FlyerInOKC

My Feedback: (6)

You do realize the struts are functional on a SIG Cub? The airplane is NOT intended to be flown without the struts, consequently the wing dihedral should be checked with the struts firmly bolted in place with the jury struts installed. Only then can you be sure you have a problem.

Nauset

OKC I think you are missing my point entirely. I know the cub needs the struts. The question has been asked several times on this thread what the dihedral should be on the cub and it has been stated several times that if you build according to the plan the dihedral is set by the angle of the wing tube holes in the center section ribs. BUT when you plug in the wings prior to constructing the struts the wings will droop due to gravity pulling down on them. This is an issue as you need to have the wings in place to set the length of the upper strut fittings. If you just follow the instructions and install the wings and then build the struts you will end up with a negative dihedral. You either need to block up the wing tips to hold them up, or as I found it was easier to flip the whole thing over and just place a small shim under the center section. This also makes building the struts easier as you can access things better. Hopefully that will help some future builder of this model.

acdii

I built two of these and never had to flip it over. I built the struts on the plans, then attached them to the wings, and both planes have the correct dihedral. What I did have a problem with was excess covering at the trailing edge that cocked the wing ever so slightly against the fuse, and the very first landing it went CRACK, and busted the outer fuse rib that the wing bolts to. I have since doubled and tripled the strength of the upper fuse and only in a crash will it break again. The first one I built is a blast to fly with a Saito 100 in the nose, the second one I bashed into a bi plane, and had a not so successful first flight, and its in need of repairs, but the upper wing has the correct dihedral even though the struts come halfway up the side of the fuse. I don't remember exactly how I measured to get them the correct size, but they fit nice and tight.

Nauset

acdii, sounds good. It is a testament to the accuracy of the kit and the plans that you could build the struts right off the plans and everything lined up properly. Even the instruction manual states to mount the wings and then put the struts in place before epoxying the upper strut fittings to the struts. I'm building custom struts from K&S aluminum tubing so I need to have the wings in the proper position and build them right in place on the plane. I'm setting up the struts to fold flat for transport/storage as I didn't like the idea of having them hanging off the wings all the time. I'll post photos of the struts later.

acdii

I remember that step, but I had the wings off the plane when I did that. The trick I used was to cut the slot for the brackets to be an exact fit, so maybe that's why I never had an issue. I do remember placing wax paper down, then attaching the strut to the wing while the epoxy set.

One thing I did find out that is a must, brace, and cross brace, and brace some more the outer rib that the wing bolts to on the Fuse on the door side. It is very weak. If I were to build another I would replace it with 5 ply instead of the 3 ply from the kit, and double it up on both sides.

Nauset

Here is my take on struts for the cub. I just have to pull the two jury strut screws and I can fold it flat. This will store better and fit in a wing bag for transport.

crankpin

My Feedback: (15)

Going to join up here. I had a 1/5th Sig Cub once, got into other stuff, gave it away. I have one being delivered today, and just purchased a new Saito 90T. Also wrote to TN Products for info on their dummy Continental A-65-8, which is also made in 1/5th scale. Thinking I may need the other L&R cylinders for realism, to compliment the 90T.
Robart gear will be in the works. I did a smaller Cub sometime back, will post a few pictures, sold it when I got the pattern bug. I may have some questions as I go along, and in what class can this Cub be entered, Stand off scale, etc. ?
I will use SolarTex Cub Yellow, and do a light clear coat, or semi-gloss clear coat after covering. I just did a plane with Solar-Tex, good learning curve, like it.
Vince

Nauset

crankpin, congrats on your new kit. I think I've seen those photos or ones like them before. Are they from your other Sig cub? What engine is on it?

crankpin

My Feedback: (15)

