sudstad

Thanks Mike!
The Lightning is by far the most complex RC plane I'm attempting... which is the reason for soooo many questions!

EDIT:I'm going to buy a new transmitter. I just want to be sure to get "the right one". I was thinking DX-7 soley because I wanted seven channels. Would anyone recommend a different transmitter for this application? If so, why?

Chris Nicastro

My Feedback: (3)

Sudstad,
Your already invested in Spektrum so its wise to stay within that brand and or JR which is compatible.
Right now the best deal for you and for going forward in your hobby interests is the DX18. Yes its pricy at about $750 but you wont need another radio for years to come. I have one and its great for a lot of complex models and includes an internal sequencer for gear and doors.
I also have been flying a JR XG11 for a few years now and I can tell you while I like the feel of the JR better for the same price the DX18 has more features. The DX18 is getting its first outing in a TF GS P-51D I have so Ill know more about this radio soon. I bought it because of the number of channels and features going forward Im going to need that.
buying a DX9 wouldnt really get you anywhere and the next model is the XG11. So for the same money just get the DX18.
Another option is the XG14 at about $650 and its similar to the XG11 in feel and function.

70 ragtop

My Feedback: (24)

Short flyby video
https://www.youtube.com/watch?v=T4i2mVS-REc

sudstad

Mike... WOW! Flown with BIG BRASS!!!

sudstad

Chris,
I want to keep it as simple as possible...throttle, ail, elev, rudder, flaps and gear. Also, this will likely be my most complex plane I'll ever attempt.

Okay... I admit it... I'm cheap.

Other than the internal sequencer, is there a reason to go with more than the DX-7?

BigTeeEldorado

I keep giving away my 2 cents which is why I am poor and also "cheap". If I could just keep to myself and save all those pennies......yada, yada, yada. Anyway, I own the DX9 and have flown other radios at the field. The DX9 is smaller, it fits my hands nicer and is noticeably lighter and has all the features of the DX18 minus a few channels and switches I know I will never use ever. I think it fits in the category mentioned above of all the radio you will ever need. Yes the 7 seems to fit your needs mathematically but I just finished a 38 with all the features you mention you want and it has:

2 elevator
2 rudder
2 aileron
3 landing gear
3 gear doors
1 steering
1 flap
2 throttle

lets see.....16 servos I needed to plug in somewhere and I wanted to use two batteries to keep the flight surfaces and non flight functions, i.e. gear, doors, steering and flaps on separate switches so that if a gear or door unknowingly jammed in flight and ran down the battery I wouldn't loose flight surfaces. I also wanted to be able to control the throttles individually as well as together on one stick. Now granted the two battery setup added complexity to what I was doing but think through your setup and how many servos your using and how will they function if say steering and rudder are on on the same port. You would lose the ability to trim out ground control without changing rudder trim.

Bottom line....I have a 9 and had to incorporate a matchbox to get everything plugged in and functioning the way I wanted and be able to electronically adjust speed, end points, travel and throw among other things for almost all the servos. Is a 7 going to give you the flexibility you might want/need or are you going to end up wishing for more ports during setup?

Oh and the 9 has the internal sequencer!!

Dang....that's two cents that I could have put in the next project jar!!!

70 ragtop

My Feedback: (24)

If investing in a radio, I would not go less than 9 channels. You can use them up pretty fast

Chris Nicastro

My Feedback: (3)

Yes you can use match boxes and double up on servos and y-harnessing etc but the more you do this the more complex it becomes. You increase the chance of confusion and points of failure.
By buying a radio with more channels you single out functions and have more control directly with the function.
Either way works but you will spend money on accessories that you may as well spend on the radio itself.
Like I said, it will last you many years, buy nice or buy twice!

sudstad

Agreed.

As I’d said, this will be my most complex aircraft... ever.
That said, can I use a 9 channel radio with Y-cables for the rudders, elevator, gear, gear doors, ailerons and flaps? Use internal sequencing for gear and gear doors? Mixing to combine the two?
A better question might be… is any of the above a bad idea and why?

BigTeeEldorado

Chris answered this question already with the points of failure. He is absolutely right about more channels making the project easier and safer with fewer cables to manage.

The real question you are asking us though is where is the diminishing point of return on the money you will spend to have more radio to work with. And the answer to that is there is no answer to that.

