waynemia

My Feedback: (2)

I am in a build for this model. I plan to use an OS91FX. I ordered a Bission inverted muffler in advance. Well, I did the engine check and this is not going to fit inside the cowell. Now I need to find a new muffler or use the stock one. Any help would be appreciated.

I have read a lot of information and suggestions. I guess I need to add some ply under the landing gear. I have also had suggestions of knocking out the #6 hardware and tapping the wood for 1/4 x 20 nylon. I also saw one option to use nylon #6 screws and add one 1/4x20 (three screws total). I would like to know what mods have worked to strengthen the landing gear. My landings are generally gentle but we do have a fairly rough field.

What about sealing the control surface hinge areas? I have read about using hinge tape. Are there any other recommendations or just leave it alone.

I thought the suggestion of leaging the extra axle length and letting it extend out the other side of the wheel pant. It did not look bad. A local recommended not putting the wheel pants on. I guess these have been known to come off?

I also saw issues with gluing on the canopy. I have the recommended glue. So glue, screws, or what? I also have some canopy trim I could use.

Tru-turn has made some suggestions on a spinner. The provided one is pretty small. I will probably use a 14 x 5, 14 x 6, or 15 x 4 prop. I am planning to wait on the spinner and fly without it until I settle on a prop. I am using a 14 x 6 on a Big Stik and it works very well turning about 10,800 and unlimited vertical.

I also do not like the tail wheel assembly! I was thinking of using a Sullivan. Does anyone have recommendations in this area? I checked and it seems like the bottom of the fuse is solid and would support the Sullivan 60 - 90 size.

Any and all info would really be appreciated. I will update on how it goes.

Thanks a million.

Wayne

nitro wing

My Feedback: (1)

I can only answer some.Use tape to seal the edges,its easy,like scotchtape for Xmas presents..
Most engines dont fit the cowl well,dont worry about the 91,its probably a good choice for this one.
Sullivan wheel is OK but not the best,better than stock by far.
Good choice to wait on spinner until you find the perfect prop.

rclement

My Feedback: (1)

I concur with the above. For the landing gear. Yes, the block might come out. A friend of mine took his all the way out and replaced it with a block he made from a carved down 2x4, then he tapped it for 1/4-20 and uses nylon bolts. You might want to add an extra nylon bolt in the landing gear. The stock landing gear is too weak for the 60. It starts getting springy too quickly and looks to me to be undersized for the weight of the 60. A couple of us bought and installed the carbon fiber type but it's so stiff that it doesn't move at all and then transfers all the load into the landing gear block. The problem we had was that on a rough field with the carbon fiber gear, the nylon bolts would shear off. I had to drill and the tap the block and install a third nylon 1/4-20 to fix it. Oh, about the wheel pants, you can adapt them so they stay on better but if the landing gear comes off they will poke holes in the wings. While you're upgrading the fuse, add some extra epoxy to the firewall, just in case.

rolliedog12

My Feedback: (3)

I fly the U-can-Do 46 with an O.S. 91 FX, the above are great suggestions, the only thing I can add is to pick a prop that will help you limit speed. I fly 1/2 throttle most of the time with a 14 x 6 prop. This plane will come apart flying fast. The landing gear really needs to be beefed up. But it is a great plane that I'm sure you will enjoy. There is nothing better than taking off, pointing the nose to the heavens and watching this plane go.....and go...... and go.......

waynemia

My Feedback: (2)

I have seen all the speed warnings. I have a Futaba 9 CAPS. I thought I might just reduce the throttle travel a bit if necessary. This would prevent accidental over accelleration.I am planning to try a 15" prop too. I don't want a prop so large that the engine suffers. It seems to really like the 14 x 6 I am using on my Stik. I am thinking the APC 15 x 4W might be a good match for the UCD.

waynemia

My Feedback: (2)

Is it necessary to seal both sides? I would think one would be OK but it might collect trash.

rclement

My Feedback: (1)

You'll only need to seal one side. [8D]

waynemia

My Feedback: (2)

Good, I have some 3M hinge tape. I will use that.

