Gun drilled gear legs?

[Jcurry]

Hello,
Wondering why Vans came out with the "gun drilled" main gear legs? Notification N 19-02-28 states that this is an upgrade. The synopsis in the notification is vague to me on why the notification came to be. Other than the brake fluid passing through the gear legs therefore eliminating the brake lines, is there any other benefits to the upgrade?
Although not mentioned in the synopsis, I wonder if corrosion had anything to do with this?
Has anyone experienced severe corrosion with the legacy gear legs?

Thank you,
Jack

 

[rcarsey]

As far as I know, it was just a technology improvement which enabled them to do this. Unless you happen to find a pair of salvaged gun-drilled legs, its not at all worth it to scrap your legs and upgrade. It does remove the need for the 1/4" soft aluminum brake line tubes running down the rear of each leg.. and zip ties. If Van's offered an "upgrade" service whereby they take your old legs and drill them... then maybe it is financially feasible.. just for the aesthetics of it.. but thats about all.

Older RV-12's had "raw" legs.. and I have seen surface corrosion on them.. usually a white dust on them.. so I think its encouraged to put some sort of coating on raw legs.. whether it be paint, primer, or powdercoat.

 

[bbaggerman]

Hello,
Wondering why Vans came out with the "gun drilled" main gear legs? Notification N 19-02-28 states that this is an upgrade. The synopsis in the notification is vague to me on why the notification came to be. Other than the brake fluid passing through the gear legs therefore eliminating the brake lines, is there any other benefits to the upgrade?
Although not mentioned in the synopsis, I wonder if corrosion had anything to do with this?
Has anyone experienced severe corrosion with the legacy gear legs?

Thank you,
Jack

I had some corrosion bubbling up under the paint on my gear legs so this year we decided to take them off, clean them up, and repaint them. My soft aluminum brake lines were kind of dinged up where they exit the fuselage so I got the Aircraft Specialty replacement lines and made the fuselage opening a bit bigger. I've been real happy with the replacement brake lines from Aircraft Specialty. Like Rob I don't think the gun-drilled legs are worth it. External lines, when neatly done, look fine and where they are at you can barely see them anyway.

 

[rvbuilder2002]

The design change was made to delete the need for exposed brake lines on a gear leg that has no fairing to cover them.
It would not be possible to gun drill a legacy gear leg because the drilling is actually done before the bends on the leg are made.

 

[bobnoffs]

i dont know why vans didn't start gun drilling years ago. i custom ordered a gear from grove gear 20 yrs ago and it was a $100 option. i got the gun drilled gear. when did housing start burying plumbing in the walls vs attaching it to the drywall?

 

[Jcurry]

Thanks for the replies. I bought a flying -12. It came with painted gear legs. I installed the Aircraft Specialty brake lines during my last CI. I also stripped, alodined, primed and painted the MLG legs due to corrosion. 5 months later and it's back. Living in Florida, I clean my airplane and the gear on a regular basis. I fear I may have to replace it....

Thanks,
Jack

 

[rvbuilder2002]

i dont know why vans didn't start gun drilling years ago. i custom ordered a gear from grove gear 20 yrs ago and it was a $100 option. i got the gun drilled gear. when did housing start burying plumbing in the walls vs attaching it to the drywall?

I do.

It is because the vendor used to produce the gear legs didn’t have the capability previously.
Shipping a heavy crate of gear legs around the country to different vendors for a bunch of different production steps isn’t cost effective…. As already mentioned, the gun drilling has to be done after making the gear leg but before making the bends.

 

[Harvey rv12]

I noticed corrosion on both gear legs on my -12 recently. It's a legacy build, sn 120278. The builder did not paint the legs. I am in the process of pulling them, examining closely, removing all corrosion, and thinking of painting with a 2 part epoxy. I read somewhere, and now I can't find it, Vans says do not powder coat or alodine the legs. I'm thinking the heat used in the powder coat process might affect the heat treatment properties. I will reach out to Vans on this as well as the restriction on alodine. I considered purchasing new powder coated gear legs from Vans, but with the recent pricing changes, I will do all I can to save the legs I have.

 

[bobnoffs]

I do.

It is because the vendor used to produce the gear legs didn’t have the capability previously.
Shipping a heavy crate of gear legs around the country to different vendors for a bunch of different production steps isn’t cost effective…. As already mentioned, the gun drilling has to be done after making the gear leg but before making the bends.

i guess i assumed that gun drilling was a pretty basic operation and if 1 vender had it 20 yrs ago they all had it.

 

[Jcurry]

I noticed corrosion on both gear legs on my -12 recently. It's a legacy build, sn 120278. The builder did not paint the legs. I am in the process of pulling them, examining closely, removing all corrosion, and thinking of painting with a 2 part epoxy. I read somewhere, and now I can't find it, Vans says do not powder coat or alodine the legs. I'm thinking the heat used in the powder coat process might affect the heat treatment properties. I will reach out to Vans on this as well as the restriction on alodine. I considered purchasing new powder coated gear legs from Vans, but with the recent pricing changes, I will do all I can to save the legs I have.

I will also do everything I can for now to save my gear. My SN is 120229. Nothing I can do about the alodine I applied. I painted with 2 part paint and thought I would get maybe a year before I had to treat again. Wrong!

 

[Harvey rv12]

I will also do everything I can for now to save my gear. My SN is 120229. Nothing I can do about the alodine I applied. I painted with 2 part paint and thought I would get maybe a year before I had to treat again. Wrong!

CORRECTION;
I stand corrected. After reviewing my KAI, dated 12/2009, it states the gear legs can be alodined!. It further states the gear legs can not be anodized or powder coated. So Jcurry, your alodine was a recommended and approved finish.
The latest KAI is as follows. Step 1: Clean then prime the U-1220-L/R Gear Legs using a two part epoxy or other high quality primer. Using a paint compatible with the primer paint the gear legs.

 

[Jcurry]

CORRECTION;
I stand corrected. After reviewing my KAI, dated 12/2009, it states the gear legs can be alodined!. It further states the gear legs can not be anodized or powder coated. So Jcurry, your alodine was a recommended and approved finish.
The latest KAI is as follows. Step 1: Clean then prime the U-1220-L/R Gear Legs using a two part epoxy or other high quality primer. Using a paint compatible with the primer paint the gear legs.

Hi Harvey,
Thanks for the correction.