Serious problem ?

[gyroplanes]

I found this condition and would like some opinions on it. I'll try to word this as descriptivley as I can..

You have a heavy gyro with the requisite heavy, long rotor system.
When you move your joystick forward, off the rear stop, and set the massive rotorhead and rotorblades in motion and suddenly stop the stick, would you expect the inertia of the head/blades to bend the joystick?
Would you tolerate the flexing of the stick metal?
What do you think would eventually happen?

I don't know if the above scenario has ever happened to anyone.
But I found an even scarier one exists, in a large percentage of the fleet.

RAF & GBA gyroplanes have the "cross over" tube (the "tube" that connects the rotorhead torque tube to the pushrods) I quote "tube" because, unlike other gyros, the RAF & GBA use a solid aluminum bar, i believe they call it a gimble actuation arm.

The next time you go out to your RAF or GBA SH, move your joystick to neutral. Wait for the teetering to stabilize.

Now, with some vigor, pump the stick back and forth about 4 inches watching your torque (tube) bar.

The center of the bar and tips of the cross over bar will move in different directions. This movement, viewed from the front or back, will resemble a bird flapping it's wings.

I realize that we don't often pump our joysticks in flight, but every taxi out or exaggerated movement of the stick can cause a flex in the crossover and those flexations cause metal fatigue.

I believe it's just a matter of cycles before failure.

[Caribean_gyro]

In my twinstar is a hugh triangualr plate.
ChuckP

[Mark Sanders]

I found this condition and would like some opinions on it. I'll try to word this as descriptivley as I can..

You have a heavy gyro with the requisite heavy, long rotor system.
When you move your joystick forward, off the rear stop, and set the massive rotorhead and rotorblades in motion and suddenly stop the stick, would you expect the inertia of the head/blades to bend the joystick?
Would you tolerate the flexing of the stick metal?
What do you think would eventually happen?

I don't know if the above scenario has ever happened to anyone.
But I found an even scarier one exists, in a large percentage of the fleet.

RAF & GBA gyroplanes have the "cross over" tube (the "tube" that connects the rotorhead torque tube to the pushrods) I quote "tube" because, unlike other gyros, the RAF & GBA use a solid aluminum bar, i believe they call it a gimble actuation arm.

The next time you go out to your RAF or GBA SH, move your joystick to neutral. Wait for the teetering to stabilize.

Now, with some vigor, pump the stick back and forth about 4 inches watching your torque (tube) bar.

The center of the bar and tips of the cross over bar will move in different directions. This movement, viewed from the front or back, will resemble a bird flapping it's wings.

I realize that we don't often pump our joysticks in flight, but every taxi out or exaggerated movement of the stick can cause a flex in the crossover and those flexations cause metal fatigue.

I believe it's just a matter of cycles before failure.My sparrow hawk has that set up and in flight every movment is very sudle and when I am making a full stop landing after the nose wheel touches the ground then the stick is brought full forward on the stop and the blades are still over 100mph and no sign of a problem so far and I have not herd of any yet. the rotor brake is not engaged until the blades are at or below 75 mph.

[gyroplanes]

I guess I'm not very good at getting my point across. I tried to elaborate on my concerns in the GBA thread above. I will consolidate my answers there instead of running two separate threads. (see GBA thread above)

[Steve Osborne]

Here is a photo of the part RAF updated a few years ago.

[gyroplanes]

I hope you all note the "?" in the thread title. I'm not an aeronautical engineer or metallurgist, but I do know, that if any part of my control system flexes, it WILL lead to fatigue failure at some point. "When" is the only unknown.

[LASsociety]

Many hombuilts (i speak of fixed wing experience) have people add things that they think will make the aircraft stronger and end up with a heavy, over-built aircraft. Gyrocopters are probably the exception for me. The extra weight of a triangular piece or reinforced brace wouldn't adversly affect anything, and would certainly help me sleep at night.

[tomhall]

Anyone know a source ( other than RAF in Africa ) for that new & improved torque tube ? Tom T. Hall in MN

[Steve Osborne]

Tom, how are the new blades working?

[tomhall]

Steve, Thanks for asking. I had only 3 flights with the new blades last Nov. before weather and darkness arrived. On each flight I had to apply significant back pressure on the stick to remain level. I thought my mast may have shifted, but it had not. Ther answer, from Ron Menzie, is quite simple: the Sportcopter blades are " cleaner " than the RAF blades, which offered more drag. I was trimmed to the RAF blades; I changed " wings " , the cleaner wing would by nature put me nose down a bit. Last week I switched from mast position # 3 to #4 ( more verticle ). I still have to apply some back stick to keep level. I would still like to level the gyro without a lot of trim spring pressure, but I may try 2 springs on each side ( not 1 stronger one ) in case 1 breaks. I was hoping I could simply put on the new blades and fly into the sunset; but everything is inter-dependent. It was suggested I make a new torque tube with the offset 1/8" closer together; that seems a bit dramatic. Anyone else with Sportcopter experience ? Thanks Tom

[LARRYEBOYER]

Tom. Does the gyro fly faster with the nose down? How you doing Man? Call me!!!

[CLS447]

Tom, I see that you got no response to the SC blade question.

I would do a forum search.....at least a few guys switched to the SC blades with great results.

Stan Foster, Tim O conner & others. Good Luck

[kss1000e]

Do you there is the size diagram paper? Thanks

[giro5]

Steve, post 6, the picture. Those lightning holes in the horizontal bar look too big ie, not enough metal left on the top and bottom of the bar. That bar is scary to me.

[earthbnd misfit]

Even the 4 x 6 mm bolts that hold on the piller posts seem weak. It doesn't take much to strip the threads.

