Yamaha RX1 Engines

450 posts in this topic

Posted (edited)

I'm not in this game, but sure that others are - How do you determine which vendor is truthful, and which is full of advertising BS?  I have tried to read all the posts to understand them.  Maybe one of my planes someday will be powered by one of these engines - I hope the smoke clears before then.   I did a lot of research back in the 1990s on Hi-Vo chain drives, like they use in screaming race car engines - even talked to one builder of Hi-Vo redrive for EA-81 engine in Nikiski Alaska and got plans from him, but never built one - I think they are probably the most "Bullet-proof", even better than the good cogged belt drive on my Dave Johnson engine and on Stratus engines,  but don't know a thing about clutches.   EDMO

Edited by EDMO

Share this post


Link to post
Share on other sites

Posted

Heck, I'm arguably the least experienced/least knowledgeable person on this site. FWIW, I won't give a penny to any vendor who's tone puts me off. I honestly like what I see in the MA product line. However, slinging mud is a horrid form of promotion.

 

Sing the virtues of your product and leave the insults at the door.

7 people like this

Share this post


Link to post
Share on other sites

Posted

At this point I feel as if I must chime in:

If you've followed this post you know I recently re-powered my Highlander with a Yamaha.  I originally had planned to use the Mohawk/Greg's clutch that was advertised as ready to go.  Long story short I was delayed for over a month getting it fitted and once I received the part it was recalled before I could even install it.  The particular clutch I had received had failed, been rebuilt and failed again with another customer (which was the reason for the recall).  Greg's attitude through the entire process basically was as if he was doing me a favor and I should be having fun experimenting with his parts on my experimental.  I quickly felt as if I as if I would be testing a prototype of his clutch and got to the point that I did not trust him.  I did offer to continue working with him if he would provide a free clutch, but he refused.   On the other side of the coin Teal Jenkins, Steve Henry, Twisted Metal Racing and Rotax Rick provided professional and prompt delivery of products with impeccable support on the re-power.    All these guys are great, they're having fun helping folks get in the air.  Simply put the money is secondary.   I'm sure a 75 hour inspection will be less hassle than what I experienced working with Greg.  The unprofessional nature of his post is very much indicative of my experience. 

Jody  

3 people like this

Share this post


Link to post
Share on other sites

Posted

And I  edited my last post.  Toned it down a little (probably still not toned down enough LOL) 

Sorry for getting a little fired up and feisty!

:wacko:

Share this post


Link to post
Share on other sites

Posted (edited)

Catholic Sister:  "Those working men are uncouth, vulgar, and I don't want the children to walk thru that construction site"!

Mother Superior:  "Why Sister?  Those men are hard working, salt of the earth, honest, they just call a Spade a Spade".

Catholic Sister:  "No they don't - They call it a F'n Shovel"!

Call it as you see it - No apologies needed, IMO.  EDMO

Edited by EDMO
2 people like this

Share this post


Link to post
Share on other sites

Posted

 This is Steve Henry and I’ve never been on this forum before but Greg‘s  accusations towards my friend Teal was brought to my attention so I thought I should say something. 

I have known Teal for several years now and he has always been very truthful and honest with me as I’m sure he is with everyone else.  He has never said he would do or provide anything for me that he hasn’t 100% followed through with.  I have met Teal personally, and spent time with him, I’ve been to his house and shop and hanger.  He’s the kind of guy that I wish was my neighbor instead of a friend who lives 800 miles away. I could give you examples of things where he has gone above and beyond but I just don’t like to spend too much time doing these posts. 

 Steve Henry, Wild West Aircraft  

 

5 people like this

Share this post


Link to post
Share on other sites

Posted

Speaks volumes, right there.

 

Thanks for stoping by, Steve.  Please come back again.

2 people like this

Share this post


Link to post
Share on other sites

Posted

I purchased an adapter from Teal for an RX-1 conversion. I installed that adapter and there is no doubt it was made with care and precision. Teal offered me other items to build my engine mount and electrical system. His prices were more than fair. I had trouble with my adapter fitting. Teal offered to send me another one immediately but took his personal time to help me find the problem which was extra casting on the ROTAX Flywheel causing clearance issues.

This is the second attack on Teal I’ve witnessed from Greg on an open form. The last one Teal respectfully countered and Greg toned it way down.

