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ibjet

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About ibjet

  • Rank
    Senior Crew Member

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  • Location
    Kingman, AZ, USA
  • Interests
    Flying, mountain biking, dancing, singing (Karaoke), camping, hiking, do-it-yourselfer.
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    Male

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  1. I used multiple strikes with a mini sledge hammer. Just made 2 holes so far, but they both came out very straight and clean (amazingly). I will try the same method with my home made punch. I've got a 6 foot roll of rubber, won't run out, ha ha. I can always machine the OD if I need to (but it's a mess and very slow. I realized I didn't share the finished MRA, so attaching. I have not redone it to show the number, but It's 20-021-USA. When I start machining the steel parts, I'm going to add a cutting oil flood system. I bought the flex outlet hose, but I'm making a gravity flow system with a supply jug and drain jug. Lots of little steps to this project! But, as I have said, really enjoying the challenge. 3-29-2020 update: Finished making my punch to blank out the rubber shock discs. Thought I'd share a couple pics. It is quite sharp: I nicked myself when taking it out of the fixture and it cut me! I'll have to find a container for it so the knife edge won't get bent up. I didn't make a handle, just put the rubber strip down on a 2 x 4 (I use the end of the 2 x 4, the punch cuts into the end grain easier), put the punch on top, put a piece of birch 1 x 2 on top and struck right over the punch with my mini sledge. BTW: That's a 1/8 dia. carbide end mill. The supplier said I shouldn't need cutting oil (and I didn't have it set up) so I did this dry. When I saw these online I realized it would exert far less cutting force (when I cut out the periphery of my chrome moly sheet parts). It did just fine, the part and the cutter stayed fairly cool. MRA - Engine Mount rev 3-16-2020.pdf
  2. Poking along on this engine mount repair. I am really enjoying the challenges. I have bored out the 2 flanges in the mis-located tube and polished out the paint. I bought a hone to finish polishing it. I made one trial rubber shock mount. I machined the OD and punched the hole (with a store bought punch, very reasonable). I'm sharing a picture of my holding fixture for machining the chrome moly spacer (don't have the hardware to clamp it to the mini rotary table yet). This piece of chrome moly tube I am actually going to make into a punch to punch the OD of the remaining 5 rubber shock mounts. I'm amazed how well the punching works, it takes 3 or 4 hits with a mini sledge, but makes a very precise hole. This first rubber shock mount meets my repair drawing dimensions/tolerances, yay! BTW: Got my MRA approval a few days ago. Big yay!
  3. My floor is asphalt. If you have concrete you could drill a hole with a concrete drill and install a concrete anchor. That would be easier with a hammer drill, they are very reasonable now. Removing and replacing your wheel pants would not be legal for an owner to do unless he has an IA to sign off the work. I went and got a Repairman license before I took delivery of my CTSW. Then I realized I had a very good IA very active at my airport! But, he is not very familiar with LSA's. If you have mechanical aptitude, you might want to see if there is a local (maybe retired) IA that locals use for owner assisted annuals. If so, and if you can do the work, I'm sure he would inspect and sign off very reasonably. You might want to consider going to the Repairman training (I believe the standard is 16 days). Allows you to sign off your work and Annual inspections. Still the very complex service (like pulling the wings) you need to get checked out to do. ET
  4. I have removed my nose wheel twice now. I made up a stand that goes just behind the firewall/engine cowling (like they describe in the service manual). Also drove a heavy steel stake into the floor just in the right place to pull down the tail. That is the main way to lift the nose wheel enough to drop the wheel/fork. The stand is a fail safe.
  5. I thought I was adding a link, it just shared one picture, grrrrr! I'll have to see how I share that post, my title was "Lubing the stabilator cable" (which is a misnomer, the push/pull cable does not need lube). I will make another attempt . . .
