SBACH - Pilot RC 35%

 

Build/Review SBACH – by Pilot RC

After building the last two airplanes and selling them I decided to do one for myself and dust of this Sbach I had custom covered from Tony at Pilot. It’s been sitting in the corner of the shop for a few months.  I have a brand new DA 120 for it and will be using BLS157HV’s all the way around.  The design of the wings on the Sbach are similar to the Edge and lend itself to stability in a harrier. The straight leading edge and light tapper on the trailing edge help lock in the plane and deter wing rock.

I hope to make this build as entertaining as possible with some cool custom covering work on the internal parts of the plane. 

Unboxing

I have built planes from most the entire top brand manufactures except one 3D Hobby.  They all have learned through trial and error how to best ship I think but I am always happy with Pilot’s solid packaging.  It’s no secret that I am partial to Pilot and friends with Tony the owner but no one company is perfect and I always like to give honest objective opinions and I have a few on this build.

I have built most all the Pilot planes and I have learned that buying direct from Pilot has some major advantages although you will pay a little more for shipping.  When shipped from Pilot direct the boxes have minimal handling.  They don’t get crammed into a container and sit waiting to be loaded on a ship and then unloaded, trucked and unpacked again only to be moved over and over again as sales staff search for planes to be shipped from a us warehouse.  From Pilot direct DHL picks it up and ships it direct to me in three days so the only hands on after leaving Pilot is DHL. Makes it hard for DHL to deny anything.  The best part is the custom schemes.

Spats First

I always install my trademark Spats first on my planes so it has something to sit on.  I painted the Spats to match the scheme.  I will be installing smoke so I am going to seal and fuel proof as much as possible while keeping the weight to a minimum. I sealed all the wood under the gear and in the exhaust tunnel.  The covering job was excellent so little iron and heat gun work was necessary before sealing the important seams.  I filled the Spats with Whiterose wheels and titanium axels. They not only look cool they are very durable and I have never had the rubber roll off the rim.  I also used a Whiterose tail wheel with a straight wire tiller arm to relieve the rudder servo of stress and use less battery to work the rudder servo.  Spring tensioners tend to make the servo work harder.  The factory tail wheel from Pilot is actually one of the better ones I’ve seen come with a kit and I have used them in the past.  

Control Horn Details

I always like a finished look so I paint all my control horns to match the planes scheme.  Sometimes I even use colored ball joints to match but on this plane I use black all the way around which brings me to one of the honest reviews I need to make.  I have noticed more often on the last few planes from Pilot the hardware has been lacking in quality.  In fact some of the nuts included had absolutely no threads on them.  My confidence is bruised in the hardware so I replaced most all of it on this plane with RTL hardware.

Rudder Servo In The Tail

The Sbach is one of the few Pilot planes that have a pre designed spot for the servo in the tail, most other planes need to be custom designed and installed.  I have seen several where people get the geometry wrong and proper smooth operating is not executed effectively.  I made the same pushrod I always do with a carbon fiber rod set up. This has no flex in it and gives the rudder such a great feel. No slop or delay causing over correcting.  I use one servo on the 100cc rudders as long as it’s powerful enough.  I also re-enforced all the glue joints around the tail where the servo mounts.

Switches and Fuel Dot

A while back I put the Fromeco switches to test. While getting a little loose, careless and to low with my Decathlon I put the spinner in the tail.  I bravely used the Fromeco switch again in another plane and on the third flight it failed but failed ON as it’s supposed to operate. The Fromeco switches can be a little challenging to install but the durability is worth it IMO.

I like Mcfueler fuel dot’s, they are solid and easy to use and do not twist the fuel tubing. I installed one for the fuel and one for the smoke oil with nice big labels so as to not make the ultimate mistake and smoke the fuel if you know what I mean.

Engine

I am using a DA 120 with Pro Flow cans. Had I not finished so much of the radio and fuel tank installation I would not be so upset at this point.  I never would have expected to find what I did with this plane. I have built all the other Pilot RC planes and expected the can tunnel to be of normal size to fit normal cans. Well to my surprise it’s made several inches short. Your choice is to cut the back out of the tunnel for the cans to extend back further which I would do next time or cut the headers short. I cut the headers which means the engine may have a slower response on the low end and most of the power band on the top end.

