|LongEZ - N961EZ on the tarmac in Alamogordo, New Mexico|
I FLY EZ
27 Feb 2007. Hydraulic Pump, again!
Sorry for the bad focus, This is the exterior of the reservoir. These two fittings are VENT lines. The 90 deg fitting goes to the Emergency Blow Down valve. When the Emergency Blow Down valve is used, the UP pressure fluid is routed to this line. The Straight fitting goes to my overflow bottle. Normally this fitting location is a small vent fitting used for checking/servicing the hydraulic fluid. My Overflow bottle is just a small container that also has a vent line installed. Because of the location of my pump, its hard to check/service the hydraulic fluid. The overflow bottle will be mounted so it can be serviced from the front access hatch. The vent line will be routed overboard. I used JB Weld on the threads of both fittings to lock them in place. As described in the post below, an internal vent tube became dislodged. To keep this from happening again, I reformed the tube so the two vent fittings won't hit it. I also put a small dab of JB Weld on the tube before pressing it back into the housing. To make sure it doesn't vibrate loose again, I secured it to one of the internal pickup tubes with a stainless hose clamp. AND, Just in case anything leaks. I'm making a small pan that the pump will sit in. I still need to weld the seams and I'll weld an AN4 fitting on the end to connect to a drain.
26 Feb 2007. Hydraulic Pump!
These are the stainless actuator arms for the lower gear doors. The rest of the hardware is on order and should be here by the end of the week. I had a small seepage of hydraulic fluid from the pump. It was coming from the seal ring between the reservoir tank and the pump body. I removed the pump and disassembled it. I 'll use a small amount of "Right Stuff" on the seal when I reassemble. This stuff is a little expensive, but I guarantee, it works. During the disassembly, I noticed that there was a small 1/4 inch aluminum tube laying inside the reservoir (Seen in photo 1). I believe this tube is a vent tube for one of the pumps internal bypass. It presses into a small hole near the top of the pump. The tube can be vibrated or shaken loose and is not mechanically secured. This is not good quality (Pump made by OilDyne). When I reassemble the pump, I'll scratch the tube with sandpaper and put a small ring of JB weld on the tube so it stays in the hole. There was no signs of residue or debries in the bottom of the reservoir and both pump intake screens were clean.
25 Feb 2007. Main Gear Door - Closing the grasscutter door!
This photo shows the gear partially retracted, the gear is about 18 inches below the wheel well. This rigging and cable is temporary with makeshift parts. It purpose is a proof of concept of the rigging and geometry of the cable required to pull the small grasscutter door closed. And also verify the routing so as not to interfere with the other cables or hoses, and the location of clamps required to secure the cable. I'll use nylaflow tubing and stainless cable in the finished product. And, I'll order the correct length AN42 eye bolt instead of the one I modified for full length threads. I'll repost photos of the finished product when I reassemble it. In the photo, you can see the temporary pull arm on the lower door (grasscutter door). The real arm will be made once the correct geometry is verified. As it worked out, this arm has the correct geometry, and the opening and closing of the door is 100% perfect. I made a template of the arm and will probably make the real arm out of .032 stainless. I also have the correct clamps and stainless cable on order. 1 and 2) These show the cable attach point at the top of the gear with the gear retracted. Photo 1 is viewed looking outboard, 2 is viewed looking inboard. The cable thimble is attached to a standard AN42 eye bolt. I used a 10x32 dye to thread the rest of the shank so I could adjust the cable tension. The AN42 eyebolt is mounted through the strakes end bulkhead. You can see the threaded end sticking out in Photo 2. 3) This shows the AN42 eye bolt connection when the gear is fully extended. The AN42 is mounted through the Strakes outer bulkhead. These three photos show the grasscutter door atuator arm in various stages of the door closed. With the adjustments and geometry shown, When the gear is fully extended, the door is almost parallel to the ground (90deg from the gear leg) (Photo #1). When the door is fully closed and flush with the bottom of the strake when the the gear is retracted. (Almost fully closed in photo #3)
24 Feb 2007. Emergency Valve leak
I left the gear retracted last weekend. Today when I went into the shop, I found a small puddle of hydraulic fluid in the front seat. The leak source was the Emergency valve. I dissasembled the valve and put new o-rings in it. This valve, like the rest of the gear was in storage for over ten years. If I were to do this again, I would have put new o-rings in everything before I installed it. While rigging the lower "Grasscutter" doors on the landing gear, I discovered I mounted the left grasscutter on the right gear door. Not a big problem, just pull out the hinge pin and swap the doors. I also found out why the left gear door was hanging up, there was a dimple on the lip of the door. 10 seconds with the power sander took care of that.
