I am building a Skymaster L-39, and I am looking for a door sequencer that will open doors drop gear close doors, then ,, open doors retract gear the close doors. All doors and gear will be air operated.

which brand will work for the functions I need?


Mark

Hi.

If you like using pneumatic valve, then the Ultra Precision UP2 valve is the way to go. I used it and it worked
flawlessly. However, the only draw back of it, is that you will have to spend some time tuning the delay
time between doors open and doors close to allow for the gears to retracts fully.

See todd at dreamworks

Or Tom Cook at Jet model products or Bob Violett at BVM. Both sell good sequencers.

I already have the Jet tronics door sequencer.... I have never had doors on the gear before, is the Jet Tronics brand popular? or would it be easier to go with the UP 2?

used the one Todd sells on my F16 works great
air power AP-EVSQ 69.99 it has the features you're looking for

The UP 2 works fine but it will take some patience to get it right. I have had some that I never could get right and some that worked great.

I am in the same situation as you Mark, Just got a Fei bao f-5 1/7th scale, never had a plane that had functional gear doors. I got the jet thru global so it has air cylinders already installed. They did a great job on the jet. I may take the doors off temporarily just to get it flying and then go back and start messing with them!

Hi,

I think the Ultra Precision valves are the best.

hi , look at the new one from detail4scale , i think i will try this one for my airworld l-39 .
Isaac

Why not go with your Jetronics sequencer, even I can programme one (F16), works fine, easy to set up, Gary.

I use the Mini Hobby electronic sequencer in combination with two Robart/BV valves and mini servos. Easy to set up and very reliable. I also like the option of being able to physically move the valves independently (without the radio on) to open/close the doors and gear. Makes adjustments, transportaton, troubleshooting, etc. much easier.

Craig

http://www.minihobby.com/electronics/mhgdc.htm

Hi Mark

I've got the EV5UPRO 5 function valve, works really well and keeps the installation nice and clean. I use these and the standard valves on most of my builds. I did have a few problems recently but the product support is excellent.

Ive used the UP valves and have found these to be good especially if your wanting something less expensive. Talking of Ultra precision I'm a real fan of their air rams. I normally replace all the rams supplied in kits with these. Their action is really smooth and they tend to work better at lower pressures.

Alex

Mark
It's a NO Brainer...... Just go with the Jet Model Products sequencer .. two small servos and his small values both easy to set up or the UP 2 value ..... NO BLACK MAGIC Boxes ... Look at the B*tches on the rcu forum about the electronic sequencers . JMO... BTW ... Hope you don't have to go out in the snow this weekend ,& Merry Christmas ....
Semper Fi
Joe

if you have the room, I agree with the JMP sequencer. Just installed one on my new Firebird, along with Tamjets Gear Failsafe. Nothing to program except the failsafe pressure setting on Tam's unit. On Tom Cooks unit, all you do is flip two dip switches, one for gear doors closed after gear down, or gear doors open, and the other sets the gear door delay at 3 or 5 seconds......Seeeemple!

It does require 2 servos and 2 gas valves, but takes up less footprint than the EV units.......Tom's gas valves pass more than enough air to operate his humungous cylinders on the Firebird's retracts.

UP-6 or Smooth Stop II for proportional brakes........

I agree with YellowAircraft, the UP-2 valve would work just fine. I've used them for years and have never had a problem with the factory settings on the needles, plus it's just a single servo operated valve.It takes all the guess work out of setting the airplane up.

Mark, I have a JMP Hustler that uses the UP 2 Valve and it works great. When I purchased the Aircraft it had the JMP door sequencer. In fact, I have the whole airsystem with door valves and fill valves with a gauge. I have it if you want it. I make you a great deal. Give me a call.

Dennis

918-269-3594

used a jomar sequencer w 2 servos & 2 robart valves on my P-47; works fine. the jomar has several dip switches for various functions.

On the subject of sequencers, is there a fitting out there that when connected will allow air to pass, and when disconnected, seal off any air from escaping? ie. a check valve of sorts. I have an F86 and need to have the wheels down (inner fuse doors closed) to remove the wings. Problem is that my nose gear remains down and I would like to retract it for transportation. I see a couple options, one is to carriy long air lines connecting the wing to the fuse so that the wings can be slid out far enough to retract the gear before disconnecting the airlines. Not desirable, as then I have extra line that I'm sure will get kinked as it's pushed into the fuse at assembly. The other option is to trap the air in the system when the air lines are disconnect between the wing and the fuse, then the nose gear (and inner main doors) will continue to work as a closed circuit. Any thoughts on this?

BTW, Tom, nice install. Is that CF plate actual CF (ie. Dragon Plate) or is it the simulated plastic sheet you can get? Looks nice.

Robart Airline Quick-Disconnects with Checkvalve
Shut-off Disconnects - Keeps Air In System
RB-193 $19.95
dream works

Hi Sean,

K12rc has it on the nose. I use them on the airline connects to the speedbrake on my F-15, keeps air pressure in the system which is convenient since the top hatch containing the brake has to be removed each flight.

Dave

Sean, the C/F is real and is a sanwich of top and bottom C/F with plywood in between. It is very thin and lightweight, but very strong. Total thickness of the boards is about 2.5mm.

Tom Cook uses loads of C/F throughout the Firebird fuse, gear mounts, and radio and servo mounting boards. While I have not yet flown the FB, all ground range checks are excellent in all 4 quadrants, despite the use of C/F.

Tom i have to disagree with you, i have a EV5 and i have built a Firebird and the EV5 has a smaller foot print than the three valves and servos that are installed in the Firebird.

I would suggest a UP2 for simplicity and cost or a EV5 for a complete package.


Alan

You are sort of right about the size Alan...all depends on orientation, length of pushrods, air-line exit directions, etc.........I have an EV-5, as well as using UP-2, UP-3, and UP-6 dating back to 1999......but I still have a sweet spot for Tom Cook's and UP's simple, reliable stuff as it has provided absolutely foolproof, never-fail service over the years. Everything else I have used at various times including JetCat sequencer, JetCat Electronic valves for retracts and brakes, EV-5, Original PowerBox, Emcotec Powerbox have all failed at one time or another and one of my recurrent going-postal scenarios is replacing gear doors and repainting fuses, or more major repairs when that happens. Before going 2.4, I was on the Ham Bands, and whenever I got the 50 Mhz TX antenna too close to a JetCat sequencer, it would wipe out the volatile memory and usually fold up the gear.....[:@]

My FB was built and painted by Kirk Jensen and came pre-packaged with almost all of stuffing stuff for me to install.......otherwise, I probably would have gone the KISS route with a UP-2/UP-6/Tamjet FS, which is what I have on my Bandit.

I've mostly used a UP2 valve and have had excellent results when using high quality door cylinders and retracts. However, when using lesser quality cylinders/retracts, leaks in the cylinders can prevent the backpressure buildup required to shift the spool valve in the UP. As such, I'd be inclined to go with the two valves/servos and a sequencer. As CraigG said, having the ability to manually move the valves for access/troubleshooting/maintenance is handy.

Regards,

Jim