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View Full Version : converting from fergilli rams to air . but no power


cosworth34677
11-23-2012, 02:24 PM
ok i been converting my excavator from fergelli rams to air power pneumatics. i got every thing to gether but i have no power . it works once but then in wont' move my actuators, i have the pump going straight to the valves. and the you would think it would be super strong but its not very squishy and spongy. any one got a idea how to help thanks

Acadieman
11-23-2012, 02:55 PM
Please take this with a grain of salt as I have never worked with RC pneumatics before.

Unlike a hydraulic system, most air systems have a tank that the pump will pressurize. The attachements are ran off the tank to assure there's suffiecient flow and pressure. One of the reasons for this is air is compressable.

I would almost think a tank would be needed.
With that being said, I'm awaiting replies from others as well. :)

carp
11-23-2012, 04:07 PM
You will struggle if you are using the hobbyking rams because they are so small, diameter of maybe 4mm? not sure how much pressure you compressor makes? like acadieman said you would probably need a tank for it to work better. Here is how it can be done hydraulic using similar valves to the ones you have, wont be very precise though http://umstech.in/admin/Uploads/pdt_brochure/Hydraulic%2012kg%2003.pdf

cosworth34677
11-23-2012, 04:18 PM
Hi all.

I am with you on the air tank idea to keep the pressure up to the air rams.

Now for the dumb question could you use a fluid through the system to make it a hydralic type of set up.

Regards Ralph.

i guess but the pump is the thing i can't really afford. i can't really drop 200-400 dollors in just ta pump. if i can find something under 50 that wil work then id go that way.

cosworth34677
11-23-2012, 05:02 PM
what about a windsheid wiper pump?

cosworth34677
11-23-2012, 07:39 PM
ya but i already have parts that i just got today and running out on money for this project
arge!!

RCP57
11-23-2012, 08:41 PM
It's only my opinion but I don't think that you will ever get air to work properly because it will always compress. No matter what you do it will be spongy and springy because of that. Hydraulics work smoothly even with a large amount of pressure or force because the fluid doesn't compress and is always consistent. You may get your air system to have a lot of power by cranking up the pressure but you will have a hard time controlling it smoothly and you will definately need an air tank to maintain any air volume/pressure.

Just my thought...

cosworth34677
11-23-2012, 08:52 PM
could a just add a hydraulic pump to the set up instead of the air? or is ti different in the way it works?

carp
11-24-2012, 04:33 AM
You wont get proportional control your valve works either on or off like a switch and constant pumping against your cylinders with oil might not work, when it bottoms out it will blow the pipes off.

cosworth34677
11-24-2012, 08:09 AM
You wont get proportional control your valve works either on or off like a switch and constant pumping against your cylinders with oil might not work, when it bottoms out it will blow the pipes off.
ya im taking off the air stuff putting back on the actuators, im going to have to rethink the hole set up. now is this stuff no good or is there something i can use them for? i got a truck project in the works

rcguyfarms
11-24-2012, 08:47 AM
The money u have wasted on the actuators and air system could have paid for hydraulics by now. I have been down this path before on a track loader project.

cosworth34677
11-24-2012, 09:53 PM
The money u have wasted on the actuators and air system could have paid for hydraulics by now. I have been down this path before on a track loader project.

ya i know it hurts when you waste a bunch of money on a idea but i had to try. it would of killed me not knowing if it would or would not work . but im already thinking of wht i can do with the parts

carp
11-25-2012, 06:03 AM
You dont know if you dont try, you could use them for small stuff, try filling them with water and piping 2 together so you push 1 rod down and it pushes the other up, then attach 1 to something you want to move then attach the other to a servo or actuator, only works well if you get no air in at all.

cosworth34677
11-25-2012, 07:53 AM
You dont know if you dont try, you could use them for small stuff, try filling them with water and piping 2 together so you push 1 rod down and it pushes the other up, then attach 1 to something you want to move then attach the other to a servo or actuator, only works well if you get no air in at all.

ya i was playing around with them. and kind of found that out. looks good for my next build. i hope they hold up hat way. i may switch to oil like 3in1 or brake fluid