Broken Axle

[texasbagpiper]

Not really an accident or incident but it could have been if I hadn't came accross this problem.

I was installing my Shock/Strut kit from Buckeye and I noticed the angled axle tube has a crack in it right next to the 2nd frame bracket that attaches the axle tube to the main rail tube. The crack covers about 2/4 of the tube from underneath the tube up both sides. It looks rusted so I'm guessing I've been flying for a while with it like this. The only reason I noticed it was because I was laying on my back underneath the PPC.

I'm leaving to go to the ASC nationals on thursday so I'm in a race against time to get a new axle on my PPC. My CFI told me last night that he has an old DM axle so I'm going to pick it up tonight and drop it off at my welding buddy's place and have him reinforce it so It will have less of a chance to circum to the same fate as mine did.

Dave said it will only take about an hour to drop the old axle and put the new one on. This seems too fast but he's been doing it for years. I hope the spring rods come out. Seth

[Desert Fox]

Good Catch Seth! Guess there is no such thing as too much Preflight Check or inspection. I fly a Pegasus but am still going to climb under tonight.

[texasbagpiper]

Good Catch Seth! Guess there is no such thing as too much Preflight Check or inspection. I fly a Pegasus but am still going to climb under tonight.

Yea, Hops is overnighting me a new axle and I'm going to have it installed on thursday with the help of Dave English. I hope all works out so I can fly at the ASC nationals this weekend.

Do the spring rods come out easily?

[Boback]

Good Catch Seth! Guess there is no such thing as too much Preflight Check or inspection. I fly a Pegasus but am still going to climb under tonight.

I do climb under my Pegasus frequently, at minimum to clean it off. Being Yellow in color, the dirt stands out pretty good.

My Pegasus does has a little slop in the front fork. I suspect the hole where the front fork pivots to steer is getting worn and the hole may be getting worn out of shape. My winter project is to pull that apart and do something about it. Since the front fork pivot is load bearing it can wear easier.

Also, I plan to pull my rear wheels and A-frame and check those pivot points. Since they are just holes drilling in the tube they may get worn also. They are not load bearing pivots so the wear should be less. The load bearing is on the shocks and I plan to check them out carefully also.

Then I need to figure out what I want to do to fix the front fork (I don't think anything needs repair elsewhere on the aircraft suspension). Somebody mentioned getting a brass tube with the inside diameter the same as the AN bolt, and then drill the frame member to the outside diameter of the brass tube. The length of the tube is the exact width of the frame member. Once done, put it back together and the brass tube should prevent future wear. The brass tube, being a softer metal, may need to be replaced every couple of years yet should save the frame from getting more wear.

Anybody have any thoughts on this?

Of course, I could call Powrachute and order a replacement frame member the same color and just reassemble.

[mignazito]

Use a brass bolt for the fork and replace it periodically. Remove it and grease it annually to check for wear. Simple solution for those not having a machine shop or access to one.

[Boback]

Use a brass bolt for the fork and replace it periodically. Remove it and grease it annually to check for wear. Simple solution for those not having a machine shop or access to one.

I thought of that. I may have to go to the next size bigger and drill out the existing holes to the same size as the hole for the bolt, I suspect, is already worn.

[Dennis Garrett]

On mine, the steel, unlubricated bolt in a dry steel hole had started to gall & wear a little. I reamed my pivot hole out oversized, and installed two thin bronze bushings that met in the middle. I trimmed them flush at each end with a file, greased up & intalled new bolt. The new bolt was just the right length to install a castle nut & cotter (instead of the Nyloc which was always needing tightening, and it is at a pivioting point) and still safely clear my front tire which is a little taller than the original. Even with a close fitting bolt and bushings, it still developed a little slop as it broke in, but I can live with it. Just characteristic of the design I guess. I remember pre-flighting my examiner's 912 Pegasus when I took my SP check ride, and having him tightening his up a little before we took off. I like the idea of closer tolerances & some real grease. I think I'll take it apart at this pivot point at each annual, clean it up, inspect it, and lube it up for another year in the trailer, & a few flights.

[Desert Fox]

I do like the idea of a Bronze Bushing and staying with the AN bolt over using brass. I'm sure you counl go online and find a bushing. May have to buy one over length and cut it but that's no big deal. Went out and checked my Pegasus and all looks fine. BTW Bob and Dennis, I'm in Bucyrus and have a Metal Lathe if you ever need something turned. Your welcome to stop by the shop.

[mignazito]

Once these get some wear on them, they are trickier to correct for no slop. What I did on my DM was put a brass bolt in right from the start as brand new. The bolt is rifle drilled and cross drilled, then tapped for a 1/4-28 grease zerk which I greased each year at annual time. This stayed very tight and slop free for a long time.

Travis, how's it holding up?

I used to make and sell replacement forks for Sixchuters and HHFs with thick insert type bronze bushings and grease zerks. These had a large grease pocket inside and stayed very tight. I sold about 100 of these until SC came up with a better design.

