Olibuilt 's New Cub project

[skywagon8a]

There are special flatter ground drill bits for drilling titanium. With the correct drill bit, it is not difficult.

 

[8GCBC]

i find drilling titanium easier than stainless.

Harder to driil means better heat reflectivity?

it's been a few years ago but i found a scrap sheet of ti on ebay. Was a lot cheaper than getting a small amount from a supplier.

Ti is insanely high in price.

But, Ti is the best metal out there for moderate heat (not high oxidation) applications! "Grin and bear" for "sticker shock."

 

[Bill Rusk]

Sorry for the delayed response. I REALLY liked the electric trim and am planning to do it again. I have ordered a different motor, not that I disliked the last one, but this one has a lot more torque and spins a little faster. Funny how we always want more. BDPG -38-86-12V-3000-R51 from Anaheim Automation

http://www.anaheimautomation.com/products/brush/dc-gearmotor-item.php?sID=248&pt=i&tID=103&cID=46

I have not used it yet so I can not confirm it but it looks good on paper. See the thread on "Building a Smith Cub" to get all the info from the last electric trim install with motor specifics etc

Hope this helps

Bill

 

[jgerard]

The Atlee firewall is flanged also, That way the side parts of the boot cowl rivet directly on to the fire wall not a secondary aluminum flange. that saves weight and complexity in building the firewall/boot cowl. Stainless and ti are not easily flanged around a corner like aluminum.

I don't think there is any problem with aluminum rivets on the firewall. It's not like you normally operate with an engine fire. If you crash and burn having rivets melt is honestly of no concern. If the fire is hot enough to melt rivets it's going to melt the entire boot cowl as well. I have never ever heard of any tube and fabric airplane have a firewall/boot cowling come apart because of an in flight engine fire. I know many certified aircraft use monel or stainless rivets but i would have no problem using aluminum rivets on a cub type aircraft. The firewall/boot cowling is not structural. I think the question would be what is more corrosion resistant when using dissimilar metals.

Jason

 

[tcraft128]

Sorry for the delayed response. I REALLY liked the electric trim and am planning to do it again. I have ordered a different motor, not that I disliked the last one, but this one has a lot more torque and spins a little faster. Funny how we always want more. BDPG -38-86-12V-3000-R51 from Anaheim Automation

http://www.anaheimautomation.com/products/brush/dc-gearmotor-item.php?sID=248&pt=i&tID=103&cID=46

I have not used it yet so I can not confirm it but it looks good on paper. See the thread on "Building a Smith Cub" to get all the info from the last electric trim install with motor specifics etc

Hope this helps

Bill

Bill, does it go in the old gear box?

I have a clone of Bills "old" system and I get a 7 second lock to lock transit time. If you think that is to slow, go time a piper arrow or lance, if is almost 20 seconds.

 

[Bill Rusk]

No, this one is direct drive, no gearbox. I sure don't remember mine making stop to stop in 7 seconds. Wow. I remember spinning the manual trim crank as fast as my arm could go and it took something like 12 seconds and the electric took slightly longer. So the whole premise of a faster motor was based on getting it to spin as fast as I could do it manually.
I was quite happy with my electric trim but thought more torque would be nice, the extra speed was a bonus. It may not work out and I may end up going back to the original set up. I should know in about a month. The downside to extra speed is it can be harder to make small changes. Fast equals easy to overshoot.

Bill

 

[Olibuilt]

Was starting with a new-old fuselage.





Decide to save some weight and waist some time drilling holes... Suprisly long how long to save a pound more steel...




Then came the jig.






Tube notching with a hole saw

 

[Bill Rusk]

Update. The new trim motor did not work out so I am back to the system I used on the last build.

Bill

 

[Olibuilt]

Thanks for the info Bill. What did not worked with the trim motor? It sure looked good on paper... Sad because mine is travelling between California and Canada right now.....





An homemade notching-marking tool made from welding rods and hoses worked perfect for me






The mirror notch were made by reversing the paper templates on the next tube.





Fixed fuselage

 

[Bill Rusk]

The motor was a direct drive unit and was too long thus hanging down into the elevator cable run.

Bill

 

[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.


View attachment 5479

View attachment 5480

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: