Center Console - Assembly Part 2

There is quite a lot of M4 rivnets that have to be installed through out the center channel.

I purchased a metric step drill bit so that could quickly up-size all of the holes to accommodate the M4 and M5 rivnuts. The metric size removed a lot of the trial fitting because I could just tape the bit where I needed to stop at and move on to the next hole.

I didn't want to over drill these holes because I need these rivnut to fit tightly and minimize any of these rivnuts spinning down the road.

Tip

In several places I needed to use a 90 degree drill attachment to get into tight spaces when up-sizing holes. This drill attachment will come in handy through out the build process and I would highly recommend purchasing one.

All rivnuts are installed with J-BWeld Steel Reinforced Epoxy

Forward center channel skins attached to the firewall

 Installing M4 rivnuts on the forward center channels supports.

Center channel support and lower support rivnuts installed

Rear center channel support rivnuts installed

Control skin covers

Installation of rivnuts in the floor boards

In the picture above I am actually missing another rivnut, based on the build manual there are supposed to be three holes but I only have two.

I will have to followup on these missing holes at some point, they are easy to add at any point in the future if they are needed.

Notes

1.  All of center channel skins were cleaned using Simple Green aircraft cleaner and then washed in Bosh Aluma Bright and Bonderite 1201 aero chemicals to treat and prevent surface corrosion.
2. All center channel skins were power coated and prepped for final assembly.
   

Center Console - Assembly Part 1

The center console assembly is quiet easy to complete.

The manual is not super detailed on this part so I spent some time understanding how it fit together with the seat rails, and connector plates that hold the center console skins.

Parts were prepped using my established procedures for cleaning and treating components prior to assembly.

This part doesn't call for any dimpling, however; I wanted a smooth finish when the upholstery is glued in place.  I have seen other builds that used the domed rivets where the rivet heads shown through the leather.

Highlighted in red is where I dimpled what would have been 3.2 x 8 domed rivets.

I used 3.2 x 10 countersunk rivets giving the sides the smooth surface I was looking for.

Though not pictured here, I also dimpled the four rivets holes highlighted below.

The trick with this part of the assembly is gluing the leather under the top part shown above then riveting the four holes using the 3.2x10 counter sunk rivets before gluing leather to the sides.

TIP

Leave the lower 1" of leather material at the base of the console unglued, you will need to cut a stip of the leather away where the seat rails will attach to the console.

Evan Brunye has a very detailed and helpful video on the assemble of this part.

 3.5. Sling TSi Fuselage Throttle Quadrant and Center Console

Console fully wrapped and the inner seat rails attached.

The extra work to counter sink these rivets was worth the effort and produced the nice smooth finish I was looking for.

No rivets are visible through the leather!!

Front Seat - Upholstery

Front Seat Upholstery

 Very happy with the color and stitching

 I left the seat back pockets off at this time.

Seat hinge pivot point.

Front Seat - Assembly

 The seats are fun and easy to assemble, unfortunately I cannot find my assembly pictures.

Here is a another highly detailed blog of the assembly of the front seats.

Sara's Sling Build Log - Seats

My kit shipped with version one of the seats that has the Rube Goldberg seat latch mechanism.

I planned on having my seats power coated for durability as they are in a high use item.

I wanted the latch handles to be red so they were visible inside the cabin.

I determine that I could partially assemble the latch mechanism and the seat pin supports and provide some rigidity to the part so that I did not damage the paint due to the flexibility of this part.

 

In this picture you can see that some rivets are pulled prior to painting which hold the seat pin guides in place.

In this picture you can see that the guide pins inside the latch mechanism.

 

With the parts painted I was ready to complete final assembly.

 

It took a bit of careful assembly but all parts were installed including all nylon guides.

 

With both seat locking mechanisms built I could permanently attach them to the bottom of the seat.

Closeup-up the latch pull fully assembled and installed.

Seats prepped and ready for upholstery

Flap Assembly

The flap assembly is another easy and rewarding part to put together.

Evan Brunye has a very detailed and helpful video on the assemble of the part

2.3. Sling TSi Wing - Flaps

Here is another highly detailed blog on the assembly of the flaps

Sara's Sling Build log - Flaps

Parts were prepped using my established procedures for cleaning and treating components prior to assembly.

This assembly also requires ribs to be dimpled as well as sections of the forward part of the skins.

If you didn't purchase the large table mounted DRDT-2 go with the tools below, they worked perfectly.

ATS Pro Rivet Squeezer w/1.5 yoke

ATS Pro 3" Yoke

Pop Dimpler 1/8" 

TIP

• Make sure you use the correct dimple die for the 4.0 x 12 counter sunk rivets.

• Make sure to pull the three rivets for parts #9 & #13 to part #14 as you will not have access to those holes once you start riveting part #10 the flap control bracket.

Here are few more pictures of the assembly verifying alignment prior to closeout.

Preloaded Cleco's and rivets to get all of the holes lined up and minor match drilling where absolutely needed.

TIP

• When you are ready to pull the rivets for the those in the picture below, you will find that the riveter won't fit. I used a specialty tool from ATS that has been invaluable for close quarters locations.

