ericrcpilot

My Feedback: (145)

I am very interested in this part. I am trying to figure out how do this on my BUSA cub build. Could you PM me here or on FG with details of this process.

Thanks, Eric

SunDevilPilot

Eric...

I will make sure and detail the entire build process of the struts on this thread. I have not done too much yet, just completed the cutting of some of the basic aluminum parts. Details will be here shortly.

SunDevilPilot

ericrcpilot

My Feedback: (145)

I see you are using the 3/4" and 5/8" for the long struts. What size will you be using for the smaller struts that go straight up to the wing? Also, do you just flatten out the ends to fit over the aluminum brackets? I am sure you will cover all of that, but those questions just came to mind.

WacoNut

Sundevilpilot,
Not sure if you are trying to go scale on your struts or not. If so see the attached pic. The struts attach individually to the fuse. They attach at the rear of the landing gear bracket.

I have alot of Cub detail pics, thay are of a J-3 but I just confirmed that the struts mount the same on the Super Cub.
Later!!
Anthony

SunDevilPilot

I will cover all aspects of the struts as I go... However, here is a little "Pre-View" from the construction of my 1/5th Scale Cub. The jury struts, while not scale, will be made from the 5/8" air foiled aluminum. I like the look of it and it works perfect.

SunDevilPilot

SunDevilPilot

Thanks for the pic of the strut.... I decided on my previous build, and this build, to make it a simple "V". I did this for simplicity. At the field I need only attach one bolt per side. Maybe in a future life I will try a scaled out plane but for now I think my patients only allows for "Close Enough".

Fortunately there is a small fleet of Super Cubs based about 2 miles from my house... They teach full scale pilots how to fly taildraggers with them. The Chandler Air Service operates them at Chandler Municipal Airport here in Arizona. So.... When and if I am ready to try something with all the scale details I will take a whole bunch of photos.

There is always the Balsa USA 1/3 Super Cub that I have always been looking to buy... I just need a bigger vehicle.

Couple more photos of my 1/5th Scale Cub with the struts attached... It will duplicate this on the 1/4 Cub... Also a photo of one of the Chandler based Super Cubs.

SunDevilPilot

ericrcpilot

My Feedback: (145)

Thanks for those pics. That gives me an idea of how it works at the fuse. Can't wait for the details on the rest of the attachment points and construction.

SunDevilPilot

The construction will continue next weekend... I had to order some aluminum to continue with the construction. I didn't consider the width of the fuse and the need to cut the lower strap prior to cutting out the other parts and making my aluminum sheet too small for the longest piece. The aluminum I ordered is K&S brand and was purchased at Tower. They have a couple sheets that are a better quality aluminum. Was nice to find the aluminum is 6061-T6 and not that ultra soft type found at the big box stores.

SunDevilPilot

ericrcpilot

My Feedback: (145)

That is where I plan on ordering my supplies. Could you give me a list of what is needed?

SunDevilPilot

Needed to complete struts (Minus the Jury Struts which will be covered later):

A .064" X 6" X 12" sheet of aluminum (K&S Stock # 3070) - Note, there are more than one type of sheet of aluminum in this dimension. The one provided is for the 6061-T6.
Two 3/4" X 35" Pieces of Streamlined Aluminum (K&S Stock # 1105)
Two 5/8" X 35" Pieces of Streamlined Aluminum (K&S Stock # 1104)

Here is where I am now. All the pieces, with exception of the streamline aluminum, are cut. I am starting at the fuselage and working my way up to the wings. So far I have drilled and bent the lower attachment point onto the fuselage. The instructions call for a right side and a left side to be made of separate pieces. I chose to make it one piece and would have to be torn in half to fail. I also added a piece that sits under the front gear mounts to keep things level.

The wings will be attached to the lower mount via an 8-32" bolt on each side.

The piece was bent by clamping the part in a vice and bending it by tapping a piece of wood against the area to be bent with a hammer. This was done gradually and easily bent the part to the correct angle. I clamped the piece between two pieces of aluminum scrap to prevent my vise from digging into the part. This would not be needed if I had a vise with a smooth face within the clamping portion. Mine has teeth and would gouge the part if not covered.

The angle for the bend was found on the plans.

SunDevilPilot

SunDevilPilot

Finished my efforts today with a little work on the tapered ends of the airfoiled aluminum. I got the left side done.

The taper was done on my belt sander, taking off a little, checking fit, and adjusting until it was perfect.

I also got all the parts bent to sit on flat on the wings when in place. Some minor adjustments may be needed as the struts come together.

SunDevilPilot

do335a

Not to be disparaging of your fine work in any way and also noting that the model is only stand off scale, you may still be interested to see that the point at which the wing struts attach to the fuselage is slightly ahead of the point at which the rear langing gear legs attach.

Sig altered that location on the model. With your Robart gear, that point is the same. Still not quite on the money.

That reminds me. Another question baffles me. I've been curious on this for quite some time. Never brought it up previously since I didn't want to step on any toes here. You have spent tremendous time and effort making modifications to the fuselage at the cabin area and the wings as well so that they are separate panels which bolt on, similarly to the full size plane. Yet there is one very striking difference. Sig lowered the spine on the fuselage top to be at the trailing edge of the wing. Yet this is not where it is on the fuill size plane. It ends at the rear of the window in the top of the fuselage. Sig fudged the fuselage shape behind the wing. Yet it is a simple correction to bring it in line with the full size plane. I'm surprised that you did not change that.