[Hognose]

Steve, post 6, the picture. Those lightning holes in the horizontal bar

LightEning holes. Lightning holes were made by lightning.

look too big ie, not enough metal left on the top and bottom of the bar. That bar is scary to me.

The material in the middle of the bar carries relatively little of the load. So one might as well cut it away; it's dead weight. The details require a little bit of book learnin' -- for the layman interested in experimental aircraft I'd recommend Dan Raymer's book on homebuilt aircraft conceptual design.

Most of the strength in a bar is around the outside. The mass in the middle helps in compression, and a little in shear, but mostly it's just mass you have to carry.

If one is concerned about the possibility of fatigue failure, a steel tube might be a better choice, but there are tradeoffs there also. (Steel is more vulnerable to corrosion, and corrosion can lead to cracking, for one).

I understand Tom's concern, and I know that RAF redesigned this bar at least once (there's a thread here about why and showing examples of the old and replacement bar). I do believe that no mishap was due to failure of this bar in the field, and these aircraft have flown thousands of hours.

I'd feel better about it if the aircraft had been designed by an aeronautical or structural engineer, but it wasn't. But while the RAF may have some issues, this isn't one that punches pilots' styx tickets.

cheers

-=K=-

[davreich]

Hi,
The aeronautical engineers at Sparrowhawk copied (oops) engineered them the same as the RAF 2000 original. I believe the parts are interchangeable for some reason.

[fiveboy]

But while the RAF may have some issues, this isn't one that punches pilots' styx tickets.
-

Can you spell erudite? (Better question can most people pronounce it correctly?)

[Harry_S.]

This looks like a really nice job as evidenced by these photos.

Wayne asked me to submit these fotos for him...no easy task as I'm now with a new 'puter, with Vista at that. A big ole jump for me.

Maybe Wayne can come in here and give you more info.


Cheers :)

[WHUBBS]

Harry, i traced around my original torque RAF bar and added some of my own design to it, machined it out of 6061-t6 material and now looking for a place to get it, Anodized the same color to match the rest of my machine. although i have never heard of a failure of this part, i just feel better with the extra beef. i have over 160 hours on my RAF and the original part shows no sign of deterioration.

Wayne

[Russ Hobbs]

Wayne, there was a recent article on Anodized aluminum, (Nov-Dec 2008) anodizing reduced the overall strength of aluminum significantly, somebody correct me if I''m wrong. The article was about a part failure in a Safari Helicopter with very low hours

[Mayfield]

I generally do not like to anodize a part that will experience any flexing.

http://resources.metapress.com/pdf-preview.axd?code=mj50343764u6001m&size=largest

Jim

[WHUBBS]

Thanks Russ and Jim, for your response, i did read the article in our magazine on Anodize metal and the Safari that crashed, possibly i will get my part powder coated as i have a friend here in town that has a business of powder coating and he has a hangar on the other side of the wall from my hangar. Think i will do it in Yellow to match my rocker box covers that he has already powder coated, some time ago.

Wayne

[davreich]

Hi,
It has always been my understanding powder coating a flight critical part is a very big decision. The temperatures can change the strength of the aluminum and has a fine tollerance. If you go this path I would go with company that does aircraft parts. Just my opinion.

[Riff Raf]

This looks like a really nice job as evidenced by these photos.
Wayne asked me to submit these fotos for him...no easy task as I'm now with a new 'puter, with Vista at that. A big ole jump for me.
Maybe Wayne can come in here and give you more info.
Cheers :)
Harry
I think all my questions about the hub bar winglets have been answered here with your photos (I have the same ones as you do) I'm good there.
Now I would like the other new part you have there, where do I get one??

[Harry_S.]

Harry
I think all my questions about the hub bar winglets have been answered here with your photos (I have the same ones as you do) I'm good there.
Now I would like the other new part you have there, where do I get one??



That's not my machine, Roger...it's Wayne Hubbs' and he had it made. I would suggest you PM him for the info.

Methinks if enough people want to change over, arrangements could be made to make a run on 'em?!


Cheers :)

[WHUBBS]

As mentioned by Harry, i have a local machine shop friend that made my hub bar, per my drawing and if you would like one to the same shape and dimensions as i have made for my machine, i would be glad to have it done for everyone. it is machined from 6061-T6 material and to the same thickness as the production one that come with my raf kit.

he charged me $85.00 and i am sure he would make one for that, plus i would have to ship it to each person, after finished, for the extra shipping cost. he did a beautiful job as usual and he said he could much prefere, to make a ten piece run if possible.
if you would like one, send me an e-mail at WHUBBS@DTCCOM.NET

[Greg Lockhart]

Wayne,
Do you know if the dimensions (holes, etc.) of this RAF part are the same as on the SparrowHawk.
Thanks,
Greg Lockhart

[WHUBBS]

Greg, i am not 100% sure but a friend of mine has a SparrowHawk, which i was looking at the other day and i really think the two are the same, but we must know, for sure and i appreciate you asking, i Bet Jim Mayfield would know and i am sure he has been looking at this thread and if so, Jim, would you know for sure that the Torque Tube bar is the same Dimension for the RAF as the SparrowHawk??

Wayne

[Harry_S.]

I just read an e-mail from Wayne Hubbs saying he already has orders for 4 ea.of his new torque tube crossarm.

He thinks he can have 'em made and shipped for less than a "C" note; that is within the contiguous states, methinks.

Now's the time to get a new crossarm if you've been thinkin' about it. Wayne measured and compared the RAF arm to his friends SH and they are the same.

Ya' want one, better PM Wayne now. ;)


Cheers :)

[WHUBBS]

Greg, i took a flight yesterday to Sparta Tn. to check the dimensions of the torque tube bar on a friends SparrowHawk, and they are exactly the same as the one off my RAF. at this time i have orders to build 5 bars and the machinest has placed the order for the 6061-T6 material and he said it would arrive today and he would get started on the parts.

