Psru

Jazzenjohn

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Milan Mich.
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Gyrobee, My design
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Are you certain it wasn't one of these knock offs that blew up Johnathon?
 

1946

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Joined
Sep 6, 2010
Messages
675
Location
China
Aircraft
Cessna150
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16
After working on a subaru package with a brand new auto flight gear box on it last year. The prop shaft broke on the ground while the engine was running, with no real load on the prop. . If it had been in flight, the results could have been fatal. All the parts went back to NZ and never heard from Neil again.

Not sure if Neil is actually making gear boxes anymore since the customer last I had heard never got a replacement gearbox. If these pirates did in fact copy that design I hope they made improvements to keep the prop shafts from departing the box.......along with other numerous improvements......

For no sum of money will I fly an autofright gear box. And most certainly not one made in China. Then again maybe it was one made in China that would explain a lot......

Jonathan


At reversing the engineering and subsequent Dyno test on the AeroFlight 33 we found there was a ‘small’ problem at the bearing retaining the propeller shaft, by removing the oil seal on the inside of the bearing the box cooled considerable and now getting proper lubrication. In any case our gears and shafts are all X rayed and magna fluxed for possible material defects. I am sure the NZ manufacturer will honor the warranties. Perhaps you will reconsider using a box made in China, free..?
 

Resasi

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Jul 2, 2007
Messages
7,351
Location
London/ Kilifi Kenya
Aircraft
Gyrs, RAF 2000/Mgni/Bnsn/Hrnet/Mrlin/Crckt/MT-03/Lyzlle AV18-A/Prdtor. Pax ArrowCopter
Total Flight Time
100+ gyro, 16,000+ other
I must confess that the term reverse engineering does imply to me that a copy has been made working backwards from an origional rather than a plan and set of specifications.

The only reason I can see for doing that is to bypass paying for the right to produce the item.

This may be a perfectly legitimate venture, however China does not have a good record for respecting intellectual property rights. It would be good to know for sure that this is.
 

Ernie_B

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Oct 30, 2003
Messages
316
Location
tampa fl.
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Dominators
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7K +
If you want to do a service , why don't you "reverse engineer' a Rotax 912 or 914 or even the 2 strokes? Maybe, because the BIG guys will slap you down? Much easier to steal from a small guy with limited resources to fight back!
Go ahead , make us a cheaper 912/ 914T, I am sure Rotax users would love the competition! I for one would gladly give 10K for a "better engineered " 914 T.
 
Last edited:

JEFF TIPTON

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Feb 17, 2007
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2,860
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DICKSON, TN
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Grumman AA5
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Brent; for the Weber application would you think the gearbox would need to be between 3.1 and 3.4 gear reduction?
 

automan1223

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Joined
Nov 3, 2003
Messages
3,760
Location
Oriental, North Carolina
Aircraft
2p Tandem Air Command "Big Red"
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250
Back story....

Back story....

I have seen the autoflight box survive a prop stoppage during a ground event. The internals on were inspected and we only ended up replacing the rubber coupler (for drill) , everything else looked fine.

I worked on a members gyro when he was trying to get his EA 82 running correctly. This engine vibrated so badly it damaged the newly rebuilt carb, that resulted in a flooding out situation. This member brought the whole gyro, and engine package to me and I started to run the engine after I repaired the carburetor. This engine vibrated so badly and so rough and choppy I had never seen anything like it except when we left a flywheel off of an engine during an R & D session back in my college days. I reproduced this effect by leaving unbolted a torque converter on a engine we were trying to find a vibration on as well years later...(Flywheel effect) . It only made things worse. Fast fwd to this EA 82 and I discover Neil has used only the flex plate from an automatic application to use as the coupler to bolt the rubber coupler to. I spoke with Neil about how rough this engine ran and why I thought it ran that way. He disagreed.......On another front I could not get the engine to rev up to any kind of rpm and in short order the carb started leaking again from the excessive vibrations. During my second attempt at getting this engine to run, I had maybe a total of 2 to 3 minutes on the thing when all of a sudden the prop stopped turning and the engine immediately smoothed out. It was a 4 blade warp drive prop brand new btw... Anyhow I remarked how smooth the engine ran and how how nicely it reved. even though there was now no load on the engine had there been any defect in the engine it still would have shown up. I stopped the engine and saw that the propshaft had backed out of the gearbox about half an inch. I pulled on the prop and the whole thing slid out the back of the gear box. I almost $hit myself. I took photos, wrapped up all the parts and sent the contents to Neil for inspection. He never got back to me about anything. The customer as far as I know never got a refund or if they did, it took a very long time.

The rubber coupler looked like jello in some spots and was cracked. I do not know why it did what it did but the thickness of the prop shaft was a bit light in my opinion. However there was no power but above idle applied to this package while I started to debug it. I had the whole thing apart and could not tell you why it blew up. I do not know to this day why what happened, happened. Unable to get the correct gear box in a timely manner, the owner repowered with another setup.

Proper materials for the job along with proper heat treat is critical for longevity. Heat treat cost money with energy costs being the way they were everything from coil springs in your mattress and springs and gears on your automobiles, to crankshaft heat treat on Lycoming engines has had more filler in the hot dog and stuff will not last. But that is just my experience. Things may be better or worse now. I do not know.

Seriously, the China box has my interest piqued but like I told Master Gyro pilot Ron Awad, Talk to me when you have 100 hours then let me know when you have 300 hours, then I know you might have something. Rotary engine and 3 cylinder engines being the harshest on PSRU's........

That is the story.....

As far as a free one, I would be willing to put one on the dyno to see what it does but that will not duplicate the gyroscopic forces during a real flight test, etc.


What materials are the shafts made out of ? To what rockwell number are they treated to ?

J







At reversing the engineering and subsequent Dyno test on the AeroFlight 33 we found there was a ‘small’ problem at the bearing retaining the propeller shaft, by removing the oil seal on the inside of the bearing the box cooled considerable and now getting proper lubrication. In any case our gears and shafts are all X rayed and magna fluxed for possible material defects. I am sure the NZ manufacturer will honor the warranties. Perhaps you will reconsider using a box made in China, free..?
 

C. Beaty

Gold Supporter
Joined
Apr 16, 2004
Messages
9,672
Location
Florida
Copying someone else’s design is more than a matter of ethics.

Competent designers don’t need to copy.

As we’ve seen time and again in this tiny universe of homebuilt aircraft, copy artists often don’t understand the basics and the copy backfires, sometimes with fatal consequences.
 

automan1223

Banned
Joined
Nov 3, 2003
Messages
3,760
Location
Oriental, North Carolina
Aircraft
2p Tandem Air Command "Big Red"
Total Flight Time
250
unless

unless

Are you certain it wasn't one of these knock offs that blew up Johnathon?
Unless Neil was feeding his customers this stuff from China.... Maybe. I have no way of knowing.

I do know that it was next to impossible to get up with Neil, and that from the subsequent exchanges he had with the customer, Neil was working on other things than gearboxes.



J
 

1946

Banned
Joined
Sep 6, 2010
Messages
675
Location
China
Aircraft
Cessna150
Total Flight Time
16
If you want to do a service , why don't you "reverse engineer' a Rotax 912 or 914 or even the 2 strokes? Maybe, because the BIG guys will slap you down? Much easier to steal from a small guy with limited resources to fight back!
Go ahead , make us a cheaper 912/ 914T, I am sure Rotax users would love the competition! I for one would gladly give 10K for a "better engineered " 914 T.
Yes, there is a problem with this Rotax 503Ul/582/ is already made in China, and some parts for the Rotax 912S is manufactured by the Chongqing Loncin Industrial (Group) Co., Ltd in China, and shipped to Austria as ‘Made in Austria’ According to a spokesman for Rotax at the recently completed Davos conference in China having the engine parts manufactured in China saves about $4,000 in costs. However, the remainder of the engines is assembled in Austria. Remain to be seen if the savings are passed to the consumer..

