skhell

Hi!

I am a complete newbie on the RC World, and I am looking build an application that could use some material from the RC world.

I need a needle valve, just like the ones that you use on your engines to fine tune them. The problem is that I need a valve than can some how be controled by some electric/electronic circuit.

Is there any valves like this on the RC world, perhaps any valve that can be adjusted by the controller while the plane is up on the skies?

If there is something like this, where can I buy it online?

Sorry if this is a stupid questioin

Thank you all

Flying freak

Yes theres such a thing its used for ducted fan I dont ahve a link for you though....

bkdavy

My Feedback: (1)

What you probably need for this application is a "continuous rotation servo" rather than the limited rotation servos we use. Do a google search and you'll find lots of options. An alternative approach would be a stepper motor.

Brad

skhell

Are you guys talking of something like this?

http://www.real-kbase.co.uk/csm_mixture.html
http://www3.towerhobbies.com/cgi-bin...&P=SM&I=LXDG65

A needle valve connected to a servo motor?

JohnBuckner

My Feedback: (1)

My rear exhaust Rossi .61 has a remote in flight mixture control that rotates the entire needle assembly about 20 degrees as a secondary to the primary needle adjustment. It is simply operated by servo and pushrod to its actuating arm. I find it unnecessary and it's just tightened off.

skhell

How much power/torque a servo needs to control a needle valve?

JohnBuckner

My Feedback: (1)

Well, no more than is neccessary for a throttle but that would also depend on the design of whatever the heck it is we are talking about. However I have a feeling you are talking about some use that is no relation to what any thing we know and therefore questions like that are impossible to answer These type of guessing games when you won,t explain exactly what the function desired is and other parameters are really just moot.

skhell

Well the application is quite simple.

I have my car running on LPG(liquid propane gas), and it has a kit to lubricate the valves of the engine. This kit is very simple, but has some flaws;some times it seems not to be working. This kit is composed of a bottle of lubricant and a needle valve that control the amount of lubricant that goes to the engine. The outlet of this needle valve is connected to the engine air intake, so its the vacuum on the air intake that sucks the lubricant into the engine.

What I want to do is replace that needle valve by one of the ones you used to adjust the mixture on the RC engines, and then connect a servo to that valve, so it opens the valve a bit bore when engine speed rises. Obviously I would need some kind of electronic gadget to control the servo according to the engine speed. For that I will use the Arduino (http://www.arduino.cc/), which is a small, cheap, opensource board that allows to make things like this.

I hope that with these explanation, you can understand what I want to do.

opjose

Are you saying that you want to replicate the car setup on your AIRPLANE ( this is a PLANE forum ) ?

skhell

No, thats now what I want.

I you look at my first post, I state that what I am doing is not to be used in RC world. In my last post, when I say my car runs on LPG, the car is a real size car(normal car) not a RC car.

I created this topic on this forum as I thought that I could use some material used in RC planes on my application(modifying the valve lubricator that I have in my car)

Sorry for the confusion [&:]

flyX

well...there's a hole at the tip of most needle valves, Most people mount an extension to it.

what if you mount a rod with threads so you can thread a thing of ma roo with an ear so you
can hook a cleves to the ear.

You know....the think of ma roo..like the ones on the rods for the airlerons if you mount the wing at center of the wing.

If you have access to a machine shop...just make a disc with a stud.

A sileniod to activate the servo..not sure what your set up is.

use air or electric to activate the sileniod.

skhell

Something like this?

flyX

Yeap...