Greg, instead of batting your gums about Teals product how about you work on proving your own product and getting it out to people who can verify it’s worth to the marketplace. This Experimental business is full of blowhards claiming the next best thing. What we as Experimenters want is proof in product. Maybe you have some good products but we have not seen them and Teal as you can see from people’s testament has proven his and made a few good friends in the process. You might be the worlds best engineer Greg but talking mad crap about another mans product just seems like a real sorry business angle.

Vance Simons

Post Falls, Idaho

 

4 people like this

Share this post


Link to post
Share on other sites

Posted

Hmmm sound like a legend in your own mind, I also dealt with Teal and he was a very helpful straight shooting guy and have had no issues with his adapter or c drive, time will tell I guess. I think your post will drive away more business than it creates unfortunately ,not my way of doing business

2 people like this

Share this post


Link to post
Share on other sites

Posted

Unfortunate, but hurling insults and character assassination somehow became a tolerated part of the business game. In my business experience, acknowledgement and respect for competitors strengths produced much better long term results for me. Doesn't matter if you build a better mousetrap, not many folks will beat a path to your door when they have to wade thru chest-deep horseshit to buy one. Whatever, there are some lessons best learned the hard way. I'll say the same thing I said many pages back... Info and products from multiple vendors is a good thing, just look at the popularity of this thread. Choice of E-AB products is sorely needed but buyers do your research well and, as always, caveat emptor.

2 people like this

Share this post


Link to post
Share on other sites

Posted

I got to hang out with Teal at the High Sierra Fly In and I recently made a large purchase from him. Nothing but good things to say.

Share this post


Link to post
Share on other sites

Posted

Talk about blowing smoke!!

A lot of us here know Teal, and know how humble and great of a guy he is.

I doubt he has made more than lunch money along the way for all the hard work he has done, and I'm sure he has no regrets... because he is not it this for the money.  He does all this development as a side hobby to his normal job.... all out of the love for the sport, the yamaha engine, and helping others. 

This blowhard "fake news" of a rant you just posted shows alot Greg.  Man that post is a case study example of using "high and mighty" unsubstantiated garbage in an easy to see through cheap shot attempt to play the oldest juvenile card in the book:  Trying to propel one's self upward by grabbing at people around them and dragging them down.

As far as the reputation of Teal's kit,  I'll let the real world track record and results of those flying it speak for themselves.

Greg, you know I've been a strong ally for you along the way... just look at the posts I've made here on your stuff and all the contributions I have made on FB.  But this is way out of line, (as was deleting the posts I made merely showing Teals products over on your Facebook Group).

I would have preferred to continue to be your ally Greg, but the time has come to call you out for being so unfair.

 

100% agree. I could not even read through the post above this one. 

1 person likes this

Share this post


Link to post
Share on other sites

Posted

REALLY?! I've been following this threat with great interest as I had the opportunity to see Willis' (Marshawk) Yamaha Conversion come to live with Teal's help. I don't have a re-drive or Yamaha yet, ..but don't think it will ever be bearing a Mohawk sticker.  Just my .02 cents! ;-) 

1 person likes this

Share this post


Link to post
Share on other sites

Posted

 

Share this post


Link to post
Share on other sites

Posted (edited)

Attached here is the bearing data that indicates Rotax C bearing life when used on an RX1 engine, as well as info for all other PSRU's in use today by every other shop selling RX1, Apex and Nytro  conversions today. The bearings in the  Rotax C box  when mounted to a Yamaha RX1 engine turning 7200-9000 ERPM / 6000 - 7500 SRPM @ 90 lbs torque at the output shaft have a life of 310 hours with 90% certainty.  That data is arrived at by using the exhaustive formulas published by every major bearing manufacturer in the world, and the information how to get to that answer is all over the web.  I have arrived at this conclusion using the NTN engineering handbook, and it is available in PDF for free by contacting 

info@mohawkaerocraft.com

You are invited and more than welcome to do the research and math in order to check my work.

The calculations include a torque adder of 6% for the additional radial load that the bearings see due to the gear tooth angle of contact (not to be confused with a 19.8 degree helical cut, and the resultant axial loading); and a prop harmonics fudge factor of 10%.  Even if there are no harmonics present, then the best one can hope for is roughly 340 hrs TBO.  While we're at it, let's take out the 6% adder, just in case:  still just about 360 hrs, hm? 

