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Single bolt prop Hub for DLE 35?

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Old 05-07-2013, 05:15 AM
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ekir
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Default Single bolt prop Hub for DLE 35?

I am getting ready to order a DLE 35. What are to advantages and disadvantages of purchasing the single prop bolt hub?
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Old 05-07-2013, 05:59 AM
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Default RE: Single bolt prop Hub for DLE 35?

Lengthens the prop mounting distance, adds a few grams of weight.
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Old 05-07-2013, 06:34 AM
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Default RE: Single bolt prop Hub for DLE 35?

More convenient.....Opens up the ability to mount any prop, particularly the newer competition APC line of props which is particulary well suited to current 2 stroke 30-40cc engines. APC's are world renowed for their ability to convert power to thrust and minimizing noise. Many other makes are not....Noise is a killer of power and thrust. The only downside is their heavy weight compared to wood and carbon; and if you don't use common sense, their razor sharp trailing edge will bite you

Thesesingle nut adaptersadd quite a bit of weight. I looked at one a couple years ago and realized quickly that it weighed twice what the 4 mounting bolts weighed.
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Old 05-07-2013, 08:53 AM
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Default RE: Single bolt prop Hub for DLE 35?

Sometimes those 4 bolts get sheered off and they can be tough to get out.

The extra weight of the adapter helps with planes that need added nose weight.
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Old 05-07-2013, 12:55 PM
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Default RE: Single bolt prop Hub for DLE 35?

"sheered bolts" are a neglect sign, like pilot error, OR, the bolts bottomed out and seemed to be torqued well, but were not.
Properly fitted multiple bolts, properly torqued will not shear or break ever.
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Old 05-07-2013, 04:35 PM
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Default RE: Single bolt prop Hub for DLE 35?

If you get them at the same time from Valley view, I am pretty sure they will install it for you. It is not the easiest thing to do, in all honesty.

You need to periodically check the 4 bolts to make sure it is staying tight. There have been a few reports of failures, but this is most likely because they had come loose.

I have one on my DL 50 and love it.
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Old 05-08-2013, 12:03 PM
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Default RE: Single bolt prop Hub for DLE 35?

I have read a few comments from others that while starting, the engine kicked back hard enough to shear off the bolts. I had one engine, single bolts hub, kick back hard enough to loosen the nut, only happened once.

" "sheered bolts" are a neglect sign, like pilot error, OR, the bolts bottomed out and seemed to be torqued well, but were not.
Properly fitted multiple bolts, properly torqued will not shear or break ever."
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Old 05-08-2013, 02:37 PM
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Default RE: Single bolt prop Hub for DLE 35?

The bolts don't break from a single kick back. They break because they have been bent to- and fro due to lack of backplate friction to the prop.
This friction is a function of prop clamping force and material properties. Prop clamping force is a function of bolt torque only. So, too little torque will cause broken, not sheared, bolts. Shearing the bolts is impossible when using a soft prop against a hard back plate.
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Old 05-08-2013, 04:27 PM
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Default RE: Single bolt prop Hub for DLE 35?


Quote:
ORIGINAL: vertical grimmace

If you get them at the same time from Valley view, I am pretty sure they will install it for you. It is not the easiest thing to do, in all honesty.

You need to periodically check the 4 bolts to make sure it is staying tight. There have been a few reports of failures, but this is most likely because they had come loose.

I have one on my DL 50 and love it.
I've got one mounted to my PTE36R and it was simple. A little BLUE lok tite on the treads and it wont come loose, or shear bolts. The weight is marginal and the simplicity to mounting a prop is PFM (pure f**king magic). Some of the smaller three bladed props have no hub space for a multi bolt hub so this works out great.
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Old 05-08-2013, 06:55 PM
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Default RE: Single bolt prop Hub for DLE 35?

I have single-bolt adapters on ALL of my DLE's and my VVRC 40cc twin, and have had no problems at all. The bolts were all installed with blue Loctite.
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Old 05-08-2013, 07:55 PM
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Default RE: Single bolt prop Hub for DLE 35?