18 Feb 2007. Intake scoops and Gear doors
Sand and fill the cooling intake scoops. I'll take them all the way to primer, then flox them in place on the fuselage. Having problems getting the left door to line up correctly. I'll look at it some more this week.
17 Feb 2007. Gear reassembled, Wheel Well Clearence OK
Before reassemblying the gear, I touched up the paint on the gear from the machine work I did. While I had a small amout of paint mixed, I painted the stripes on the prop tips. They look much better. After reassembling the gear strut, Slow retracts and checking the wheel well clearence. The wheel now centers nicely in the well. While I had the strut removed from the plane, I also machined the axel to correct for a wheel toe out problem. Initially, it looks OK, but I need to measure the toe out when I get the plane off the stands.
15 Feb 2007. Infinity Gear, HOW IT WORKS
I moved this entry to the RETROFIT / INFINITY GEAR page.
14 Feb 2007. SNOW DAY Happy Valentines Day
16 hours of heavy snow, PLUS, 40 mph winds out of the north made for five foot snow drifts all around the house and shop. I spent most of the morning clearing snow and helping the neighbors dig out. Then the rest of the day working in the shop
Left Gear Leg
I had two issues that needed to be dealt with regarding the left gear. 1) I needed to re-correct a wheel well / tire clearance problem; and, 2) I had a toe out issue that need to be corrected. While disassembling the wheel axel assembly to start fixing the two problems, I noticed the retaining ring on the bottom of the gear leg was not fully in its groove. At this point I decided to disassemble the entire strut and see if I could explain why the retainer wasn't in the groove, plus, I had a couple other questions I wanted to answer. The main question I had, "Could I make an adjustment in the strut to correct the toe out problem" ANSWER - NO, Once the foot was pressed onto the bottom of the strut (at Infinity Aerospace ) that was it. PLUS, I was curious as to how the strut worked, how it maintained wheel alignment, and how difficult would it be to service in the future. REPORT - This particular gear set is approximately 10 years old. I bought it from an individual who had purchased it from Infinity Aerospace but after many years, decided not to retrofit his LongEZ. The Infinity Aerospace design, materials, and workmanship are of exceptional quality. The strut assembly is a precision fit piece of equipment, The machine work on everything I inspected looked to be very high caliber . During the disassembly, I was looking specifically for any signs of debris, metal shavings, or other residue inside the strut. I found none. Although I didn't inspect all the o-rings, the ones I did look at were round with no nicks or scratches, and seemed to have the same resilience as new o-rings. I'll re-use them. Once I got the strut disassembled and examined its parts, it was obvious how it works. The upper portion of the retractable strut rides in two notches in the upper guide. There are four roller bearings. The notch and roller bearings can be seen in the photo below. Because of all the parts that are visible, the enclosed photos probably don't make sense. I took them mainly for re-assembly reference. I'll take a couple more photos tonight and put some captions in them so you get a better idea how this gear works.
Wheel Well clearance
I remachined the half fork so the mounting surface is again flat. This surface is mounted against the strut foot (Bottom of the strut). This should move the tire aft about 1/4 inch inside the wheel well. I originally machined the fork half to put a small angle on it. This was meant to correct for a wheel well alignment problem that didn't exist.. So, this should correct the correction!!!
To correct for the toe out, I was going to use shims behind the axel. However, because of tight clearances between the fork half (when its retracted) and the gear door, I decided instead to machine the correction angle directly on the mounting surface of the axel. I machined the mounting surface of the axel for about a two degree toe in. After mounting on the half fork and strut, this should give me about 1/2 degree toe in. I'll measure it after I get everything reassembled.
This is one of those type of rings that is a full 720 degrees, it wraps around on itself. During the course of disassembly, I looked for the reason behind the loose ring (The end of the ring was not in the groove). Paint on the ring leads me to believe its been like that for some time. I couldn't find any reason why it was popped out. I'm betting that at some point in the past, when I was whipping off the gear with a rag or towel, I snagged the end of the ring and pulled it out of the groove. I can't think of any other explaination. NOTE FOR FUTURE: Use caution when cleaning bottom of gear, recheck ring is not pulled out of groove.
12 Feb 2007. Gear doors
Making fine adjustments to the right gear door fit. This requires adding / subtracting shim washers on the four mount points. I started fitting the left gear door. To be continued.
