Archive for July, 2011

Installed Floor Stiffeners – 6 hrs

July 31, 2011 Leave a comment

Sunday Jul 31, 2011

This morning I finished light-weighting the rudder pedal center support bracket by cutting about an inch off the end and drilling three holes in it. The largest (2.125 inch diameter) and the smallest (1.0 inch diameter) holes were drilled with hole saws which I happened to have. The middle hole is 1.5 inch diameter and I cut that the hard way using a ring of small holes followed by considerable filing with a rotary tool.

Then I started working on the floor stiffeners for the forward fuselage. The angles come “pre-bent” with joggles on each end to accommodate the step up over the bulkhead flange at each end. Unfortunately they are far from perfect and many builders complain about them. I have followed the lead of other builders by “tweeking” the angles to help them lay flush on the skin. The next three photos show the before, tweeking, and after stages of one of the stiffeners. In the first you can clearly see how the stiffener sits on a high point in the joggle.

Here is the simple setup I used with my pneumatic squeezer to flatten the flange up to the joggle. I adjusted the squeezer to put just enough deflection on the flange to flatten it. It springs back a bit so you have to over compensate just a shade to get the desired result.

This photo shows the finished shape. It lays pretty flat now right up to the joggle.

Then I aligned the ribs in the fuselage and match drilled them using the skin holes as the guide. I found that the holes did not fall right on the center of the flanges on the middle two ribs when clamped in place per the instructions but the edge distance is fine. The outer two stiffeners are aligned based on a centerline drawn down the flange of the stiffener.

The boring photo shows the skin drilled to the stiffeners.

There are three holes on the inside that are a bit tricky to drill. At first I thought these would be tough to drill even if I had a 90 degree angle attachment for my drill because they are very close to the skin and the bulkhead. Then it occurred to me to remove the skin and drill them using a 12 inch drill bit which I could flex to allow me to offset the drill enough to miss the adjacent bracket. That actually worked pretty well as you can see here.

Categories: Fuselage, Fwd Fuselage

Finished Rudder Pedal Install – 6 hrs

July 30, 2011 Leave a comment

Saturday Jul 30, 2011

This morning I picked up where I left off last night on the rudder pedal assembly. I drilled out the holes in the pedal weldments where the AN3 bolts fit because the power coat reduced the hole size a bit. Then when installing one of the pedals I discovered that one of my angle brackets was misaligned by about .06 inch and would not fit into the weldment. So I had to remake that angle bracket which side tracked me for about a half hour. When that was resolved I installed the pedal assembly into the fuselage to check the fit.

The Matco brake cylinders in the kit do not have any adjustment capability to align the brake pedals so you have to drill the holes in the pedals carefully or you may end up with one pedal tilted relative to the other. I made a simple tool like other builders to help with this. It is simply an AN3 bolts with the end ground to a point. With the two pedals clamped together and held at the nominal position I used the tool to scratch arcs across the face of the pedal horns as illustrated below. Then I tool the horns off and drilled the holes in the center of the horn along the arc.

Then I put them back together and presto – pedals aligned!

Next up was the center bearing and its support. Like the side bearings I marked and drilled holes through the bearings for the mounting bolts first. But the bearing comes as a single piece in the kit and it has to be split along the horizontal centerline. So I marked the center and set it up in the bandsaw and cut a nice straight line down the center.

The bearing support has to be notched to avoid an interference with the firewall recess so I did that next. There are also a set of five holes that I marked and drilled along the forward edge where it will mount to the firewall. Then I removed the firewall recess and clamped half the bearing to the pedal tubes and the support and adjusted the position relative to the firewall. At that point I was able to drill the holes in the firewall rib through the bearing support using the holes I just drilled a few minutes earlier. That set the position of the support on the firewall. Then I was able to drill through the bearing block and the support for the bearing mounting. But that is just for one position of the pedals. Since I drilled holes in the longerons for three positions of the pedals I had to unbolt the pedals, move them to the next position, reset the center bearing clamp and drill the next set of holes in the support. I did that for all three positions.

With that task completed I removed the pedal assembly from the fuselage and began to set up to install the floor stiffeners. I will drill the lightening holes in the center bearing support later. In the mean time here is a stupid candid shot of me inside the forward fuselage upside down. That is mainly for Mr. FAA.

I had not yet match drilled the holes along the lower longerons in the forward section so I did that next. It just took a while because the material is pretty thick there and the firewall parts are steel.

Categories: Fuselage, Fwd Fuselage

Rudder Pedal Bearings and Mounting Holes – 2 hrs

July 29, 2011 Leave a comment

Friday Jul 29, 2011

I was back on the project tonight after standing down a few days due to job demands. I picked up with the rudder pedal bearings which have to be drilled for the mounting bolts. I marked the hole locations and drilled first a #30 pilot hole then opened them up to a #10 which gives a good fit through the plastic for an AN3 bolt.

Then I measured 3 inches back from the firewall and marked a line on the auxiliary longerons, then removed them from the fuselage for drilling. I used the bearing as a guide to drill the first two holes through the longeron. Then I moved the bearing aft by 1.08 inch and drilled another pair. I repeated that one more time so I have three positions for the rudder pedals with slightly more than 1 inch between positions.

Here are the resulting holes in the right longeron.

Then I set up a couple of supports and mounted the pedal assembly on the work bench.

Categories: Fuselage, Fwd Fuselage

Finished Preping Rudder Pedals – 1.5 hrs

July 26, 2011 Leave a comment

Tuesday Jul 26, 2011

Tonight I finished preping the rudder pedals for assembly. I finished making the F-6117C angles and I aligned them to the pedals, match drilled holes and countersunk them for flush head rivets.

