FenderBean

I need these for gear door sequencing only, will the gear door side work if im not using the landing gear side? My gear will be electric so no airlines to run for the gear up/down plugs.

The f-15 has three doors and two that close once gear is down. If there is another way to skin this cat let me know. Thanks

stevekott

I have the UP-2 on my F-5. It's basically a valve with two completely separate circuits. It seems they both switch on and off at the same time and then the way you control the sequencing time is to control the exhaust rate. They do share the same air supply input so if you are not going to use other side of the valve you may need to just plug the cylinder outputs. If you were just using it for doors you could have 2 seperate door circuits sequenced by controlling their respective exhaust ports.

I don't think you could use it by itself to close one set of doors after the gear is down while leaving the other set open. Both circuits are either opened or closed with a adjustable time delay but they operate at the same time.

One way to sequence doors and gear is to put them on seperate RC Channels and then let your TX do the work. On the Futaba you slow down the servos to your complete cycle time and use the AFR or a programmed mix to tell the doors when to open or close with respect to the gear.

Hope that helps.
Steve

mr_matt

My Feedback: (10)

The UP valves door circuit sense when the gear has stopped moving (with some sort of internal shuttle valve I suppose), so I don't think they will work if no gear cylinders are installed.

I would do this with 2 separate servos/ air valves and a sequencer, either in the TX or on the plane.

None of these set ups are ideal as they cant sense if the gear is really up or down. Now with these electric gear the cycle times have gotten crazy long, even more chance for something to get out of sequence in an open loop system.

FenderBean

yeah thats what i figured [:'(] so I will save myself the hassle and just get two small reg robart valves and see if I can do some 18mz programming magic. I also ordered another button valve, should be able to rig something so when the gear is down it hits the button valve which closes the required doors. This is how I do my canopy locks to prevent need another 2way valve just to lock. I post the final outcome in my build thread thanks for the help, if it doesnt work out im throwing 7 micro servos on the doors and being done with it

mr_matt

My Feedback: (10)

that button deal has worked better for some that others. The trick is to have a method that maintains the door open UNDER CYLINDER PRESSURE (or at least with a spring) while the gear is moving and then release "door open" pressure and applies "door closed" pressure when the button is pressed. The only buttons I have seen are single action, so they can't do both.

If you don't have positive cylinder (or spring) pressure holding the door open at all times the door can blow closed when the gear start to retract but have not yet pressed the door closed button. Works fine on the ground then hangs up in the air. Having said that some guys get lucky and it works, some it does not.


Door servos can work but require delicate set up. Now days, doors can be held closed with rare earth magnets, so servo set ups are less critical. Plus you have so many channels now, and channel expanders, throw adjustors etc. it might be a better way to go.

stevekott

If you are using the 18MZ and you have 3 seperate channels for the Gear, Open-Open doors and Open-Closed doors You've got it Made.

You program 3 channels activated with the same switch. Then you slow the travel of each of them down to say 10 seconds to cover the whole travel. Then in the AFR (Advanced Function Rates) in the Model Menu you select "Line" that allows you to select a line like an xy graph where you can pick where you want your servo to be at any one point during that 10 second sweep.

It's confusing at first but once you've played with you will never use a sequencer again. When you are playing with it and setting up you can assign one of your knobs instead of a switch so you can experiment with your timing and not accidentaly crash your gear into a closed door (learned the hard way) another good thing to use is the servo monitor in the model functions. Then you can get all the timing worked out without even turning on the plane.

I'm having the Same problem Matt is describing above with the Doors Blowing shut before the gear retracts on my SM F-5 . That's using the UP-3 Type valve controlling the exhausts. I'll be working on that soon.

I use this Transmitter control method on my SM F-18 and it works great everytime. Like Matt pointed out it has the advantage of having full air pressure on the doors until the servo tells them to close.

Here's a link where it was done on a 14MZ. He uses a Programmed Mix instead of a single switch and the AFR function .. Two different ways of doing the same thing but it shows how the Line function works.

downloads.hobbico.com/misc/fut/team-tip-009-gear-door-sequencing.pdf

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bchapman

I have a T-34 that uses the UP4 and UP2 valves. The main gear door close when the gear is down, but the nose gear doors remain open.

Just hook it us per the instructions, except on the gear circuits, loop them together. Up signal to Up signal, Down signal to Down signal, for all three gear. I would try to regulate the retraction speed of the doors and gear until you find one that works. You have quite a bit of adjustments built into the valves, not including the electric gear as well.

shepp

fender,
I have used both and I dont see why they wont work with the gear ports plugged. Although the up4/ up2 works , I found the timing was a little tricky and I had problems with the nose door not clearing .So I went with regular robart variable valves and the jetsonic sequencer. I would think this might resolve your problem with a electric/pneumatic hybrid. The timing with the jetsonic sequencer is quite broad and should do the job. Not familiar with the programing variables on your transmitter. I will talk to Randy tonight as he uses one and is very talented in working out sequencing issues. BTW I understand you are relocating to Clarksville soon. The Nashville Jet Band meets at my Shop on Wednesday nights, and would love to have you join us when you get settled. We are working on new engine installation for Randy,s Turbinator and having funeral services for his F-18 this evening. He is handling the F-18 loss quite well, in fact a lot better than I would. Also I have both of the valves you mentioned in the shop and will be glad to check out their operation this evening.

Shepp

FenderBean

yeah with the electric gear things get tricky because of the delay time on the gear itself. I need to draw everything out on paper and brain storm some.

Pondus

My Feedback: (1)

What about using Lado Edoor actuators? They are fully programmable, setting delay or if they are to stay open or closed is easy to setup if you buy the optional programming card. I am setting up a jet using these together with Electron ER-40's now, and it was pretty easy to get it all to work as desired, I set it up so the main geardoors close again after gear extends while the nose door has to stay open, no need for any sequencers I just spent some time with my Futaba 12FG adjusting the speed of the retract and gear channels and it works like a charm. Only downside to these is they are a bit bulky and large so may not be easy to fit in all jets.

FenderBean

I have considered this as well, its not out the window since it still may be the best solution ans just go all electric since the only things that will be air is the canopy and gear doors.