WAYNE

[Greg Lockhart]

Thanks Wayne

Greg

[WHUBBS]

I now have orders for 7 torque tube crossarm, parts that will fit a SparrowHawk or RAF 2000. i should start shipping the parts out by this SATURDAY i think, or the first of March.
They are $85. plus shipping to your location from Smithville Tennessee, Two of the 7 folks have sent me $100. and i will send their change back in the package with the bar, if you would like, one. to respond to me , i would rather you e-mail me at

whubbs@dtccom.net

Wayne Hubbs

[WHUBBS]

i now have 8 bars on order and picked up 5 that were finished yesterday from the machine shop. i have also received two checks, and today i shipped each of the two folks their part. the shop is building more at this time. i am shipping ground UPS and one went to IL. which cost $12.70 and the other went to CA. and only cost $11.63, go figure, at first i was afraid the fifteen dollar, i was asking for shipping might not cover the cost, but now i think all will be ok. i put the change left over from the shipping cost back into the package, to return, to the customer. as soon as i receive your check for $100. i will get your part out, and your shipping change.

Wayne

[Greg Lockhart]

Thanks Wayne,
I sent you a check today.

Greg Lockhart

[Harry_S.]

I can't imagine how these fellas could thank you enough for what you're doing in this regard Wayne.

Personally, I don't think you're making a penny on this deal, anywhere...material cost, machinist, packing and shipping and even returning any change on the shipping...plus your personal time and effort.

I haven't ordered one of the units but I'd like to say "Thank You." :first:


Cheers :)

[WHUBBS]

Harry, i appreicate your comments, and you are correct, i am not making anything and i am driving about 50 miles round trip to pick up the parts, and the only thing i am worring about is, i am asking 15 dollars for shipping and that has been enough at this time and i am sending all change back with the package, but if the shipping is over 15 dollars, i am not sure what i will do, then. i really like providing work for my friend that owns the machine shop, and due to hard times, his work is down and i just want to help him and all the good folks that loves the same flying hobby that i do. i really think this cross bar design will give much added strength in this control area of our machines.

Wayne

[WHUBBS]

Moving alone, i have now received orders for 12 Torque Tube Cross arm Bars, and each have said they would send their checks, in the mail, and todate i have received three checks and i have shipped three Bars. and returned their change for shipping in the package, the cost of shipping has ranged from $11.63 low to $12.83 for a high and all have been shipped ground UPS. i will pick up 7 more finished Bars late this week, as soon as i receive your check, i should be able to ship. i am letting each person know the date i ship and the tracking number. i polished the Bar that i have installed on my RAF, using a cloth buffing, wheel, on my grinder, and Jewelers Rouge as a buffing commpound, in about 15 minutes, the Bar looked just beautiful and shining like chrome. i would suggest you do the same, when you receive your part.

whubbs@dtccom.net

[cgmg]

Wayne,

Received my bar today, and will polish it like you suggested.

Again, thanks for the time and effort you're putting forth to help fellow members out!

Personally, as I told you regarding my order, I think you should keep the shipping change. The price you're quoting on the bar is a steal. If anyone doubts that, go try to have one made yourself!

[WHUBBS]

Thanks, Mark for your comments, and glad you got your part, i appreciate your offer to keep the change, but i just hope you will fly safely for many years to come. just a suggestion to make it easier to install the Cross Bar, if you attach both rod ends to the bar first and then attach it to the torque tube on the rotor head, i found it to be much easier and if you have someone to slightly move the cyclic stick, it will relieve a little tension on the springs and the two bolts that attach it will go in very easy. also i install the rod end bolts, to where the nut is facing out, so you can see it, and the cotter pin better, when you do your preflight.

Wayne

[rgraffeo]

Mr. Wayne,
Add me to the list I would like one of your crossbars.

[Harry_S.]

This a foto of Wayne's new crossarm...after the polishing session.

Very stout and very pretty, ay. ;)


Cheers :)

[Mike Stone]

Wayne...
Is there time to get one ordered for myself? If so, please send let me know.

Thanks
...Mike

[AirHorse1]

Wayne,
I would send you a check tomorrow, but I don't have an address to send it to. I'm not sure if you received the 2 emails I sent you a few days ago because I haven't received any response. I'm just assuming I am one of the new orders you have mentioned. You definately deserve a big thanks for your efforts to do this for such a bargain price.

Ed

[WHUBBS]

Ed, i have sent you messages but they must not be getting through. just send the check, $100. to WAYNE HUBBS 2309 ALLEN FERRY RD. SMITHVILLE, TN. 37166

MY E-MAIL IS whubbs@dtccom.net

[WHUBBS]

Sorry, everyone but i am getting so many orders for the cross arm bar that it is hard to keep things straight dealing with the private messages and e-mail.

THE BEST THING TO DO IS CONTACT ME AT whubbs@dtccom.net
my mailing address is WAYNE HUBBS
2309 ALLEN FERRY RD.
SMITHVILLE, TN. 37166
the part is $85. plus send me $15. more for shipping and i will send your change back in the package for a total of $100. check or money order.
i am letting every body know when i ship the part, tracking number and all packages are going ground UPS.

I want to provide a bar for everyone that wants one, and it is helping my friend that runs the machine shop as most of his work is gone with the industry being down in this area.

Wayne Hubbs

[WHUBBS]

Just an update, i have received 7 checks and shipped seven parts, then i ran out of parts, now i have received 5 more checks and have no finished parts, to ship, but the machine shop is building 10 more parts, at this time, and i should be able to ship more parts this coming week, of 3-9-09. i am still waiting on 5 more checks that have placed orders. i do not cash the checks until i ship the part, as i am always at the mercy of the machine shop, i will return each check if i am not able to deliver.

the shop has decided to polish each part before delivery, at no charge, he was not able to do that before but has purchased the equipment, to add that to his process, and i think they look excellent, with the polished look.

