options...
pparaska Posted August 21, 2003 Share Posted August 21, 2003 Tannji, I had that same idea. But it was to make one adjustable "Cam" on the throttle lever of a carb or TB. I too like to make things adjustable . How about this? : Attach it to the existing throttle lever with a few screws, spacers, etc., and adjust away. Once you have a nice action you like, cobble up a cam. Quote Link to comment Share on other sites More sharing options...
tannji Posted August 21, 2003 Author Share Posted August 21, 2003 Joe... I like your idea a lot... but like the reliability, or perhaps predictability of the mechanical cam better personally. Like I said, I would love to see it done your way tho.... it would own Pete, you have put me over the top, I will start the test fab on it soon, but I will design it so that the cam is easily and quickly swappable.... so that you could have 2 or more "profiles" available with about 20 seconds of labor. I still need to find a kit for fabbing custom throttle cable lengths, and putting the end-caps on them, but that and the mounting hardware are the only real concerns.... thanks for the input, everyone!! this will be a fun and probably useful mod to implement. I will keep ya updated. tannji Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted August 21, 2003 Share Posted August 21, 2003 .... I still need to find a kit for fabbing custom throttle cable lengths' date=' and putting the end-caps on them, .....tannji[/quote'] See this link: http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=4223&prmenbr=361 Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted August 21, 2003 Share Posted August 21, 2003 Greimann: I think you under estimate the quality of the model airplane electronics. I cant see any good reason not to use them. I'll figure out how to do it' date=' but i need to get the car on the road first... Joe[/quote'] My concern is relilability, safety and functionality. Automakers that put drive-by-wire systems in their cars have spent many many man hours developing and testing the systems so they can perform hundreds of thousands cycles (if not millions) under harsh environmental conditions like heat and moisture. Model aircraft electronics are not designed to survive in those conditions. Fail safety is another concern. How would you ensure that a broken circuit would not leave the engine at WOT, or suddenly go WOT at a stop light? Automakers developed drive-by-wire so the throttle can be integrated into traction control systems. There really is no other reason to make something so simple, so complicated. There are Lots of reasons not to home brew up a drive-by-wire system and not too many why you should. My $.03 Quote Link to comment Share on other sites More sharing options...
JoeinCA Posted August 22, 2003 Share Posted August 22, 2003 Greimann, all you have to do is set up a saftey return spring and a safety relay. the spring will return the throttle to idle if there is voltage loss to the servo. The servos that are made for boats will definetly stand up to heat and moisture. They are often used next to small nitro powered engines, often DIRECTLY next to them, wedged between the fuel tank and the engine. I admit that there are complications, i just dont think that servo durability is one of them. it really does not take much force to open the throttle, and with the proper return spring, the load on the servo really would not be that large. most servos employ a brushless motor setup, (like cooling fans, and most other electric motors that are expected to operate under continous load for very long periods of time.) I'm a nerd. I want to set up fly-by-wire throttle control just for fun. I agree that the Cam would be easier, and simpler. Hey, i have an idea for how to make the cams change out quickly. You can set up an oval (or a rounded I shape) pin that has small bearings in the side, that release pressure when you push a button on the end. (like ratchets, just oval(or...) with like 7 smaller bearings) the bearings would slide into a precisely shaped groove, and would hold well. just a thought, Joe Quote Link to comment Share on other sites More sharing options...
tannji Posted August 22, 2003 Author Share Posted August 22, 2003 The thing to do with the actuators and motors would be to call the manufacturer and found out what kind of duty cycle rating they have. I agree that many are designed for withstanding the environment, but will they withstand several hours of use per day for years? I am thinking of something similar for swapping out the cams, Joe.... but it will have to be a bit down the road, if it becomes popular.... the cost of my first actual machined unit, (as opposed to the rough ones I will make at home) will be rather high. The only major wrinkle I have come across is making the cams fit all carbs and throttle bodies. I can either provide a blank cam (to anyone besides myself who like this idea) and the end user can drill the opening for the TB axle, or I could have special mounting center pieces made for each person (very expensive) or the whole assembly could be unattached to the actual TB, and instead tie into the existing throttle cable. The good news is that once the design is finalized, the actual cost of machining the components does not appear to be very high. Most of the cutting will be by laser, Approx $35 setup fee per component. If I can avoid machining completely, material and cutting costs will be very reasonable. laser cuts are actually inexpensive, once the cad is setup. tannji Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted September 1, 2003 Share Posted September 1, 2003 tannji, Just thinking about your idea. What if you took a piece of aluminum tubing and bent it into the form for your cam, then you could grind the tube along the outer curve to open it up and make a track for the cable to rest in. If you could then attach this track to a wheel with the cable mounted in it in such a manner that it could be swapped in and out then you could make any number of aluminum tracks for the cable and just swap them in and out in seconds. Here is a crude drawing of my idea: The wheel with the slacked cable is on the left, and on the right is an example of a track that would bolt onto the wheel using two screws through the holes. All you would have to do is let out some cable slack to get the track in, then tighten the cable back up. (I think) Quote Link to comment Share on other sites More sharing options...
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