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General control line discussion => Open Forum => Topic started by: Scott Richlen on April 18, 2017, 05:46:03 AM

Title: Landing gear door attachment suggestions?
Post by: Scott Richlen on April 18, 2017, 05:46:03 AM
I don't like to use these to attach my gear doors to my landing gear wire as they always seem to end up moving around.  I've tried other approaches but they are not always easy to do (soldering on wire clips, etc.) and don't necessarily work better.  What is a simple way of  mounting thin plywood gear doors?  Suggestions?

Thanks,
Scott
Title: Re: Landing gear door attachment suggestions?
Post by: fred cesquim on April 18, 2017, 06:42:44 AM
i do a balsa / plywood sandwich glued with 30 min epoxy
scuff the wire with 80 grit sandpaper, clean with alchool and epoxy the layers
cut a balsa filling (minus the wire width), CA to the outer 1/16 ply skin and then attach with epoxy to the leg. add a inner 1/16 skin and clamp
you will have plenty of time to properly align the door.
if you want to streamline the door, do it on the balsa and then CA the skin holding the shape
Title: Re: Landing gear door attachment suggestions?
Post by: Avaiojet on April 18, 2017, 06:46:16 AM
I don't like to use these to attach my gear doors to my landing gear wire as they always seem to end up moving around.  I've tried other approaches but they are not always easy to do (soldering on wire clips, etc.) and don't necessarily work better.  What is a simple way of  mounting thin plywood gear doors?  Suggestions?

Thanks,
Scott

Scott,

Unless you make the door part of the gear wire, not removable in that case, there probably isn't what would be called a "simple" way. If there is, I'd like someone to share it with me.  LL~

I use four light tin tabs easily made or could be made from brass stock. They look like your nylon piece. I solder them to the gear wire then solder small nuts to the tin to except the bolt from the plywood side.

I see other models where the bolt heads are visible, shinny and look nice. Just like mine.  ;D

Doesn't take long actually to solder eight of them, four per gear wire. Or not solder. That will work also, just bolt them up!. They might move around without the tin soldered? I solder to prevent this.

I have a few builds where I show this gear construction in detail. The ARGO and the Mig-3. Both builds and photos should be over at CFC Graphics vendor's corner.

I hope this helps.

CB



Title: Re: Landing gear door attachment suggestions?
Post by: Scott Richlen on April 18, 2017, 07:42:22 AM
Thanks guys!

Yes, I've done the soldered tabs in the past.  Just hoping there'd be an easier way.

I've also embedded the wire with epoxy, but this gear set-up doesn't lend itself to that.
Title: Re: Landing gear door attachment suggestions?
Post by: Avaiojet on April 18, 2017, 08:09:33 AM
Thanks guys!

Yes, I've done the soldered tabs in the past.  Just hoping there'd be an easier way.

I've also embedded the wire with epoxy, but this gear set-up doesn't lend itself to that.

Scott,

Fred's application is clean as can be. Also, as you can see, without the placement of bolt heads in the way, it lends itself for the use of nice graphic detailing.

I may try this on my next project, and Fred will be helpful as always which makes things easier.

CB

Title: Re: Landing gear door attachment suggestions?
Post by: Avaiojet on April 18, 2017, 08:39:30 AM
i do a balsa / plywood sandwich glued with 30 min epoxy
scuff the wire with 80 grit sandpaper, clean with alchool and epoxy the layers
cut a balsa filling (minus the wire width), CA to the outer 1/16 ply skin and then attach with epoxy to the leg. add a inner 1/16 skin and clamp
you will have plenty of time to properly align the door.
if you want to streamline the door, do it on the balsa and then CA the skin holding the shape


Fred,

Photo of the other side?

Your work is outstanding!

CB
Title: Re: Landing gear door attachment suggestions?
Post by: jfv on April 18, 2017, 10:47:02 AM
I use a very a very simple method that uses 2 pieces of 1/8" square balsa on either side of the wire.  Secure with thin CA.  Remarkably robust.  In 2 years I knocked them off once with a landing a bit harder than it should have been.
Title: Re: Landing gear door attachment suggestions?
Post by: fred cesquim on April 18, 2017, 12:36:00 PM
thanks a lot Charles!
Scott, if there is multiple bends, Charles solution is the way to go,mine is only good for a straight leg
follows detail pics
inner side is flat and outside is streamlined
Title: Re: Landing gear door attachment suggestions?
Post by: Steve Helmick on April 18, 2017, 01:17:43 PM
One of the systems I've seen that looked practical and slick was on a 4-Runner from Jerry Eichten. He added a 1/8" plywood tab (could use epoxyboard, CF plate, or aluminum) to the outboard end of the LG block. The LG door pivoted on one screw to that tab, and one of those nylon fastened the lower end of the LG door to the wire.

As the wire flexed, the nylon fitting slides up/down the LG strut a bit. It should be easy enough to use flathead screws and finish over them. Might be good to keep from corrupting the screw slot or socket, maybe with a dot of hinge sealing tape, then finishing over it. Alternatively, one might incorporate the three screw heads per door into some sort of inking detail..."DiLithium Crystal Refill Port", "Muffler Bearing Access Panel", etc.  ;D Steve
Title: Re: Landing gear door attachment suggestions?
Post by: Scott Richlen on April 18, 2017, 01:51:44 PM
Jim: Now that's what I'm looking for.  Do you do any special preparations to the wire?  Medium or thin CA?
Title: Re: Landing gear door attachment suggestions?
Post by: jfv on April 18, 2017, 02:35:30 PM
I just clean the wire with alcohol then sand with 400 paper.  I use thin CA.
Title: Re: Landing gear door attachment suggestions?
Post by: Paul Wood on April 18, 2017, 03:38:04 PM
I use the same method as Jim, but instead of CA, I use a thin film of JB Weld. Adheres well to the wire gear and also to the wood. Never had a failure (yet).

Paul