Prop bushing for Mccauley

I can machine one for ya for free.. Freight will probably cost you 3 bucks...

Confirm it is OD = .625

ID = .375

Length = .687
 
N801BH said:
I can machine one for ya for free.. Freight will probably cost you 3 bucks...

Confirm it is OD = .625

ID = .375

Length = .687
Click to expand...
That's what it's supposed to be -- I'll measure tomorrow and verify.
 
Bravo Zulu, Ben!

Added benefit: you'll know that you are getting legitimate quality.
 
Wait. Where's the outcry from certain POAers that use of such a non certificated part would surely lead to catastrophic failure of the aircraft and extended federal prison terms for the perpetrators?
 
Lance F said:
Wait. Where's the outcry from certain POAers that use of such a non certificated part would surely lead to catastrophic failure of the aircraft and extended federal prison terms for the perpetrators?
Click to expand...

Actually, per Office Space, it'd be "Federal Pound-Me-In-The-Ass Prison," not just Federal Holiday Prison. Let's be clear. ;)
 
So something seems a bit odd, I probably need to head to the hangar and measure the prop.

Basically there were 5 bushings. They look like this:
2eFOs.png

Dimensions of bushing in above picture, longer what seems to be correct one:
OD: 0.633"
IN: 0.372"
LEN: 0.6575"

Then there was one bushing that is much less tapered and is shorter..and had some washers to try and make up for it:
G8bhD.jpg

Dimensions of bushing in above picture:
OD 0.624"
IN 0.3725"
LEN .508"

The spruce link above that I believe to be the right bushings are:
OD = .625
ID = .375
Length = .687

So the "incorrect" bushing has what appears to be closer measurements to the Spruce bushing except isn't long enough.

Not sure how tight the tolerances on this stuff really are..
 
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I wouldn't bet on it, but this looks like some kind of adaptor kit to make a prop fit an instillation it wasn't meant for.

show me the back of the prop and the front of the prop flange.

and where these bushings go.
 
Tom-D said:
I wouldn't bet on it, but this looks like some kind of adaptor kit to make a prop fit an instillation it wasn't meant for.

show me the back of the prop and the front of the prop flange.

and where these bushings go.
Click to expand...
That's the normal setup for props fitted to the A-65 tapered shaft prop hub.
 
Dan Thomas said:
That's the normal setup for props fitted to the A-65 tapered shaft prop hub.
Click to expand...

yes i do believe it to be normal. the only incorrect thing I believe is the one smaller bushing.

I'm headed to the airport now to measure the holes in the prop where the bushings go..and some other things.
 
Working up a drawing now of what I need.
 
Ben, this is what I need, I understand if this is too big of a PITA for you. I have no idea what kind of effort this takes..and that angle may complicate things:

Side profile:
http://i.imgur.com/bUDxV.png

Top profile:
http://i.imgur.com/7qcYf.png

Angle view:
http://i.imgur.com/TmbdG.png

Drawing (forgive my poor cad skills):
https://dl.dropbox.com/s/5xh20gjtbtqefjk/bushing.pdf

Considering how "wrong" what it had was..I am sure there is a pretty decent amount of wiggle room on this. Might not even need that angle.

So basic dimensions:
Length: 0.655"
ID: 0.375"
OD: 0.625"

I'm not sure why the Spruce length is 3/100ths larger. Perhaps they were compressed under installation and shrunk over time. Or perhaps the Spruce number is just wrong since that was an easier fraction.
 
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jesse said:
Ben, this is what I need, I understand if this is too big of a PITA for you. I have no idea what kind of effort this takes..and that angle may complicate things:

Side profile:
http://i.imgur.com/bUDxV.png

Top profile:
http://i.imgur.com/7qcYf.png

Angle view:
http://i.imgur.com/TmbdG.png

Drawing (forgive my poor cad skills):
https://dl.dropbox.com/s/5xh20gjtbtqefjk/bushing.pdf

Considering how "wrong" what it had was..I am sure there is a pretty decent amount of wiggle room on this. Might not even need that angle.

