hydraulic retracts
 

has anyone any experience in converting air retracts to hydraulic. i'm thinking of using jet fuelpump as the hydraulic motor and controlling with Arduino micro controller. Anyone interested in the idea. One thing that irritates me with air retracts is the lack of control. it's either bang up or bang down.

RE: hydraulic retracts
 

There are a lot of details in the jet legend mig-29 thread about converting air to hydraulic. Go take a look using the search function

RE: hydraulic retracts
 

Save your time and frustration.........just go electric

RE: hydraulic retracts
 

Already played with electrics. Just think running fluid at 100psi would give a much smother travel and would be fairly easy to convert. Have surfed for some info but i run on a budget so can't go for these expensive systems.

RE: hydraulic retracts
 

Been using hydraulics for years. The latest conversion is to my Skymaster A10. I can't see myself going any other way now. Same speed up and down no leaks just brilliant.

m

RE: hydraulic retracts
 

Mick will you share your designs.

RE: hydraulic retracts
 

Of course I'm not a million miles from you, live in Southend

RE: hydraulic retracts
 

i played with the hobby king hydraulic system and it works good ,i think it is priced right for what you get

RE: hydraulic retracts
 

http://www.hobbyking.com/hobbyking/s...Retracts_.html

RE: hydraulic retracts
 

The Hobby King hydraulic retracts are made by UMS, of India. I have used this system on my Mig 29 and have now got them installed on my FB15E twin. It works well, is not very heavy. Many people see electric retracts as the way to go but my flying buddy has had nothing but trouble with his Lado retracts. He has had as many wheel up landings as good ones due to jamming and stalling of the electric motor. Give hydraulics a go.




John

RE: hydraulic retracts
 

The system say's for two gear only. What are you doing to operate three gears. Is it just a matter of T-ing the nose leg into the system.

RE: hydraulic retracts
 

mustang 493

Take a look here      http://umstech.in/view_product_detai...anding%20Gears

Regards
Dragan

RE: hydraulic retracts
 

Yep, just use a T union and add a 3rd. The Hydraulic oil is obviously denser than air so it won't leak even if you use robart rams etc! I just use Dot4 brake fluid and haven't had any trouble yet!

RE: hydraulic retracts
 

Thinking of converting AeroWorks P51 to hydraulic would this be a good idea using their gear?

RE: hydraulic retracts
 

Yes I'm going to build a hydraulic system. Having looked at the umstech gear I think an improvement wouldbe a pressure sensor to tell the control when the gear is up or down. I've found a cheap source of micro pumps in china so hope to be able to build a tri gear system for under £60.00. I know that makes no sense when you can buy it for £70.00 but it's the challenge. I think it would be interesting to incorporate brakes and air brakes into the design. Thanks Dragan, john and Mick for your replies.

RE: hydraulic retracts
 

Hi Guys,

Given the price on the HK unit, I'm going to order one and give it a go. Has anyone tried using this setup in conjunction with JetTronic valves and, if so, did it work out okay?

Thanks,
Garrett

RE: hydraulic retracts
 

I've used jet tronic valves to control the gear doors. I've also used program mixes in my tx. For the hydraulic control I am using the UMS controller, which senses electrical load. I have also used micro switches in the past. I know Mick uses hydraulic control on his doors as well. No more coming open under high g loads.


John

RE: hydraulic retracts
 

<div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: rgb(255, 255, 255); font-family: Arial; font-size: 12px; -webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); ">Just ordered HK hydraulic system,  no point reinventing the wheel.  Mick if you're reading this do you build your own rams for gear doors etc?</div>

RE: hydraulic retracts
 

No I have used the originals. I think you may find 3mm lines for the gear too small, mine are all 4mm.

m

RE: hydraulic retracts
 

How do you address the problem of removing the wing and disconnecting the gear lines??
Thanks,
Vin...

RE: hydraulic retracts
 

Garrett,

I've got a UMS hyd unit here if you want it.

Let me know.

RE: hydraulic retracts
 

Wing removal is not a problem, you can fit self seal festos (QSK4). Or make sure the pressure is zero and just disconnect, you get almost no fluid loss. Furthermore the system does not need bleeding.

m

RE: hydraulic retracts
 

Here is a video of my A10, about half way through you can see the gear operation and how the transit speeds are similar.

http://youtu.be/-KNPjkWOVPU

m

RE: hydraulic retracts
 

Why does the system not need bleeding, where does the air go??
Vin...

RE: hydraulic retracts
 

Some air in the system has no effect, if the volume of the cylinder is greater than the volume of the pipe it will bleed itself.

m