SunDevilPilot

Good info DP335A... The struts are going to progress as planned but I'm amused you spotted the spine modification made by Sig. My model is going to be setup like the full scale, with the spine continuing into the area forward of the wing's trailing edge. If you examine the photo below you will see I still have not added the last piece to the area of the fuselage where the trailing edge of the wing is. I intentionally left the forward spine off until I install the elevator and rudder servos. This will allow me to get in to the fuselage from the top instead of only through the door. When the servo mounts are in the fuselage will get the last few parts.

Also a photo of what I plan for it to look like.

Good catch!

SunDevilPilot

ericrcpilot

My Feedback: (145)

Not always true in the strut mounting point. Lots are mounted at the rear landing gear point.

SunDevilPilot

This morning I spent some time getting the struts fitted to the plane. Was fairly straight forward with a little fiddling here and there.

The angles provided by the plans for all the strut pieces were almost perfect.

I will likely JB Weld and pin the struts as they are then proceed with the construction of the jury struts.

You can see in the last photo the small amount of dihedral I put into the wings, far less than the plans call for.

SunDevilPilot

SunDevilPilot

I just finished JB Welding all the components of the main struts (Minus the Jury Struts). Just a quick photo of the notches I made in the edges of the parts to allow them to lock into the struts. I also roughed up the part with some 80 grit sandpaper to give the JB Weld a little something to bite into. After the JB Weld sets up I will remove them from the plane and pin them with some solid 1/8" brass.

SunDevilPilot

SunDevilPilot

I got the struts pinned today. There should be no chance of the struts coming apart now. The pins are solid 1/8" brass and are glued in with some JB Weld. The hole was drilled into the strut, JB Weld injected into the hole with a hobby syringe (Tip cut back to allow the thick JB Weld to flow out of the end), and the pin installed. JB Weld cleans up well with rubbing alcohol which was used to clean off the excess.

The pins were placed in about the midpoint of the aluminum insert to maximize the strength of the section of the strut with the hole in it. The idea being the aluminum insert will strengthen the spar in that area.

Next up jury struts then the tail feathers get installed..

SunDevilPilot

ericrcpilot

My Feedback: (145)

Looks great. I just finished the jury struts on mine and I am doing the final prep for covering. I used screws on mine. I like the looks of it even though it is not very scale. Does anybody know where to get some bungee covers?

SunDevilPilot

Looks good Eric.

After the JB Weld cures I will file / sand the pins flush hiding the fact they are even there. Your design is really similar to mine.

SunDevilPilot

ericrcpilot

My Feedback: (145)

That is because I copied you.

Zor

Hello PA18 lovers,

I am not sure if this thread is approriate for this link.

I just think that you guys may enjoy seeing this.

You may try this with your PA18.

http://freedom4um.com/cgi-bin/readart.cgi?ArtNum=133255

I will test that the URL is correct and will edit to show the results.

Zor

Edit:
It works fine.
You have to scroll down a bit and click to start the video.
End

Zor

When I poste #96 the link was definitely working.

For unknown reasons the link is not working tonight .

Zor

AmishWarlord

My Feedback: (5)

LOL your late Zor.

I covered that in post #143 of this thread.

http://www.rcuniverse.com/forum/fb.asp?m=10613474

Go back and look at it then check out the next few post under it.

There a video of a guy that is using real Cub tail wheel tires for his mains.

Looks cool but we think it may be expensive.

Then we learn just how expensive! LOL

Zor

Hi AmishWarlord,

You sure did and I did not remember where I got that and saved it because of my interest.

I just went to post #143 which was a while ago. Obviously I do not read nearly 300 postings each time I post. LOL .

While on #143 I tried the link and it worked ok.
I came back to my recent post where the link had worked OK when I wrote it and tried the link again.

While it had not worked (responded) the next day (and I posted about that) I find that today it is working again properly.

Computers justare not my friends. I can never predict how they will function.
I am glad that computers are not my hobby. At least I can predict how model airplanes will respond .

Thanks for the note. I think it will not do any harm that new readers may have a look at what can be done wih a Super Cub.

Best regards de Zor

SunDevilPilot

I went to Fly-In at a local airport yesterday so I did not get too much done on the Cub this Saturday. I also had to replace some bearings in the electric motor for my helicopter. However, after all that I was able to continue on the struts. Today I filed / sanded down the brass pins on the struts and began construction of the components for the jury struts. The piece of air foiled aluminum in the last photo is a guide I am using throughout the construction. So far I have made the pieces that will connect the vertical strut to the main strut. I still need to bend the strap but at least I am started.

The part was made from some .025 X 1/4" brass strips. The piece was bent around a 2-56 bolt which will pass through the strap connecting the piece to the main struts.

The part was bent initially by hand then the folded strip was placed over the bolt and "crushed" at the edge of the bolt with a pair of channel locks. I noticed the teeth of the channel locks I have are smooth at the tip making them perfect for this process. After the part is "Crushed" I open it back up slightly, put a small piece of solder into the opening, then held it with pliers while heating the part with a torch to melt the solder. With the solder already in the center of the part this process is simple. After it cools I trued it up the end with the disc sander and drilled it.

While at the Fly-In I was able to take several photos of various full scale Cubs. I paid close attention to the jury struts. Mine should come out very close to the full scale.

SunDevilPilot