Olibuilt 's New Cub project

[Check Six]

Bill,

Just to make sure I understand correctly - you're back to the original trim motor from McMaster-Carr?

Part # 6409 K18, 12 volt DC gearmotor and coupling Part # 6208 K142?

Thanks,

Tom

[Bill Rusk]

Yes, that is correct.

Bill

[Olibuilt]

The titanium firewall turned out to be easy to work with. A fly-cutter worked perfectly for bigger holes. A 4 pounds more weight saving from the old stainless steel one.

For less then 200$ with the flange, it makes a really nice piece.

Now I need to proove to Transport Canada: ''the firewall will will not suffer damage sufficient to endanger the aeroplane if a portion of the engine side of the firewall is subjected to a flame temperature of not less than 2000° F for 15 minutes. "

I guess that with more than 3000 F melting point for the titanium 6-4, it is more then enough.

[Olibuilt]

Found an stock low time O-360 C4P. So I worked on the engine mount. Engine lowered by 1 inch, and thrustline built in it. Should save more than a pound without the steel thrustline block.

The hard part was making a jig.... Don't mind the final tweeking with the ratchet straps....

[Olibuilt]

Decide to go with the same brake setup of my white cub. They work perfectly with double puck calipers and 35''. Strong enough to lock the wheels but weak enough to land with the brakes on for short landings.

Wagaero homebuilt brake pedal and master kit. Speed holes to save more than half a pound....





They fit right over the brake reinforcing channel.

[Olibuilt]

Will cover the hole fuselage finally. Didn't like the idea of increase drag. So goiing extended rear baggage. Rear interior panel for cargo aera only. Sides and floor, no top. Choose Kydex to try to cut down the ratling sound of alumium. Front will not have any interior panel.

First time for me with Kydex. Nice material to work with. Did all the bending at cold. The beeds were made with a old die to form aluminium.











Die to form the beeds

[Olibuilt]

Been busy today starting to fab the boot cowl from 2024-t3 .020. Not that easy... A lot of cartboard template. Decided to go with 3 pieces (thanks to this forum).

What nutplate (anchornut) do you suggest to use? And where to buy?? At the firewall, the channels and the joint....

Nutplate to the channel too for easy removal??
What to use for the joints???

[Olibuilt]

Now is the time for me to plan the wings project... Would really like to have some advice from you for my first wing project.

Already have some old wings for parts that I would like to re-use. Belcranks, pulley brackets, aileron flaps ribs, hinges, 30.5g gas tank, strut pickup, etc.... I need to buy a few parts... The wing mesures a little less than 16' without the wingtips.



My plans:

-Keep it light
-Stock airfoil wing (square end)
-17' spar with small wing tip
-stock 102'' aileron, 98'' or so flaps to fuselage

something like that. Trying to figure out the lighting holes in the spars




My questions:

1- Whats up with the difference between wing flaps tunnel and ailerons tunnel ??
Do I keep it like that or can I put ''flaps tunnel'' all the way?? Don't really understand the difference and I need to buy my stamped ribs soon...





2- Why does my wings have 1 nose ribs betwwen each full ribs?? Is it necessary with .016'' leading edge (.020'' for gas tank area)






3- Why does my wings have 1 ''stifner rib'' betwwen each full ribs?





4- How many ribs, and do I put them in the stock location to built my wings?? Spacing between? Just like the stock plans?

[docstory]

The titanium firewall turned out to be easy to work with. A fly-cutter worked perfectly for bigger holes. A 4 pounds more weight saving from the old stainless steel one.

For less then 200$ with the flange, it makes a really nice piece.

Now I need to proove to Transport Canada: ''the firewall will will not suffer damage sufficient to endanger the aeroplane if a portion of the engine side of the firewall is subjected to a flame temperature of not less than 2000° F for 15 minutes. "

I guess that with more than 3000 F melting point for the titanium 6-4, it is more then enough.

Make sure you seal that flange well, or tuck it behind the firewall at the bottom like Piper did. Otherwise, any oil that may get on the firewall will find its way to the inside of the bootcowl.

[Olibuilt]

Was thinking sealing up the firewall flange with black high temp sealer.


Would really like to have some input about the aileron - flaps ''cove''.


Backcountry wings seems to have aileron coves all the way.




This beautifull wing looks like it has a aileron cove shape different than the flap cove.




My rebuilt crashed wings too...





I really wonder what is the purpose of the differences in the cove shape. Round shape for the aileron and flat shape for the flaps. From what I know, flaps need to be air-tight on a cub.

Do I buy half the ribs flat butt and half round butt?


Thanks

[jgerard]

So why not do like the PA-14 and put the flap style cove all the way out and use the 12/14 style LE on the ailerons.

I believe the nose ribs are there to strengthen the leading edge "D" tube to stiffen up the wing. Also you want the aileron false spar supports between the ribs to help take the air load on the false spar. There is a lot of torque applied to the TE of the wing when the controls are deflected. You should use the 16 rib wing spacing in the tank bay area for max support of the TE in the flap area. Especially if you have high HP and will be beating the crap out of the flap with prop wash.

Jason

[Olibuilt]

Thanks for the info and for the PM. I will go with round end ribs for now.


Need to find a couple parts before the project starts.


10X - Aileron pivot point at the wing (without the aluminium block). If they come without the ''riveting bracket at about 9'' it's ok...



2X - Flaps pivot - pushrod bracket


4x - Flap hinge bracket




1x -Aileron middle hinge bracket (or two if a little different then the pic)

[courierguy]

You'll sleep better at night, knowing you took the time to lighten things up. Keep it up, some may scoff, but heck it adds up......the time spent is worth it, if it's too light you can always add weight!?

[Olibuilt]

Having a hard time figuring some mesure for the spar-strut pickup and the spar-fuselage attach.... Want to have those bracket just like Piper.



Rear spar is ok. 121.25'' from second hole to third hole (outline in blue)

But the front spar plan is giving me a hard time. Can't find a good mesure from hole to hole... The two types of fuselage section are confusing.

[tcraft128]

The middle hole on the N strut is 121.25" from the reference line.

[Olibuilt]

Thanks. It is so clear after seeing the little dotted lines...

[Olibuilt]

Started the wing part of the project. I now realize that there is a few hours needed to built a set of wings.

My plans: full 17' spars, stock wing / flap / aileron airfoil, square tips, aileron to the tips, flaps to the fuselage, 2400 pounds capable wing, Atlee 30.5 g gaz tanks.

Now I need to make a choice. Flaps and aileron lenght....

-should I go with 102'' aileron and 100'' flaps? 3 hinge each.
-or 80'' aileron with 10 feet flaps? 4 hinge flap... heavier

What do you do with the strut aileron cable placement with aileron extended to the tips? Add another pulley??


Score a set of local stamped ribs. 9.48 oz each. A little weird looking nose section, but stock airfoil.


Beefed up spars. Plan to drill a couple of hole to save a few pounds.



Built my spar-struts bracket, spar-plane bracket.






Wing temporary assembly. Need to make some choice before goiing any farther.

[Olibuilt]

It's been a long time. Did not work on the project since last spring.


I made my wing plans:

17' spars
15 ribs at 13'' each+-
102'' ailerons and flaps (3 hinge)
aileron driven by the inboard hinge
flaps by the middle hinge
stock placement for: strut bracket, pulleys, spar to fuselage, etc







?Beginer questions?
Any info would be really appreciated

Is it normal to have a gap between the front bottom of the ribs and the bottom ''N strut''??
(I did give a little more angle of attack to the ribs on the spars...)

Should the round aluminium spacer (between the strut braket) toutch the spar?

Aft spar and leading edge made in .016'' 2024T3

How should I reinforce the hinge aera??

Had a little fun with my homemade dimple tool.
Should save a little more than a pound for the 2 wings...
The best part is that a beer fits just right. Lucky this time.

[cub12]

looks good are those Cloude G's rib's and spar?

[Olibuilt]

looks good are those Cloude G's rib's and spar?

Yes. But for your your information, Claude died a year and a half ago. I had the chance to work with him at the end of his life. He teached me all the little I know about working on airplanes. I would have loved to have the time to learn more.... He brang so much to the small world of aviation. What a great man he was.



If you need his ''Piper'' spars, struts, or float rigging material, let me know I have access to those.


One of Claude Guilbault contribution:

[cub12]

i just finished my second project,the first was a smith pa-12 with tcow wings the second a tcow fuse built by javeron with Cloudes ribs and spars.I new that he had passed as he died shortly after i got some parts from him.One of the planes that i restored years ago was built by him called a krate looked like a maule but with a cub wing.He really had some nice stuff and very well priced.If you know who is continuing to make his parts the info would be appreciated.

[Olibuilt]

Hard work and a lot of time invested in this project. Every little thing is very long to fabricate.

A little traveling with the O-360 in the back of my Honda or in the back of the white Cub. Engine ready for rebuilt.






Aileron and flaps from this:





To this:



Homemade flap-aileron hinge:



Wing on to check flap lenght to fuselage, flap pulley placement and top deck fabrication

[Olibuilt]

For the fuel line routing I really wonder how.. With doors on both side, it is impossible to give a good slope for the rear lines, when on 35'' tire and tall landing gear...

Red line would be: front and rear line to the windshield tube.
Green line would be the rear line down the window to the front..

Do you see something wrong with both front and rear line routed in front (like the red in the drawing) ???

[docstory]

For the fuel line routing I really wonder how.. With doors on both side, it is impossible to give a good slope for the rear lines, when on 35'' tire and tall landing gear...

Red line would be: front and rear line to the windshield tube.
Green line would be the rear line down the window to the front..

Do you see something wrong with both front and rear line routed in front (like the red in the drawing) ???

Run the red as front lines, the green as rear lines and put a sump line at the low point of the green lines to the belly with quick drains. That way you can drain the water out of the rear lines. If you run it all to the front there's no need to even have a rear line from the tanks, unless you're doing it for redundancy.