  6. There is a large counterbalance weight on a tube that is connected to the stabilator hinge. As I remember my stabilator is fairly balanced with neutral trim. There is a pretty strong spring that is attached to the stabilator hinge also. When I pre-flight mine, I move the stabilator up and down with 2 hands by moving the stabilator main structure and watch the "trim tab" as it bifurcates up and down (it goes up and down more than the stabilator). So, as I remember, I think mine is more neutrally balanced than you are describing. I had a corroded swivel bearing in mine which drove me crazy for a month until I realized that was the problem. You might look at yours with a flashlight and see if it looks corroded. I think you would need to disconnect the elevator (push/pull) cable to make sure that it swivels freely (it has to swivel for the bell crank feature to work). I wish I could come look at it with you! You probably don't have another CT on your airport to look at/compare to. Mine had a slight binding during travel that was making it hard to flare correctly on landing. Anyway, you might look at the post I did, I shared several pictures. I'll add a link to it here in a few minutes. You will want to get some good lube for all your moving joints back there. I posted a picture of the version I got (it has a needle applicator stem). Just viewed Dicks input, that's great info, confirmed what I remembered, mine is pretty level when trimmed. Here is a link to my post, a bit long, the second page has some pictures that will be helpful, one shows the balance weight: ET
  7. Set up my engine mount on my mini mill today and machined the first flange off up to the point of the weld bead (I thought it was brazed, would have been easy to machine). Anyway, it was very hard and it would have ruined my boring bit. I quit for the evening and shopped online for a way to grind the weld off. Ordered 2 sets of rotary bits. The second one is very promising: Dremel makes a mandrel and abrasive discs that are 1.5 dia! The tube ID is just under 1.5, so I can size the discs, then plunge cut to clean out the weld/remaining flange. I am enjoying this because of the challenge. I think I will do the MRA tomorrow, I love the drawing/technical writing too.
  8. Tom - Machining the flanges out of the engine mount and making the new details is a pretty difficult task. I will hire a specialist to do that (me, ha ha). But, once I have the parts made and clean up the bore inside the lower left engine mount tube, the inspection of the parts and assembly (which will be detailed in the MRA) is a minor repair. And, for good measure, I will have my hangar neighbor/resident IA sign off my repair. BTW: I found Loctite 620 which is for bearings and it is high temperature and high strength. It is rated 3,800 psi and rated for 450 degrees F. The mating surfaces of the flanges and the spacer will be over 4 square inches. And, for my fail safe retention, I'm now planning to make 2 custom washers which will be larger diameter than the tube and would keep the engine mount bolt from pulling out if the Loctite should fail. The washers and the custom flanges will be made from 1/16" thick 4130 steel condition N which is stronger than the ST37 steel used in the original mount. The bigger OD washers will keep the rubber from bulging out of the tube like they did before (you can see that in my picture with my first post above). I'm gonna hate machining the 4130 on my mini mill, but I ordered 5 carbide endmills so I can do it (and a 4" rotary table). ET
  9. Tom - I will not consider this to be a major repair. Removing and replacing the engine is definitely not a major repair (but yes, I have done it before). I do have a very good IA in the hangar next to me. I have been showing him what I'm doing too. I think he will be very tickled that I am doing this without welding. Thank you for the info. ET
  10. I do have authority to sign it off for annual inspections and authorized repairs. Are you citing some regulation?
  11. Tom - I appreciate your critical eye, that's what we all need here. I have not finished my total MRA package yet. The retention of my 2 new flanges and the spacer is a big concern to me. It is TBD ("to be determined"). I will have some type of a mechanical retention as a fail safe (but the weight of the engine is on the tube, not the flanges). Those flanges and the spacer will have to withstand 1/4 of the thrust of the prop. I confess - I'm not really sure what the force diagram would look like! As far as someone signing off on this work, I have a repairman license and Tom Peghiny will sign the MRA. As far as the custom rubber isolation discs, I will have the tools to make them with and a source for the rubber to make them from. And if you want to understand why I am doing this, I would rather make something than buy it. The offer of a discount was if I could wait several months for FD USA's next big delivery and then I would have to pay for delivery from back East. If I wanted it delivered to me, it would be "about $3,200" (same as retail price). ET
  12. Some kind of loctite + maybe a couple of high strength rivets as fail safe. I could have them brazed, but I think I don't want to do any heating. I found loctite 272, but I think I'll use a bushing retainer. Anyway, TBD, ha ha.