So basic dimensions:
Length: 0.655"
ID: 0.375"
OD: 0.625"

I'm not sure why the Spruce length is 3/100ths larger. Perhaps they were compressed under installation and shrunk over time. Or perhaps the Spruce number is just wrong since that was an easier fraction.
Click to expand...

Not a problem Jesse.. I am going flying now and need to finish laying a few hundred square feet of tile at the FBO today... The material I have chucked up is solid round 4130 steel. The drive lug should take me about 8-10 minutes to fabricate.... Do you need just one ? It will be done by 5 am Monday and I will get it in the mail to ya first thing tomorrow. US mail ok ? should take 2-3 days to get to you.... PM me your address.
 
N801BH said:
Not a problem Jesse.. I am going flying now and need to finish laying a few hundred square feet of tile at the FBO today... The material I have chucked up is solid round 4130 steel. The drive lug should take me about 8-10 minutes to fabricate.... Do you need just one ? It will be done by 5 am Monday and I will get it in the mail to ya first thing tomorrow. US mail ok ? should take 2-3 days to get to you.... PM me your address.
Click to expand...
The current bushings are aluminum and weigh in at 6 grams. I suspect that the weight difference of steel could throw the prop balance off a bit.

PM w/ address sent.
 
jesse said:
The current bushings are aluminum and weigh in at 6 grams. I suspect that the weight difference of steel could throw the prop balance off a bit.

PM w/ address sent.
Click to expand...

That is why I said to ship me one and I'd dupe it and send it back.

are they plated?

do we know if the internal Dia. is not worn?
 
jesse said:
The current bushings are aluminum and weigh in at 6 grams. I suspect that the weight difference of steel could throw the prop balance off a bit.

PM w/ address sent.
Click to expand...

Aluminum it is.. I have dozens of feet of 6061 billet rod..:yes:
 
Done.... Took all of 7 minutes.

OD = .625
ID =.375
Length = .655

To the postal workers out there.. can I just put it in an envelope or will the bulge screw up the auto sorter machines ?
 

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N801BH said:
Done.... Took all of 7 minutes.

OD = .625
ID =.375
Length = .655

To the postal workers out there.. can I just put it in an envelope or will the bulge screw up the auto sorter machines ?
Click to expand...

Awesome! What does it weigh? Wondering if it happens to be 6 grams.

Put it in a small box, or a Tyvek envelope, or wrapped in bubble wrap before a normal envelope. By itself, in a normal envelope, it will probably escape the package (tear a hole).
 
TangoWhiskey said:
Awesome! What does it weigh? Wondering if it happens to be 6 grams.

Put it in a small box, or a Tyvek envelope, or wrapped in bubble wrap before a normal envelope. By itself, in a normal envelope, it will probably escape the package (tear a hole).
Click to expand...

The gram scale is at the airport in the ACES prop balancer kit.. My gut feeling is the bushing is lighter then 6 grams. Jesse can weigh it in a few days to confirm.

Maybe I don't grasp the location of the bushing as I figured it was the drive lugs that transfer the power from the crank flange to the prop. On my experimental I fabricated 4130 steel drive lugs , but then I am passing almost 400 HP through to the prop, that is why I originally loaded the 4130 in the lathe.
 
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N801BH said:
The gram scale is at the airport in the ACES prop balencer kit.. My gut feeling is the bushing is lighter then 6 grams. Jesse can weigh it in a few days to confirm.

Maybe I don't grasp the location of the bushing as I figured it was the drive lugs that transfer the power from the crank flange to the prop. On my experimental I fabricated 4130 steel drive lugs , but then I am passing almost 400 HP through to the prop, that is why I originally loaded the 4130 in the lathe.
Click to expand...
The bushings take the place of the drive lugs you normally see in a prop hub; the ones that fit into the counterbore in the back end of each bolt hole.

