robart-joe

Speaking for robart only, in the past years, we only tested a percentage of air tanks. A year and a half ago we switched to 100% leak checking every tank. This has drastically improved our quality. As for valves and other air accessories, they have always been 100% tested.

It is good practice to lube o-rings as they dry out over time based on environment and cycles. Robart sells rebuild kits that include o-rings and grease. Oil is not recommenced as it will attract dirt. Care should be given anytime a valve or cylinder is disassembled as a small cut can cause leaks.

And last, most retract systems are not closed loop systems. This means the system operates at a loss every time they cycle. (Air is never put back into the tank as the pressure is always highest in the tank and vented out of the valve upon cycling.

Ozmodeller

Guys
Thanks for taking the time to assist with my request, some very useful tips that I will certainly employ with my T33 retracts. Regarding lubricating the pistons, do you disassemble them to carry out the procedure or do you inject oil into them from the fill valves, also what do use as a lubricant?

Again thanks for the advice.

Regards
Peter

rcjets_63

My Feedback: (4)

Hi Art,

I'm glad you found the grouped tank system info handy. I'm sure you'll be happy when you replumb your system.

Just a thought on your use of the UP-2 or UP-3 for the retracts/doors. A UP-2 (doors open - gear moves - doors close) is more scale than a UP-3 (doors stay open when gear is down) so you probably have a UP-2. I believe UltraPrecision makes great products, and I used a UP-2 for many years. A few years ago, I switched my Gripen to have individual servos and valves with a sequencer to control the gear and doors. The reason for the change was that there are times when performing maintenance that it was really handy to be able to leave the doors open and I would recommend this to you. RCBee makes a great sequencer (available from DreamWorks) that is quite inexpensive.

Glad to hear you figured out your voltage issue. Nope, I didn't find the leak in Jason's system at the JWM. He was working with Scott and they figured out a temporary solution to do the third flight, I believe, until he could get the bird home and find the root cause of the problem.

It was great seeing you and Barbara in Switzerland.

Regards,

Jim

Jetflyer3000

The best fill valve you will ever find is a car tyre valve. Just remove the rubber with a knife and solder a nipple into the end to connect the air line to. These are the best fill valve you will ever find and tyre places will often give you a handful free when you next buy new tyres for your car. If not just ask to buy a few.

Easy to connect to most air pumps (as we generally use car tyre pumps) and leak free.

Also the air kit you get with a FB plane is fine to use. Why people advise throwing perfectly good kit away is a constant source of amusement to me in these forums

Countryboy

My Feedback: (25)

Can't add much to what has already been said here except, if using soldered metal tee's make sure to run a sized drill bit through the tee . I have found after the fact that the solder has blocked one of the ports, which caused me a lot of grief & head scratching .

tp777fo

My Feedback: (28)

Clippard.com has great connectors. T-22-2-PKG (tees), X22-202-PKG (4 way), C22-PKG (connectors)

warbird_1

My Feedback: (61)

Being new to air retracts i'd say .... keep it simple .. i have seen many people get frustrated over air systems because they don't work, then i look at what they have and the install job they did and see why they have problems . i've been using air retracts for over twenty years and have about 5 problems in all that time. and one was my fault. " i pinched a loose airline in between a former and the wing. I don't use robart airline because in my experience it loses is elasticity in a short time and then starts bleeding air. i like the stuff from dreamworks . it holds tight and i have no problems. Another thing is ... i stay away from century jet retracts . i've owned a few sets and i hate them . robart is the only way to go for me. i can get parts and they don't fall apart . CJ retracts use a high strength loctite to glue there stuff together and it just doesn't work well. another thing is make sure you have more air than you need like a big enough airtank(s) to cycle the gear a few times. stay away from fancy stuff like gear safe and things like that . The more links you add to a chain ,the weaker it becomes.keep it simple. i use 110 psi in everything . good luck to ya. WB_1

Art ARRO

My Feedback: (5)

Jim and All,
Note that David Gladwin described an "Emergency Landing Gear Extension" solution in the AUG/SEP 2012 issue of RCJI magazine.
He uses a micro air switch and 1-way valve with a standby tank for a single shot "blow down" of the retracts and doors. The system is cleverly actuated by a mix of your retract servo which is switch-actuated on the transmitter. Seems like it would work just fine.
Also, I've found that the Ultra Precision Valves work better with a servo-slow function mixed into the retract channel- about 1-2 seconds is a good start point. Finally, good airline is mandatory and I've had good results with the stuff from BVM. The worst airline was from B&D Retracts followed by Robart.

Art ARRO