You also might wanna do a little of reserch on passing gears or how the passing gears acts activated on
automatic transmission of an automobile. Maybe you can wire it to passing machenism...this way it'll
only kick in at certian rpms or when you punch it

Maybe just hook it up the to the damper of the air intake....I dunno..i have to be there in person.
But i know there's a damper to the air intake.

alfredbmor

Yes I believe that you already had the answer, that is a kind of an electronic sensor that can activate or deactivate the move of a servo which in turns will move the valve, you will need an electronic converter to have something like 4.8 ~ 6 volts from your car and that can activate that electronic circuit. The question about the torque of the servo could be answered with the arm that will fit the valve, on some engines those valves are very tight, then the arm should be larger and the servo should also be very powerful, but yes, you can use those kind of things for you non r/c project.
Good luck!!

skhell

Thank you guys, you have been very help-full

I am not quite sure of how I am going to open/close the valve according to the engine speed, but I am thinking on monitor the timing/pulse-width of the fuel injectors and open the needle valve as the timing/pulse-width of the fuel injector rises... but so far, this is just a few ideas...

Villa

Hello skhell
That is an interesting project you are working on. Is the lubricant you are injecting into the engine air intake an item that is normally found in the gasoline the engine normally would burns but that the LPG gas does not have? I was not aware that this was required when using LPG to power a car. I assume the lubricant is required to extend the valve seat and valve live since the rest of the valve is lubricated by the normal engine oil. In the old days of leaded gasoline this job was done by lead in the gasoline. I have wondered what was used when the lead was removed, but have assumed that improvements in valves/seats made a lubricant not necessary. If you have some details on this I would like the read about it. Thanks.

skhell

Hi!

It is just as you said.

Gasoline has some additives that LPG doesn't have, which may cause the valve seats to recess. Also, the burning temperature of LPG is a bit higher than gasoline. The conjunction of this tow factors, may damage the valve seats of some engines that have "soft valves". There is a list with some of the engines that need that protection when running on LPG( http://www.borel.fr/faisabilites/veh...sables-gpl.php ) , but usually all Japanese cars need it because they tend to have "soft valves". Any way, I think that is recommended to install a valve saver kit on any car running on LPG.

There is a kit called Flashlube( http://www.flashlube-europe.com/en/p...saver-kit.html ) that is very used worlwide but have some flaws. The one I am using is similar to that one, but has some little differences. The main difference is that when the additive gets to the air intake is already vaporised in air, and with the flashlube, it only gets vaporised when it gets on the air intake, which can make the oil not be equally distributed.

Also the kit I have increases the flow of additive with the engine charge, while in Flashlube is always constant....

What I want is to fine tune the amount of fluid that gets in the engine, because relying in the vacuum of the air intake to control the flow of additive is not very good and not very accurate, because the are many turbulence, making the flow of additive to change allot...

If you need any info let me know

Villa

Hello skhell
Thank you for an excellent explanation. It is possible that in the near future the USA may start using Compressed Natural Gas for some cars.

skhell

Thats great

Either LPG or Compressed Natural Gas are very good alternatives to gasoline. In Portugal (where I am from) there is LPG a long time ago, CNG is now starting to appear, but there are no refueling places...

Charlie P.

Here is another possibility for gas metering - the B&B Smoke Control Valve. This is a linear action flow control for the smoke oil used in R/C models.

http://bennettbuilt.com/smoke.htm

Not sure how it would work with a compressed gas, though.

plugin

In Colombia, Compressed Natural Gas is very common. I drive a '97 Ford Explorer every weekend to the field with gas conversion. The tank lasts for about 70 miles and filling it costs around $8-9.

combatpigg

My Feedback: (3)

There aren't any contraptions like this in the RC world that are industrial or OEM grade........nothing that would last 200,000 miles like what we expect from our cars nowadays.

skhell

The valve will not work with gas, but with a special kind of oil that protects the valves of the engine

skhell

In my project, I will also need to pump the additive to the needle valve. I was thinking on a electric fuel pump from our every day cars, but this are too big and powerful ..., then I thought again in the RC world and found some pumps I think that are used only to refill the plane/car/helli.

What do you say about this pumps?!? I think they would not like to work 3 or 4 hours in a row and would break very soon.

Is there any electric pumps in the RC world used to take the fuel from the fuel tank to the engine carburator of the car/plane? If there are any, that would be the ideal pump to my small project

Villa

Hello skhell
The R/C electric fuel pumps used to refill the R/C fuel tanks seem to have a short life.