It is different for each of us. I am less a fan of the DX18 and more of a fan of the DX9 for reasons that would probably make Chris just smile at me and walk away. You could make a 7 work but you got 3 people who all agree that would be a bit tough and probably not worth the money savings it in our opinion. You have me that is happy to use y-cables (I make my own by the way) and likes the size and weight of the 9 and it has all the functions I'll ever need. Chris prefers the straight line to the receiver for every servo he might use and then electronically not mechanically making all the servos do exactly what he wants and is willing to pay for that. (it is easier electronically)

I know it is tough to make a decision like this one, and I agree it is an important one, without personal experience to draw from. Which is why your smart enough to be asking the questions. Trouble is on this one I think you need to look inside your own wallet (something we can't do for you) and make an honest judgement on your skills and where you want your hobby to go next.

Chris Nicastro

My Feedback: (3)

Spot on Tony!

I wouldnt smile and walk away by the way, your set up is legit. However one day if you have an issue I might smile reading about it. Ive had issues with complex overlapping of this type including match boxes so I can see it does work but its time intensive and detailed.

We can armchair QB this debate all day. As Tony said it comes down to what you imagine the future of your hobby might be and what kind of investment your willing to make in it.

Best radio I had for years and if you can find one used it will be super cheap, JR 9303 with Spektrum module or later variant. Great mixing, easy to use, good feel, durable, and its programming is the basis for later radios from Spektrum and JR. I sold mine for about $250 a couple years ago now. Maybe buy one from a trusted source?

sudstad

My old/old school brain likes "simple" and is leaning towards custom Y-Cables like Tony mentioned. I've been happy with the Spektrum radios that I've had, but open to JR. Comparing the DX9 and JR XG14.

I was also leaning to springs and strings for the gear doors... until the knowledgeable folks on this thread mentioned "mixing and sequencing". That alone is reason to go DX9 or better.

As always, I really appreciate the sharing of knowledge and experiences!

Chris Nicastro

My Feedback: (3)

Look into using trip valves to close the gear doors. You can have the gear hit the valve which closes the doors when the gear is up and locked. The gear will come down after the doors because the load on them is greater and the doors are light. Just have them open at the same time as the gear. I use air line restrictors to slow the gear which further assists the doors to be clear of the gear when opening.
Super simple, no electronics needed.

Also look into a UP3 valve, its awesome and does the sequencing mechanically/pneumatically, Im using one in this P-38.

sudstad

More new technology!

Chris... trip valves/UP3 valves are completely new to me. Is this the config you're describing? Do you have a recommended dealer? JB... do you sell these?

[TABLE="class: Product"]
[TD="class: ProductGraphicLeft"] [/TD]
[TD="class: ProductText"]Ultra Precision UP3 Valve
99.50
UP3
Retract Valve with Automatic Door Control
(Doors open when down)

[TABLE]
[TR]
[TD="colspan: 2"]Specifications: [/TD]
[/TR]
[TR]
[TD]Dual speed control for legs[/TD]
[TD]3-10 seconds recommended[/TD]
[/TR]
[TR]
[TD]Dual speed control for doors[/TD]
[TD]0.5-3 seconds recommended[/TD]
[/TR]
[TR]
[TD]Single air inlet[/TD]
[TD]30-200 pounds[/TD]
[/TR]
Four outlets for legs[TR]
[TD]Four outlets for door cylinders[/TD]
[TR]
[TD]Standard servo actuation[/TD]
[TD]0.3 inches travel. Special slow servo is not required.[/TD]
[/TR]
[TR]
[TD]Size:[/TD]
[TD]1.94 x 1.25 x .62 inches[/TD]
[/TR]
[TR]
[TD]Weight:[/TD]
[TD]2.4 oz[/TD]
[/TR]
[/TABLE]

[TABLE]
[TR]
[TD="width: 497, colspan: 2"]Sequence of Operation [/TD]
[/TR]
[TR]
[TD="width: 240"]Strut in the up position
Door Closed:[/TD]
[TD="width: 253"]Strut in the down position
Door Open:[/TD]
[/TR]
[TR]
[TD="width: 240"]Down selected -servo moves spool[/TD]
[TD="width: 253"]Up selected - servo moves spool[/TD]
[/TR]
[TR]
[TD="width: 240"]Door opens[/TD]
[TD="width: 253"] [/TD]
[/TR]
[TR]
[TD="width: 240"]Leg lowers[/TD]
[TD="width: 253"]Leg raises[/TD]
[/TR]
[TR]
[TD="width: 240"]Leg locked down[/TD]
[TD="width: 253"]Leg locked up[/TD]
[/TR]
[TR]
[TD="width: 240"]Door stays open[/TD]
[TD="width: 253"]Door closes[/TD]
[/TR]
[/TABLE]
[/TD]
[/TR]
[/TABLE]

sudstad

I'm sorry... my EDIT didn't stick.