Albert
 

Neil Hintz

Senior Member
Joined
Feb 22, 2004
Messages
434
Good on you jonathan! Shall we go into the reason the Autoflight gearbox on your customers craft was wrecked? I offered your customer a new unit at cost, a good offer seeing as I didn't wreck this unit. This engine was assembled wrong and the customer told me it ran so bad he thought it was going to jump out of engine frame. You told me it had run three minutes, your customer told me he had already run it some time like this at his place. No gearbox is going to stand up to this punishment. The rubber drive was destroyed this points to a severe engine resonance issue i.e. the plug leads on wrong or cam timing badly out. Something a " mechanic " should be able to pick up!
 

Passin' Thru

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Jan 15, 2006
Messages
2,679
Location
Naranjito, PR
Good on you jonathan! Shall we go into the reason the Autoflight gearbox on your customers craft was wrecked? I offered your customer a new unit at cost, a good offer seeing as I didn't wreck this unit. This engine was assembled wrong and the customer told me it ran so bad he thought it was going to jump out of engine frame. You told me it had run three minutes, your customer told me he had already run it some time like this at his place. No gearbox is going to stand up to this punishment. The rubber drive was destroyed this points to a severe engine resonance issue i.e. the plug leads on wrong or cam timing badly out. Something a " mechanic " should be able to pick up!
Now we get the rest of the story! :yo:
 

Neil Hintz

Senior Member
Joined
Feb 22, 2004
Messages
434
I am aware of these china copies, there is not much I can do to stop them. The price of a New Zealand made Autoflight gearboxes reflects the cost of development in the first place where the cost of a "china gearbox" does not. This is a niche market and Autoflight manufactures these units because we are involved in gyro aviation and enjoy it. You will find we are the only manufacturer supplying a dedicated offset down unit for the gyro industry. If this copying continues there will be no reason continue designing new units for new engines just to have them stolen and copied. This rubbish about a German company building these units in china is untrue. You will see the picture of the "Aeroflight " ( even climbing in on my name! ) gearbox in their advertising is in fact an Autoflight gearbox not even their own! I know where this gearbox was taken from.
I have a document the copiers sent me telling me so, I will post this shortly.
They are rubbish and you will get what you paid for, remember that!
If these guys are so clever why don't they design their own unit? They don't have the ability!

Neil Hintz
Autoflight Ltd
New Zealand ( not china )
 

automan1223

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Joined
Nov 3, 2003
Messages
3,760
Location
Oriental, North Carolina
Aircraft
2p Tandem Air Command "Big Red"
Total Flight Time
250
Resonance ?

Resonance ?

Neil,

Since you were not too interested in this situation back when....let me refresh your memory again...., I ran the engine without a load on it and it ran fine. This master mechanic knows in his sleep when a cylinder is out of tune, mixture is off, cam timing is off out of phase (eg : 180 degrees) Yes you can run an engine with the cam timing out 180 degrees. Runs like $hit but there is no mistaking it. . You could have put a glass of water on the top of this engine with the redrive off of it so there is no doubt in my mind that the problem was with the redrive. As far as a resonance issue between the 4 blade and whatever gear ratio you had provided that is a possibility but you never suggested it. Frankly it would not have changed the outcome. Had you seen how little time this engine ran you too would have been alarmed at the condition of the prop shaft. Prop shaft should be THE LAST thing that gives up I do not care what resonance nonsense you want to HIDE behind. . If it does give up then there should be retaining system of some sort. Your design lends itself to a retaining system. I strongly suspect you sourced hardware that was not up to spec. This did happen with the redrive (soft gears) I currently use and the problem was sourced to an improper heat treat.

