Part 3 Slick 540

I tackled my first try at vacuum bagging and it went off with out a hitch.

The box part of the fuselage is complete and weight came in just under 3lbs so I am very happy with that especially with all the custom mods I did to strengthen that landing gear area and engine box up.

I have decided on using a different engine than originally planned. I was going to use a DA 120 but they shake so bad that I am worried with the hyperlite build I might shake the plane apart so I just ordered a GP 123 which I will break in on another plane for about 20-30 flights.

The canopy hatch is sheeted and the lower belly pan is in the vacuum bag tonight. Tomorrow I will cut some weight saving sections out of it using a router bit and a hot knife.

Sorry the video got cut short but I posted a picture of the vacuum bag with all the air removed.

Vacuum pump set at 5.5-6.5 lbs

I cut the bag and added the nipple

Air vacuuming out

Sheets taped and ready to cut to shape

Tracing the hatch onto the balsa

All the air is vacuumed out

Hatch is sheeted

This is the belly pan

The belly pan is the length of the fuselage so for shipping it's cut in half. I had to first join it together with epoxy and micro balloons

The wood is cut and ready to put resin on.

Its in the box foam ready

All the air is vacuumed out and will sit all night.



The box constructions of the fuselage is complete. Gussets, W, X, diagonal and balsa bone bracing is finished.

 

It almost looks like a plane now.

I got the sides into the jigs over the plans and mounted them to the engine box. I used titebond and CA. Then came the cross section. Here you must pay special attention that they are cut to fit precisely or your fuselage side will bow, bend in or worse banana shape. I admit I threw to the scrap pile more than 3 under cut ones. I soon learned start with the long ones so the short cuts can be used down the line. Once out of the jigs this is your first time to see if you really did build it all straight. I don't mind sasying, I did a hell of a job! Next came all the gussets. I am sure I am not the first to do this trick but I put about 5 at a time on a 3/8" piece of balsa and cleaned up the tab cuts on the bench disc sander (see pic)

I squared everything back up and turned the fuse over hanging the box off the bench. I used my Snap On chair, raised it up and put a rag between the plane and chair for a perfect soft, supported stool. Once the planes is weighted down level I put in the phenolic tubes and supports in place. I made sure the bench was perfectly level and then sighted everything thing up with the laser level. Then glued the phenolic tubes in place with 30 minute epoxy and micro balloons. This needs to dry until tomorrow and then I will cut the tubes and put those aside to be glued into the wings.





Slick 540 HyperLIGHT

ARF planes have lost their challenge and of course I need another plane because I have NO room for all the giants I have now.  But I found a challenge to fill my time. The 42% HyperLIGHT  Slick Edge 540 Starter Kit.

 

Short kit includes:

 

Full scale Cad Drawn Plans, Reference Sheets, Manual in PDF

 

CNC Router Cut Engine Box  

 

CNC cut Foam Wing, Vertical & Horizontal Tail, Front & Rear Deck and Lower Belly

 

Premium Vacuum Formed Canopy

 

Premium Fiberglass Cowl (2 Piece)

 

My goal is to keep this extremely light but strong with a finished weight of 27lbs and unlike most 40%ers that weight around 40lbs use a 170cc, this will use a 120cc

I am using ultra-light balsa from National Balsa and I’d like to point out they shipped the day after ordering, great service and very nice balsa. The wood to complete the plane will run you around $400.

The carbon fiber wing and stab tubes are from JTEC. The kit calls for TNT tubes which I did order from and have not heard from since so more on that later.

In the old days 30 years ago we used cement blocks for weight when sheeting the foam wings with epoxy for pattern planes that made the plane weight 100lbs it seemed like. But now we have better options so I will be using a vacuum bagging system that I am putting together this week and resin to sheet the wings.

So onto the build:

I have framed up the motor box. I did some weight savings by cutting out some wood from the firewall. Most of the box is framed up with CA other than the landing gear area I used 30 minute epoxy with micro balloons. The jig fit box is extremely strong and very well deigned to be light. It is very important to get the box square since the rest of the fuselage will be built off of it.

I was a little disappointed when I finished it because that’s it for pre-cut parts. Lots measuring and cutting from here on out.

 

First things first, start with the signature Spats.

The starter kit comes in five boxes of foam and fiberglass.

Un-boxed it all is packaged good and arrived un-damaged.

I removed some wood for weight savings from the firewall.

This is the motor box framed up. Everything gets jigged together and then wicked with CA.