Wayne Hubbs

[Harry_S.]

Wayne, you are really extending the effort in supplying these new control crossarms to the RAF and Sparrowhawk owners as a volunteered service...and may I add...nary a penny profit on your part. Kudos.

Thank you again.


Cheers :)

[StanFoster]

Wayne is my model of a person I want to become. You can trust him with anything....and he does superb meticulous work. What an asset we have here.



Stan

[Riff Raf]

Thought I would post a pic of the cross bar I got from Wayne, and had it anodized blue.
Thanks Wayne

[Harry_S.]

That's nice Roger.

Any fotos of your "whole" machine, or ones that I have missed?!


Cheers :)

[WHUBBS]

Roger, that looks very nice, and the blue is the same color that is on my RAF. would you mind telling us the cost to get it anodized, at your location. i now have a total number of NINTEEN ORDERS, have shipped SEVEN parts and the shop should have 13 more finished this week, and i will get them on their way A.S.A.P. i have 8 checks from customers in hand at this time, which i will not cash until i ship.

Wayne

[Riff Raf]

Harry
I have no full photos as of yet, but soon when I start a keel mod/engine drop thread,
along with some other mods coming up.
The paper the part is laying on has some drawings of the keel mod on it, they are not finished yet.

Wayne
I paid $20.00 out the door for the part to be ano. I thought it was cheep.

[Vance]

In my opinion, anodizing a highly stressed flight critical part is not best practice.

Studies have suggested that it weakens the part.

Thank you, Vance

[WHUBBS]

just got a call this evening and i have 13 Torque Tube Cross arm bars, ready to pick up tomorrow morning, at the machine shop, i have 9 checks that have prepaid for the bar, and i should have 9 bars shipped tomorrow, which will catch me up on all the orders that i have in house. if anyone else would like to replace their origional bar on the SparrowHawk or RAF, just let me know and i will get it made.

This project reminds me of the time Stan Foster, took orders from lots of us, for both black and white T-Shirts, with our flying machine logo on them, and in the color of our machine, which i purchased 4 total, and just love them, as they are of good heavy quality material. he did not do this for profit, for himself, but to give his friends company the business, and made lots of gyro folks happy with their purchase, which is the reason i am doing this BAR project, for a friend that owns a machine shop and i do believe it will make our machines just a little more safe.

Wayne

[asmuzsr]

Wayne if I could get one that's not anodized I'd like one also. I've also heard it makes the part more brittle.

[Dan_Reagan]

A few years back I had an occasion to test the strength of one of these stock crossarms.

My problem was my complaisancy / stupidity curve got all out of whack. Something like that height / velocity thingy. As my hours went up, (about 200) my complaisancy went up proportionally. Contrary to all theories that say stupidity goes down with age, in my case it seemed to be exponentially proportional.

So on my complaisancy / stupidity curve, when the two lines met it caused my rotor blades to go east and my control arms to go west and the tail to go north and luckily I went South. At the end of my $10,000 cross arm test, the arm was distorted about 1/2 inch horizontally on one end but did not break.

I just thought I would give my observation so it relieves everyones curiosity and they don't have to test theirs.

I just sent Wayne a $100 check for a heavier one.

Wayne thanks for your efforts.

Dan Reagan

[Riff Raf]

In my opinion, anodizing a highly stressed flight critical part is not best practice.
Studies have suggested that it weakens the part.
Thank you, Vance


This is a very thin anodizing, the thickness of the hair on a gnats arse and has absolutely no adverse affects on the material strength of this part!, This is to avoid oxidation of the part.
and yes I do agree, if it was a hard anodizing I would NOT do it on a highly stressed part, that is a bad idea.
There are, many different types or scales of Anodizing.

Isn't there another thread for this discussion? (Anodizing alum parts?) where some very fine points are made about this.
http://www.rotaryforum.com/forum/showthread.php?t=19936&highlight=anodizing

Wayne if I could get one that's not anodized I'd like one also. I've also heard it makes the part more brittle.

Wayne did not have this Anodizing done, I did.

[Russ Hobbs]

HBlearn2fly thanks for posting that info, I to was concerned.

[Harry_S.]

That will be shipped, probably tomorrow to those eagerly awaiting 'em.

Thanks again, Wayne.


Cheers :)

[Skyjinks]

There was a lot of interesting information in this thread originally. The thread has beeen sustantially redacted, can anyone advise why?

[Harry_S.]

Redacted in what manner Charles?

Are you against the publication of improvements?


Cheers :)

[WHUBBS]

This morning, i shipped the last two Cross arm bars that i had orders for, and i only have two left that are finished and ready to ship, if anyone else would like one of the new stronger bars, just let me know, i felt i would have more orders and have ask the machine shop to build 6 more parts, and that will be all i will make, unless i have more orders. i have shipped a total of 20 Cross arm bars, since building the one on my machine. i flew my RAF two hours today, across the lake to Sparta Tenn. with the new bar on my machine and got there just in time to see a first flight of a RV-4 fix wing fly after a major teardown and rebuild, all went well with the first flight.

Wayne

[Gary_in_Orygun]

Wow, I'm behind on my forum reading. I've been thinking of this upgrade. Count me in. I'll go back over this thread and see if I can find what I need to do.

[AirHorse1]

Wayne,
I received the crossbar today and it looks much better than the original thats on my machine and well crafted. Again, kudos to you and your machinest for your efforts with a high quality product !!

[asmuzsr]

Hey Wayne
Got mine today also. Looks real good. Got one of Larrys stabs on the way. Now I just need the rest of my kit.