Nauset - Thanks for the reply. The engine. Truthfully, I forget. I sold that Cub to a guy from Miami, did not fly it. I can look at all my past purchases, if still available on PayPal, etc., see who I bought it from, I bought it new. I siamesed the cowl for easy access mounting, etc. I think that Cub was a Hangar 9 ARF that I bashed.
Now, I am trying to think, did OS make a twin like that, in .60 or .90, or has it been a Saito 90T all along ? These pictures are from our Florida home, we are in east TN, now, with a new home in construction, 20 miles from Knoxville. We don't get in until around 3/1/17, and are in a rental house now, my shop is one of the bedrooms. I just needed something to build, decided to do this. I bought the new 90T from Galaxy in Poland. Paid with PayPal, so I am settled on that, and they have excellent feedback. PayPal is best when dealing with anyone.
I did buy a used Saito 100T off of RCG, and may just turn it around now and sell it. The company in Poland had one 90T left, so I decided to do it. I contacted Hobby Horse, he has these on his site, but his site has not been updated, and he messaged me that he does not stock them or parts.
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Thanks for listening, l may do a little thread on this plane. I have threads on RCU under Crankpin for the Phoenix 6 pattern planes. I am looking forward to SolarTex this Cub, maybe do some weathering on it.
Vince

I just found the thread on that Cub, dating back to 2005. I plugged in crankpin cub on RCU search. It is a Saito 90T, and I was talking about the Sig 1/5th scale Cub, but that was not it, I am sure now, GP.

Nauset

Very cool. No need to lookup the engine. I think those photos are what inspired me to to mount my engine sideways and make a dummy for the left side. I'm not a big fan of mounting glow engines upside down and I like the look of a twin.

crankpin

My Feedback: (15)

TOP NOTCH
Continental A-65-8 Engine Assembly Manual This company in TN, has kits like you are making in different scale sizes. I have to determine two or four cylinder.

Nauset

Yup that is where I got the construction method from. Probably should go with 4 cylinders if you want true scale look

acdii

The SIG 1/5th is a great kit, built two of them and powered them with Saito 100. 10' roll and pure vertical. Put a larger prop on it and now still a 10' roll, and good vertical, but half throttle is 100% scale like in both sound and speed. That 90T is a twin I take it, and will sound great. I have a Gemini twin 120 on a GP Ultimate Bipe and it sounds awesome with twin straight pipes.

crankpin

My Feedback: (15)

I bought the Saito 90T today from Galaxy in Poland. First time to buy something from overseas at a price like that. Paid by PayPal, so I should be safe. Looking back now at the Cub I showed above, I believe it was a 90 also. Now that TopNotch company that makes the dummy Continental heads, maybe put two of those cylinders L&R, behind the 90T.
Got the Cub today, will check it out in the morning. Picture from Galaxys site, and two from Google search. Plenty of Cub stuff.
Vince

FlyerInOKC

My Feedback: (6)

Nice!

crankpin

My Feedback: (15)

Going to do more research. Those two pictures above from a google search. I don't want to go crazy on the build, won't get anything else done. Stand off, OK, if there is still such a thing.
I found rocker covers on horizons site. I can make the dummy rear cylinders, then use the stock covers that are like the real thing. This 90T due in about 7 days, coming UPS from Poland.

Got the Cub box out last evening, digested the instruction book. Kind of straight forward, no issues, just build the cabin, then the rest. There is some good threads on this build.
Thanks Nausert and all for comments. Heres the real thing, and my J-3 from the past.
Vince

acdii

One suggestion I can make is to beef up the cabin top where the door attaches. There is a lot of stress on those two ribs and they can break very easily on a hard landing. The wing tube slips into them, and the cabin roof covers them. There is an 8-32 bolt that secures the wing to the outer rib. If there is any stress on those parts when assembled, the shock of landing can cause the outer one to crack at the rear of the opening.

crankpin

My Feedback: (15)

Thanks Acdi. Possible make those ribs out of light plywood. Will check it out. Note: 12/10/16. I just found the original build on the finished J-3 above. It is the H-9 Cub, 81" , the engine is the Saito 90T. I should have kept it . Sourcing accessories, a msg in to Esprit Models, I put the 1/5th scale Cub gear and DuBro 1/5th scale wheels in my cart, then sent a msg off to see if these items are in stock. Esprit sells the gear $22.00 less then on Robarts site.
I am sourcing instruments, msg's in to two sites. BalsaUSA has 5 meter rolls of Cub Yellow Solartex.