11 Feb 2007. Actuator Leak and Cooling Intakes
I had a small hydraulic leak in both actuators. The left seemed to be a little worst. It was seeping two or three drops per day. I started to remove the actuator to troubleshoot the leak, When I removed the bolt for the piston rod end bearing and swung it down, I noticed there was a lot of paint overspray on the piston shaft. Paint on the shaft was fouling the shaft o-ring and not allowing it to make a good seal. Even though I was confident that this was the cause of the leak, I decided to completely remove the actuator and perform full inspection. When I disassembled the actuators, I found the inside of the actuator cylinders were clean, no residue or metal shavings. I did find one small strand of teflon tape, probably from the fittings that I removed. The o-rings showed a very slight "flattening" from their age, so I decided to replace all o-rings.
I installed new o-rings on the piston (AS568-221), end seal (AS568-222), and shaft seal (AS568-113). Note, the dash number is the o-ring size. There are two rubber "scrappers" on the piston, one on each side of the o-ring. These scrappers were not damaged, so they were reused. NOTE FOR FUTURE: Don't allow paint to get on the actuator shaft
The intake ducts are now glassed on the bottoms and sides. After they cure, I'll clean out the foam from the center duct. Once the outer skin is filled, sanded, primed and painted, theses will be floxed in place on each side of the aft turtle deck.
7 Feb 2007. EAA 582 Builders Visit
Our local EAA Chapter, 582, is very active in all phases of aviation. One of the activities that our chapter presents, is a monthly "Builders Meeting". Each month, interested members gather at the home, workshop, or hangar of the "selected" host. Well, this month, it's my turn in the barrel. (I think they choose me for February, because they know I have a heated shop) Members came and went as their time permitted. At peak, I estimate there were twenty people. We even had several visitors show up "Via the Web", courtesy of the Watch Waiter Work web cam. (RIGHT: Webcam snapshot photo taken during event). Although many of the guests had seen my project before, There were two main interests tonight; The Cowling, and the Landing Gear. The "Presentation" part of the meeting lasted about 60 minutes. Referring to this web site (I had a display that all could see) I provided my guests with a brief history of the project. I reiterated my goals of this retrofit program: significantly reduce drag, and, update the avionics and instrumentation. Because the LongEZ airframe is already aerodynamically clean, any seemingly minor improvements that can be made to reduce drag have a significant impact. One of the major sources of drag is the cooling system. I then spent a few moments on how the new "Downdraft" cooling system was designed, rather than "trial and error". A review of the Lycoming Cooling charts, airflow pressure tables, and a little math showed how this design had half the drag as the old "Updraft" system, yet provided significant improvement in cooling performance. Of course this mushroomed into the need to custom make new cowlings. Everyone was interested in this topic. Again, using this web site as reference, I walked through the process of creating a mold out of foam, then glassing the mold to become the shell for a new custom engine cowling. The next major topic was the Retractable gear. A discussion of how the Mains, Nose, and Speed brake are all tied into a computer, with sensors for airspeed, throttle position, canopy, ground proximity, and even fuselage deck angle. Through computer software, the pilot operation is simple and straight forward, UP-OFF-DOWN. The system is simple to operate, provides safeguards against accidental retracts, and allows numerous emergency extend/retract options. I pointed out one of the unique requirements of the main landing gear is the need to compress the struts prior to retraction. If the struts don't compress, the tires hit the fuselage and won't fully retract into the wells. I manually moved the gear up without compressing the strut to show my point. Then the big moment, The room filled with silence as I hit the "RETRACT switch. The audience gasped with awe and amazement as the pumps hummed and motors twirled. The Infinity Mains cycled and gracefully hide inside the well, the speed brake came up and went flush against the belly, and the nose wheel disappeared into its cubby hole. AWESOME. The crowds cheered, "Do it again, Do it again". (and we did, several times) Is this cool, or what :-) After the main presentation, the group split up for individual chit chat, questions, answers, and even some refreshments provided by Goldfish. I want to thank all those who attended. I hope you had an entertaining and informative evening. I also need to acknowledge the Goldfish (my wife), She played a major part in cleaning up the shop, and getting everything ready for the night. Thanks Honey. Waiter
6 Feb 2007. Mop and Clean - Visitors Coming
Waiter's Workshop will be the hosting EAA 582s "Builders Meeting" tomorrow night. Start about 6:30 pm and run till 9:30 or so. That means stop work and do an annual Shop Cleanup.
SEE YOU THEN
4 Feb 2007. Paint and Gear Doors!