So you are admitting that if a spark plug lead were to come off then I have 3 to 6 mins or so before the redrive spits the prop shaft out the back of the unit ? ? from "resonance".... Come on Neil, get a grip what kind of stuffing are you trying to pawn off here.. I have seen an ea 81 wipe out 3 blades to a full stoppage and the unit held up. The shaft should bend before it gives up. nothing magical or complicated about an EA 82.....



Good on you jonathan! Shall we go into the reason the Autoflight gearbox on your customers craft was wrecked? I offered your customer a new unit at cost, a good offer seeing as I didn't wreck this unit. This engine was assembled wrong and the customer told me it ran so bad he thought it was going to jump out of engine frame. You told me it had run three minutes, your customer told me he had already run it some time like this at his place. No gearbox is going to stand up to this punishment. The rubber drive was destroyed this points to a severe engine resonance issue i.e. the plug leads on wrong or cam timing badly out. Something a " mechanic " should be able to pick up!
 
Last edited:

1946

Banned
Joined
Sep 6, 2010
Messages
675
Location
China
Aircraft
Cessna150
Total Flight Time
16
I have seen the autoflight box survive a prop stoppage during a ground event. The internals on were inspected and we only ended up replacing the rubber coupler (for drill) , everything else looked fine.

I worked on a members gyro when he was trying to get his EA 82 running correctly. This engine vibrated so badly it damaged the newly rebuilt carb, that resulted in a flooding out situation. This member brought the whole gyro, and engine package to me and I started to run the engine after I repaired the carburetor. This engine vibrated so badly and so rough and choppy I had never seen anything like it except when we left a flywheel off of an engine during an R & D session back in my college days. I reproduced this effect by leaving unbolted a torque converter on a engine we were trying to find a vibration on as well years later...(Flywheel effect) . It only made things worse. Fast fwd to this EA 82 and I discover Neil has used only the flex plate from an automatic application to use as the coupler to bolt the rubber coupler to. I spoke with Neil about how rough this engine ran and why I thought it ran that way. He disagreed.......On another front I could not get the engine to rev up to any kind of rpm and in short order the carb started leaking again from the excessive vibrations. During my second attempt at getting this engine to run, I had maybe a total of 2 to 3 minutes on the thing when all of a sudden the prop stopped turning and the engine immediately smoothed out. It was a 4 blade warp drive prop brand new btw... Anyhow I remarked how smooth the engine ran and how how nicely it reved. even though there was now no load on the engine had there been any defect in the engine it still would have shown up. I stopped the engine and saw that the propshaft had backed out of the gearbox about half an inch. I pulled on the prop and the whole thing slid out the back of the gear box. I almost $hit myself. I took photos, wrapped up all the parts and sent the contents to Neil for inspection. He never got back to me about anything. The customer as far as I know never got a refund or if they did, it took a very long time.

The rubber coupler looked like jello in some spots and was cracked. I do not know why it did what it did but the thickness of the prop shaft was a bit light in my opinion. However there was no power but above idle applied to this package while I started to debug it. I had the whole thing apart and could not tell you why it blew up. I do not know to this day why what happened, happened. Unable to get the correct gear box in a timely manner, the owner repowered with another setup.

Proper materials for the job along with proper heat treat is critical for longevity. Heat treat cost money with energy costs being the way they were everything from coil springs in your mattress and springs and gears on your automobiles, to crankshaft heat treat on Lycoming engines has had more filler in the hot dog and stuff will not last. But that is just my experience. Things may be better or worse now. I do not know.

Seriously, the China box has my interest piqued but like I told Master Gyro pilot Ron Awad, Talk to me when you have 100 hours then let me know when you have 300 hours, then I know you might have something. Rotary engine and 3 cylinder engines being the harshest on PSRU's........

That is the story.....

As far as a free one, I would be willing to put one on the dyno to see what it does but that will not duplicate the gyroscopic forces during a real flight test, etc.


What materials are the shafts made out of ? To what rockwell number are they treated to ?

