RCU Forums

RCU Forums (https://www.rcuniverse.com/forum/)
-   RC Jets (https://www.rcuniverse.com/forum/rc-jets-120/)
-   -   Braking with Elevators Set up (https://www.rcuniverse.com/forum/rc-jets-120/11675212-braking-elevators-set-up.html)

CARS II 02-12-2020 02:06 PM

Braking with Elevators Set up
 
Last year at BITW ( can't wait to go back ) I was told by my good friend Alaska Bob to set up my jet's brakes using Elevator control, doing so I don't have to move my right hand to reach for the right slider and could concentrate on directional control on landings.

I know how to do the mixes but, I decided to do a search to read other jet flyers opinions, I found the info on a thread asking the same question answered by no other than Todd W. still getting help from him even though he is no longer with us.

I also like to hear your opinions about using braking with the Elevator on TO and Lan.

Tks.
https://cimg8.ibsrv.net/gimg/www.rcu...9d6fdd766.jpeg
https://cimg5.ibsrv.net/gimg/www.rcu...e698ed088b.png

BarracudaHockey 02-12-2020 02:42 PM

Not sure with that radio but on Spektrum and CORE I setup a mix controlled by a switch that turns the mix off with the gear up, then from mid elevator to full down progressively applies the brakes until full brakes are full down elevator. I don't like taking my fingers off the primary sticks when landing and looking for a button or slider.

camss69 02-12-2020 02:51 PM


Originally Posted by BarracudaHockey (Post 12582706)
Not sure with that radio but on Spektrum and CORE I setup a mix controlled by a switch that turns the mix off with the gear up, then from mid elevator to full down progressively applies the brakes until full brakes are full down elevator. I don't like taking my fingers off the primary sticks when landing and looking for a button or slider.

Mine are the same way, I have a mix that disables when the gear are up. When the gear are down mid-stick is no brakes, full down elevator is full brakes. The only problem with this is if you really have to get on the brakes, you are probably moving pretty fast still which means down elevator could be lifting the rear tires, the ones that are supposed to be doing the braking.

Thud_Driver 02-12-2020 03:16 PM

For me, to do justice with a slider for brakes, I have to let go the stick and use 2 fingers. I hate it.

Use a curve mix to set it up. Use the gear switch to turn it on and off. Mix elevator to the brake channel. No trim, no includes no D/R or Expo, etc. Set the curve points on the Up elevator side to -100% (full off). Set the first point past neutral on the Down elevator side to -100%. Ramp the remaining points up to +100% or to wherever it makes sense. You'll have to adjust the mix to work whatever your brake device is correctly. You may want to ramp up from elevator neutral depending on the feel you want. Depending on the brake unit, It may only have to be somewhat negative on the Up side of the mix.

Devices like Jetronics valves can be set so they engage with slight down elevator and full on just before full down. You can adjust the curve mix accordingly.

You want some leeway on the down elevator side without engaging the brakes so that you can release the stick to neutral after touchdown then push into the braking. Or, to not use air in the traffic pattern if air based brakes. For me it has a comfortable, natural feel to it. No fumbling around, full control of the jet.

I've done literally thousands of landings with down elevator brakes and all the bad things people tell you will happen don't.

CARS II 02-12-2020 04:03 PM

Thank you for sharing your experiences on the subject, very much appreciated.

Agrav8ed 02-12-2020 04:23 PM

What about programming in a intermittent mix similar to anti lock brakes on a car? That way full breaks could be applied without fear of flat spots on the tires. I have it mixed I to my electric brakes. I believe the same thing can be done on air brakes with a flutter valve.
Tone

CARS II 02-12-2020 04:26 PM

I just completed the braking via the Elevators set up on my Boomer and it end up kind of proportional, the brakes comes on on the last 20% of the down Elevator which is what I wanted, I wanted them to give me drag to slow down only, I understand it is bleeding air when the brakes are applied but it isn't much and the brakes are effective all the way down to 10% of air remaining in the tank.

Perfect, can't wait to try them tomorrow :)

ps: The brakes are on chl 5 in order to have access to the right slider on this radio, gear is on chl 10.
https://cimg9.ibsrv.net/gimg/www.rcu...35d47eeb18.jpg
https://cimg4.ibsrv.net/gimg/www.rcu...555099a486.png

RCISFUN 02-12-2020 04:56 PM

On my Jeti, I set up a brake mix with the application of down elevator, I use my retract switch to turn off the mix when the gear are up, it also shuts off nose wheel steering…

Auburn02 02-13-2020 06:23 AM


Originally Posted by camss69 (Post 12582709)
The only problem with this is if you really have to get on the brakes, you are probably moving pretty fast still which means down elevator could be lifting the rear tires, the ones that are supposed to be doing the braking.