  13. Andy - I pulled my engine because of a coolant leak in the back (turned out to be just the hose connection to the coolant elbow) and because my engine was sagging (the spinner was getting too close to the lower cowling). Then when I saw that the lower left engine mount tube was so mis-located (see picture above) I started measuring the hole pattern (1/4" different on the left side than on the right side) and started thinking about how to fix it. Once I realized that the lower left engine mount tube had a metal to metal condition I was sure that I could not put it back together that way. My airplane is extremely noisy in the cabin while flying and I didn't worry much because I bought 2 nice David Clark head phones with noise cancelling. But, now that I know about this situation, I suspect the extreme noise is due to the vibration being transmitted there. I hope to notice a big improvement. Darrel - Re: larger washers - brilliant suggestion , ha ha. I was thinking I should do that! Re: the type of rubber for the shock mounts, I started researching last night and most shock mounts are made of Neoprene. Some are made with Silicon rubber and I just found a specialty called Sorbothane. I also searched for a gauge to measure rubber hardness. I was pleased to find they are very reasonable. I bought one last night for $24.99 from Amazon. I read that the softer the rubber the more the vibration dampening. So, I will get rubber the same hardness as the existing discs. I'll post a copy of my MRA when I get it done. AGLyme - No, I am not correcting the location. If you compare my Mod drawing to the picture of the mis-location it is essentially the same. I just compensated for the mis-location inside the engine mount tube. The machining I will do is to carefully bore out the 2 flanges inside the engine mount tube. I'm doing that because I need to make room for a total of 6 shock discs instead of the original 4 (and that is just "gut feel" engineering). I probably will end up with this mount having less shock absorption than the others, but it will have to be way better than metal to metal. Thx folks! ET
  14. AGLyme: Thanks for the compliment! Correct, no welding. To put it simple - My lower left engine mount tube is mis-located up .180", so I will move the center hole in the rubber shock discs down .180". If you look at my drawing, you can see there is about the same amount of mis-alignment externally, but there will be little or no mis-alignment inside the mount tube. So, the toughie for me, I have to find a suitable rubber and make 6 offset rubber shock discs. I will use a steel rule die technique, but I'll probably just get the correct diameter steel tubing and sharpen the end to a knife edge. Then I'll cut the rubber "cookie cutter" style but I'll make up a little press frame and use a hydraulic jack to shear the rubber. If anyone wanted to understand my madness more, ha ha, here is the description that I sent to Tom Peghiny: What I plan to do is make special rubber shock discs with the center hole offset .180". I decided to make this work I would need 3 shock discs on each side of the mount tube. I will also need to remove the 2 flanges inside the lower left mount tube (I will bore them out with a boring head on my mill, I will clean up the inside of the tube very precisely). And, to replace those 2 flanges, I will make and install 2 new flanges with the center hole shifted .180". And, instead of welding them in I will rig them into position and lock them in place with loctite 272, High Temperature/High Strength thread locker. I plan to use .375 thick Neoprene sheet to make the shock discs. I found a source for it, but I will have to verify they can supply the right hardness and grade. I will cut the ID and OD with a home made steel rule die, I've done that before (not that thick, but I'm sure I can do it). The other details I will make from High Strength Low Alloy Steel. McMaster Carr sells it in small sheets in thin sections and tubing by the foot. I found out we have a good welder in Kingman (the local I.A. at the airport has used him many times). I may ask him about brazing in the new metal parts. Or, look into putting in a couple of high strength rivets to lock the metal parts in place (just as a fail safe). ET
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