[WHUBBS]

Ed & Tony, glad both of you received your Bar, and glad you like the machinest work, i have been very impressed, watching him build the bars and the tight tollerance he holds on every area of the bar. looks like i might be in debt for 6 bars as i pay him when i pick them up. i have two finished bars here at home and have two orders for them and just waiting on the checks and will ship them out as soon as they arrive, the 6 was just in hopes that i would be able to sell them, if i don't i will take them to Mentone and possibly someone would want them.

Wayne

[WHUBBS]

Just wanted to let everyone know, that i have only one order, for a cross arm bar and his check is on the way, but while i was at the machine shop yesterday, i ask the machinist to build SIX more bars, just to use up all the stock we have purchased. Remember this cross arm bar fits both the SparrowHawk and RAF. If you would like this stronger bar, for your machine, it is not to late, but after we make these last 6 parts, that is possibly all we will make, unless i get several orders to make it worth the shop setting up the tooling.

Wayne

[SARAF]

Hi All

May I just ad that RAF SA does not condone the purchase of copied parts from any machine shop. This is extremely dangerous and a life risk.

Regards

SARAF

[Harry_S.]

Say What??


Cheers :)

[Passin' Thru]

Say What??


Cheers :)
Yeah, my thoughts exactly!

[Mayfield]

Hi All

May I just ad that RAF SA does not condone the purchase of copied parts from any machine shop. This is extremely dangerous and a life risk.

Regards

SARAF

I don't often do this, but it is astonishing to me that the owner of this particular company could utter the highlighted words.

R/S

Jim

[Passin' Thru]

I don't often do this, but it is astonishing to me that the owner of this particular company could utter the highlighted words.

R/S

Jim

Irony, at best! ;)

[WHUBBS]

RAF/S.H Cross arm bar, some have ask the weight difference between the first six bars made, and shipped, that did not, have the 4 round holes in them Vs. the rest, that were shipped, with holes. i will have that information soon as i picked up the last 6 bars that are finished and ready to ship, yesterday, the shop made one without holes so we can weigh it and get a good accurate number for the folks that would like to know, the difference in weight. if you want one of these last six bars just finished, just let me know.

[WHUBBS]

RAF/SparrowHawk cross arm bar, just some information, that some folks have ask for, i purchased a set of digital scales today that weighs in gram and ounces, to weigh the production RAF cross arm bar, and the new stronger bar, that some folks have purchased here on the forum.

Original RAF Bar, weight is 271 gr. or 9.56 oz.

new design bar with 4 round holes in them, weight is 450 gr. or 15.87 oz.

the first 6 bars sold had no round holes in them and weighed 529 gr. or 18.66 oz.

CONCLUSION: THE NEW STRONGER, DESIGN CROSS ARM, BAR, WEIGHS 6.31 OZ. MORE THAN THE ORIGINAL RAF BAR.

Wayne

[Greg Lockhart]

Thanks Wayne,
That's helpful information. I/we appreciate your time and effort in helping us with this part.
Greg Lockhart

[Gary_in_Orygun]

CONCLUSION: THE NEW STRONGER, DESIGN CROSS ARM, BAR, WEIGHS 6.31 OZ. MORE THAN THE ORIGINAL RAF BAR.
Wayne

Holy cow!, I'll need to dump half my water bottle out before each flight to make up for the extra weight.
:D

Just kiddin' of course. I'll fly with more confidence with my new cross arm.

[WHUBBS]

Gary, if you drink the water before your flight and leave your bottle on the ground, your weight should be a wash??? ha ha just having a little fun.

[WHUBBS]

One person sent me a message, that has received a new stronger bar, asking if you need to adjust your push /pull tube, rod end bearings any different, with the new stronger bar, and the answer is NO. the bar thinkness is the same, as the original, and all hole locations are exactly the same.

Wayne

[Harry_S.]

A foto of Wayne's new arm installed on his machine.


Cheers :)

[WHUBBS]

Just an update, i have had orders, for 23 stronger cross arm bars, for the RAF & SparrowHawk, and have shipped 23 bars, was gone out of town for 3 days and on return, checking my e-mail, i found orders for 5 more bars, but only have 4 in inventory, will ship the 4 bars this week, and have ask the machine shop to build 6 more as the machinist said he would rather make 6, at a time, even if we do not sell them.

Wayne Hubbs

[TJMay]

Wayne,

Just having the stronger cross arm above me makes me feel safer flying.

Any plans to fabricate any other parts?

Tommy

[WHUBBS]

Tommy, their are parts that we could build, i was helping a friend on his RAF pre-rotator, i removed it and replaced all the bearings inside. i noticed where the two smaller bearings set inside, the metal was being eat out, i believe we could make this whole piece and when my friend brings his machine back to my hangar this summer, i was thinking about taking it back off and doing just that, for a much better job. this same problem has happened with the pre-rotator on another RAF, that belongs to another person that i know. i really suspect their are more out there that needs to be repaired or replaced.

Wayne Hubbs

[WHUBBS]

I have Seven (7) new RAF / SparrowHawk, stronger, Cross Arm bars just made and delivered to me, to bring to Mentone on August, 4-8 . i have no customers for them, so first come first serve. $85. each.

Wayne

[enewbold]

I have Seven (7) new RAF / SparrowHawk, stronger, Cross Arm bars just made and delivered to me, to bring to Mentone on August, 4-8 . i have no customers for them, so first come first serve. $85. each.

Wayne

I'll take one right away. Where do I send the money?

