RFD rotor head and non AN hardware?

[Foamandtape]

Hi all,

First post but have recently acquired a nicely built bee and am just going through it and replacing any thing questionable or just upgrading bolts to AN drilled with castellated hardware for any supercritical components but have noticed the only non AN hardware on the machine is on the rotor head and its associated bolts?? After doing some digging I found this was a factory thing and am quite shocked that using JH grade 8 hardware is the stock stuff it came with. I have replaced the teeterbolt with the appropriate AN bolt since I can add a castellated nut and cotter pin it, the same was done for the pitch and roll blocks. I dont have any documentation on the bolts that hold the bearing to the block and don't want to disassemble it further as I don't have any experience with the rotor head. Seems sort of trivial to save a few bucks on hardware especially for something as critical as the rotor!

Thoughts?

thanks again!

 

[JohnS]

RFD rotorhead. Seems to be all AN hardware. Hope this helps.

 

[MikeBoyette]

Dad used grade 8 hardware where he could. There’s always been a misunderstanding about AN v/s hardware grade bolts. AN is grade five. Usually the difference is also the grip length v/s the thread length. Dad always sourced grade 8 bolts from the factory with documentation to prove the authenticity. He only used bolts that could be verified. 35 years building gyros and rotorheads using these methods and supplies. He hates castle nuts and cotter pins. Seems an antiquated way of doing things when you can just use lock nuts. The nuts that are used often enough should be replaced every so often. Grade 8 bolts are far stronger than A/N. BTW The A/N designation has nothing to do with aircraft. It’s short for Army/Navy standard.

 

[j4flyer]

Mike, I don’t like using grade 8 bolts in critical areas for a couple of reasons. Grade 8 bolts are stronger but they gain strength through hardness. They are more likely to fail if a crack or wear mark developes vs bending or completely wearing through like the AN5. The grip length on a grade 8 is different. You need a physically longer bolt as threads add length. Having said this, I’m not aware of a single failure on a RFD product that uses grade 8. So I must assume that in a Gyroplane environment the hardware would be at the builders digression. I hope your Dad is doing well. Also, I haven’t seen or heard Chucks name for a while. Is he still healthy ? Thanks Bob

 

[Tyger]

It just goes to show that you cannot assume that you know the reasons why the designer/builder made the choices he did.

 

[j4flyer]

It just goes to show that you cannot assume that you know the reasons why the designer/builder made the choices he did.

It’s also why you shouldn’t divert from the designers plans. One change may bring about something you don’t want.

 

[Abid]

Mike, I don’t like using grade 8 bolts in critical areas for a couple of reasons. Grade 8 bolts are stronger but they gain strength through hardness. They are more likely to fail if a crack or wear mark developes vs bending or completely wearing through like the AN5. The grip length on a grade 8 is different. You need a physically longer bolt as threads add length. Having said this, I’m not aware of a single failure on a RFD product that uses grade 8. So I must assume that in a Gyroplane environment the hardware would be at the builders digression. I hope your Dad is doing well. Also, I haven’t seen or heard Chucks name for a while. Is he still healthy ? Thanks Bob

Lots of shit going on with Chuck Beaty. Not my place to divulge any details but if someone is a personal friend they should say hi and check up.

 

[JETLAG03]

If you check the shear strengths of the bolts you may be surprised. Anyone have data for bolts that have given way?

 

[MikeBoyette]

Yeah Dad had all that data memorialized when it was his job to do so. He always had paperwork to trace the pedigree if every bolt he used. He got really good at spotting counterfeit hardware. I’m not sure the exact number however one of the arguments for using AN bolts over grade 8 is grade 8 bolts are brittle. Dad’s argument was so who cares if it takes twice as much stress to break it then not bending before breaking is not a concern.

 

[j4flyer]

Mike its not just bending that causes failure. A hardened part is more subject to fatigue cracking. I believe that and the lower weight of grade 5 is why military hardware is grade 5. Grip length plays an important part as well. To get proper grip length you will have excess threads. Some mistakes have been made where builders have used grade 8 bolts that were too short and had critical parts riding on threads vs shaft.
Having said this, for your Dads design it appears that history has proven he worked out these issues for his product. They seem to hold up well and are a popular design. I like they way they are capable of landing in most accessible areas. I also like the many engine options he offered over the years. I think he ran the range from Rotax to Subaru. His Subaru accessories were well made. I saw one flying at Mentone several years ago. Are his plans and kits still offered ? Have you taken over the business ?

 

[MikeBoyette]

Mike its not just bending that causes failure. A hardened part is more subject to fatigue cracking. I believe that and the lower weight of grade 5 is why military hardware is grade 5. Grip length plays an important part as well. To get proper grip length you will have excess threads. Some mistakes have been made where builders have used grade 8 bolts that were too short and had critical parts riding on threads vs shaft.
Having said this, for your Dads design it appears that history has proven he worked out these issues for his product. They seem to hold up well and are a popular design. I like they way they are capable of landing in most accessible areas. I also like the many engine options he offered over the years. I think he ran the range from Rotax to Subaru. His Subaru accessories were well made. I saw one flying at Mentone several years ago. Are his plans and kits still offered ? Have you taken over the business ?

Yes sir, he did work all those issues out with the Grade 8 bolts. He and Chuck Beaty used to preach about threads in bearing being very bad. Plans haven’t been available for several years. They were very dated so the machine you could build with them was very different than the one he sold in the end.

 

[Georgi]

Lots of shit going on with Chuck Beaty. Not my place to divulge any details but if someone is a personal friend they should say hi and check up.

Suddenly, there are no personal friends of his any more, at least here on the Forum!? The same situation happened with Ralph Taggart here on the Forum. Are we too "nice" people or just regular "no bad news" hypocrites?

 

[Vance]

Suddenly, there are no personal friends of his any more, at least here on the Forum!?

I am proud to know Chuck Beaty and consider him a friend.
I suspect I am not alone in this.
The details of his personal life are personal.

 

[Georgi]

I am proud to know Chuck Beaty and consider him a friend.
I suspect I am not alone in this.
The details of his personal life are personal.

Oops, sorry, my bad...... If I knew Chuck considered you a friend, I would never ever opened my mouth Good day?!
P.S. My regards to your support group. You need it.

 

[j4flyer]

Yes sir, he did work all those issues out with the Grade 8 bolts. He and Chuck Beaty used to preach about threads in bearing being very bad. Plans haven’t been available for several years. They were very dated so the machine you could build with them was very different than the one he sold in the end.

Mike is the any information you can share on Chuck ? We had some heated debates years ago but, I always considered him a very knowledgeable and passionate Gyro designer. I truly miss his posts. I don’t get on the forum much anymore. But, when I did, I gravitated to his postings. I confess some of his posts were above my pay grade and I didn’t understand them, especially the ones where he presented a formula used in his analysis. Anyway, I wish he and your Dad well. I appreciate your replies. Bob

 

[MikeBoyette]

Suddenly, there are no personal friends of his any more, at least here on the Forum!? The same situation happened with Ralph Taggart here on the Forum. Are we too "nice" people or just regular "no bad news" hypocrites?

Plenty on personal friends just not my place to put his personal business in a public forum.