Vince

acdii

I thought I had some photos of the fuse, but guess not. Right now it is locked in my trailer with limited access, but I have the Biper downstairs with it busted at the exact same space, so I can at least show what I refer to prior to my repairs.

crankpin

My Feedback: (15)

Acdi - Thanks. I went to Esprit models for the 1/5 scale gear, then looked at Robart, then to Tower. Tower had it for around 122 and a $25 coupon and free shipping for the Robart gear, ordered today. I may make the wing one pieced.

V

acdii

Thats for the P-51 Mustang BH that is under the Warbirds section.

I dug out my damaged Cub to show the weak spot of the SIG kit. If I have any complaint, this is it. These parts should not be made of lite ply and had I thought about it at the time, I would have fabricated new ones from aircraft ply.

So in order to repair I make new pieces of the ones totally destroyed like the inner one, and glue it in, then take 1/4" aircraft ply and epoxy those to the fore and aft members that go across the fuse, and then use angle stock to secure the sides to the rear. So far it has held up well in my other Cub to quite a few hard landings and one incident of striking corn which busted up the leading edge of one wing. I will get to repairing this Cub later on, I have to pull the Saito and replace the bearings. I bought it knowing the bearings were iffy, and they are horribly loud when running. So fro $13, it will get new bearings.


This Cub was a kit bash Biper Cub I built and had the CG horribly wrong and was way too tail heavy. I almost got it down safely, until some A***ole drove a bobcat across the runway right in front of me, and then their dog was sniffing my legs while I was trying to get it back around to try again. Somewhere along the line I lost an aileron servo as it wanted to roll left suddenly and with full right stick I barely kept it level. I was able get it down into some soft grass and thankfully minimal damage. Top wings are fully intact, this is the only fuse damage, cowl has a crack. The only difficult repairs will be the lower wings as the two inner ribs were torn out. For now just going to repair the fuse, make normal wing struts, and cover up the lower wing mounts and fly it as a regular Cub.

jollyroger

My Feedback: (6)

When I covered mine I made the mistake of covering just the turtle deck and then attempting to cover the fin separately. It appears the instructions about covering the turtle deck and fin together with one piece of covering would have been the best solution.
The question is now do I strip off the covering from the rear deck and cut new Solartex to cover that and the fin together or just go ahead and try to make the best of it covering the fin?
This is the last part to be covered and really need to get this plane finished although it won't be in the air until April or May. winter just hit us up here in Northern Michigan and for the most part outdoor flying is done for the season.
Anyway, I'm going to continue to work on this and see if I can get it finished.
Cheers

acdii

I used Koverall and Dope, son not sure what you would do with Solartex. With the Koverall and dope you can sand the seams smooth and not see them.

FlyerInOKC

My Feedback: (6)

Covering the fin an the turtleback in one piece (each side) isn't easy it took me several tries but it looks great! .

crankpin

My Feedback: (15)

Are you guys saying, lay the fuse down with fin, etc., then do one piece, whole fuse side and fin combined ? Are you sealing in the area between the fin and tail of the fuse without cutting separate pieces? This take away the seam line?
I have another comment. The first SolarTex covering job I did, a BTE Venture 60, using Cub Yellow. Covering over plain prepared balsa, that is with light clear dope on the surface, the grain of the balsa shows thru.

On the turtle deck, I put two layers of ST on, that cured it, except now I am adding weight. Your opinions here. Dust it with cub yellow spray, then light sand?
I need a close to scale tail wheel for this Cub.

Vince