Maj. Woody's Skymaster 1/5 F-86
12-08-2018, 03:49 PM
#102
I prepared the BVM hinges my trimming them as shown. Next I glued them in place with 30 min epoxy mixed with milled fiber. Note that I also made a second door cylinder attachment tab out of carbon fiber and glued that in place as well. The doors look pretty crude at this point but clean up well with some sanding / filling and look good when painted.
12-08-2018, 04:06 PM
#104
The next order of business was to install a second door cylinder. I chose Robart 3/8" X 1.5" stroke cylinders. They have an 11 pound rating. I played around with the location of these for a while as there is not a lot of clearance in the well with that big main wheel in there. I settled on a spot and glued in a bass wood block as a standoff. I then installed a 6-32 blind nut. The assembly is bolted in place with a wheel collar acting as an additional spacer which allows the cylinder to pivot freely. The doors operate freely but I fear that they may still open in flight as I can still pry them open with my fingers even at 120 psi. The reason for this is the location of the tabs on the doors. They are very close to the hinge line and do not provide much leverage.
12-08-2018, 04:17 PM
#105
Before I could begin work on mounting the retract, I needed to have the wing firmly bolted in place so that I had accurate centering for the wheel. There is a 4mm bolt that runs through the fuse and into the wing root. Since there is a gap between the wing and the fuse, over tightening this bolt could cause the wing root rib to crack. To prevent this, I shaped and glued in a basswood wedge. Now you can tighten up that bolt as much as you like and it draws the wing in nice and tight.
12-08-2018, 04:21 PM
#106
Up front the wing is held in place with an aluminum tab that mates up with a plywood block in the fuse. The threads in my tab were poorly tapped so I ran a 4mm tap through it and cleaned up the threads. H
ere is what it looks like with the provided 4mm cap screw.
ere is what it looks like with the provided 4mm cap screw.
12-08-2018, 04:33 PM
#108
So the retracts come preinstalled with wood screws. I have two issues with this. First I do not like wood screws. I like Dubro bolts and blind nuts. Second, as delivered, the position of the retract caused the wheel to not fit inside the well in the fuse. To correct this, I needed to relocate the hole location for the retract bolts. This is accomplished by epoxying in hardwood dowels and then sanding them flush with the retract mounting rails
12-08-2018, 04:43 PM
#109
At this point I had already completely disassembled the main gear retract units and reassembled them with loctite. I was disappointed in the amount of play between the trunion and the trunion pivot pin. It is excessive and this causes a problem with ensuring the wheel can clear the door cylinders inside the fuse. In these photos you can see the the effect of the slop and how it drastically changes the clearance between the tire and the door cylinder. When the jet is on its gear the slop will be fore and aft not side to side but if the jet ends up wobbly on its gear, I will have to reach out to Anton about some replacement trunions / pivots.
12-08-2018, 04:51 PM
#110
With the retract positioned to clear the door cylinder, you can now drill the new holes for the retract bolts. I used a centering drill to establish my pilot hole. You can clearly see that the location has changed. Please note that by the time you go up through the drill bit sizes to accommodate the blind nut, the dowel you glued in place will be gone but if you did not glue that dowel in you could not possible drill the hole with the precision required to clear that door cylinder. By the way it takes me forever to get these holes drilled since I step up the drill bits slowly only skipping one size each time all the way up to the final hole. Its something like 6 or 8 different drill bits. The benefit of doing this is that you will precisely maintain your center. Going to a large bit right away can cause the hole location to shift.
12-08-2018, 04:59 PM
#112
That was the easy side. The opposite rail has a plywood vertical web in place making the location of the hole problematic and also not allowing access for the blind nut. I decided I needed to open this up but ran into a problem. My 90 degree Dremel attachment was too large for me to get in there and grind the slot.