J
Jonathan

I discover Neil has used only the flex plate from an automatic application to use as the coupler to bolt the rubber coupler to.


The area in improving the AeroFlight 33 was to have a serious look at the configuration you mention above, using a flywheel with a low mass moment of inertia will undoubtedly create what is called torsional vibrations. We have eliminated this by delivering this particular box with a proprietary engine coupling system, which typically consists of an engine specific weight pressure oil filled flywheel, the starter gear, and in between the flywheel and box we have a Centaflex rubber coupling connected to a splined hub, and splined shafts connecting to the gearbox. The improved coupling system removes over 99% of all engine torsional pulses which the engine produces at takeoff and cruise power, and provides the propeller with an operating environment which is essentially devoid of engine torsional excitation. The company will not sell the box without the above. The box is sealed, any attempt to repair the box other than authorized personnel will devoid of the warranties.


What materials are the shafts made out of ? To what rockwell number are they treated to ?

All gears are manufactures according to Gitin M Maitra specification and Case Carburizing to HRC 55-60 and of the core around 30-40, the original gears somehow had not the correct tip circle,root circle, addendum, flankl of tooth, ect, they were all redesigned and the box is delivered with matching gear pair. All gears at chemically etched, with date of manufacturing, machine operator and box destination. Gears are mass manufactured by VW-china. Boxes are made from 3xx.x series alloy and T-6 tempered, all castings are made by FAW Group Corporation, and makers of gearboxes for the US automotive companies.

As far as a free one, I would be willing to put one on the dyno to see what it does but that will not duplicate the gyroscopic forces during a real flight test, etc.

Good news are the AeroFlight 33 has been in trail service since Feb 2008 and currently in operations with a Shandong aircraft maker in training aircrafts with over 4000hr in flight service with a Subaru EJ225 N/A VTC detuned to 190Hp engine and a 3 blade electric MT -CS propeller with electric governor.


There is a huge market in China for aviation reduction boxes for the Chinese aircraft industries, being made in China, the boxes must have not equal but better standards of to pass Chinese Airworthy Certification and unknown to many experimental aircraft builders in the US that in accordance with the U.S./People’s Republic of China Bilateral Airworthiness Agreement and the associated Schedule of Implementation Procedures, airworthiness certification of aeronautical products is reciprocally accepted.


Thank you for your attention
Albert
 

Resasi

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Joined
Jul 2, 2007
Messages
7,351
Location
London/ Kilifi Kenya
Aircraft
Gyrs, RAF 2000/Mgni/Bnsn/Hrnet/Mrlin/Crckt/MT-03/Lyzlle AV18-A/Prdtor. Pax ArrowCopter
Total Flight Time
100+ gyro, 16,000+ other
Unfortunately the material flooding out of China all over the world has in the main proved to be substandard, poor quality, short lived and in some cases dangerously deficient.

Looks good, lasts no time at all.

It will be a while before they manage to overcome this image.

Japan was in a similar situation but has now managed to become a byword for high quality.

It can be done but it is going to take a while to regain peoples trust lost through the substandard crap and copies that has been the norm till now.
 

automan1223

Banned
Joined
Nov 3, 2003
Messages
3,760
Location
Oriental, North Carolina
Aircraft
2p Tandem Air Command "Big Red"
Total Flight Time
250
Homework

Homework

Sounds like you have done your homework..... Congratulations on your hard work.

Since you have addressed issues I had discovered early on and Neil said they were not issues, it is refreshing to hear that someone looked into the design carefully and made it what it should be. Strange how us "dumb" old mechanics could be wrong all this time cause no one else had a problem its not an issue....... Yeah right. I got a bridge to sell.

Best of luck with your sales.

Jonathan.

Jonathan

I discover Neil has used only the flex plate from an automatic application to use as the coupler to bolt the rubber coupler to.