[cub12]

that's how i ran my lines except the green line goes under the floor. lots of flow even with min fuel

[DarrenLucke]

I really felt compelled to write in on this one....

I had a 1986 F21B TCraft.... N4417Q, which was designed to run out of fuel in "level flight" (similar to what your red lines depict and in the absence of the green lines).. I found this out via one of the people responsible for the aircraft certification and flight testing (now that's an intelligent way to design an airplane fuel system {being facitious here}) after the fact, this happened in rough air. So, of course, used to learning in a PA-18-90.. I slowed my flight in order to decrease turbulence (read tail dropped because of slower flight, no flaps). When I did so, it got a bit quiet...

I was only a couple of miles from the airport so let the tower know I was making a landing on the highway below (I believe I used the term "making a precautionary landing"... landing was heading West on an uphill portion of the highway, crossing high tension wires, etc.. with wind 19 kts gusting 26 kts @ 190, I was fortunate in that my son and I walked away and didn't bend anything up... sure could've used a blast on the tail as it came down.. plenty of gas still in the tanks (assuming level flight). Put gas in either side (21 gallon tanks - both only, not left, right, & both) afterwards, highway patrol (which were now at the landing location) blocked the highway for me on the N/S road at that intersection. I took off and landed at the airport 2 minutes later.

Understand your airplane, know your fuel system, and how it's designed to run out... Hope this helps in your decision making on running your lines...

[skywagon8a]

Do you see something wrong with both front and rear line routed in front (like the red in the drawing) ???

Olibuilt, If you are asking what I think that you are asking, when you are climbing with the tank only partially filled the fuel will not be able to flow up to the forward door post and then down to the engine. The reason that there are two tank outlets, with the lines being routed as Piper did it, is so that there will always be fuel flowing in large nose up or down pitch angles.

Using your drawing, picture in your mind how the fuel will flow when there is only a small amount in the tank.

[cub12]

thats way the green line is their. low fuel in a decent it feeds from the front in a climb it feeds from the rear.

[Olibuilt]

Maybe my first drawing were not good.

I'm really not an expert in fluid dynamic or hydrolic. I just wanted to have the line out of the passenger feet.


My 2 doors 360 white cub is setup like the green and red line, with a drain at the rear line. No problem in steep climb on 1 tank only. 1 tank, 2 lines and 1 valve for each side. Both, left, right and off.


But I don't understand the difference between the two setup below, beside rear drain being the one in the gas tank for red only setup. Both setup have a positive slope for ground and climb attitude.

Thanks for the input BTW.

[8GCBC]

In the marine business drawing # 2 has an anti- siphon loop.... Not good is my first impression.

[cub12]

go with the first drawing, the second i don't think is safe you will be trying to make the fuel flow up hill in a climb with low fuel. VERY BAD in an over shoot.In the first drawing the rear lines are all below the fuel so gravity will do it's job.Both my cubs are similar it works good with no header tank. Also keep in mind were you will put your drains on the rear line you want to pick a spot that will be the low point an wheels and floats.

[Olibuilt]

It make sense now. Better ask being dumb than asking starving... Will go for the first drawing.

Thanks

[8GCBC]

Better not to depend on siphoning for fuel. Have all lines below source.

[skywagon8a]

Maybe my first drawing were not good.

I'm really not an expert in fluid dynamic or hydrolic. I just wanted to have the line out of the passenger feet.


My 2 doors 360 white cub is setup like the green and red line, with a drain at the rear line. No problem in steep climb on 1 tank only. 1 tank, 2 lines and 1 valve for each side. Both, left, right and off.


But I don't understand the difference between the two setup below, beside rear drain being the one in the gas tank for red only setup. Both setup have a positive slope for ground and climb attitude.

Thanks for the input BTW.

This is the one. You could move the lower green to below the floorboards if you want, or just leave it.

[tempdoug]

Oli, where you might have trouble is if your plane would sit for awhile it could put water in the bottom back corner of the green line. If you run that green line right below your door, hard to tell from a drawing, will the line slope back up to the fuel valve or gas filter? How low is the door you made? And do you have your fuel valve in pipers spot? Any header tank? One thing Oli, your a builder. ps. i like your overhead hoist system.

[8GCBC]

My 8GCBC has a drain at the lower corner of green line...on wheels, a good sampling sump.

[DW]

The first drawing with the sump is the way to go but think about the sump location if your going to put a belly pod on.

DW

[Olibuilt]

My second door is just like the stock PA-18 door but to the left.

I did not place the fuel valves yet. Was planning 1 front line, 1 rear line, both routed to 1 valve (each side). Both valve go to the gascolator.

What would be a good placement for a 2 doors cub??

Good advice DW, just need to know were the belly pod would go.

Thanks

[DW]

I would go with one valve left side just in front of your door and low enough to allow for your throttle quadrant. less is better.

DW

[DW]

One more thing on your sump..recess it!