Spring Landing Gear

[SWeidemann]

After jacking up fuselage, loosening the gear blocks, centering the gear and tightening the blocks, I went for a ride. As before, the gear spring again shifted sideways.

My intent is to install the roll pins. My question is: Should I remove the gear and take it to a machine shop for drilling & install of the roll pins or can I use a hand drill to make the holes for the roll pins? I want to do it right. Any opinions?

Thanks much, Skot

The older gear springs do not have the roll pins. The newer springs do.

When speaking with Grove about retrofitting an older spring, they suggested that these (1/4" x 1" ?) be installed by drilling the spring and pressing in locally sourced pins.

If your gear is slipping again after this readjustment, this may be something you would want to do.

[SkyPirate]

If you have the gun drilled lines for your brakes, do it on the opposite side of the fittings for brake lines

[SWeidemann]

I had thought about drilling into the gun drilled channel by mistake, but I notice that all the new gear (looked at several at Oshkosh) and found they have roll pins on both sides (front and back) of each side of the flat gear. So...I assume the drilled hole is not near the brake line hole, just how far away?

If you have the gun drilled lines for your brakes, do it on the opposite side of the fittings for brake lines

[napierm]

At a minimum, I would support the gear in a drill vise and carefully mark and drill the holes that way. Start with a smaller pilot drill and work your way up. Don't do it by hand.

Having said that, I can also say that sometimes despite all my efforts a drill will still sometimes wander off center. Even a pilot hole may not be enough if the drill finds some "grain" in the metal. When I drilled the gear legs for my BD-4 I made a jig out of steel and then used the jig to drill the holes. Even then the holes needed some light reaming to get all four bolts through.

If you have any doubts, let a good shop do it.

FWIW,

Mark Napier

[SWeidemann]

I like the advice about taking the gear to a good machine shop to do a straight hole. Question is however, just how far away from the edge is the gun drilled brake line channel?

At a minimum, I would support the gear in a drill vise and carefully mark and drill the holes that way. Start with a smaller pilot drill and work your way up. Don't do it by hand.

Having said that, I can also say that sometimes despite all my efforts a drill will still sometimes wander off center. Even a pilot hole may not be enough if the drill finds some "grain" in the metal. When I drilled the gear legs for my BD-4 I made a jig out of steel and then used the jig to drill the holes. Even then the holes needed some light reaming to get all four bolts through.

If you have any doubts, let a good shop do it.

FWIW,

Mark Napier

[SkyPirate]

Without actually seeing it i would put them inboard close to the inboard side of gear bolt

[SkyPirate]

Center your gear, take a 5/16" center punch put it right up against the inboard side of bolt, center up and down an set a dimple, if you use a 1/4" center punch, i would think it would be too tight and flex in the gear would eventually bend the dowel pin and wear on the bolt

[SkyPirate]

Again without looking, if it is gundrilled, there should be a hex bung on the very bottom of the gear leg, check its orientaion if its centered or more toward front or back, the gear is tappered, evenly tappered bothe front and back or straight front and tappered back, if its evenly tappered, measure to center of hex bung plug, from the opposite side of brake lines, then measure width at bottom front to rear, then measure widest part of gear at fuselage front to back, check difference on opposite side of gun drill

[SkyPirate]

If your taking the gear completely off you can remove the brake fittings and check depth of holes under the fuselage, subtract that from width of gear, you should have plenty of room to put a 1/2 deep hole on the opposite side but better safe the sorry