Rocketman_

The following are my answers to your questions based on my experience:

1. OS .91FX fits entirely inside the cowl except for the stock muffler (see photo).
2. The landing gear seems to be strong enough for grass runways unless you land off the runway in tall tough weeds. However, it is springy and may occasionally need to bent back into shape.
3. No control surfaces are sealed and there is no flutter. The UCD 60 appears to be less flutter prone than the other UCD's. The early UCD 46 was known to have flutter issues with it's stabilizer and the Giant UCD's wings can explode. My friend can testify to that because he lost his $499.99 Saito 2.20 in a pond when his Giant UCD's wings failed.
3. Grass fields can be hard on wheel pants but I always put them on. Letting the axles stick out through the wheel pants will only make the hole big and ugly due to vibration unless you reinforce the hole with a piece of hard wood or plywood on the inner side of the pant.
4. For the canopy I used RC56 canopy glue and back it up with screws because the glue doesn't adhere very well to that canopy material.
5. I used a 2.25" dia plastic spinner with a metal back plate on an APC 15 x 6 (not wide) prop for the OS .91FX and it works very well.
6. The stock tail wheel was replaced with a Sullivan tail wheel bracket for 10 to 22 lb models and is a perfect fit in the space provided on the fuselage.

waynemia

My Feedback: (2)

Thanks for the input and the picture. I talked to another flier this evening and he did not think I need to do much to the landing gear. Our field is a cow pasture with an electric fence to keep the cows out. We also get a gopher hole once in a while [>:]. It is really not too bad but it is not a grass field either. I like to practice MCA so my landings are usually not too bad. I will defer the wheel pants too until I see what I am working with. That can be added later. We are having a swap meet tomorrow so I put the Bisson muffler up for sale an I ordered a MACS black muffler. Hopefully that will be the end of that problem.

Your canopy looks good. I will study about that for a while too. I want to take my time because I want this too look good too.

Glad to have the input on the Sullivan tail wheel too. Did you just use wood screws or were you able to get the blind nuts in too?

Did you have any balancing issues? What about lateral balance?

The spinner sounds like the one I have on my Stik.

I have the ailerons hinged. The rudder and elevators are ready for glue.

All the input is great. I am sure it will improve the end result.

Rocketman_

waynemia,

I used wood screws and 30-minute epoxy to mount the Sullivan tail wheel. I removed a strip of covering so the tail wheel bracket could be epoxied to bare wood. This method also works on heavier 1.60 size models and I have never had one come loose.

Since I used 3 light weight servos in the tail I thought I needed to move the CG rearward so I made a hatch in the bottom of the fuselage for the battery. The photo shows the battery hatch is located 28 inches back from the wing leading edge. I did not do a lateral balance.

waynemia

My Feedback: (2)

Update: I have a new Saito 125A and I think I will go with that engine instead of the 91FX.It will save some grief shuffling engines with the Big Stik. There is some information that indicates this would be OK. I have no experience with 4 strokes but this engine seems to get good reviews. I liked it because it was same size and weight as the 91FX. The weight (not to mention cost) of the 4 strokes has been the main objection. I mounted on my test fixture today and will start. breaking it in next week.

Not much build time today due to the local swap meet. Will have a little time tomorrow. I plan to trial balance the plane as soon as I can get all the surfaces to stay on.

rclement

My Feedback: (1)

I had a Saito 125 in mine and it seemed to be just right for it. It fits in there good, no problems there. Also I brought the fuel line over the top of the mounting rail and then down to the carb. It seemed to help a lot in keeping it from flooding when just sitting on the bench.

waynemia

My Feedback: (2)

Spent 2.5 hours breaking in the 125A. It is running very well and should do nicely.

All surfaces are hinged. I added a piece of ply under the landing gear and added a 1/4x20 nylon bolt in the middle. I plan to use 6x32 nylon bolts for the other two holes. This should be plenty of support. I have found that the Fiskars paper cutter makes quick work of cutting those hinge strips.

I trimmed the covering on the bottom of the wing for the belly pan. This was not resommended in the manual and probably not necessary sinve it weighs almost nothing and there is no load. You have to be really careful on the sides, the sheeting does not come out much past the belly pan. It is easy to get too close to the edge. I saw trimming noted in a number of posts but I would recommend only trimming the leading and trailing edge areas. This will make sure there is good adhesion without the risk of getting to close to the edge of the sheeting.

No trouble trimming the canopy. I used a bright light to help me see the corner. This is the first canopy I have worked with so I did not know what to expect. I sanded the edges and it looks good for now.

I mounted the blocks for the cowel. They seem to be really close to the engine mount. I may have to trim them later. I mounted them just after the curves.

The wing fits very tightly. It is going to be a pain the fist few times working with it.

I found a 2 1/2" spinner with an aluminum back. This looks good with the cowel. I may use it if it fits with the prop I plan to use.