This is the problem I ran into on one of my jets. My little BVM F-86 lands hot and if I want to get on the brakes good it will get real light on the mains and end up unstable and scraping a wingtip. I switched that one to a slider and can hold full back elevator and apply brakes and haven't scraped a tip since. My other jets don't have this issue so I have brakes on down elevator and can go full down with no adverse affect if needed. Really wish I could settle on one or the other for all planes. Would prefer to be on elevator for all the common reasons mentioned.

Len Todd 02-13-2020 06:54 AM

I used to have the brakes on the elevator stick. But that just contributed to poor braking on both my faster jets with electric brakes. It did work O.K. on the Sprint with air brakes, but I took the Sprint's brakes off the elev stick to keep all the jets the same. Ultimately with the elevator down, the plane ends up with extra pressure on the nose wheel. Then, the mains are light causing premature skidding. Also, the nose wheel "wheel-borrows" into any crack or depression. With EBrakes and LGC 15s, I have them set so that I just move the slider fully and the brakes are set to slow the plane down. The LGC 15 has ABS, proportional braking and the gyro keeps it going straight using the nose wheel and the brakes. It actually uses the brakes to steer the plane straight. It also has independent power adjustments to each brake, just in case one brake tends to pull a bit more than the other. Once I got things adjusted, I just push the slider fully up and the plane does the rest. Shortened my rollouts by at least 60%!

camss69 02-13-2020 08:19 AM


Originally Posted by Len Todd (Post 12582828)
I used to have the brakes on the elevator stick. But that just contributed to poor braking on both my faster jets with electric brakes. It did work O.K. on the Sprint with air brakes, but I took the Sprint's brakes off the elev stick to keep all the jets the same. Ultimately with the elevator down, the plane ends up with extra pressure on the nose wheel. Then, the mains are light causing premature skidding. Also, the nose wheel "wheel-borrows" into any crack or depression. With EBrakes and LGC 15s, I have them set so that I just move the slider fully and the brakes are set to slow the plane down. The LGC 15 has ABS, proportional braking and the gyro keeps it going straight using the nose wheel and the brakes. It actually uses the brakes to steer the plane straight. It also has independent power adjustments to each brake, just in case one brake tends to pull a bit more than the other. Once I got things adjusted, I just push the slider fully up and the plane does the rest. Shortened my rollouts by at least 60%!

This is the way I’m going to go on my next one for sure.

CARS II 02-13-2020 09:28 AM

I'm trying the elevator braking today, if I don't like it then, it will go back to the slider only.

We will see.

Steve Collins 02-13-2020 09:37 AM

I have always used the down elevator to apply brakes. While thinking about this setup and everyones replies, it occurred to me that a partial brake setting could be mixed with full flap so that the plane starts slowing down as soon as the mains kiss the pavement.

gunradd 02-13-2020 10:08 AM

Braking with down elevator is simply not a good way to do it. I have done it back in the day when I had little radios and ran out of channels. I would never do it now with the technology we have now.

cons
1.makes the ass end of the plane lighter that reduces the effectiveness of the brakes.
2. puts lots of pressure on the little nose gear. This makes steering suck and can lead to snapping it if you have a side load and hit a crack.
3. If landing hit the last thing you want is down elevator. This will cause it to bounce causing more damage.
4. it’s a bad habit to cram down elevator when just touching down. Say a gust brings the plane back up while you are moving the stick. All bad.

pros....
1.well it saves a channel.
2. guess it can be easier for some.

tp777fo 02-13-2020 10:15 AM

I prefer down elevator for brake activation.. You have the stick in your fingers when you land and don't have to fumble around feeling for a new one. If you are too fast it doesn't matter which brake switch you use they wont work when there is still lift being produced. Land on speed and in the first third of the runway and your brakes will work with any switch to stop on the runway. Land long and fast and you will be just like full scale landing long and fast off the end of the runway. If your approach isn't right GO AROUND and set up again.

Westwindpilot86 02-13-2020 04:22 PM

I have mine on a slider. I have never owned or flown a jet with elevator being used to brake. With that said.
The main thing I see wrong with using the elevator stick is what if your 3 minutes into your flight and all of a sudden your gear (AIR) come down due to loss of air pressure. You have your gear and your brakes on two different setups (should) but the elevator braking is only activated when gear switch is down. But because you see your gear come down you have a (dumb) moment and say "ok, gear is down, Ill setup for a landing." Upon touchdown you go to apply brakes and you got nothing. You quickly flick your gear switch and you try to brake but it runs off the edge of the runway.