I can’t imagine what Tony was thinking, this may be the biggest design flaw on a Pilot plane I have ever seen. Had I known about it from the beginning I would have made adjustments. It would be nice to get a disclaimer in the plane stating the tunnel was designed for a cox .049 engines exhausts!  Next time I talk to Tony I will be voicing my cheap opinion. 

Have you ever wondered why two identical planes can fly so different?  I never just mount the engine to line up with the cowl. I block the plane level and check the incidence on the tail and wing to match the engine with the correct down thrust and side thrust. Rarely will it line up perfectly with the cowl.  Twice I have removed the cowl ring on planes and re-glued them. I know this works because the last three planes I built needed no trimming except for one click up elevator.  They fly true straight in any angle.  This plane was no exception and I had to correct the cowl just slightly.

Radio Install

I did a custom install similar to this on another plane recently and couldn’t wait to do it again on a plane for myself.  It adds several hours to the build but the result is what you see, just awesome looking!  I balance my planes before I even start the build. After placing certain parts where they must go i.e. engine, cans, servos, tank etc. I then place the batteries and any other parts on the CG point and start moving them out to the closest mounting point so as to keep the weight as close to the center of gravity while keeping it balanced.  This way I am not moving weight around to make up for weight somewhere else.  By keeping as much weight to the center of the plane at the CG point makes for a good responsive, clean flying plane.

Final thoughts

This plane has a great flying reputation and is considered to be one of the most stable 3D planes available.  The plane is built as usual from Pilot RC, very good.  The wood is quality and appears to have no weak defects and the covering was applied well and tight, it needed very little re-heating.  Some of the hardware was not up to the quality I was expecting from Pilot. The can tunnel needs to be redesigned.  One of the best features of Pilot RC planes is the ability to order custom build options and color schemes. Pilot RC did a great job with all the custom features and covering I asked for. 

Thanks for reading, 

Spats

 

 

 

The PAU Edge 540T

I have built and sampled most all of the major 3D plane manufactures except PAU (Performance Aircraft Unlimited) so after I was given the opportunity to try one out at a substantial savings how could I say no.  I spent a little time talking to Herve the owner of PAU at a recent huckfest where I acquired this plane. He described some features and thoughts that went into his planes and the importance of his quality control. Herve is very approachable and ready to assist with any concerns, to my surprise he telephoned me twice after I returned home with the plane just to check if I had any questions and check progress. He also offered up some helpful programming to make the plane fly to my style.

Opening the boxes

Everything was packaged very well in comparison to other manufactures. The boxes were double boxed and lined with thin wood. Any damage that may occur during shipping probably could not be avoided by the manufacture. There is only so much they can do to protect it and if the shipping guys want they can put some pretty big crunches and holes in boxes. After a quick inspection it appears the QC is very good, I like the fit and finish.

 

Wheels and Tail Wheel

I started with my signature build part as I always do, the “Spats” that I put on all my planes. The main gear is very light but strong carbon fiber and I was very impressed with the paint quality on it compared to some other manufactures. I weighed the supplied wheels against the White Rose wheels I intended to replace them with. No gain of weight loss was noticed on the tail wheel but the main gear White Rose wheels were heavier due to being made of aluminum and not plastic but that weight gain was offset by the light titanium axels from White Rose I am using so no change in weight with the bling. I should note that I am not trying to build ultra-light but more durable and still maintain a respectable light weight.  I had to modify the Spats a little to fit the gear by trimming the top ¼”.

The fuselage is already drilled with blind nuts installed for the tail wheel. After marking the location of where to drill the holes in the tail wheel I used lock washers and Loctite to secure the unit. After I install the rudder I will connect to tail wheel tiller arm to it. 

 

 

Engine

I already had a DA 120 for another plane and decided to use it in this one but I am thinking it’s a bit much. For one thing it is a very tight fit. As usual I will be using Pro Flow 3D canister mufflers for best sound and transition.

