# The Ranger, an easily built high wing LSA runabout

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by Victor Bravo, Feb 19, 2019.

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1. Feb 27, 2019

### erkki67

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Fritz, don’t worry, it’s not the Ranger, it was another critter of a similar style;

That is me sitting in the bay.

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2. Feb 27, 2019

### Victor Bravo

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Yep, he definitely needs another 4 inches or so of additional headroom, and six or eight inches more distance between the backrest and instrument panel.

3. Feb 27, 2019

### erkki67

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From the backrest or a wall, measured I’ve 127cm of leg length, if the legs would be straight on the ground.

My sitting height from the bottom to the top of my head is 97cm, also measured, while sitting on the ground against a wall.

But for this I’ll build first this mock-up, and then we will see 1:1 what is the matter.

4. Feb 27, 2019

### Marc W

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Interesting! I am just over 6' tall. When I sit with my back against the wall, the top of my head is also 38-3/16", or 97cm, from the floor. I usually don't have a problem with leg room but most homebuilts don't have enough head room. I have big feet too. I wear 13's or 14's depending on the brand. I have a special pair of shoes that I wear when I fly that don't have a lot of sole sticking out to catch on stuff under the panel.

5. Feb 27, 2019

### Tiger Tim

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As a data point, I too am 6’5”, 230lbs and wear size 13 clown shoes.

6. Feb 27, 2019

### FritzW

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I'm 6'2", size 14 and I "park my Cadillac in the garage" (a nice way a saying I could stand to loose a pound or 50).

There should be enough room, even for big folks. My fearless crash test dummy is 6'2" and has perfect posture. Sitting like a real human buys you an inch or two.

Erkki's sitting like a real human. If he sat at attention like the pilot model his head would go through the roof. That mock up almost looks like the first wood CE, if you still have the drawings I could overlay them on the Ranger and see what it looks like

...but if the Ranger has to be bigger, it has to be bigger. Easy enough to do at this stage.

>>>

On another note. I heard back from Grove, a set of free standing gear for the Ranger would be $1,400. I would be happy to go that route for a set of plug and play gear but it is painfully pricey. >>> On another, another note. I talked to Mary (super nice lady) at Carlson Aircraft yesterday to make sure they were still in business (they've been trying to sell the company for a while). They're still in business and fully stocked with all their spars and struts. ...this is where the tube spar guys light their torches and grab their pitchforks I did a quick comparison between tube spars and extruded I beam spars looking at cost, weight, strength, availability (in the U.S.) and ease of messing with (the data might make an interesting, separate, thread). ...anyway, my tube spar wing idea turned into an I beam wing idea. XEPS foam (I think). It would require a 48" CNC machine with at least 4" of Z travel. Any machine will plow though foam as fast as you want to run it. It would be super fast/easy/cheap to build, very light and strong. Perfect for hauling big guys out to the sticks on a hot bumpy day. #### Attached Files: • ###### Spar comp.jpg File size: 24.5 KB Views: 37 7. Feb 27, 2019 ### Pops ### Pops #### Well-Known Member Joined: Jan 1, 2013 Messages: 7,132 Likes Received: 6,023 Location: USA. Since we all are different its impossible to try to come up with dimensions for everyone. I have a long torso and arms and shorter legs, I need a longer distance for head room and usually have little trouble with the leg room. Bob Barrows is the opposite, with long legs and a shorter torse but we are about the same height. I built the SSSC to fit me and he couldn't get his knees under the instrument panel. With the JMR, I built the prototype for a lot of headroom to fit me. Someone else my want to build the 1.5" shorter cabin model . Could you have plans or kits were people would have a choice in different dimensions up to a certain amount ? 8. Feb 27, 2019 ### Pops ### Pops #### Well-Known Member Joined: Jan 1, 2013 Messages: 7,132 Likes Received: 6,023 Location: USA. Wouldn't Cub type of main gear be lighter in the complete installation and far cheaper in cost ? 9. Feb 27, 2019 ### Victor Bravo ### Victor Bravo #### Well-Known Member Joined: Jul 30, 2014 Messages: 6,081 Likes Received: 4,861 Location: KWHP, Los Angeles CA, USA To the malicious drooling toothless hordes advocating tube spars... I see your picthfork and raise you a trebuchet The I-beam spar wins any and every contest where structural efficiency and G-loading is important... like when it's my corpulent arse suspended up above the Earth! Please do continue with the investigation and rendering of a Ranger version using Carlson I-beam spars and struts. Pops likes this. 10. Feb 27, 2019 ### ScaleBirdsScott ### ScaleBirdsScott #### Well-Known Member Joined: Feb 10, 2015 Messages: 1,033 Likes Received: 656 Location: Uncasville, CT I'm all for Carlson I beams and maybe a combination of aluminum and foam ribs. 11. Feb 27, 2019 ### Victor Bravo ### Victor Bravo #### Well-Known Member Joined: Jul 30, 2014 Messages: 6,081 Likes Received: 4,861 Location: KWHP, Los Angeles CA, USA What good do foam ribs do? If you are Cnc cutting the ribs the difference is very small. Pops likes this. 12. Feb 27, 2019 ### addicted2climbing ### addicted2climbing #### Well-Known Member Joined: Jan 27, 2012 Messages: 957 Likes Received: 270 Location: Glendale, CA Fritz, How are the foam ribs attached to the Carlson spar? Are the ribs capped in Plywood and glued in place? Being from the Tubular spar camp I can put my pitchfork down and see how this plays out. My only concern is Tubes can be found anywhere on all sides of the planet. What happens if Carlson closes for good or a builder does not want to pay to have spars shipped to Europe. For example, the only thing stopping me from building the Demoichelle was the difficulty in getting the custom spar and no equivalent here. Love seeing this come together. Battler Britton likes this. 13. Feb 27, 2019 ### Wayne ### Wayne #### Well-Known Member Joined: Jan 15, 2013 Messages: 406 Likes Received: 498 Location: Chicago, IL Can you please make the rudder pedals adjustable so that handsome short chubby guys can fly the Ranger as well? I'm a foot shorter than you guys but at least I don't give up any weight to yoj! 14. Feb 28, 2019 ### FritzW ### FritzW #### Well-Known Member Joined: Jan 31, 2011 Messages: 3,655 Likes Received: 3,266 Location: Las Cruces, NM They're strong, light, cheap and easy. Two sheets of 3/4" XPS from Lowes and an afternoon and you've got all your ribs ready to slide on to the spars ...at about$1.50 per rib, even for the deluxe v 2.0 ribs with 1/16" ply spar doublers (see below). No bending, fluting, stapling, sanding, clamping, drilling, deburring, clecoing, riveting, etc.

