Secondary Drive Assembly

This section has turned out to be of chronicle of the secondary drive
and our intention is for it to contain a past to present day format. It's pretty intense and we'll keep adding to it as we find more and more about its history.

If you have any pertinant data to add please send it to us.

It's going to take us some time to get all this information posted this way but once it's finished we'll be able to see just how this unit has performed from as far back as we can find information on it until the present day.

 
Exec 90
A-13

-3

1993?

Exec 90

30

3 Bearing

-

-

-

Chain

N5251B

100

Wiley

NO NTSB

Idaho

It was believed at this time that improper installation was the problem

Exec 90, 162F M-11

Exec, Exec 90,162F
A-26

-1	92 Exec	145	30	3 Bearing	-	-	-	Chain	N71RF	169 hours	Ronald Froberg	NO NTSB	-
1	before 1997	-	30	Double	-	-	-	Chain	-	-	Tom Smith	NO NTSB	Tom told Hans
2	before 1997	-	30	Double	-	-	-	Chain	-	-	Tom Smith	NO NTSB	Tom told Hans

It was believed at this time that improper installation was the problem

3

07/97

-

30

3 Bearing

-

-

-

Chain

C-FMAP

70

Hans Svendsen

NO NTSB

-

It was believed at this time that improper installation was the problem

4

10/98

162

30

Double

-

-

-

Chain

-

-

verbal

-

EPI SITE NO RECORD

5

11/99

162

30

Spherical

-

-

-

Chain

-

-

Steig

NO NTSB

Factory Ship

Not reported to NTSB and no cause listed for this one

Feb 14th 2000

Exec 162F
A-34

The first secondary Drive Shaft break with a Pro Drive Unit installed on a ship belonging to Joe Martain of West Virigina

7	4/6/00	162	30	Double	-	-	-	Chain	N21901	-	NTSB	LAX00LA173	Factory Ship
8	08/00	162	30	Double	-	-	-	Belt	-	-	Verbal	-	EPI SITE NO RECORD
9	09/00	162	30	Spherical	-	-	-	Chain	-	-	Mark Wolf	-	Factory Ship
10	11/00	162	30	Spherical	-	-	-	Belt	-	-	Joe Martin	-	In WV
11	before 1/01	90	30	3 Bearing	Above upper bearing	-	-	Chain	-	-	Craig Hook	-	-

This is a setup or two that someone came up with in an effort to keep the shaft from breaking.

I'm not sure but I think these are fixs either done by Joe Martin or Craig Hook around 2000.

-2	2001	162F	30	Double	-	-	Chain	N864KP	250	Barry Pinnix	NO NTSB	-
12	03/01	90	30	Double	-	-	Belt	-	-----	Craig Hook	-	Terrys Exec 90
13	03/01	?	30	Spherical	-	-	Chain	-	-----	Email	-	Robbin Burrows - Tasmania?
14	03/01	162	30	Double	-	-	Chain	-	51	Rotorheads	-	Duane Grummett/Canada
15	03/01	?	30	Double	Didn't break	Spun upper Bearing	Belt	N124CF	-----	Rotorheads	Scott n Brett Newhart	EPI Showed Break
16	5/16/01	162	?	?	Didn't break	Loose lower bearing	Belt	N311RM	-----	NTSB	CHI01LA141	EPI and Rotorheads Showed Break

On May 2, 2002  Rotorway sent out a bulletin, (A-38) recommending that everyone change over to the New Style 35mm setup they're offering.

On September 27, 2002,
at 45 hours on a new design 35mm shaft there was a failure
the first one known to the public anyway.

17

09/02

162

35

Spherical

Belt

45

Rotorheads

-

McLaughlin

You can check out an engineering report written by Matthew Dock,P.E. on it in the January 2003 addition of RotorHeads Newsletter.
From what I gather RotorWay had an engineering report made which came to the conclusion it was from stress and pointed fingers at the cog belt drive.  Its said there has been at least three 30 mm shafts breaking at the RotorWay factory with chain drives and a few more we've heard of and I think that makes 7 at last count I think.

18	10/1/01	162	30	Double	-	Between  bearings	-	Belt	N8270U	113	Jerry & Linda	NO NTSB	-
19	10/07/02	162	30	Double	Inside the upper bearing race	-	-	Belt	N1955Z	153	Owner	CHI03LA006	Mark Wolf
20	10/19/02	162	30	Double	-	-	-	Belt	N162AZ	-	NTSB	LAX03LA011	Jimmy Johnson Tuscon, AZ

Exec 90, 162F
M-21

21	1/1/03	162	30	Double	1/4 below upper bearing	-	-	Belt	N140GW	16	MSN Site	NO NTSB Pics in File	Tom Uppman
22	2/5/03	90	35	Spherical	Midspan	-	-	Chain	N9876D	561	Bill Cobb	LAX03LA084	Factory Ship
23	07/03	162	35	Spherical	-	-	-	Belt	-	55	Jim Liss	-	-

John had a meeting about the shaft issue

and from what I gathered from it it's now thought that the upper bearing race squeezes the shaft causing it to be larger above and below it. There is also foreign matter falling into the joint where the race meets the shaft helping the race to put an etching so to speak around the shaft. Upon rotation of the shaft, the shaft itself bends a bit thus compressing the foreign debris into the shaft causing it to fatigue to a point where it simply snaps.

This is just a rough way of putting it and everyone concerned needs to put in a call to John Spurling or his engineer to get it correct.