Thanks,
Ed Newbold

[Heron]

Hello Mr. Newbold, how are you doing?
Time really flies doesn´t it?
Be good!
Heron

[WHUBBS]

We built a total of 39 stronger cross arm bars, and delivered them, all by mail except a few that i hand delivered for the RAF & SH, which i think is pretty good. in the beginning i was only going to build, just one for myself. i powder coated the one i kept for myself, and i understand some folks think that is not the thing to do and i respect their opinion. everyone paid in advance for their bar, , except one person, that did not pay, but i paid the machine shop out of my pocket for all the bars as i picked them up. so out of the 39 bars i lost $85.00 plus all the traveling that i did, picking them up and shipping them. i think that is pretty good and i would do it again, because i really enjoyed designing, and building these bars to make our machines just a little safer.

Wayne

[Harry_S.]

Well Wayne, there are 39 appreciative guys out there, including one asshole who didn't pay up.

This was strictly a gratis undertaking on your part and this one individual ended up costing YOU, money. :rant: Oh boy!!!


Cheers :)

[flying-i]

Chaps just some thoughts:

1. Once your blades are spinning there is very little force on the cross arm as the blades take up their own weight.
2. The design of the cross arm is of such a nature that it is designed to absorb/ flex and is made from a specially destressed material.
3. Various forces are absorbed by a little flex in the cross arm and a little flex in the vertical tubing and so on. Now with no flex in the cross arm the vertical tubing must absorb/ flex more than it used to.
4. A flexible component may bend under abnormal/ extreme conditions but a rigid one will at some point just break and be of no further use with no warning.
5. So the heavier, stronger and rigid component may not be all it is cracked up to be. In fact we do not know what material was used or if it was even destressed.
6. I would imagine that a lot of questions were asked and answered before this component was originally designed by the RAF people and that it was designed with the mechanism as a whole in mind.
7. The SH aeronautical engineer did not change this component when they copied the RAF.
8. So now we have a bunch of people out there with an untested critical component just so they can wank their stick around while in a static position and see no flex in the control arm. All now believing that they have a safer machine. Hope they all noted this mod in their logbooks.

I suggest proper rotor management and stop yanking your stick around. I was certainly never taught to do that during my preflight.

Many aircraft components are stronger in their flexible design than they would be as rigid components - e.g. blades flex, wings flex, props flex etc. Some may be surprised as to the amount of flexibility.

[Harry_S.]

Mark, I just read your Post #90 and do appreciate your thoughts, but...

What makes you state that there is "no flex" in the Hubbs' crossarm? Hubbs' crossarm is only 6 oz. heavier than the original RAF arm. In addition, it has lightening holes which, in my layman thinking, would give it "more" flexibility than the RAF redesigned arm: No?!

Even a solid alum. bar would have "some" flexibility.

I do fervently endorse your suggestion on proper rotor management.


Cheers :)

[flying-i]

Howdy Harry,

My impression form the originator was that he was concerned that when he yanked his controls around the cross bar flexed... The result is an aftermarket crossarm made from a tracing of the original component out of an unspecified material (by unspecified I mean its exact type and its exact de stressing preperation), that is stronger (here I read no flex as that was the original "serious problem")

There is no control as to this batch of critical components - should one fail how would the others know?.

Regardless of the type of aitcraft and I am involved with a few (both certified and non certified), I always favour the part directly from a manufacturer as they take responsibility for its performance and offer advice as to further treatments ie some people have anodized theirs. Even with some further words of caution it has been justified by pointing out that it is only a very thin layer - either its anodized or it not? either it weakens the material or it does'nt?

Point is Harry we should be real careful what we do and research is a key to safety and improvements. Manufacturers worth their salt tend to spend some time on reasearch and development.

I definately don't want a traced out cross arm made form a machine shop struggling for work without it being tested in some way shape or form by someone with credentials. I would rather seek clarity on all these questions from the original manufacturer.

Original Quote with concern for flexing:
"I realize that we don't often pump our joysticks in flight, but every taxi out or exaggerated movement of the stick can cause a flex in the crossover and those flexations cause metal fatigue."

The component is designed to flex - it is not a serious problem - none of these components have failed - why is there a run on a critical component that may be substandard? Maybe it is not but hey why take the risk and it is a risk..

You only have to have ONE critical component failure in flight before you to really respect what being airborne means - I really respect what being airborne means.

Again my thoughts.

[bmoore2156]

Flying j,
I purchased one of these and installed it on my machine, after I heard that RAF has a stronger, oem replacment on the market.
The "Special material" you keep refering to is plain ole 6061 T6 aluminum.
I am in agreement with your statement that this bar does not have alot of force applied to it.
I think your on to something when you say that sometimes things need to flex, in order to prevent cracking. I think your jumping the gun when you say this new bar will just break.

Finally, I will attach 2 photos. The first one is the weak oem part. The next one is the stronger oem part. I think there is already a photo on this thread of the aftermarket part. The 2 sronger bars are close to the same.
SportCopter uses a steel bar in place of this aluminum one! I wonder why?
Keep in mind this is the company who sells a high thrust line gyro, with a high fatality rate and they still claim it needs no H-stab. I am sorry if I don't share your complete trust in them.
Brad

[flying-i]

Brad hi

None of the RAF fatalities were due to the failure of an original manufactured part. This is a forum for gyro's in general and this thread is under the RAF section.

I see you have gone solo - well done, now you can enjoy your solo hours and learn everything she has to teach you and most of all respect her. She will keep you busy and you will learn to enjoy her more as you gain experience.

If you had gone solo at 25 hours as was the case many years ago, you to may have been one of the fatal stats. There are gyro's that you can learn to fly in 25 hours but the RAF is not one of them. Even the addition of a HS will not change that. RAF require a minimum of 40 hours before you go solo. A new breed of RAF pilots are emerging and they are all being trained on exactly the same stock standard aircraft but with no incidents/ fatalities.

If you want to talk about high thrust lines then there are threads elsewhere on this forum. Be sure to acknowledege that modern gyro's like the Xenon, MTO3, ELA and the Magni all have high thrust lines. I cannot comment on any of them as I am not rated on them and I feel that that should be a minimum requirement before I give an opinion.

