I pulled a Jeff and got a new project: ESM 71" SBD-5 Dauntless

[willsonman]

I took another look at that landing gear and those grub screws were indeed set with loctite. I'm not sure what to do about it other than to cut into the aluminum to create grooves for a screwdriver, as stupid grub screws strip out with the allen key so easily. I was able to wiggle the strut out a bit but not entirely and you can clearly see that the grub screws dug into the pin very well... but softened over multiple landings. Its just damn frustrating... like gear always seem to be.

 

[jaredstrees]

I feel your pain. As I get better and better at building, I find that landing gears stills seems to be my Achilles heel.

 

[FOGeologist]

I feel your pain. As I get better and better at building, I find that landing gears stills seems to be my Achilles heel.

I find landing on surfaced runways tends to be my Achilles' heel; the gear take a beating and then it's a struggle to get them to deploy or raise appropriately.

Subscribed. Looking for a video!

 

[willsonman]

Video WILL be shot at FF... maybe...?

So, I started to tackle the troubled gear last night. I had used loctite on the grub screws in the aluminum trunions so I knew it would be a struggle to get them tighter... or out for that matter. Ended up stripping the hex part of them. Seems that happens all the time with these small grub screws. So, I tried my method of cutting a slot with the dremel and then use a screw driver... no good. Started to drill out the grub screw with some oil and still no love on my cheap bits. Went out a got a carbide bit for hard metal drilling... broke in less than 5 minutes of use. I did manage to get the pin out of the trunion so there is progress there. I'll pick up another bit today and keep at it. The plan is to drill out one hole much larger for a much larger grub screw and have it set like a boat anchor.

Got the exhaust pipes glued on this morning. Forgot to snap a pic. With the air cylinders for the Corsair expected tomorrow, there is a strong possibility I may not get the trapeze mechanism done for FF... one day at a time.

 

[willsonman]

Got the one grub screw out. Drilled and tapped for 1/4-20 and the new grub screw is solid. Too her out this morning for taxi testing and she did great. I spent time adjusting the tail wheel too so she would track better.

 

[willsonman]

So, moving along, I'm not sure I'll have time to complete the trapeze mechanism. I've a couple of other smaller priorities for my final prep for FF. I do have tomorrow off and will be starting my vacation time on Friday. So, I will have time, but I'm not sure it will be enough to complete it. I'll try as I think it will be a greatly added feature.

 

[willsonman]

Had a productive 4th of July.

I removed the moulded plastic belly pan and started to figure out where to place the servo. It ended up being further back that I would have liked due to the location of the flap servo on the opposite side. Oh well.


Then, I carefully measured and drilled out 1/4" holes for 1/4" oak dowels. These were epoxied in place after being cross-drilled out for the pivot pin. First set were too short so I cut a new set that were longer to have the clevis point on top of the belly pan. After the pins had cured, I re-attached the belly pan after trimming a hole for the servo to protrude as well as a hole for the pins.


Mounting the pivot bracket I realized that I could get some binding from the clevis so I offset the bracket using a prop bushing. This allows good clearance of the clevis so that it will not bind on the oak dowel.


After testing functionality, I painted all the hardware white and whipped up some hard points for the bomb to rest against. I did not want the bomb to sway side-to-side or interfere with the linkage so a 5-minute design and a couple of 20-minute prints later I was in business. During the printing, I got the bomb painted up a bit too. I used shrink tube over the mount pins to keep paint off them so that the release would not bind.


While this is not PERFECTLY scale, it serves the same function and its the first time I've done, or even seen a functioning trapeze release mechanism. I'll take some time to work on the programming of the release and she will be good to go.

 

[willsonman]

Reporting back:

She did not fly. The canvas runway is a good idea but not an ideal one. The temporary nature of it does not lend itself well. What happens is that the model, due to it's weight, sinks into it and creates a ripple in the fabric ahead of it. The sinking also creates additional drag on the mains causing the airplane to want to pitch forward. This makes the tail quite light and weight on the tail wheel is too little for handling before the tail has enough airspeed for good control. The hard runway was also a good idea BUT at each end there was a ramp of sorts... not great for gear if you hit it.

Long story short, it is a short story. I tried to take off and she lifted too early as I tried to keep the tail down with elevator and she stalled a bit, I tried to recover and she went into the beans. No major damage but the landing gear mounts need to be repaired and that is all. I did do some taxi testing and the weight of the bomb was too much for the trapeze. I'll try to cut up the bomb model differently for printing and vacuum form a bomb to make it lighter.