John is proposing that if we send him a new 35mm secondary setup
he will make the necessary fix's and return it better than new and if all goes as planned there won't be any more broken shafts to worry about.

A fellow named Al Behuncik has a cog drive system
that has different sprockets and also uses a different kind of belt.

It's my understanding that Al believes the shaft breakage problem is caused by the tension put on the shaft from the chain/cog drive and that using his system will eliminate shaft breakages providing you use his system.

 Al's setup also uses a tensioner on the left side of the cog belt which maintains a constant 10lbs of pressure on the belt "I think" under what ever power setting you have on the ship at the time.   I got to see one at Homer's in July 2004 in Al's personal helicopter but I didn't get any pictures of it.  It's very hard to obtain any information or pictures of this system because Al doesn't have an Internet site and about all you can do is read tidbits about it here and there.

To Donna and I's knowledge to date there has never been a reported shaft breakage related to Al's system.
That may sound good BUT no one has any idea about exactly how many units Al actually has flying around out there so only time will tell.

This is the way most people are mounting their bearing temperature sensor.

24

07/04

162

30

Double

just below top of lower bearing

-

-

Belt

N162FA

97

Owner

NO

Clell and Donnas Ship

John Spurling of Pro-Drive has something going on now
with a new improved Secondary unit. 

You can learn more about it and get updated information
plus learn about a new product announcement on John's Pro-Drive's site at
http://www.pro-drive.ws/

Pro Drive holds a seminar at Homers July 04 Fly In.

It looks like there's a new kid on the block regarding the secondary shaft breakages

His name is Jack Kane of Epi-eng.  It appears he's come to much the same solutions as John Spurling of Pro-Drive with the exception he's using a different type of metal for the shaft.   Donna and I missed most of his seminar he held at Homer's July 04 Fly-In and that's the jist of the information I received from folks who got to witness the whole thing.  I've looked his site over and read his explanations about it all, but truthfully speaking not being an engineer, most of it goes way over my head so here too, just like you, we're on our own.  Once I get all this information decoded down to my level of thinking I'll post our opinion.

www.epi-eng.com

Page 1

Page 2

A fellow named Bob Carter has a new gizmo
he feels will solve the secondary shaft breakage problem.

Bob was one of the 3 people/companys
that gave a seminar at Homers 2004 Fly-in.

These are Photo's from Pro-Drive's web site of the new Secondary Shaft they have in production now.

At this point there are several of these units out in the world now
and according to John Spurling at Pro-Drive he's sure this new setup has once and for all solved the issue of the secondary shaft breakage issue.

Pro-Drive's new design secondary shaft with 85 hours on it.
You can't even tell it was ever installed.

Pro-Drive 40 mm bearing after 85 Hours       Vs.     RotorWay 35mm bearing after 35 Hours

33 Hours, 35 mm

280 Hours, 30 mm

25 Hours, 35 mm

100 Hours, 35 mm

         photos of unbroken shafts that were disassembled for new secondary upgrades

Jack's been working pretty hard on a new shaft

and it's definitely different than I had imagined from the little I got out of it at the seminar at Homer's.  He's not only using a different type of metal he's also designed all kinds of other ridges and bumps into it.

It's supposed to have something like 3 times the life span of the original RotorWay shaft and two times the life of the Pro-Drive shaft according to the data he has posted on his site.

I couldn't even begin to touch on everything Jack has on his site here so be sure to take some time and check it.

Make sure you have plenty of time to do it to because his site is pretty intense and if your serious about it your going to be at it a long long time lol.  It's worth the time spent because when your finished you'll come away with a much better understanding of what it is that's really going on in our little ships.

As far as the figures Jack has posted in his charts and things you'll just have to trust that they are right unless your already an engineer or you've got time to go to engineering school, it's pretty difficult for the typical layman to comprehend it all, the reason I brought that up is because Jack and John have a different way of arriving at the final figures and If you look at John's Pro-Drive site it all adds up and at the same time you'll see that Jacks figures on his site all add up to.

There's an old joke that says
If you put 5 engineers in the same room, all working on the same project at the same time, they will come up with 5 different answers.
From what we're all witnessing here it's no joke, it's very much the real deal lol.

The only down side about Jack's site is the constant bashing of the Pro-Drive system.

If he follows suit, Al Behuncik's drive system will be the next thing he trashes out all though up to now he seems to give it credit here and there on the site.  To date as far as I know there has never been a shaft of any size on one of Al's setups break so it will be interesting to see what happens.

If I didn't know better I'd say John must have stolen Jack's wife or something, it won't take you long to figure that out on your own.Jack may have a very workable solution going on with his new unit and it's obvious he's no dummy but if he doesn't find a nicer way of getting his message across to people " just like his predecessors in the past" he isn't going to get very far, at least that's the view Donna and I have.

Jack is claiming to have 2 or 3 of these units out in the world

someplace at this time but
for some reason he's keeping it secret as to whos ships they are installed on
not to mention how many hours they have put on them.

www.epi-eng.com

last updated
Nov 2004

Donna's and I's Analysis at this point

To date, according to Jack's site in a table he has posted on shaft breakages, there have been

5 chains
8 belts

plus 4 breakages with unknown drive types
and 2 broken Pro-Drive belts

Adding our ship to the list, what I see in this data is that out of the 13 confirmed broken shafts 8 of them had Pro-Drive units.  Jack has come to the conclusion and is trying to convince us with the aid of a few o