I fired off a couple of emails and established that anodizing is no problem as it is not a heat treatment. The material is not a problem and requires only that it passes through a destressing process after being machined to allow it to be flexible. I do not have the detail pertaining to this process. The weight is not a problem for the RAF.

Regarding the soild bar I simply wanted to point out that without flex they would or could break without warning - I did not say that it was going to break. I don't know why others have a solid stainless steel bar, but I am sure they can answer that. Remember that the originator of this thread requested input and opinion from others... I just entered the discussion.

It is generally always easier and quicker to fit an oversized extra strong component that to spend time designing one that is purpose built.

I was just asking/ discussing the merits of aftermarket components especially critical components. I know for sure that you will never approach your gyro again without glancing at that crossarm and yes RAF did upgrade the component - it costs $120.

Perhaps I am too critical but I work every day with equipment that lives depend on, including my own, so my default is to abide by the manufacturer recommendations.

Be careful who you learn from as they may be singing off an old hymn sheet.

Cheers for now.

[Vance]

If you had gone solo at 25 hours as was the case many years ago, you to may have been one of the fatal stats. There are gyro's that you can learn to fly in 25 hours but the RAF is not one of them. Even the addition of a HS will not change that. RAF require a minimum of 40 hours before you go solo. A new breed of RAF pilots are emerging and they are all being trained on exactly the same stock standard aircraft but with no incidents/ fatalities.

Cheers for now.

Hello Mark,

I read the NTSB accident reports so that I can believe it won’t happen to me.

I had more than 40 hours dual instruction before I soloed.

I do not imagine that makes me a safe gyroplane pilot.

I don’t know when you feel that the new breed started.

I was told in 2002 that I needed 40 hours to solo in an RAF gyroplane.

Many of the fatalities in RAFs had the prescribed training and ended up dead anyway.

I felt from your response that you hadn’t read the thread carefully and thought about what it said.

I hope you will open your mind so that you can learn about what makes gyroplanes fall out of the sky and see what you can do to mitigate the risk.

Thank you, Vance

[gyromike]

If you want to talk about high thrust lines then there are threads elsewhere on this forum. Be sure to acknowledege that modern gyro's like the Xenon, MTO3, ELA and the Magni all have high thrust lines.


Also be sure to acknowledge that all of the above mentioned gyros have generous horizontal stabilizers as part of their stock configuration.

Just sayin'...

[C. Beaty]

If the intent of the cross arm is to serve as a spring, there is no worse material than aluminum.

There is no level of flexure in aluminum (item 7 in the chart) at which failure will not occur at some point; one reason engines don’t use aluminum valve springs.

The correct design, if in aluminum, is to make it as stiff as possible and to install proper springs elsewhere if springs are deemed necessary.

[MichaelBurton]

Now you know why Sport Copter uses steel for that part.

[C. Beaty]

Be sure to acknowledege that modern gyro's like the Xenon, MTO3, ELA and the Magni all have high thrust lines. From the Xenon website:

Stability - The Xenon's thrust line goes through its overall center of gravity so handling is very stable. It passes the ASTM stability tests for static , dynamic and G load stability. The strong box tail section is directly in the propeller slipstream and is on a long lever arm giving it effectiveness with or without engine power.

http://www.xenongyroplanes.com/special_features.htm

[Vance]

If the intent of the cross arm is to serve as a spring, there is no worse material than aluminum.

There is no level of flexure in aluminum (item 7 in the chart) at which failure will not occur at some point; one reason engines don’t use aluminum valve springs.

Hello Mr. Beaty,

Wouldn’t that also apply to the hub bar?

Isn’t the hub bar just a big spring that manages the interaction of the two blades?

Thank you, Vance

[C. Beaty]

Yes indeed, Vance.

That’s the reason aluminum rotor blades on certificated helicopters have to be replaced after 1,000 hours or so.

In the case of a hub bar, most of the cyclic flexing occurs during ground operation when the rotor isn’t turning. Inflight flexing isn’t a large factor if the rotor is reasonably smooth.

The blades, however, do undergo considerable flexing as the load center shifts inboard to outboard with rotation while in forward flight.

[WHUBBS]

In the past couple of weeks, i had a call for 5 more cross arm bars, and i shipped the last one today, that i had orders for. the shop wanted to make Ten, at one time, so i now have 5 bars left if anyone is interested, in the stronger bar, which fits the Raf and S/H.

Wayne

[WHUBBS]

I still have four (4) Raf / SH torque tube, stronger, cross arm bars left, if anyone is interested. if i have any left, during the PRA air show at Mentone, i will bring them with me, or possibly to Bensen days.

Wayne

[billygyro]

Let me tell you guy's,,, Wayne's Bars are the best, mine looks great and I don't have to worry about it coming apart either. when I got it and took it out of the box, the first thing that went through my mind is WOW this looks great and HOW can he sell this so cheap.

Thanks again Wayne, it bolted right up and my Bendix drive fit back on perfect with just some longer bolts.:peace:

[WHUBBS]

Thanks Billy, since you are the first to use my cross arm bar on your own design machine, i would love to see a close up photo, when you get the chance.

Thanks

Wayne

[WHUBBS]

Today, i got one order for another stronger cross arm bar and a potential order of 4 more from one person, if i do get the order for 4 more bars, i will be out and will not have any to take to Mentone this year, so i better get a few more made.

Wayne

[Steve McGowan]

I sure LIKES MINE :D

thanks Wayne

[WHUBBS]

Thanks Steve, i bet you are getting a few hours on your bar by now, forty six, stronger bars are out there flying at this time.

