Where Can I Find an Aluminum Hydraulic Cylinder?

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Goatherder

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Nov 13, 2013
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Olympia WA / Itajai, Brasil
Looking for an aluminum hydraulic cylinder with which to actuate nose gear on my canard project. Need 1.5-2" bore size and 8" travel, suitable for 1000psi. Any leads or ideas would be appreciated.
 

Head in the clouds

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Looking for an aluminum hydraulic cylinder with which to actuate nose gear on my canard project. Need 1.5-2" bore size and 8" travel, suitable for 1000psi. Any leads or ideas would be appreciated.
That's one hell of a lot of actuating force, up around 3000lbs at max pressure ...! Is this a B52 canard?

Seriously though, it's very unlikely you'll find just exactly what you're looking for. Most hydraulic cylinders are custom made for the job at hand. In any case you'd be needing a double-acting cylinder, making it all the harder to find exactly what you need.

What kind of pump will you be driving it with?

Have you considered an electric linear actuator? They're so much simpler and lighter, and easy to get the length of travel you require. Unfortunately they make emergency manual gear deployment rather more difficult though, unless you can remove a lock-pin and have the gear drop down due to gravity or slipstream.

Regarding the actuating force, you ought to be able to balance the up/down load by a number of means, counter-balance weights if necessary, springs preferably, and/or using the slipstream. The actuating force shouldn't really exceed about 50-60lbs in a well designed system, assuming we're talking about a small two-seater.

If you're set on hydraulics, I'd urge caution in designing around an aly cylinder, as soon as you introduce a steel (or worse still, stainless steel) piston rod you'll be inviting all sorts of corrosion problems for your cylinder. If you do use aly then don't use brake fluid (it's hygroscopic), use transmission fluid instead and select suitable O rings.

A very light and durable cylinder can be fabricated using a length of CRMO tubing, machined end-caps and external draw-bolts, a bit like the grey/white cylinder in the centre of the picture below. It's my throttle cable splitter not a hydraulic cylinder, but shows the general idea of external draw-bolts.

Hope it helps.

SDC11136.jpg
 

Goatherder

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Nov 13, 2013
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Olympia WA / Itajai, Brasil
C'mon guys, I've looked in all the obvious places.

Many canards use an electric nose lift made from a linear actuator...but I have hydraulic main gear so the power source is already on board. Obviously I could have something custom made...but I'll just use a readily available steel cylinder and eat the 5 lb weight penalty before I spend a fortune... or do a bunch of over-thinkage.

Then again...I do have a lathe and a TIG welder, so maybe I could build one.
 

Richard Schubert

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Feb 5, 2009
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Pittsburgh, PA
My E-racer used a cylinder from a Cessna gear door to actuate the nose wheel, I removed it for an electric system...

I don't remember the part number, but there are a few of them around due to Cessna owners removing the gear doors.
 

Doggzilla

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Jun 2, 2013
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Everywhere USA
Many Canards use servo tabs. You control a tab on the control surface that pushes the control surface using the airflow. It works with up to about 150 tons and 300mph, so any GA aircraft should be fine.
 
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