Best gear fail safe unit
 

Who makes or sells the best stand alone gear fail safe unit?

thanks in advance.

I use Tamjets. Never needed it yet but every time I test it it works well. As for is it the best ! Well I'll let the experts and know alls answer that one.

I've use the tam one and the Dreamworks one, I like the integrated pressure gauge on the DW one but you really need to use an electronic valve with it because it makes servos erratic! The tam one seems to a bit as we'll but it's still usable

as for which is best, they all seem to work so take your pick as far as I know

I use Tamjets. I always end my flying day with my gear retracted to pack away the plane, then the next time I fly I start my day at the field by turning on my receiver first, because the fail safe reads zero PSI it actuates the "gear deployment" servo (no TX required for this check), then as I fill it with air my gear deploys. This is my Tam fail-safe pre-flight check, I deploy my gear like this every time & have never had a gear up landing.
good luck, Jay

I use 42% scale. It has a digital pressure readout.

In my case, it has saved my Bandit so many times. Worked every time. I was using EZ Air fttings for mains, everytime I pulled high G's they would leak. Took me a while to find out, in the mean time the failsafe worked perfectly!

'42-Percent Products' is now 'Take Control Hobbies'. Just realized it looks like they were bought.
I use the 'Air-Jockey'. Has worked good and I like the 3 seven-segment displays for pressure reading.
It has saved my KingCat once so far in 3-years.
http://www.takecontrolhobbies.com/air-jockey/

Tom

How do you guys make them work with a separate servo or controller for doors. Need doors to open first. .?

Use a gear sequencer.

I have an EV5 from Dreamworks in my Hawk. If you want door sequencing and proportional brakes with two air bottles and digital readouts it is a handy device. On my Electra and UF I use the Robart one. it is an excellent unit in my opinion. There is an optional digital readout for it but you can count its flashes to tell you the psi. That one drives a servo to operate an air valve and in both cases I also use the same servo for brakes. I have no idea if they are the "best" but they both work.

Hi,

Is the DW failsafe still offered? I don't see it on the site.

IMO, Tam is hands down the best for mechanical setups. Although the DW one is really nice, it does not work well with servo throw ATV's dialed down to 50/65.

Rex

+1

I had a jet with a known but unfixable (by me) air leak in one of the cylinders and I really wanted to fly. It may not have been the smartest decision but I flew 3 or 4 times, relying on the Tams unit to extend the gear when the pressure reached 50lbs. It worked every time.

I've since fixed the problem but it gave me great confidence in the Tams fail safe.

Craig

The best gear failsafe is an alternative extension system, good enough for so many fullsize jets, (Like the F4) and SO easy to incorporate in models. Simpler, cheaper and puts YOU in control of your gear if you have a leak, not something dropping the gear at 200 mph with no warning. Details were published in RCJI some months ago.Fire away !

David G.

Dave is there any links on this ? Sounds like a very good idea.

Shaun, just sent you a PM.

Jerry

I have a DW fail safe unit. I have used it on my UB and find that the servos tend to jitter and this is a known issue since long. This makes me a bit nervous and I have removed it since then. I have seen David Gladwin's method and thats very impressive indeed. Never used it but plan to use it on my upcoming futura. I am looking for a unit for the UB... maybe Tam is the answer.

I wrote it up for RCJI about a year ago.

To be clear, I am sure the Tamjets is an excellent unit and works very well for many people. However, for my big SkyGate Hawk with huge doors I don't want a possible uncommanded gear extension, possibly at high speed, ripping off the very large doors with perhaps a large pitch change at an inopportune time.

One of the first jets I flew, the Jet Provost and several other military jets such as the F4, extend the gear using compressed air in the event of hyd. failure to blow the gear down.

On my model system I do the same. The alternate air supply is the brake tank (or another dedicated tank in my Hawk which has the space) This air is supplied to the gear valve ONLY when the gear is selected down in emergency mode, it otherwise remains isolated from the system, protecting it from leaks. To achieve this a mixer is arranged on the Tx mixing gear to gear so that when the gear is selected down, activating the mixer causes the gear valve servo to overtravel slightly and open the air micro switch directing reserve air to the gear system. This air cannot dump into the main air tank because a Clippard one way valve is installed in the main air tank delivery line. I will also have a backup air supply to this backup using compressor bleed air from the Olympus. This pressure will be only about 40 psi but this should be enough to extend the gear and get the downlocks into position.

If you are using an electronic gear valve one can simple Y a small servo into the gear cable to operate the air micro switch if and when needed.

As the leak will have occurred when the gear is UP, this should result in gear extension.

The drill is simple. Extend gear, if nothing happens due air leak, wait until all sequencing timing is complete. Then select gear DOWN and immediately activate the mixer, gear should then extend on alternate air.

It may sound complex but in fact is very simple to install and operate. I have extensively tested it and it works perfectly

I am currently refining the hyd. system on my FC Mig 29 (about to be powered by the new JetCat 140 RXI, making engine installation so simple) Although the system has two hydraulic pumps ( a Hausl and a UMS) operating in parallel at 10 bar but isolated from each other by NRVs , I am working on an emergency system which will blow the gear down in the unlikely event of a total hydraulic failure. If I can get it to work I will pass on the details.

David G.

Thanks for the info David.