Antique

My Feedback: (4)

Some have suggested that I start my own thread..OK, here it is, you happy now ?
My new G62 lite uses a smaller hub, 1 1/2" diameter, to save a little weight...I was concerned that it might not be strong enough or the bolt might strip...
The hub is made from 2024 aluminum, the bolt is a 10mm 1.25 pitch...
I tapped a scrap piece of hub material and put 2 sides on it so it could be clamped in my mill vise...Put a wood prop on it and used a bolt that went into the hub about 5/8...
Put a 14mm box end wrench on the bolt and tightened it...As hard as possible with the 8" long wrench...NO strip...Put a 18" long bar on the wrench..Still no strip...If anyone can strip one of these by himself, one hand holding the prop and the other holding the wrench, his name is King Kong and is 8 feet tall and covered with hair...
What's YOUR prop hub made from..HMMMMM ????

Robby

My Feedback: (18)

Welll,, RCIGN1 ,,
You need to do a minor comparsion...
Not many people are familar with 2024..

So, compare 6061 to 2024 to give people
an idea how strong it it...
Most people know wing tubes and landing
gear is 6061..
Strenght and weight comparsion of the two...


VVVVVVVVVV VVVvvvVVVV

Tired Old Man

My Feedback: (1)

That wasn't so hard now, was it?

Antique

My Feedback: (4)

Will do, have to look it up..OK,
2024 is 27% stronger than 6061 and .002% heavier per cubic inch..
18% more yield strength..
35% more shear strength
So it makes much better hubs than the more common and easier to strip 6061...
Costs more, but worth it....
Anyone want to see these numbers, they came from Google...
[8D]

RTK

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I learn something new every day, or at least I try too

stephensackro

My Feedback: (6)

I'd still be interested if you did the same test with 6061 T-6. It's more readily available and much cheaper. Maybe it would hold up to a 6' King Kong instead of a 8' ??

marzo91

My Feedback: (57)

That would be neat to see. No sense in spending extra time, effort, or money on over-kill. I'm not saying it is over-kill, but it would be nice to know that it's not.

marzo91

My Feedback: (57)

Double post.

Antique

My Feedback: (4)

OK, will do tonight, same bolt..
I buy the 2024 in 10 foot lengths to use only for the part of the hub with the prop bolt..The bottom part is 6061....[8D]

stephensackro

My Feedback: (6)

Did you try it out yet Ralph or are you having trouble finding the 6 foot gorilla??

Nogyro

My Feedback: (10)

Ralph,

What type of material is the stock G62 prop hub made from? I was having trouble with my prop slipping, so I tightened it up as much as I thought it would stand with my 3/8" drive ratchet. Then I went and got my torque wrench. I was only putting 18 lbs. of torque on it. I'm running a Mejzlik prop so I torqued it down to 20 lbs. That along with sandpaper between the hub and prop it hasn't moved since. Do me a favor and put a torque wrench on that thing and see how many lbs. it takes to strip it....... No guessing then.......

marzo91

My Feedback: (57)

That would certainly be helpful information. A recommended torque setting would clear up a lot of misunderstandings and malfunctions. It would be an automatic maintainence step each pre-flight.

Antique

My Feedback: (4)

Took a 6061 aluminum bar, tapped it with a new 3/8x24 tap...Screwed a 3/8x24 bolt into it on a prop...took my 8" box end and tightened it up as hard as possible, no strip..Put a short extension bar on the box end, tightened it more..More..more..It took a lot of force, but the bolt pulled the threads out like an aluminum Heli coil..I have no idea what the torque was, way more than normal prop tightening...It WILL strip, but not under most normal circumstances..
I will continue to use 2024 for hubs...got 10' more today, $24.10 per foot including shipping.....That makes 6 or 8 prop hubs when the loss from the cutoff tool is added...
I don't think $3 is too much to spend for a hub...
Donb't know what Zenoah uses for hubs, they're kinda close with information...A little oil on the threads would goe a long way toward keeping the threads from wearing out in the hub...

Nogyro

My Feedback: (10)

I wondered about trying some oil on the threads, but was afraid it might make it back out easier.......

excaliber

RCign Still chirping away about 2024 vs 6061 T-6. who cares what you paid for it anyway.
Like somebody said if you don't have enough thread engagement you'll strip out threads.
Try it yourself in steel, screw a bolt in about 4 or 6 threads and see what happens.

Nogyro

My Feedback: (10)

excaliber,

Ralph is kind enough to share his experiences with us on what he finds out while working on all brands of engines, just not Zenoah's. I for one enjoy his posts...... If all you have is negative criticism towards him, just keep it too yourself.

RTK

My Feedback: (1)

I second that

karolh

And I third....if needed.

Antique

My Feedback: (4)

Thanks, guys, but he's easy...I think Excaliber is the one who suggested I start my own thread..OK, it's here...Questions were asked, and answered, no negative comments, just like ALL my other statements...
Who's chirping away now ?
Hey, Excaliber, here's an idea...Start a thread for all those who don't like my comments, you and your negative buddies won't have to look through all the other threads, it will all be in one place....
I might get some new ideas for my signature line

excaliber

Because its not worth the time or energy to point out how you toot your own horn and find fault with others. But thats OK. Not too worry it won't happen. I'll let you kids play with your toy planes in your mutual admiration society.

BME

Ralph, that is very smart thinking. We tried using 6061 but had problems with it. We only use 7075 now. The 6061 material is to soft for prop hubs for many reasons. If it uses a bolt instead of a stud and nut it will strip over time. 6061 also tends to mush where it meets the taper of the crankshaft. This can cause it to work loose or in a case where the hub is threaded to the crank it will tighten during use and the timing will be retarded. Quadra had the same problems with 6061. As a manufacturer for safety and performance reasons BME will never use 6061 for prop drives.

Keith
BME

Antique

My Feedback: (4)

Vindication
Thanks, Keith

Robby

My Feedback: (18)

And here I come,, again...

Lets see a comparsion of 6061 to 2024 to 7075...

This way people can see why, a choice of a certian grade material is used..

And while on the same subject....

Oil threads...? xxxxxxxxxxxxxxx Why or why not..

Use blue thread locker..? xxxx Why or why not..

Use red thread locker..? xxxxx Why or why not..





.

RTK

My Feedback: (1)

OK I'll play

Oil = reduces wear/galling, make things easily removed

Red = tough to remove, over kill most of the time (if done on "clean" threads) although I have use it many times

Blue = just right, not too hard to remove, holds well for our applications, not over kill

Other colors = some virtually impossible to remove if used on threads with out damage to attached parts

My statements based on linkages, servos and other small screw thingies we use on our planes.

Nogyro

My Feedback: (10)

Gotta put my Mejzlik prop back on my G62 tomorrow. I'm going to put a drop or two oil on before I torque it down to 20 ft. lbs. I'll let you know if it stays on as good as without it. Might save some wear and tear in the long run on the prop hub threads......