vertical grimmace

My Feedback: (1)

There is an ad by a company called More power here on RCU. They are offering a hydraulic system for powering retracts. I was curious as to others thoughts on these. It seems many would like to move to electric retracts away from the air type. I am pretty new to dealing with retracts actually, so any experienced opinions would be welcome.

Lnewqban

Actually, any hydraulic system would work with an electric pump.

The advantage, like pneumatic's, is that force can be taken anywhere using hoses in a flexible manner.
Pure electric systems transmit the force of the motor via gears and linkages.

For industrial applications, I favor hydraulic systems over pneumatic ones because in my opinion they are less maintenance demanding.

I see two disadvantages: leaks would be messy and systems with big volume of fluids would be heavier than pneumatic counterparts.

TFF

Can you post a link. Years ago there was an add on to the air retracts that put hydraulic fluid from the cylinders to an "accumulator" and the air side pressed on the accumulator to make it go up and down. Made for a more realistic action.

Avaiojet

They will eventually leak.

Gotta happen sooner or later.

BobH

My Feedback: (2)

The system that was around years ago was called hydrolock. It was a hybred system that used air on one half and pneumatic on the other half. I still have the cylinder that came with the system.. Never used it.

The good thing about hydrolics is force: you cant compress a liquid, unlike air, so the force generated can be pretty strong for it's volume.
Leaks? We Laff at leaks!..lol

TFF

Leaks can be scale!
Hydralock is what I was remembering. I think it used baby oil for fluid?

vertical grimmace

My Feedback: (1)

http://www.morpower.com.tw/ The compression issue seems like a big one to me. Also, the ability to slow them down and not slam shut so to speak. I have valves on my pnuematic systems, but it would seem the hydraulics would have more muscle.
As far as leaks go, at least you could find them! Definately heavier. Seems like it might be viable for certain applications. I wonder if it would be tough to convert say a set of Robarts to this pump?

geezeraviation

My Feedback: (3)

TFF I have three of the air over hydraulic cyllinders in a drawer here that we set up in a big Yellow Aircraft P 38 back in the mig 90s they were to be used with Robart retracts and worked OK in testing but used the same fittings and hoses that the air side of the system used and they did leak. Not gushing but constant seepage so we took em out and they been in that drawer for 17 years. Any body wants em just ask and Pm me your addy.
Doc

vertical grimmace

My Feedback: (1)

Well it seems like leakage could be solved with a certain fitting maybe. Possibly a Festo? I would think there would be a way to solve that. Maybe not worth it though.

CK1

My Feedback: (60)

I would skip the hyraulics and go with electronic . I have found that Down and Locked systems are hard to beat . No leaks of any kind ..........

BobH

My Feedback: (2)

I just reread my post only to discover that I sounded.. dumb! lol.. I ment to say that one half of the system was air and the other half liquid.

Yes I think they did use some kind of light oil for the hydraulic part. You even got a little plastic fill bottle with the system.

Scale Specialties

Euro Kit makes hydraulic systems dedicated for 3 or 2 gear retracts. They are an Italian company, but I don't believe they have a US distributor any longer. I have one of their systems and it indeed uses Festo conectors. The jet guys use them with some frequency and I believe the CARF Corsair uses it for the wing fold mechanism.

thisoldman

My Feedback: (29)

hey if you still have the gear you was talking about hydralics. ill take them.. going to change up my system and would like to try them..
tks.

al

geezeraviation

My Feedback: (3)

What I have are three cyllinders that you use with your retracts. PM me your e-mail addy and I'll send you a picture of them. If you can use them you're welcome to them if you cant I'd rather not waste the postage.
Doc

dadragon

euro kit makes the system but UHM technoligies ltd.in india has the same stuff for half the price.and it is all hydolic to the cylinders,with a brain box witch controls the whole unit.I am putting one in my 1/4 scale AD-1 skyraider.150".

cgrcjet

Have any links for the company in India?

thanks
chris

cocobear

My Feedback: (2)

Imagine a wooden built up wing filled with oil. Yuck!

geezeraviation

My Feedback: (3)

Or any wing!

Lnewqban

http://www.umstech.in/view_products....anding%20Gears

http://www.umstech.in/admin/Uploads/...lic_2-gear.pdf

cgrcjet

Thanks Lnewqban. Im in the plug process of doing a 1/7.1 scale A-10. I will be casting my own struts from aluminum alloy and i want the gear to work like the real A-10. I think with the stronger application of hydraulic cylinders over pnuematic, will be good for this setup. I will have to look for new cylinders for a scale look, but im sure i can use the system that powers there retracts.

thanks again
chris

invertmast

My Feedback: (23)

I'll probably be using a Couple of hydraulic systems in my F-14 Tomcat.
1 for the Landing gear and the Landing Gear doors ( all 12 of them)
1 for the leading edge slats and for the Speed brakes
1 for the refueling probe, canopy and wheel brakes

And possibly an emergency Air powered "blow-down" circuit for the landing gear..



Ok, not really (on the air powered blow down circuit), but i had you going!

LesUyeda

And since oil is a lot more dense that air, it is a lot easier to prevent leaks.

Les