Wayne

[WHUBBS]

Fifty one bars, are now sold and in service, but just go an order for another, Cross arm bar, now i am out, and his check is on the way, i have called the machine shop to get some more bars made. the shop usually wants to make 6 at one time, to use up the material that he purchases, i think he buys a 12 ft. length of 6061-t6 each time and that will produce about 8-9 bars .

Wayne

[Harry_S.]

We owe a big "Thank You" for your indulgence Wayne. :yo:


Cheers :)

[bmoore2156]

I have just over 100 hours on the new bar... Still working great!
Brad

[WHUBBS]

I have run out of cross arm bars, and have one person, that has sent a check to me, but, i have none left in inventory, i called the machine shop last week and got more material on order, today the 6061-t6 material come in, and he said he would start working on the bars, next week, he said he would be making 9 bars, from the stock, he just received. this will take care of the one order that i have, with 8 bars left in stock, if anyone else would like a stronger cross arm bar.

Wayne Hubbs

[willisbr]

I have the updated oem part from an original build. Is it recommended to replace the newer better oem part with this one? Or are the majority replacing the old style? Thanks

[TJMay]

I'm not sure which one of the original oem parts mine had but the one offered by Wayne is stronger with little additional weight.

Tommy

[WHUBBS]

About 60 stronger Cross arm Bars, are now out there, and the last 9 bars just made are about gone, i was hoping i would have a couple left to take to Mentone, but we will see, some have gone on machines that are built and designed by the individual.

Wayne

[WHUBBS]

A total of 62 stronger cross arm bars, are out there, and in use, i sold two at Mentone, which only left me with two bars, in inventory and that will be all that i will make, if anyone is interest in these last, two bars, just let me know. $100. which includes shipping and i will return the change for shipping. i have enjoyed providing the stronger bars, and i now have a little over 80 hours, on the one that i have on my machine, which i powdered coated yellow color.

Wayne

[bmoore2156]

Just rolled over 160 hours today on my bar... Still looks new... Thanks Wayne!

[Steve McGowan]

Hey Wayne,,

Did I say.... I Sure Likes MINE.... REALLLLLLLLLLLLLLLLY

Thank You VERRRRY Much!!

[Gary_in_Orygun]

Hey Wayne,,

Did I say.... I Sure Likes MINE.... REALLLLLLLLLLLLLLLLY

Thank You VERRRRY Much!!

Ditto...worth the "peace of mind" it evokes
http://pra73.net/ForSale/gary_rotorhead.jpg

[WHUBBS]

Thanks Steve and Brad, sure looks like you two are putting the hours on the stronger bar and i am not doing bad myself, i still do not have, 100 hours on my bar, but getting close, while at Mentone this year i noticed 3 RAF machines , and one Sparrow Hawk, had the stronger bar on them, and they also looked just like the day i shipped them out.

Wayne Hubbs

[Mike484]

Thanks Wayne, mine's not on yet but I love it already.

[WHUBBS]

Just sold my last stronger cross arm bar, and that makes 64 in total, the machine shop has agreed to make another batch, of 9 bars, without orders. if you have been thinking about replacing your older bar, i should have the new batch in a couple of weeks, from now.

Wayne

[WHUBBS]

Two more cross arm bars shipped, for a total of 66. Happy Holiday season, to all, starting with the turkey holiday.

Wayne

[WHUBBS]

Just got 9 more cross arm bars built, and shipped two out this morning, just in time for Christmas, have 7 left in inventory.

[willisbr]

I'll take one. Looking for your address info on here. PM me please and I'll get a check in the mail. Thanks.

[willisbr]

Nevermind. FOund it. Check sent. Thanks.

[WHUBBS]

Brian, got your message and Bar will be on the way this coming Monday Dec. 20th. hope you get it in time for your trip to New Year flyin.

[StanFoster]

Wayne- Those bars you make are jewels. Hey, I picked up a flying magazine last month that featured your neighbor and country legend Arron Tippen. Nice article and you two would be the coolest neighbors. Stan

[WHUBBS]

Thanks Stan, I moved to Tenn. in 1982 and have found the folks here in this area, are some of the nicest folks on earth, Aaron, and his wife Thea are locals at our little airport. one day i called Thea, and ask her to come to my hangar, so i could take a photo of her setting on my Air Command, as i wanted to send the photo to Bill Finnegan, within an hour she was there, and that is the kind of folks that live here. Allen Jackson and John Anderson have homes very close to my house, in fact i can see John's house out across my back yard, i live on a mountain top and John lives across on another mountain top, and the airport is in between the two of us.

Stan, i hope you and your family have a very Merry Christmas and keep those flying videos coming.

[WHUBBS]

After building 9 more cross arm bars, i thought the market was saturated, and now i only have three of them left, so i guess we still have some folks that have not gone to the stronger bar. i have lost track, but, that must be 70 bars out there, and running at this time. my bar even works in cold weather. the first bar built is on my machine, but i removed it twice, and made slight modifications, to it, to make it a little lighter, then i powder coated it, which i know some are against, but all sold are plain 6061-t6 and you can do, what you feel is the safe way to go.

Hope i have a couple left to take to Mentone this year.

[willisbr]

Powder coating shouldn't be a problem under 400 degrees.

[WHUBBS]

I just shipped the first bar out of the country, to Canada, it took three weeks for the check to clear my bank, and when all was done, the bank took $1.50, out of the check. This is the first bar i have shipped, from my local post office, and it was around $5.00 shipping, where most have been between $10. and $15. using Ups. i have had 100% success with Ups, with no loss, and sure hope the US Mail will come through just this one time. Thanks to the customer for all his patience, with our banking system.

[bobbyjoe]

your customer appreciates your patience as well and probably should have sent a money order instead...lol.I'll let you know when it arrives,thanks again Wayne!!

[Mike484]

Anyone think about trying one of these on other gyros? I have one on my RAF and I love it. Would like to have one for my KB3.