RV-12 CORNER RIVET PULLER 

I also prepped the rivet lines with red Scotch-Bright pads on all of the flap skins to help with paint adhesion. I used tape to make the lines pretty which was totally overkill, but having to look at these parts for many months prior to paint I was happy with the results.

TIP

• I found that setting a line of Cleco's along the leading edge of the skin helped to pull the skins tight to the ribs and improved alignment with rivet holes and reduced the need to match drill.

• The downside of match drilling is all of the burs created, necessitating a complete disassembly, cleaning, then reassembly which makes things tedious but a important step in the process.

• I had to use the pop-rivet style dimpler on some of the most inner holes where the yoke could not reach.Pop Dimpler 1/8" 

Here is a closeup of the leading edge and some of the dimple work required.

NOTES

Overall I am very happy how the flaps turned out, though I wish I was able to prep the skins using  Bonderite but this will be long forgotten once the parts are painted.

Some builder have had oil canning on the skins, and I had some instances where this started showing up. Removing Cleco's and repositioning the skins and a lot of patience helps.

If the holes did not line up, it was more likely that I am doing something wrong, these parts should in nearly all cases lineup with minimal adjustment.

If you are match drilling every hole your doing something wrong!!

Aileron Assembly

The Aileron assembly is pretty easy to put together, so I will highlight some tips during my assembly and suggestions provided by other builders.

Evan Brunye has a very detailed and helpful video on the assemble of the part

2.4 Sling TSi Wing - Aileron 

 Here is another highly detailed blog on the assembly of the right aileron

Sara's Sling Build log

Parts were cleaned and prepped using my established procedures for cleaning and treating components prior to assembly.

 I like the symmetry of laying out all of the left hand and right hand side components before and after cleaning and prep.

 

 Parts are well labeled and make it easy to complete hardware inventory prior to assembly.

TIP

• Each part has a part number, that is until the plastic has been removed and due to their similarity it becomes difficult to re-identify later.

• I started writing the build document reference number instead of the full part number as the P/N are typically not referenced after the cover sheet. You can use pencil or Sharpie to label the parts for identification purposes.

This is most useful when there is a delay between prep and final assembly as was in my case.

 

 

 

Parts fully prepped and rib #5 & #7 have their bolt plate doubler and AN4 anchor nut plat installed.

TIPS

• Make sure you complete the dimple process BEFORE you rivet the aileron hinge brackets because you will not have enough room for the dimple die and you will have to remove multiple rivets.

• I believe some builders with extra dimple die sets ground some of them down so they would fit in tight spaces.

NOTES

Save yourself some pain and suffering and dimple before hand, trust me. 😉

I had a bit of trouble dimpling the skins because at the time I didn't have the extended neck for my rivet squeezer.

 

*I opted not to purchase a large dimple press because the quick build kit requires minimal dimpling.

 

I did purchase a few sets of these for tight spaces and they work reasonably well but not recommend for dimpling the entire skin.

Pop Dimpler 1/8"

Ideally go with the tools below, they worked much better though a bit harder to used on the sheet metal and will be useful throughout the build.

ATS Pro Rivet Squeezer w/1.5 yoke

ATS Pro 3" Yoke

 

TIP

• As suggest leave the end-cap rib #1 off until you have inserted the counter-balance.

• When you are ready to pull the rivets for the those near the hinge brackets, you will find that the riveter won't fit. I used a specialty tool from ATS that has been invaluable for close quarters locations.

RV-12 CORNER RIVET PULLER

Completion notes

I completed most of the riveting omitting the leading edge rivets until I completed alignment on the wing.

I was missing the left and right aileron balance tubes, as these were back ordered.

Throttle Quadrant Assembly - Part 1

 

The throttle quadrant assembly is well documented and straight forward.

Evan Brunye has very detailed and helpful video on the assembly of this part:

3.5. Sling TSi Fuselage Throttle Quadrant

All rivnuts were installed with J-BWeld Steel Reinforced Epoxy.

Parts were cleaned and prepped using my established procedures for cleaning and treating components prior to assembly.

 

Testing fitting the hand brake master cylinder I neglected to remove the required 5 threads this caused the piston to bind on the brake handle and limit travel.

 

I deviated from the instructions rejecting the supplied parts and purchased a new parking brake valve that already had the required National Pipe Threads (NPT ).

The valve shipped with the kit uses British Pipe Thread (BPT) that need to be re threaded to NPT.

I found a replacement valve on MSCDirect:  Miniature Manual Ball Valve: 1/8″ Pipe

The valve mounts need to be slightly enlarged to fit larger diameter valve body but this is fairly easy to do.

Final assembly was delayed several months because I was missing the poly base that is mounted under the throttle quadrant cover. This delay gave me some time to get parts powder coated and laser etched.

I had a local shop power coat the brake and throttle parts and MidWest Panel Builders painted and laser etched "Sling TSi" on the top.

So very shiny.

TIP

• I recommend getting this part powder coated with your panel at MidWest so they can match your instrument panel color. They can also add customized logos if you want something unique for your plane.