Inside the motor box is lined with 3/8" triangle balsa glued down with CA. Plenty of cutting and sanding.

Clamps are a must and lots of them. This is the landing gear supports being glued in with 30 minute epoxy and micro balloons.

1/2" oak rails installed for the landing gear.

I use 3/4" angle aluminum attached to the bench for straight edges while framing up the side of the fuselage over the plans and wax paper.

Once the sides are framed I then sand them on a sanding board to clean all the glue joints. The board is 3/4" A Ply with 80 grit glued on to it.

A flat solid surface is a must of course so a new bench was in order.

 

It is not in the picture but sound board is placed on top of the bench to accept T pins.

 

Two full days of locked in the garage and it's just a couple tweeks away from flying.

Maiden Thanksgiving Day is just three short days away so I am full throttle attacking this.

More parts arrived Monday so with no time to waste I went to work.

First I mounted the engine so I could get the throttle servo in and start measuring for the headers and can mounts.
 

Throttle Servo set up

To get a perfect linier throttle I use a throttle arm the same length servo arm as the throttle arm on the carb. Then place the throttle at half open and the carb half open. I then make the pushrod to fit this distance. If done correctly very little programming will be necessary and hovering should be easier with the throttle control. We used a heavy duty servo on the throttle also as it will be getting a work out on a 3D flying plane under heavy vibration. The last step is to program a throttle cut and an idle up/down switch. For 3D flying this is important due to some maneuvers and the G force that can stop a low idling engine.

 

Header Installation

Next I cut the headers to length (12 1/4”) for the GP 176evo is what it calls for butttttt don’t tell anyone but I like to make them a touch longer and advance the timing a couple degrease to give a more powerful and smooth throttle transition. I use a stainless safety screw and JB Weld to keep the cans from possibly coming loose. Plane Bender Products makes an adapter for the exhaust port too match the header. GP is still a fairly new engine so header companies have not yet come out with direct fit headers.\

 

Tapping the headers for smoke

Never tap your headers closer than 4” to the engine exhaust exit. I usually tap them right at 4”-5” but sometimes a better installation is behind the flex part of the header which is what I did here. I used 8/32 nipples and again I used the trusty JB Weld to help with securing it. The header is very thin metal so getting a tight fit that will not loosen is difficult but the JB takes care of that. Someday I am going to experiment with welding my own nipples onto the headers.

 

Servo Arms and Programming

We are using 2” SWB arms. I replaced all of the recycled Chinese plastic ball links with heavy duty 4-40 ball links. First step is to get all the sub trim centered at zero or as close as possible. For the ailerons I set up the inside servo first working my way out. The Fromeco quad current meter makes this process fast. The servos cannot have tension fighting each other on them when sitting at neutral or when moving the stick. A meter helps to program a smooth travel. I programmed two rates, 3D and landing low rates. I set the expo so that the stick feels the same whichever rate the plane is on. Landing should not feel unfamiliar just because you’re on low rates but it should be smoother on the sticks for a soft landing. This is where right amount of expo can help. Each plane/pilot is different and the amount of throw will all play a factor. Having owned this plane before I set it up the same as mine was.

High rates 65% expo aileron 70% expo elevator 75% expo rudder

Low rates 50% expo aileron 40% expo elevator 60% expo rudder

As far as travel for 3D it’s usually MAX on high rate and approximately 50% of that on low rates.

 

Cooling

The previous owner was going to use the plane for IMAC only so the plane did not need extra venting for the engine. Wayne is a throw down 3D guy so we need to open the cowl up to get the air out. The only wind over the engine in a hover is the prop wind and having the air just circulates around in the cowl without exiting is a death wish. First I tape off the cowl and pencil out where I will cut the cowl. After making a dusty fiberglass mess you can see the ruff cutout. I finish the opening sanding by hand to get a smooth clean finish. 1 to 3, one part air into the cowl for three parts exiting the cowl is what we want to achieve. For Yak’s I make a beveled piece of plywood to baffle the air directly over the engine cylinder heads. I ran out of day light but tomorrow I still need to finish the cowl.

Details

Bill Paul laser cut some parts for me. A bezel to go around the DC UP and a support to go behind the canopy. This will keep the foam on the rear turtle deck from collapsing under stress from high energy maneuvers. Wayne is a Futaba guy and Bill thought it would be funny to engrave it with the wrong logo. I installed the real one.

 

Inside is complete



 

And now here is the final project ready to test run the engine.

The balance is set dead center. Not tail or nose heavy.