Categories: Fuselage, Fwd Fuselage

Finished Installing F796s, Started on Brake Pedals – 2 hrs

July 25, 2011 Leave a comment

Monday Jul 25, 2011

Tonight I finished installing the F796B, C, and D parts. I first clecoed the C and D shims in position using the one pre-drilled hole then clamped them in place with a small block of wood I could drill into. Then I drilled carefully from the outside of the skin so as not to disturb the position. Then I followed the lead of several other builders and used -3.5 rivets to hold the shims in alignment while I placed the F796B angle and clamped it with a block of wood as you see below. Then I just drilled through from the outside again.

The plans warn you to be careful to drill perpendicular to the skin so I used my drill cup. Of course I held the cup while drilling but I needed a free hand to take the picture.

You can see the hole edge distances in this shot. As other have reported, it is a little less than ideal in the lowest hole but since the skin is pre-drilled it’s as good as it can get based on this design. I still need to match drill the holes through the skin into the longeron on top of this picture. I’ve been waiting for the plans to say to do it.

Going along with the instructions I started work on the rudder pedals beginning with making the F-6117C angles. In this case four angles for two pedals. I am not doing dual brakes at this time, although that could change.

There were a couple of trim cuts to make on these parts to reduce weight slightly then I clamped the parts together. Looks good for a start.

Then I deburred the pedals and brackets. That took a while since the parts are thick and deburring those holes is a pain in the neck. Here is how they looked when I quit for the night.

Categories: Fuselage, Fwd Fuselage

Finished F-902s, F-7101s, and Started F796s – 6 hrs

July 24, 2011 Leave a comment

Sunday Jul 24, 2011

More solid progress today on the F-902 bulkheads and the F-7101 Gear Attach Webs. I even made good progress on the F-796 spacers and reinforcement angles. I started by opening holes in the F-902s to 5/8 diameter forĀ  snap bushings. I also cut a notch in the adjacent flange for clearance to the rudder cable.

I checked the gap between the F-7101 webs and the F-902 bulkheads. Some people report a gap here but mine fit nicely requiring no shims.

I drilled all the flanges of the F-902 through the skins and I marked and drilled the lower and upper flanges to the longerons. I my case I just measured and marked the location on the other side of the longeron to give good edge distanceĀ  and drilled through. These turned out fine.

I did notice a slight gap between the top flange tab and the longeron so I made shims for this location. It was .032 on one side and .040 on the other. You can just barely see the edge of the shim in this photo. Remember this in this photo the fuselage is upside down.

I then checked fit the F-7101 webs. In my case the upper edge (lower in this photo) was riding up the radius on the inside corner of the F-713 auxiliary longeron. So I rounded the inside edge of the web and that took care of that. On the other side I had to take about 1/32 off the edge of the web as well as round it. Then I drilled the F-7101s though the skins and F-704 bulkhead and cleco’d it together. Next I drilled through the F-902s from the flange of the F-7101s. There are four holes on each side but I only had two clecos installed in this picture.

This picture just shows the completed F-902 and F-7101 on the right side of the fuselage because I like it.

It is not clear what stock one should use to make the F-796 C and D shims. I found this piece of stock in my box of miscellaneous kit parts. It is the right kind of material. I just hope it’s not earmarked for something else because I used it to make the F-796C shims. I had plenty of stock of .032 sheet left over from the empennage kit for the F-796Ds.

I also scratched my head on the raw material for the F-796B angles. There are several 9’10” pieces of 3/4 x 3/4 x .125 in the kit but I was reluctant to cut these little parts from that long stock. Fortunately I saw Steffen’s web site from Denmark and he reminded me that I had several short pieces of 3/4 x 3/4 x .125 scrap left over from the main longerons which worked out perfect for these two pieces. I also got a tip from several other web sites to watch out for a problem with the F-796C and D shims. The holes need to be drilled slightly offset to one side of the centerline to avoid interfering with the F-902. So I measured the location of the hole in the F-902 relative to the flange and duplicated that on the shims. Headache avoided.

I was also warned to be cautious about fitting the F-796B angles to the forward fuselage. Everybody complains that the dimensions on the drawing are not correct. So I measured before cutting the ends and was able to make these fit really nicely. Here is the one on the left side of the fuselage. Ready for drilling, but that will have to wait for another day.

Categories: Fuselage, Fwd Fuselage

Finished F-717s and F-684 Gussets – 6 hrs

July 23, 2011 Leave a comment

Saturday Jul 23, 2011

This morning I resumed work on the F-717 lower longerons. First I trimmed the1-inch flange off of the second longeron for 4.125 inches on the aft end. Then I twisted the first longeron to make it fit well against the WD-603 bracket and be flush to the skin at the aft end. The twist turned out to be about 3 degrees for those who care. I also notched the fwd end to get a “nicer than required” fit around the WD-684 and I trimmed the aft end at an ever so slight angle.

The fwd end also needed a small chamfer to clear the F-713 longeron as you can see in this closeup.

I spent a fair amount of time laying out the hole pattern on the fwd end of the lower longeron seen here. You need to be careful to get an acceptable edge distance on both sides. It would be easy to mess this up good. I first drilled it #30, then opened the holes up to #19 and finally #12 as you see here.

The F-684 gussets turned out to be a pain in the neck. The instructions are a bit vague here about how to get a good fit. You really have to figure it out as you go. You end up with something like a joggle in the gusset to sit flush against both the firewall rib and the WD-603. Again, I laid out the position carefully to preserve acceptable edge distances on the gusset and the rib. In this photo it is positioned for drilling. I put another clamp on it before drilling.

This photo shows the result after drilling. The one hole in the upper left corner is close to the edge distance limit but acceptable.

Finally I cleco’d in the F-902 forward bulkheads as a fit check.

Categories: Fuselage, Fwd Fuselage