So I made a template of the engine mount and transferred it to the firewall aligning it up with the already provided center mark. This was very easy and having the pre-installed firewall made it even quicker. The necessary distance I need is 7 ¾” from the firewall to the spinner back plate so I am using 1 3/8” standoffs from SWB.  The firewall comes mounted so the correct right and down angle thrust is already set for you. This is a step I have spent hours with on other planes. 

The next step was to remove the canister opening in the fuselage firewall. With about 10 good cuts of the exacto knife it popped out easy.  I made a re-in forced mounting plate for the can mount out of ¼” plywood. It measures the width of the fuselage by 1”. This will help keep the mount secure under the notorious vibration of the DA 120. A small amount of epoxy was all it needed.  Next I prepped the engine box for paint by using some wood filler and sanding the area with 220 grit. A light coat of primer and one more pass with the sandpaper before applying the white finish coat.

The engine mounts at the very top of the firewall so it was necessary to trim the standoffs and rear fender washers to clear the top of the engine box.  With the engine mounted I started on the throttle servo. For the proper feel on the radio stick I put the servo in the half way position and the carb in the half way spot also and then make my pushrod, this gives a very accurate feel on the radio of where the throttle position is.  Any necessary programming is based on the center spot of the carb and throttle.

I decided to minimize the holes in the engine box and drill one larger hole for the fuel line and servo wires.

 

 

 

Hinges

PAU uses Robart style hinges that need to be glued carefully in-place.  There are a few different ways of installing them and the fallowing is how I like to do it.

First I make sure they all fit in place and work properly. Then I take the hinges and fold them. I hold them with the tips up while placing a couple drops of grease or oil on just the pivot hinge part itself. This way no oil can run down to the part that will be glued. If you get oil on the part that gets glued be sure to use denatured alcohol to clean it but keep the oil on the hinge part so the epoxy does not glue the actual hinge pivot point.  I sanded a Popsicle epoxy stick to a more narrow shape so I could force glue down into the holes. I use 30 minute epoxy to do this, it can take some time to get everything lined up, cleaned up and working correctly. I slide the rudder or whatever part I am hinging on all the way and move it back and forth several times making sure to get a clean 45 degree turn on the surface. Then I use denatured alcohol to clean up the excess glue and hinge pivot point. Lots of Q tips come in handy here. I continually check to make sure the hinges are working and do not need to be cleaned more while it is drying.

I do not recommend gluing the hinges into one side at a time. If one hinge is rotated off center just a small amount it will bind during the rotation and trying to remove a glued hinge is near impossible. If for some reason a hinge needs to be removed you need to cut the hinge off flush, drill a new hole and place a new hinge in the hole next to the cut off one. Trying to remove the glued hinge can destroy the balsa. 

 

 

   

Rudder cable and servo

I like using push/pull on the rudder with the servo in the tail but on this plane I went with cables. PAU supplied all the ball links, cable and crimps, I added the heat shrink just to clean up the connections. After taping the rudder in place I centered the servo and with power to the servo to keep it in place I made the cables starting at the servo. The cables are crossed half way down the fuselage. With the wire attached to the servo I snugged the wires tight on the rudder and crimped them and then slid the heat shrink over the connection. When the rudder is turned by the pull cable the other cable goes a little slack. This is normal but it’s also what I don’t like about cables. In certain maneuvers the rudder can bang back and forth putting hard ware on the servo gears. Direct linkage does not leave room for slapping the servo gears. 

Elevators

The elevator servos are mounted inside the stabilizer. A small amount of trimming was necessary to allow the servo to drop in and fit properly. PAU does a great job on the construction where the servos mount, they glue to pieces of ply together for added strength. A long 1/16”drill bit comes in handy here. I like to use a drop of thin CA on the screws when I install them in place. PAU supplies all the hardware for all the servo connections and bravo to them they all actually fit perfectly.  

