Connecting gear door to struts????
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Looking for some help here. Just got my Robart retracts today (finally... 8 weeks) and I'm trying to figure out how to connect my gear door to the landing gear strut of my Bates SBD Dauntless.
The attached photo of the full scale plane shows some sort of turnbuckle that moves the gear door along with the strut when opening & closing. There is no fitting/attachment on the Robarts to connect to. Any idea how I can recreate this mechanism at 1/6 scale?
Thanks,
Neo
The attached photo of the full scale plane shows some sort of turnbuckle that moves the gear door along with the strut when opening & closing. There is no fitting/attachment on the Robarts to connect to. Any idea how I can recreate this mechanism at 1/6 scale?
Thanks,
Neo
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you need to fasten a tab to the door and the strut, I usually use a brass tab brazed to the strut, but you could use something like G10 and glue it, I use G10 glued to the door. You then use 4-40 rod with a ball link on each side. You will have to play with the angle between the tab points, do this before final gluing. You will see that the door changes angle as the strut opens and with proper adjustment should close up nicely against the strut. Do not get frustrated it will take some fiddling to get it right.
Mike
Mike
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Neo,
I have rigged many of these on drop check/acceptance inspections over the years.
Permanent installation: Tig is a good idea.
Temporary installation: fabricate a brass fitting and solder the brass to keep the ends together, epoxy the fixture to the strut.
The link is a threaded rod (with jam nuts) connecting two clevises, you will need strong hinges, the hinge will most likely be the weak link.
Rig the door (in the up position) with a small amount of preload and ensure that the leading edge is out of the air stream.
R. C.
I have rigged many of these on drop check/acceptance inspections over the years.
Permanent installation: Tig is a good idea.
Temporary installation: fabricate a brass fitting and solder the brass to keep the ends together, epoxy the fixture to the strut.
The link is a threaded rod (with jam nuts) connecting two clevises, you will need strong hinges, the hinge will most likely be the weak link.
Rig the door (in the up position) with a small amount of preload and ensure that the leading edge is out of the air stream.
R. C.
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I've done meny of these. As big max 1935 pointed out it is a strap on the full size. I usually get the roofing tin they put on houses just over the drip edge and I can usually get it in 36x36 peaces which allows me to make alkinds of good things with it. Anyway stay away from brass or alloys with copper in them as they are subject to fatigue break downs. You first have to decide how close to scale you want this strap to be, you can see that the scale one is very thin. The thinner you make it the more often it will break. I've found that if I make it 3x the width of the hole I have to put in it, it will last for ever.
Anyway we need to cut the strap out when cutting the strap you will notice that it creats a bur on one side the full length of the cut. I cut my straps so that that bur is on the same side for all cuts (that is why it's not going to move on you). Fit that strap to the OLEO leg by pushing it around the leg tightly and let the excess come together on the opposite side. Make sure you have a good crease where the sreap comes off the strut on both sides.
Remove the strap and cut the access to twice the length you want and bend that over on its self away from the other end of the strap to creat an ear. To make the clamp clamp we need to provide tension in the clamp. So I mark the crease on the other side of the clamp and move in strut about 1/16-1/8 (first time use 1/8 and make a new crease there. Cut that tab to twice the length I need and fold it over to creat the other ear. Now drill those ears to clear the thread of your ball link.
To install Put the strap over the strut, put the ball link threads throught the holes in the ears, and put a lock washer and nut on the other end. Tighten them down and loctite them (Final tightening is after everything id hooked up and working correctly). Lastly once confident of the location I run CA under the strap (it wicks right in), with the burs against the strut it creats a raised area that will never let that strap move again.
Ok, so it was not so simple! To me it is and I hope I've explained it so you can understannd it. This is one of those cases were a picture realy is worth a thousand words.
Good luck!
Anyway we need to cut the strap out when cutting the strap you will notice that it creats a bur on one side the full length of the cut. I cut my straps so that that bur is on the same side for all cuts (that is why it's not going to move on you). Fit that strap to the OLEO leg by pushing it around the leg tightly and let the excess come together on the opposite side. Make sure you have a good crease where the sreap comes off the strut on both sides.
Remove the strap and cut the access to twice the length you want and bend that over on its self away from the other end of the strap to creat an ear. To make the clamp clamp we need to provide tension in the clamp. So I mark the crease on the other side of the clamp and move in strut about 1/16-1/8 (first time use 1/8 and make a new crease there. Cut that tab to twice the length I need and fold it over to creat the other ear. Now drill those ears to clear the thread of your ball link.
To install Put the strap over the strut, put the ball link threads throught the holes in the ears, and put a lock washer and nut on the other end. Tighten them down and loctite them (Final tightening is after everything id hooked up and working correctly). Lastly once confident of the location I run CA under the strap (it wicks right in), with the burs against the strut it creats a raised area that will never let that strap move again.
Ok, so it was not so simple! To me it is and I hope I've explained it so you can understannd it. This is one of those cases were a picture realy is worth a thousand words.
Good luck!