problem with retracts-how to close the doors?
10-08-2002, 04:10 PM
#1
Junior Member
Thread Starter
Join Date: Oct 2002
Location: Florida
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
problem with retracts-how to close the doors?
i am getting back into building rc planes after 22 years. i am buildina an older kit model if the P-51 Mustang. I have installes retracts but cannot figure out how to get the doors shut and open when they should be. Any ideas would be helpful. John M
10-08-2002, 05:46 PM
#2
Senior Member
My Feedback: (16)
Join Date: Mar 2002
Location: San Diego, CA
Posts: 2,586
Likes: 0
Received 0 Likes
on
0 Posts
problem with retracts-how to close the doors?
I am by no means an expert on this, but I've seen some planes with retracts that use springs. The wheels actually push the doors open and the springs pull them closed as the wheels come back up.
Mike
Mike
10-09-2002, 03:06 PM
#3
Senior Member
My Feedback: (4)
Join Date: Aug 2002
Location: Richmond Hill,
ON, CANADA
Posts: 301
Likes: 0
Received 0 Likes
on
0 Posts
problem with retracts-how to close the doors?
Hmmm...That's funny you posted that question. I'm also debating on what to do on my giant P-47 that I'm building. Although my debate is more so, do I want to go to all that trouble to make doors.
But if you are interested, I have come across an article that relates to that.
Here is the link.
http://www.fly-imaa.org/imaa/hfartic...to/v9-1-5.html
But if you are interested, I have come across an article that relates to that.
Here is the link.
http://www.fly-imaa.org/imaa/hfartic...to/v9-1-5.html
10-09-2002, 09:00 PM
#4
problem with retracts-how to close the doors?
What you need is a gear door sequencer. A spring unit won't work for a P-51 because a P-51's gear doors are sequenced to close after the gear are down as well as when they are up.
Go to this link and scroll down to the gear door sequencer:
http://www.jetmodelproducts.com/landing.htm
What you want is Option #3
If you look at the pic below, here's the sequence:
Extending the gear:
A, Gear Up
B, Doors Open
C, Gear extend
D, Doors close
Retracting the gear:
D, Gear down
C, Doors open
B, Gear retract
A, Doors close
Go to this link and scroll down to the gear door sequencer:
http://www.jetmodelproducts.com/landing.htm
What you want is Option #3
If you look at the pic below, here's the sequence:
Extending the gear:
A, Gear Up
B, Doors Open
C, Gear extend
D, Doors close
Retracting the gear:
D, Gear down
C, Doors open
B, Gear retract
A, Doors close
10-10-2002, 02:15 AM
#5
Join Date: Mar 2002
Location: Galesburg, IL
Posts: 796
Likes: 0
Received 0 Likes
on
0 Posts
geardoor sequencer
Go to www.emsjomar.com and you'll find a better priced sequencer than what the previuse quote said. Especially if you don't have the deep wallets that some of these other modelers have. It is only priced at 44.95 and you can program it to what ever delay you could want. Theirs is only 89.95 and is just about the same thing depending on what you want. My 0.02 worth. 
10-10-2002, 09:26 PM
#6
Senior Member
My Feedback: (1)
problem with retracts-how to close the doors?
As replied, the inner gear doors on a P51 are supposed to be up when the gear is down. When retraction is initiated the inner gear doors open then the gear comes up and the inner doors close.
Pictures you see of P51's on the ramp with the inner gear doors down are with the engine off. When the engine is off and the P51 has been sitting for a while the hydraulic pressure bleeds off and the gear doors fall down.
What you need is the variable rate syquencing air valve from Ultra Precision.
Vince
Pictures you see of P51's on the ramp with the inner gear doors down are with the engine off. When the engine is off and the P51 has been sitting for a while the hydraulic pressure bleeds off and the gear doors fall down.
What you need is the variable rate syquencing air valve from Ultra Precision.
Vince