I know its a far-fetched scenario but it very well could happen to anybody running an air system.

Just my 2 cents.

tp777fo 02-13-2020 04:25 PM

Wont happen with me. I plumb brakes into the Down air side. No air used until gear is down.

CARS II 02-13-2020 04:30 PM

Just came back from flying the Boomer, the first landing was done using the elevator/ brakes mix, the jet landed slow, and on the center line, the brakes were applied using full elevator, it took a big effort to push the elevators all the way down ( I never do that ) and had to pay more attention to the elevator instead of keeping attention on the steering, I felt out of place pushing the elevator all the way down.

Conclusion, didn't like it because I had to divert my attention to the braking, when using the slider only, I set it and forget it, my install restricts how much it can be adjusted also, soooooooo, elevators braking is not for me.

The brakes on my Boomer are back as the were.

Tks.

RCFlyerDan 02-13-2020 05:39 PM

I don’t use down elevator for braking for a reason mentioned above about lifting the weight off of the mains. I also think for the less experienced jet pilots that approach too fast, force the landing, apply down elevator and porpoising begins. Once that starts, we all have seen the consequences. Again, IMHO.

causeitflies 02-13-2020 06:39 PM


Originally Posted by CARS II (Post 12582954)
Just came back from flying the Boomer, the first landing was done using the elevator/ brakes mix, the jet landed slow, and on the center line, the brakes were applied using full elevator, it took a big effort to push the elevators all the way down ( I never do that ) and had to pay more attention to the elevator instead of keeping attention on the steering, I felt out of place pushing the elevator all the way down.

Conclusion, didn't like it because I had to divert my attention to the braking, when using the slider only, I set it and forget it, my install restricts how much it can be adjusted also, soooooooo, elevators braking is not for me.

The brakes on my Boomer are back as the were.

Tks.

On the planes I used to use down elevator on I never used full down for brakes. Full brake was reached in about 1/4 down elevator and didn't make the wheels light or put much pressure on the nose. If the plane has trailing link gear they will squat with brakes anyway. While one or two of my jets may still have elevator mixed to brakes, I use a spring loaded switch on all of them and just pulse my finger if needed.

On my Flash, I still had elevator mixed with brakes even though I was using a push button for brakes. After not flying it for a while I made some tweaks and took her to the field a couple days. I noticed the wheels were worn more than I remembered. Well, after about three more flights the mains were almost down to the rims!! What the :confused:?? Yep, somehow I changed my mix and it now had some brake applied with UP elevator. So every time I rotated for take off the brake was applied :o I wondered why I couldn't do wheelies any more :p

CARS II 02-13-2020 08:08 PM

OMG! That is hilarious, can't wait when I get to do something like that :)

Dansy 02-14-2020 05:13 AM

I’m new to jets only 5 or so years flying them.....but I never understood using the elevator for brakes, I’m guessing it come for the DF times when radio didn’t have the slider or the programming to enable it....(don’t know never tried on my older radio)

it doesn’t make sense, because when you hit the brake the planes should have stop flying, so taking your hand off the stick doesn’t really matter....unless your not on mode 2........rudder/steering is the only thing needed.....and throttle to taxi back....

jofunk 02-14-2020 08:59 AM

I have a Boomerang XL. It has a very low landing speed. Higher speed landings with a lot of prolonged down elevator and it will "wheel burrow" , so I just blip the brakes to slow the plane. It works fine.......... Back in the day, the only DF I ever saw with brakes was the Byron F15. By todays standard describing them as cheap would be an understatement. They had plastic drums and shoes with some little aluminum pads. They functioned though....... After a successful flight you were the Jet god at the field. But before the next flight you needed to install some new glow plugs, some tuned pipe couplers, A header O ring, some brake shoes, and couple flat spotted fuel soaked bloated tires, the O rings in the fuel selector valve, and a ripped mylar thrust tube. And don't forget to make sure the head bolts were tight.

causeitflies 02-14-2020 09:20 AM

I never use a slider. I like the feel of a spring like real brakes where you apply and release. Thus the use of elevator or a spring switch.

CARS II 02-14-2020 06:46 PM

The spring loaded switch om my 10CAP I use it for smoke, easy to get from the throttle and I just release it to stop the smoke.

When I started flying jets we were running out of chls all the time, I learned to use a servo for two functions, a good example was the retracts servo, it was also used for the brakes, pushing a spring loaded mini valve like the one I posted earlier, the servo will go over center and since the valve was not been pulled or pushed at that servo arm position, we installed a valve so the servo arm could push it to brake the aircraft, turned on via a different switch mixed to that chl.


All times are GMT -8. The time now is 10:39 AM.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.