Final assembly included the clear brake line tube which was pre-bent using a heat gun to achieve the required shape. This tube is quite ridged and can easily kink if over bent.

 NOTES

This part will be set aside until I am ready for final assembly.

There is a Service Bulletin #0024 that replaces part of this assembly and a new throttle cable, which I will cover in a separate post.

Elevator - Trim Motor

This was a quick assembly and easy to complete

Holes need to be enlarged to 4mm.

The nut plate is then attached to all four corners then aligned for match drilling the rivet holes using a 2.5mm drill bit.

The nut plates are then removed so that the match drilled holes can be countersunk.

Make sure you counter sink the holes on the correct side of the part!

Installation is differed until after painting and during final assembly.

I also replaced the wire loom provided by Sling with a pre-assembled wire loom purchased through Midwest Panel builders.

Elevator - Close out

Prior to attaching the elevator skin there are several tasks that need to be completed prior to final assembly. 

Evan Brunye has very detailed and helpful video on the assembly of this part:

1.2 Sling TSi Empennage - Elevator

Trim motor access panel

The ring doubler and locking plate need their holes enlarged from 2.8mm to 3.3mm using a reamer tool.

This is performed on the left skin prior to installing the skin on the sub-assembly.

From the picture below you can see the orientation of the locking ring with the tabs bent away from the cover plate.

Tip
You also need to install an M4 Rivnut noting the correct orientation

Access panel temporarily installed to test locking plate mechanism.

Parts were cleaned and prepped for final assembly

Application of a clear vinyl film that is sandwiched between the access cover and the locking ring to facilitate smooth rotation and eliminate any surface scratching.

Everything was riveted in place using 3.2 x 8mm domed rivets.

Tip:

Following the installation guide I initially left two holes empty, later I riveted these holes, then removed the mandrel using a small center punch so that I am not damaging the skin when opening this access cover. These rivets can be replaced if they become worn or damaged over time.

 

The left side of the elevator was the most difficult to assemble for a number of reasons.

The trim tab is quite delicate due to it's shape and it takes quite a bit of patients to remove the inner plastic film.

Installation of the gussets plates is quite challenging to install in the correct position and secure underneath the skin. I eventually installed them by reaching from the main spar aft towards the rear spar underneath the skin then having a helper secure them with a Cleco through the skin.

Prior to riveting the skin in place you must also install the piano hinge and trim-tab control surface.

I found that the spacing of the holes in the trim tab skin did not perfectly align with the holes in the piano hinge. The same was also true when matching the pre-drilled holes on the trailing edge of the elevator. I attempted to align them but I found that this caused binding and warping of the hinge and resulted in poor range of motion for the trim tab.

Several holes were enlarged / match drilled on both sides of the hinge to eliminate the binding resulting a free-floating control surface.

TIP

Prior to final assemble of the left side elevator skin it is recommended to secure the piano hinge wire as described in The Installation and Use of Piano Hinges article from the EAA.

This tip, and the picture below was provided by another Sling Builder that also has a great write-up on this part of the build. (photo credit: Sara's Sling TSi Build)

TIP

When riveting the trailing edge make sure the trim tab does not start to bind, I had to match drill several holes again to maintain a friction-less range of motion.

 

Left side elevator skin attached:

The right side skin was far easier to complete because it does not contain any of the complexities that exist on the right hand side.

TIP

Careful attention must be taken when Clecos are used to attach the skin to the sub-assembly.

It is extremely easy to deform the trailing edge and cause the skin to flex up or down as show in the pictures below: (photo credit Hall Liu)

Sequencing the Clecos can help, but it doesn't fully eliminate the problem. If you find that your trailing edge is bending in one direction or the other you may need to match drill holes on both sides of the ribs to relieve the strain.

There are multiple threads on this topic on the Sling Builders FB forum.

TIP

Prior to final riveting of the elevator skins I recommend that you test fit the elevator to the horizontal stabilizer to verify everything is fitting correctly.

I am super glad I did this because I found that one of my hinge brackets did not align correctly and I was not able to pass a bolt through the vertical stabilizer hinge.

Had I not completed this step, I would not have caught this issue and only realized the problem after painting and during final assembly!

 Offending hing bracket was removed allowing me to verify fitment and range of motion. (no binding)

Assembly of the elevator tips was completed using the same techniques applied on the rudder fiberglass cap.

I used POP Rivet Washers for 1/8" Diameter Rivets to back the counter sunk holes in the fiberglass to give the rivets something more surface area when pulled.

I also used a flexible adhesive to affix the washers to the fiberglass before riveting:

B-7000 Clear Glue

I used Clecos to hold the washers in place until the glue cured.

Everything was test fit prior to installing the left and right counter weights.

Fitment of the end caps was quite easy, as none of the fiberglass required any significant sanding or repair.

Small voids will be corrected with super fill during paint prep.

I have not installed the counter weight arm for ease of storage and I have omitted the installation of the center counter weights per Sling Notification 0009 (Center balance weight removal modification)

I also delayed installing the trim tab control horn to allow the part to lay flat during assembly and storage.