 

 

Smoke

I tapped the headers for smoke and used JB weld to help secure the fittings, this has worked very well for me in the past. I don’t know what kind of Teflon tape MTW uses on their flex headers but its crap. Soooo I replaced it with a Teflon tape recommended by my mechanic at work, he said they used this tape during the Iraq war on equipment with no problems. Heck if it could hold up over there then it should be fine on my little engine.

 

Tank

PAU does not supply the tank which is fine with me; I like the 4titude 3 line pre-made tanks. 3 lines are important; this way the main pickup line to the engine is unobstructed. The fuel filter is in the fill line. I used a 32oz for the engine and the smoke system. The smoke pump is the Sullivan Skywriter. I program it down to about 30 percent and use a Fromeco 2600 Relion battery to power it.  Mcfueler DOTS are the best fuel DOTS I have found that reliably work over extended periods of time; I have one for each the smoke and fuel. 

Switches

As always I am using the Fromeco Wolverine and Badger switches from the radio and engine. They are failsafe to on and no need for separate charge jacks it’s an all in one package. 

Cowl

I opened the bottom of the cowl considerably as I want to try and not baffle the engine at all. During the build process I debated in my mind whether or not too split the cowl. I like split cowls and I don’t mind all the screws. Some people don’t like the look of the screws but this plane already has many exposed screws with the canopy and bolts for the control horns so a few more wouldn’t hurt. In the end I decided not to split it but I can always do it later if I want. 

Canopy

The canopy is not pre-installed so I had to make a decision, either glue it with canopy glue or use screws. Neither seemed very exciting to me. Gluing can get messy and requires cutting the covering to perfectly fit the canopy. With the screws the canopy can easily be repaired or replaced if necessary but looks a bit tacky with all the screw heads. I choose to screw it on which wasn’t too bad and didn’t take very long once I had taped it into place. I used the micro servo mounting screws from RTL. I should mention PAU does a nice job on the fit and finish of the canopy hatch, it fits perfectly and snug. 

 

Wings

I am using two servos per aileron so the Fromeco Quad Current Meter makes life easy. I am using two BLS157HV servos per aileron.  

CG

As I did the initial balancing I immediately started regretting not putting the rudder servo in the tail. With the cans and smoke pump up front the plane seems very nose heavy. Sooo I mounted the batteries well behind the CG to get the plane to balance just a tad on the nose heavy side for the maiden flight.

 

Running the engine

Well she is all together and ready so I took her out to my driveway and fired the DA 120 up. I made only micro adjustments from the factory settings and topped out at 6600rpm with a Flacon 29x9 prop. I think I need to get a prop with a little more pitch. I did a test flip of the smoke switch and out came billowing plumes of smoke. Everything worked great so I shut down the engine to clean her all up for the next day until !!!!!!!!!!!! I noticed the control surfaces all coming off! What could I have forgotten on all of them? I discovered that the control horns are held together by one little screw with no nut on the end, it is only tightened down. They vibrated loos with less than 5 minutes of engine running time. I spent the next hour searching my paver driveway for tiny bushings and screws that the prop wind blew everywhere.

I have come to the conclusion that I will never use these again. Besides looking ugly with giant screw heads on all the control surfaces they have one heck of a very, very, very weak link. And by not having ball links on both ends the pushrod is not free to move as easy. I found all the screws and bushings thankfully and re-installed them with Loctite, however, only about 2 ½ turns of thread is all I could get on them. I am completely convinced that if this plane ever goes in it will be due this part.  

 

Test flight

The flight itself went very well. For the first time on any plane I have ever owned I did not need to use a single bit of trim. It flew straight as an arrow. I put it into a few good maneuvers and it performed well. The plane feels like it is better for hi energy 3D and not as floaty as my other 100cc plane. It does a very good knife edge and requires very little mix.

Final thoughts

All the trim colors were barley ironed on and I had to go over them again with the iron. The wrinkles are very normal and will happen when shipped in a hot container around the world.

I will not use the factory control horns again.

The plane is very well built and strong. The fit and finish of the wood is very good.

The plane fly’s very good and will do any type of 3D. It even made me look pretty good.

Customer support after the sale is extremely and I mean extremely good, Herve waste no time in helping or answering any questions.

I recommend this plane.