12-08-2018, 05:11 PM
#113
I searched die grinders and porting tools for a couple of days and could not find anything small enough for under $500! Then I came across an ad from Bang Good .com. It's a Chinese Amazon type site. They had a small die grinder for $52. I took a chance and thought even if its junk but can at least get this one job done I will be happy. The website said it was in stock in the US but that proved to be false. I took two weeks to get here. When it arrived I was quite impressed by the unit. Although I bought it from China, the unit is actually made in Germany and is of very high quality. I am expecting years and years of service from this one! You will have to change the air hose connector to a standard 1/4" NPT fitting and I also drilled the collect out to accept 1/8" Dremel bits. Here is a link to the unit and some photos to show the size compared to the Dremel unit.
https://us.banggood.com/Wholesale-Wa...BoC_iMQAvD_BwE
12-08-2018, 05:19 PM
#114
Now that I had the blind nuts installed on both rails, I decided I was going to add Carbon Fiber to the lower rails since the plywood seemed to be very weak and brittle looking. Not even close to good old Midwest or Sig Plywood. The jet comes with Carbon Fiber over the top of the rail but I wanted to reinforce this area. I measured and cut the Carbon Rails and then milled some recesses in place to accommodate the blind nuts that I just installed into the plywood rails. 
12-08-2018, 05:31 PM
#117
After cleaning up the Main Gear door, I painted it along with the wheel well. Before I painted the wheel well, I saturated the whole area with thin CA in an attempt to strengthen the plywood. The whole area looks a lot better now!
Last edited by MaJ. Woody; 12-08-2018 at 05:34 PM.
12-08-2018, 05:54 PM
#118
You will need to plan the routing of your wiring through the wing. I wanted my wires and air lines to come out of the wing root at the LE.
With that in mind, and starting with the aileron servo, I needed to cut an opening in the aileron servo box for the wires. I am using Futaba 9156 servos for the ailerons and these are bolted to the supplied aluminum rails. Be sure to bevel the end of the rail where it mounts to the servo so that they remain 90 degrees to the servo when bolted up tight. I used thick CA on each screw before tightening them down. I do do this in place of loctite as you never want loctite anywhere near plastic as it will make the plastic crack almost immediately. The plywood mounting rails inside the aileron pocket needed some trimming to allow the servo to fit as did the fiber glass around the rails. I then attached an extension to the servo and secured the connection with shrink tubing. A drop of CA went on the servo arm screw and the 4 servo mounting screws when installed.
12-08-2018, 06:05 PM
#119
I decided to go with external linkages for both flap and ailerons. After cutting the slot for the carbon fiber horn, I glued it in place with 30 min epoxy. I then cut the slot in the hatch for the servo horn. I used the supplied hardware and used both loctite and thin CA on the push rods and clevis so that there would be no chance of these unscrewing. A clip was installed on both clevis ends and then all screws and linkages were painted before final installation. The hatch screws had a drop of CA on them when installed. The aileron throw was set at 20mm up and down as measured at the inner TE.
12-08-2018, 06:16 PM
#120
The flaps have the hinges glued into them but are not glued into the wing. After freeing them up a bit and working them so that they had no drag, I positioned them on the wing to check the clearances between the flap and aileron and the flap and fuse. Then made up a balsa spacer to put between the aileron and flap. This helps keep the flap properly positioned when gluing in the hinges. I glued the hinges in with Hysol and taped the flap in the up position while the glue dried. Once dry I installed the Futaba 9156 servo just like I did for the aileron and painted the exposed hinges and linkages. I set the flap travel to 25mm for takeoff and 65mm for landing as measured from the aileron TE.
Last edited by MaJ. Woody; 12-08-2018 at 06:28 PM.
12-08-2018, 06:33 PM
#121
The LE Slats are operated by two Futaba 9155 servos. They are installed the same way as the other servos. Once installed, I marked the location of the servo horn on the wing and then transferred these marks to the slat. I then cut the openings in the wing LE using the dimensions listed in the plans. Some milling will need to take place inside the flap box to create clearance for the slat pushrod.
12-08-2018, 06:51 PM
#124
After cutting the slot, I glued the control horn in place with 30 min epoxy. Here is the completed linkage and servo bay for the outer slat servo. Note that I broke the tab off the end of the clevis keeper so it did not interfere with the slot in the wing. The hatch screws were painted and installed with a drop of CA as with the others. I set the slat travel to 30mm as indicated in the plans. I have my slats set so that they come out to the full 30mm with takeoff flap and stay out with landing flap. Flap and slat servos have a reduced speed so there are no abrupt transitions in flight.
12-08-2018, 06:56 PM
#125
The inner slat servo bay serves as a junction where all the wiring and airlines pass. I used snake skin to protect the wires from any possible damage as they make the sharp bends in this area. To keep the wires clear of the slat push rod, I made a gusset with a hole in it so I could zip tie everything clear of the push rod.