[]I am using 4-40 hardware for everything but the throttle. I have heavy duty arms. I am wondering if I should change the control horns. The stock ones do not seem very stiff. Have any of you changed the horns?

With the Saito, I will have to put a another hole in the firewall since the throttle is on the opposite side.

I am planning to add a fuel valve and remote glow connector.

Anyway, a lot of progress today.

waynemia

My Feedback: (2)

Do you remember what prop you liked?

waynemia

My Feedback: (2)

Do you remember what prop you liked?

Rocketman_

I used to love the Sullivan Fuel Filler Valves because of their convenience and they never had leaks that I'd heard about with other valves. HOWEVER, when two of mine split in cold weather and popped apart causing ejection of the spring and ball, I removed them from my other planes.

The first photo shows an intact Sullivan Fuel Filler Valve and one that failed. You may be able to see that the housings are made of two different materials but both of them had small splits at the edge.
The second photo is from a Tower Hobbies ad and shows a third Sullivan valve material that appears to be black in color. If I asked in a very polite and gentlemanly manner, I wonder if someone who is good at making dead stick landings would try out that new Sullivan valve and report back with the results.

The third photo shows my well worn UCD 46 with a filler made from 2 bulkhead fittings and a piece of fuel tubing. This arrangement is probably infinitely more reliable than any valve but is not as pretty. It has similar advantages to the valve in that it prevents fuel from being pumped into the engine and it requires no third line in the tank.

rclement

My Feedback: (1)

Good job Rocketman. I've used the same set up as in the 3rd picture and it works great.

waynemia

My Feedback: (2)

I chose a Dubro fuel filler. It has a metal case. Probably one of the leakers you mentioned . I will use clamps to secure all the fuel lines too. There is a wire clip in the box with the 125A. I don't know what that is for unless it is to secure the fuel line at the carb. It looks like it could go through a bolt somewhere. There are two screws that hold the carb on to the back of the engine. If I tighten these, the throttle won't work. I emailed support through Horizon for a clue about that.

I don't know about mounting the glow remote. It arrives tomorrow. I saw one review that mounted on the cowel but I think that is not good. I would think the cowell would eventually crack. There was not backing support. I plan to use a bracket attached to the firewall. This would make it unnecessary to have a connector to remove the cowel.

I should have some pictures later.

waynemia

My Feedback: (2)

Pictures

The Saito is ready for the first start.
There is a view of the cut-away I did for the belly pan.
The modifications for the landing gear. There is a piece of ply added and a 1/4x20 nylon screw added to the middle. The 6x32 screws have been replaced by nylon.

I started assembling the 24" servo extentions. I have one completed.

The rest of the parts should be in tomorrow.

I found some frost paint for glass and plastic. I may use this for the canopy. It is a different effect then many I have seen.

I need a piece of trim is needed to cover the bolt holes for the stabilizer. I don't want an entire roll and the LHS did not have a match [].

rclement

My Feedback: (1)

Nice pictures. Thanks for posting them.
For the remote start, I have installed them back in the fuse above the wing and they work good there. I wouldn't put it on the cowl. For the Dubro fuel fill, keep an eye on the operation of it. They tend to leak over time and draw in fuel causing deadsticks. You can get rebuild kits for them that consist of some new orings and other little parts and they rebuild kits are fairly cheap.

opjose

Yes on the Dubro filler problem.

The filler fitting that gets inserted will frequently catch the O ring and start wearing it away or break it.

When you insert the fitting, make sure you do so straight in to preserve the O ring.

rclement

My Feedback: (1)

Yeah, I've just gone to a 3 line system with a plug for the end of the fill line. I just run the line through the cowl and carefully drill / ream the hole in the cowl so that the plug and line just fit into the cowl after filling. Works good for me. [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXK138&P=ML]fuel plug[/link]

waynemia

My Feedback: (2)

I will keep an eye on the o-ring thanks. I will check on the size. I have a lot of o-rings and probably several replacements. I will also check the probe for sharp edges. A small bit of lubricant would probably help as well. I am a SCUBA instructor and we have a lot of o-ring seals. very light amounts of silicone grease extends the life. I am not sure if the fuel lubricant should be helping that. If the o-rings are allowed to dry they crack and fail early.

I appreciate all the comments on the filler. I should be able to easily convert this to another format if it does fail.

waynemia

My Feedback: (2)

I also have a Robart Super Fueler II. I would need to pressure test it I guess. Any experience with this one?