Simple Gear doors ?
06-18-2004, 01:12 PM
#1
Thread Starter
Simple Gear doors ?
Does anyone have any pics or tips on how to make working gear doors without using air cylinders?
Like with....strings, springs rubber bands....mechanical stuff and what not....
Or is this too unreliable for a jet ?
Im thinking of my eurosport in particular......
Thanks, SJ.
Like with....strings, springs rubber bands....mechanical stuff and what not....
Or is this too unreliable for a jet ?
Im thinking of my eurosport in particular......
Thanks, SJ.
06-18-2004, 01:18 PM
#2
RE: Simple Gear doors ?
ORIGINAL: SJN
Or is this too unreliable for a jet ?
Or is this too unreliable for a jet ?
Air cylinders really are not that bad, it just takes practice. I have done every sort of over center spring, whisker, rubber band, etc...forget it, especially on a big plane.
06-18-2004, 01:41 PM
#3
RE: Simple Gear doors ?
I think Im going to use a trip rubber band on my Agressor. I will glue a tab on the inside of the nose gear hole, then the strut will pull the rubber band ank keep pressure on the door. The tab would then leave the door flush with the fuselage.
I don't see why it shouldnt work. The main gear doors are similar.
I don't see why it shouldnt work. The main gear doors are similar.
06-18-2004, 01:50 PM
#4
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RE: Simple Gear doors ?
I put doors on my Euro main struts by using a link to the door from the strut. It took a bit of fiddeling and I layed it out on paper to get the angles right but it works really well and completely closes up the undercarrage. I was thinking of making a completely mechanical system for the wheel doors also, it would be really easy and eliminate the air.
This is half the fun of this hobby.
This is half the fun of this hobby.
06-18-2004, 01:56 PM
#5
RE: Simple Gear doors ?
ORIGINAL: FalconWings
I don't see why it shouldnt work.
I don't see why it shouldnt work.
Of course these systems can be made to work, but they are generally not reliable (very different than saying it will not work). If you do not care that the gear get hung up on the doors every other flight then fine, and I am not being facetious, some people do not care. If you are one of them then do it that way.
In my experience, landing gear are about 1/2 the total maintenance needed on a heavy jet. With doors, it is about 2/3. So reliable doors have a huge impact to maintenance (in the positive sense) just as unreliable doors have a huge negative impact.
06-18-2004, 02:14 PM
#6
RE: Simple Gear doors ?
I would agree with Matt. I've tried a variety of mechanical methods, and none have proven reliable, flight after flight. Issues such as airflow overpowering springs, rubber bands that rot after a year, fiddling with the exact length of trip line, a slightly bent landing gear strut that retracts ok, but now is out of alighnment of the trip method... blah.. so much simpler to setup a air cylinder.
06-18-2004, 03:09 PM
#7
Thread Starter
RE: Simple Gear doors ?
Thanks....Ill just buy some cylinders and a 2 way valve.
I wonder why they dont make "spring" cylinders for gear doors like the springair/eurokit retracts. Air to make them close, and the spring to open them....
Anyway, does anyone have some pictures of the "unreliable" way, because I have a p-38 arf on the way that I would like to try it on anyway?
I wonder why they dont make "spring" cylinders for gear doors like the springair/eurokit retracts. Air to make them close, and the spring to open them....
Anyway, does anyone have some pictures of the "unreliable" way, because I have a p-38 arf on the way that I would like to try it on anyway?
06-18-2004, 06:32 PM
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RE: Simple Gear doors ?
RE: spring open cylinder
SJN
I used a small dedicated air tank which applied constant pressure to the "down" side of the nose gear door on a Ziroli Panther. I used about 30psi to open the door and it easily closed the door when system pressure (60-100psi) was applied to the up side of the cylinder. All you had to do was vent the "up" pressure and the door popped open. I even experimented with using a control line fuel tank, and was surprized to find that they would easily handle 40-50psi.
Johnny
SJN
I used a small dedicated air tank which applied constant pressure to the "down" side of the nose gear door on a Ziroli Panther. I used about 30psi to open the door and it easily closed the door when system pressure (60-100psi) was applied to the up side of the cylinder. All you had to do was vent the "up" pressure and the door popped open. I even experimented with using a control line fuel tank, and was surprized to find that they would easily handle 40-50psi.
Johnny
06-19-2004, 08:04 PM
#10
RE: Simple Gear doors ?
ORIGINAL: mr_matt
Have you done it before?
Of course these systems can be made to work, but they are generally not reliable (very different than saying it will not work). If you do not care that the gear get hung up on the doors every other flight then fine, and I am not being facetious, some people do not care. If you are one of them then do it that way.
In my experience, landing gear are about 1/2 the total maintenance needed on a heavy jet. With doors, it is about 2/3. So reliable doors have a huge impact to maintenance (in the positive sense) just as unreliable doors have a huge negative impact.
Have you done it before?
Of course these systems can be made to work, but they are generally not reliable (very different than saying it will not work). If you do not care that the gear get hung up on the doors every other flight then fine, and I am not being facetious, some people do not care. If you are one of them then do it that way.
In my experience, landing gear are about 1/2 the total maintenance needed on a heavy jet. With doors, it is about 2/3. So reliable doors have a huge impact to maintenance (in the positive sense) just as unreliable doors have a huge negative impact.
But I do agree with you that using air cylinders for the gear doors is the best way to solve the problem.
David
06-20-2004, 12:59 AM
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RE: Simple Gear doors ?
Larry Wolfe had totally scale gear doors on his Mirage jets way back in the 1980's and they worked REAL good . All mechanical - NO air cyls. at all.
Jackjet
Jackjet
06-21-2004, 12:37 AM
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RE: Simple Gear doors ?
ORIGINAL: FalconWings
Thanks Alejandro, but im not sure I am a father yet. At least she hasn't told me about it.
Thanks Alejandro, but im not sure I am a father yet. At least she hasn't told me about it.
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