[Desert Fox]

There you go Marty! Tap for a zerk. They actually make bronze bushing material with valley grooves that spiral through the ID of the bushing that would take the grease well. I like that now!

[mignazito]

If you use a brass bolt, you can simply file or mill a flat on it to spread the grease. On my forks I used shoulder bushings leaving a long cavity for grease with the zerk tapped to dump into the cavity. Grease the zerk till it oozes out of the bushings and your good till next year's annual.

[Limegreen]

Desert Fox, have you talked to Tony down here. I believe he has an answer to the front fork. Weather here has been great. Have been able to solo two students in the last two days. Sucks to watch your machine flying around without you in it. Morris is off to OK City to do check rides.

[texasbagpiper]

Use a brass bolt for the fork and replace it periodically. Remove it and grease it annually to check for wear. Simple solution for those not having a machine shop or access to one.


Are we talking about the bolt that attaches the goosneck to the forks, the one that goes into the top of the fork and throught the goose neck. Seth

[texas_tl]

As far as I can tell, it's doing fine. I don't notice any more play in the steering than I ever have.

You said that you greased it as part of the annual, right? I assume I don't need to do that again until March?

[mignazito]

Once a year should be enough unless you run through water every other day. It's kind of a bear to get to with a hand grease gun under that nose cone. An air operated or electric gun might be easier unless you have three hands.

Stock Buckeyes develop a loosey goosey front fork real soon. Trust me, you have a solid one there. Next time you're at a flyin, look around and compare.

[mignazito]

Almost all PPCs seem to have this iron on iron front fork setup and develop loosey goosey front forks. Under the ASTM SP rules mfgs are supposed to respond to customer complaints. If your fork on your new PPC gets loose, write your mfg about it. They are required to take some action if only investigation and keep all the letters on file with whatever action they took recorded. If enough complaints build up there may be a solution for this some day.

Even my Paraski had this iron on iron setup for the kingpins on the front end. I replaced the pivot bolts with rifle drilled and cross drilled brass bolts that have grease zerks. When Joe Albanese of Paraski visted me one day he was amazed at how smooth my front end was to steer and asked how I did that.

[mignazito]

Seth:

Yep, that's the one. Dirt simple fix for an existing PPC.

[texasbagpiper]

More on the Axle. I put my ppc on jacks last night and made sure the spring rods were goint to come out easily when Dave and I change the axle. They did come out pretty easily but they were very snug I had to turn them as I pulled them out.

Dave says this is not going to take more than about an hour, which seems very fast to me. Seems that we are going to hang the PPC from the rafters in his shop and replace the axle while its suspended in the air. Seems like fun.

Cheers, Seth

[texas_tl]

Seth, this would be a good time to fully check your CG since you can sit in the plane and measure angles and such.

Joey can provide some helpful tips there as this is what he did for his plane. :)

[texasbagpiper]

Seth, this would be a good time to fully check your CG since you can sit in the plane and measure angles and such.

Joey can provide some helpful tips there as this is what he did for his plane. :)

Daves going to help me do it, I don't feel comfortable doing it myself. Mabye next time after I see how its done. Seth

[indoruwet]

provide some helpful tips there as this is what he did for his plane. :)
You added that smiley there, because it was a bit scary, hanging from the rafters in this *shack*......

It was not the fear of falling down in the PPC, but it was the fear of may be the rest of the *shack* falling on top of me ....

lately been busy with just *trying* different set-ups.

1 - tried shortening the CG bars to get more incidence of the engine thrust line -- result = faster take off, and much steeper take off angle, but loss in cruising speed (had 4.5 degrees thrust-angle, went to 9 degrees). Did not seem to have a different cruising RPM.

2 - Next, went back to original set-up and gained cruising speed again like before ( I am a bit faster than anybody else, IF they are singe seaters). Do not really know why ....
3 - next I want to try going back to set up #1 and the adding links to B-lines to change AOA of chute and see what happens there.

hardest thing is to keep same ambient conditions.

Will let you know what happens.

[texas_tl]

You added that smiley there, because it was a bit scary, hanging from the rafters in this *shack*......

Yes, ever since you told me about that I've had this mental picture of you in your garage swinging on the PPC and your wife coming in and thinking you had gone mad. :D

I think my CG needs to be adjusted slightly...

[texasbagpiper]

Yes, ever since you told me about that I've had this mental picture of you in your garage swinging on the PPC and your wife coming in and thinking you had gone mad. :D



I think my CG needs to be adjusted slightly...

I change my CG about an inch every time I take a passenger, then change it back when I'm solo. Seth

[Boback]

Are we talking about the bolt that attaches the goosneck to the forks, the one that goes into the top of the fork and throught the goose neck. Seth

Yes (This forum said me answer had to be at least 10 characters in length, so I added this comment).