Well, It is a simple install,, but you need to have the right tools. I did not have a deep socket that had a thin enough wall to fit the center stud. So, I cut the stud off with a cut off wheel. Here is where you can get into trouble. The stud must be ground to be below the face of the thrust washer area. Otherwise the single bolt adapter will not seat properly, and a failure would be pretty much a certainty. If I do another one, (which I most likely will), I will shop for and get the proper socket to do the job. It would be nice to be able to unscrew that stud instead of cutting it off.
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Old 05-08-2013, 10:57 PM
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Default RE: Single bolt prop Hub for DLE 35?

Had all the six bolts shear in a hover on a King 70 on a ModelTech Cub two days ago. I was lucky this time as I had started the hover high and was tail sliding my way down.
Ok - now why did all the six bolt sheared - dumb pilot / operator. The bolt holes in the prop were slightly larger than the bolts (4mm bolts, 6mm holes) - constant power adjustment during a hover place great load on the hub - the bolts were worked back and forth within the loose holes till they sheared one by one.

It is very difficult to take the sheared steel bolts out of a soft aluminium hub - I spent two hours building up little weld bead heads on top of the sheared bolts - in the end I could only get five of them out - so I need to be even more careful with prop installation on this hub from now on.

Single bolts hubs are great on smaller engines, but as the engines and props get larger, the mechanism hits its limitations with wooden props. I have had single spindle / nut mounting on a 100cc converted engine running a 28/10 prop successfully, but that was on a scale plane where there were smooth power adjustments and no surges at all. On the other hand, I have had locating pins on zenoah G-62 shear many times because of power surges -



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Old 05-09-2013, 07:21 AM
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Default RE: Single bolt prop Hub for DLE 35?

Well regardless of the cause, if you don't have bolts to break then they won't break.

Quote:
ORIGINAL: pe reivers

The bolts don't break from a single kick back. They break because they have been bent to- and fro due to lack of backplate friction to the prop.
This friction is a function of prop clamping force and material properties. Prop clamping force is a function of bolt torque only. So, too little torque will cause broken, not sheared, bolts. Shearing the bolts is impossible when using a soft prop against a hard back plate.
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Old 05-09-2013, 09:01 PM
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Default RE: Single bolt prop Hub for DLE 35?


Quote:
ORIGINAL: pe reivers

The bolts don't break from a single kick back. They break because they have been bent to- and fro due to lack of backplate friction to the prop.
This friction is a function of prop clamping force and material properties. Prop clamping force is a function of bolt torque only. So, too little torque will cause broken, not sheared, bolts. Shearing the bolts is impossible when using a soft prop against a hard back plate.
Some times hard to beleve.
Bill C. BCCHI
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Old 05-10-2013, 01:30 PM
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Default RE: Single bolt prop Hub for DLE 35?


Quote:
ORIGINAL: shakeelsid

Had all the six bolts shear in a hover on a King 70 on a ModelTech Cub two days ago. I was lucky this time as I had started the hover high and was tail sliding my way down.
Ok - now why did all the six bolt sheared - dumb pilot / operator. The bolt holes in the prop were slightly larger than the bolts (4mm bolts, 6mm holes) - constant power adjustment during a hover place great load on the hub - the bolts were worked back and forth within the loose holes till they sheared one by one.

It is very difficult to take the sheared steel bolts out of a soft aluminium hub - I spent two hours building up little weld bead heads on top of the sheared bolts - in the end I could only get five of them out - so I need to be even more careful with prop installation on this hub from now on.

Single bolts hubs are great on smaller engines, but as the engines and props get larger, the mechanism hits its limitations with wooden props. I have had single spindle / nut mounting on a 100cc converted engine running a 28/10 prop successfully, but that was on a scale plane where there were smooth power adjustments and no surges at all. On the other hand, I have had locating pins on zenoah G-62 shear many times because of power surges -

Maybe try a left handed drill bit to extract that last bolt. I have done that many times on stripped out socket head bolts on cutterheads at work. It does not always work, but most of the time it did for me.

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