The area in improving the AeroFlight 33 was to have a serious look at the configuration you mention above, using a flywheel with a low mass moment of inertia will undoubtedly create what is called torsional vibrations. We have eliminated this by delivering this particular box with a proprietary engine coupling system, which typically consists of an engine specific weight pressure oil filled flywheel, the starter gear, and in between the flywheel and box we have a Centaflex rubber coupling connected to a splined hub, and splined shafts connecting to the gearbox. The improved coupling system removes over 99% of all engine torsional pulses which the engine produces at takeoff and cruise power, and provides the propeller with an operating environment which is essentially devoid of engine torsional excitation. The company will not sell the box without the above. The box is sealed, any attempt to repair the box other than authorized personnel will devoid of the warranties.


What materials are the shafts made out of ? To what rockwell number are they treated to ?

All gears are manufactures according to Gitin M Maitra specification and Case Carburizing to HRC 55-60 and of the core around 30-40, the original gears somehow had not the correct tip circle,root circle, addendum, flankl of tooth, ect, they were all redesigned and the box is delivered with matching gear pair. All gears at chemically etched, with date of manufacturing, machine operator and box destination. Gears are mass manufactured by VW-china. Boxes are made from 3xx.x series alloy and T-6 tempered, all castings are made by FAW Group Corporation, and makers of gearboxes for the US automotive companies.

As far as a free one, I would be willing to put one on the dyno to see what it does but that will not duplicate the gyroscopic forces during a real flight test, etc.

Good news are the AeroFlight 33 has been in trail service since Feb 2008 and currently in operations with a Shandong aircraft maker in training aircrafts with over 4000hr in flight service with a Subaru EJ225 N/A VTC detuned to 190Hp engine and a 3 blade electric MT -CS propeller with electric governor.


There is a huge market in China for aviation reduction boxes for the Chinese aircraft industries, being made in China, the boxes must have not equal but better standards of to pass Chinese Airworthy Certification and unknown to many experimental aircraft builders in the US that in accordance with the U.S./People’s Republic of China Bilateral Airworthiness Agreement and the associated Schedule of Implementation Procedures, airworthiness certification of aeronautical products is reciprocally accepted.


Thank you for your attention
Albert
 

GraemeClarke

Member
Joined
Mar 29, 2004
Messages
187
Location
Blenhiem, New Zealand
Aircraft
Rosco/ Bruty
Total Flight Time
110
I guess imitation is the sincerest form of flatery.
I have one of Neils boxes, and its an amazing peice of enginering.
Clearly 1946 is doing this to make money. I seriously dought that the end user will get a box any cheaper, so it comes down to quality. I have been investigating buying a peice of machinery made in china. The local agent told me that they have to dismantle the machine and replace all the bearings before they install it. I guess that says it all.
Graeme
 

j bird

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Cave Junction,OR.
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Dominator/Airworthiness Certificate 9/06/12
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26.5 duel,RAF,Sparrow-Hawk,Cavalon,Calidus.
love my 40 horse Chinese diesel tractor, 7 years and just maintenance.
 

karlbamforth

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Joined
Nov 2, 2005
Messages
1,336
Location
Langkawi, Malaysia
Aircraft
Fixed wing/ rotary
Total Flight Time
500+
Rotax is the favorite engine for a lot of pilots.

As the man said large parts of Rotax engines are manufactured in China, they seem to work just fine.

The certified engines we use are manufactured in Austria too, but I'm willing to bet a lot of the parts come from Asia.
 

Friendly

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Jan 5, 2004
Messages
4,441
Location
Woodworth, LA.
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KB2 & KB4
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Brent; for the Weber application would you think the gearbox would need to be between 3.1 and 3.4 gear reduction?
Jeff,
I thought the gear rations were to high for the Weber as well. I thought it would be better from 2.7 and lower.

Albert ,
how did you determine the ratio for the Weber and would you send me any pictures you have of the Weber setup? email [email protected]

Also are your gearboxs clones of the Autofight box?
 
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