As opposed to what? If your talking about wood or aluminum the difference is huge. With foam there's almost no cutting force on the tool, you can make a 3/4" deep cut in one pass going as fast as your bit can remove the shavings and make the corners. Because of the low tool force you can hold down a 4x8 sheet of foam with 4 or 5 drywall screws as opposed to the 7,383,296 1/2" tacks that the 1/8 ply sheets will need. On my machine the limiting speed is the speed I can move the 200 lb gantry around without the machine dancing all over the garage (inertia) ...if I hit the emergency stop button when the gantry is moving pretty fast the neighbors call to see what happened :shock:

...the 'bother to worth' of the ply doublers on the spars probably isn't worth it.

...maybe on the root rib where hangar rash tends to concentrate.

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15. Feb 28, 2019

### FritzW

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The rudder pedals mount to blocks glued to the longerons. There would be 5 or 6 inches of play on where to mount them, but I think the primary leg room adjustment will be how much you bend your knees. ...maybe several different holes in the blocks to slide the pedal tube through? ...with adjustable links on the rudder cables?

>>>

Welded gear would be cheaper and lighter, and probably a better idea. I just hate the thought of cutting out and filing all those little parts. I guess if they were water jetted it'd be no big deal.

>>>

I'd probably glue the ribs to the spars with T-88 thickened with micro balloons. In real life something like Liquid Nails would do it. (if it doesn't attack the foam or aluminum).

Yep, the only downside to Carlson spars is shipping outside the U.S. would be a killer. The time honored "L angles with a sheet web and a bucket of pop-rivets" spar would work also.

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16. Feb 28, 2019

### Victor Bravo

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I must be missing something. Wouldn't be the first time!

Are you saying that Expanded Polystyrene FOAM wing ribs are structurally capable of taking all of the air loads and transmitting those loads into the spars ? Are you saying that these foam ribs will be attached to aluminum spars using glue?

Neither of those two concepts makes sense to me. I have plenty of flight time in airplanes where plastic foam is used as part of the structure, but not without a large amount of reinforcement.

I guess I'd like to see the sandbag load test data on a foam wing rib, compared to the (known) data on the sandbag load test of a wood rib or an aluminum rib.

17. Feb 28, 2019

### FritzW

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Yes, and Yes. Just like countless other airplanes in this performance range. Take a look at your Texas Parasol plans or the Lil' Breezy pictures on page 11 of the old thread that one even looks like it has foam spar webs. Foam ribs aren't anything new, Google "foam ribs on ultralight airplanes".

18. Feb 28, 2019

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The Demoichelle uses foam ribs and only has a doubler around the cutout for the spar for glue. Than there is the affordaplane as well....

19. Feb 28, 2019

### ScaleBirdsScott

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Based on the color schemes of Fritz's foam and wood, I have a real hankering for:

Might have to call this wing method the Shortcake

20. Feb 28, 2019

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