Jesse has this hub:

$T2eC16V,!y0E9s2S65r0BQYK,9Cwb!~~60_35.JPG


The prop bolts go through the rear flange of that hub (the end of the vertical thing that's sitting on the table) and the bushings drop over the bolts. Then the prop goes over the bolts, the front plate goes on the bolts against the prop face (that's the flat plate there) and the nuts go on. The bushing transfer the drive torque from the bolts into the prop's counterbores. Their larger diameter helps keep the skinny bolts from digging into the wood of a wooden prop. Without them on a metal prop, the bolts will bend in that counterbore.

The smaller tube in the top end of that hub is the nut that holds the hub on the crankshaft's taper. And that taper looks like this:

cont_a65.jpg


When it's together it looks like this, but this pic hasn't the bushings:

coa65.jpg


Or this:

41-1.jpg


Later versions of the A-65 have the same integral prop flange as the O-200 shown here:

o-200-d.jpg


Dan
 
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N801BH said:
The gram scale is at the airport in the ACES prop balencer kit.. My gut feeling is the bushing is lighter then 6 grams. Jesse can weigh it in a few days to confirm.

Maybe I don't grasp the location of the bushing as I figured it was the drive lugs that transfer the power from the crank flange to the prop. On my experimental I fabricated 4130 steel drive lugs , but then I am passing almost 400 HP through to the prop, that is why I originally loaded the 4130 in the lathe.
Click to expand...

They go into the prop and are subjected to a whopping 75 Hp.
http://i.imgur.com/6Q0YV.jpg
 
Tom-D said:
I'm seeing a hub for a wooden prop, yet I see you are running a metal one..

E-AB,, ?????

You'd be very happy with one of these

http://www.sensenich.com/products/item/9
Click to expand...
I'm pretty sure it'd be the same hub on a J3 cub with a metal prop. I'm not sure I'd really like a wooden prop. Nor can I really afford one after the money I just put into my exhaust. Seems like more maintenance and less life for little benefit.

My metal prop is just fine :)
 
jesse said:
I'm pretty sure it'd be the same hub on a J3 cub with a metal prop. I'm not sure I'd really like a wooden prop. Nor can I really afford one after the money I just put into my exhaust. Seems like more maintenance and less life for little benefit.

My metal prop is just fine :)
Click to expand...
Why would a wooden prop be more maintenance?

Considering when you whack that metal prop you'l be paying for a new crank, it will be penny smart to have a wooden one and simply put a new prop on it and go.

Wooden props do not impart damage to the engine when you strike them.

guess How I know? :)
 
Tom-D said:
I'm seeing a hub for a wooden prop, yet I see you are running a metal one..

E-AB,, ?????

You'd be very happy with one of these

http://www.sensenich.com/products/item/9
Click to expand...

Lots of those old engines got metal props put on them. I have considerable time in a Champ 7AC with that setup and a metal prop. The same engine that broke its crank in flight due to a propstrike in the indeterminate past, leaving a crack in the fillet radius of the #1 journal that slowly propagated. It would have been prevented with a wooden prop, for sure.

Dan
 
I'm beginning to understand why JA thought that chute was such a good idea.
 
Dan Thomas said:
Lots of those old engines got metal props put on them. I have considerable time in a Champ 7AC with that setup and a metal prop. The same engine that broke its crank in flight due to a propstrike in the indeterminate past, leaving a crack in the fillet radius of the #1 journal that slowly propagated. It would have been prevented with a wooden prop, for sure.

Dan
Click to expand...

I know that many of these old engines have metal props on them, but the bushings that are placed over the bolts of a wooden prop hub to mimic the drive lugs of a crank flange, are the adaptor kit that allows that.
 
wabower said:
Did you not write about elevated risks of a wooden 41 y/o airplane?
Click to expand...

I don't see what in this thread is indicating a need for you to kick that comment my way? The engine and prop combination are the same as many certified airplanes, as is the exhaust that started all this. The minor maintenance I'm doing right now is no different than a Cub.
 
jesse said:
The engine and prop combination are the same as many certified airplanes, as is the exhaust that started all this. The minor maintenance I'm doing right now is no different than a Cub.
Click to expand...

Ever see friends make parts for certified aircraft? Legally?
 
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