Link to the UP3 valve ad: http://www.electrodynam.com/store/Retracts.html

DGM

Hi, guys.. Sold my 90 inch electric P-38 to a friend of mine and bought a new Flitework P-38 from Tower. Foamy 58 inch ARF. Comes with servos, motors, escs and electric retracts, pilot, etc. modeled after Red Bull P-38 which was Lefty Gardner's old White Lighting. Flew it yesterday (7-12). NICE PLANE. Loops, Rolls and takes off and lands very nicely. Big bonus.. You do not have to take it apart to get it to the field, flies on a 3s 2200 mah battery. GOOD plane.

sudstad

Very nice DGM! Another great flying Lightning!

My son and I started out with Banana Hobby P-38's. Once we accepted the risk associated with cheap OEM electronics... we both enjoyed flying them!


EDIT: DGM... that sounded bad. I only meant it looks like the Flitework airframe is similar to the old BH's that we flew.

BigTeeEldorado

Hey guys...haven't seen much activity here lately so I thought I would show off some recent footage. I might have to hanger this model for a while until I get a park pass to fly off an asphalt area they have, the lake bed is too rough on the gear. This one was a scratch built of my own design that flies great, I'm sure you can tell, so I kind of want to preserve it or a while. Anyway hope you enjoy.
https://youtu.be/Zs0NtgLKtR4

70 ragtop

My Feedback: (24)

Nice job Tony, what a great place to fly!

BigTeeEldorado

The wide open space is great but the surface is brutal on small planes. The bigger planes with bigger wheels handle it fine but that plane has retracts and the cake-pan surface is really tearing them up. Watch this one and pay special attention to the final shot with regard to the wheels.

https://youtu.be/ztXN6ZLAdwI

simple

My Feedback: (9)

Fantastic! unique camera angles - thanks for adding to the thread. I've been grounded for maint. and was itchin to see a 38 fly.

70 ragtop

My Feedback: (24)

Yeah this thread has gone quiet. Guess everyone is out flying....which is a good thing.

I'm grounded as well as I broke a main strut on a cross wind landing on Monday. Plane was crabbing maybe 15 degrees, but the wings were level at touchdown, and the strut snapped like a toothpick. I know Kram and his buddy both had this problem, but really haven't heard to much else about it.

My nose strut actually bent rearward on a takeoff roll bounce. I bent it back, but its not the same. It bends pretty easy now and I feel sure it is going to break.

Spoke with Charles at Yellow, and I can order just the top part of the struts, but they won't be in until late Sept/Oct.

After getting home and looking at them, its no wonder it broke. Look how thin the aluminum is??

If anyone is interested, I'm just going to make my own from 4130 tubing. Couple ounces heavier, but I feel pretty confident they're not going to break from something like this. Its $20 for material for all three, and basic hand tools

BigTeeEldorado

I'm guessing the landing that broke the strut was in the grass or do you use the asphalt I see in the background too? I would think the side forces would be greater in the grass than on the asphalt but maybe not. I ask because I am hanging mine up for a few months over concerns for the gear. It is taking a beating on the washboard surface of the Lake and I'm thinking the asphalt surface will be gentler so I'm waiting to get access to that area.

Its hard to tell but that doesn't look like a very high grade aluminum either. Seems kind of porous in the picture. There is a guy at our field that has a metal lathe in his garage and he has helped a lot pf people, myself included, by tooling "parts" out of solid stock. I have no doubt what you make will be stronger than the original. You can't be the only one with this problem.

Sure love those pictures, you saved and created a real winner!! Gorgeous both on the ground and in the air!!

70 ragtop

My Feedback: (24)

Yes, it broke in the grass. Pavement would be nice, but in this case, I'm not sure it would have made a difference.

New strut, and modified the nose with a replaceable pin all done. Less than $20 in materials and a few hours in the shop. Best part is the plane's not sidelined waiting on struts....back to flying

sforrest

My Feedback: (13)

Wanted: Canopy for a Yellow Aircraft P-38, new or used. Please contact.
Thanks
sforrest