It is probably a good thing that the Rotax C must be disassembled for removal to inspect a RK400 clutch every 75 hours, that way you will be made aware of the condition of the bearings at the same time.  

As to the alternative Rotax Hardy disk, we are aware of catastrophic failure of those at  just 12-15 hrs under normal operating conditions and therefore you need to inspect your rubber Rotax donut by removing it and looking for cracks - every ten hours.  Once again, you can check your gearbox bearings at the same time.

When you put the Rotax C box back together every 10, or 75 hours (depending on what kind of coupling you are using), after inspections be sure to put the shims back in proper order and install a new gearbox gasket as necessary.  The datum indicate, and real-life experience bears out, that loading a single Rotax C bearing in the axial direction, and not getting both bearings loaded equally, results in a failure almost immediately.  

PS:  I deleted the earlier post, as it did not go far enough in presenting hard-core engineering evidence, while at the same time going too far in the irritation direction.   

 

Bearing Life Rotax C vs the Rest .png

Edited by Mohawk Aero

Share this post


Link to post
Share on other sites

Posted (edited)

Ok.  Better tone.  That's good Greg.

But that whole analysis  (including chart) is something you derived on your own.  It is all put together by you!  

Sole source data and conclusions from someone who clearly has a prejudice in the matter....  troubling to me.

I have an engineering degree to Greg.  In this case I am far more comfortable relying on empirical data than I am on your slant.

The empirical data is clear:  Approx 30 Skytrax conversions flying with a cbox (say 2000 hrs or so?) with one bearing failure.

Had it been a shaft failure and I believe your analysis above would have had no mention of bearings.

 

Edited by MN Kitfox 2

Share this post


Link to post
Share on other sites

Posted (edited)

PS:  I deleted the earlier post, as it did not go far enough in presenting hard-core engineering evidence, while at the same time going too far in the irritation direction.   

Atta boy! Keep the pertinent, detailed technical info coming, that's the key to educating us dummies on the benefits and accepting of any new product development. Just remember many here are jumping in early on the learning curve for the Yamaha conversion products and we probably need a lot of handholding to be brought up to speed because we don't spend our time on the rotor forums.

[edit] FWIW, I would add many old fart fixed wingers (including myself) don't Facebook either.

Edited by dholly
1 person likes this

Share this post


Link to post
Share on other sites

Posted

I kept my mouth shut yesterday after reading the original post.  Made me think of a buddy of mine who owned the local Arctic cat shop.  When Skidoo came out with the single ply track he talked mad shit about it and how it would fly apart etc.  I got tired of listening to his rants and stopped hanging around the shop.  I told him I don't want to come in here and listen to a rant on what a pile of shit Skidoo and Polaris is, I want you to tell me why AC is better than the competitors.  Low and behold, the next year AC came out with the a single ply track and it was the best thing since sliced bread to him.  Years of him running his mouth about how bad the competition was instead of showcasing the product he sold led to the down fall of his business and loss of the dealership as NO ONE, even his very best of friends wanted to go into the shop and listen to him rant about the other guys, me included. 

My advise falls in along side most of the guys here.  Keep the technical data coming about your product, keep us updated on real world numbers not what you think works out on paper.  I deal with fixing engineering fuck ups on a daily basis and have to come up with real world solutions that work and result in a code compliant product.  I would love to see the same from you.  Testimonies from actual users of your engine redrive combo, real world numbers on flying hours with said combo.  I don't care one damn bit about paper numbers, they mean absolutely shit, the proof is in the pudding.

:BC:

 

1 person likes this

Share this post


Link to post
Share on other sites

Posted

My E gear box is on it's 3rd owner, 6th engine, and 3700 hrs. Original bearings and 2nd donut. I replaced it just because it was convenient the last time my engine was rebuilt......just sayin....I know your data is for a Yamaha set up but overall I'm comfortable saying that the gearboxes themselves are pretty bullet proof.

1 person likes this

Share this post


Link to post
Share on other sites

Posted (edited)

His (Greg Mills) data is concocted from picking and choosing numbers and estimates while sitting behind a computer.

He has never extensively ran a c box with a Yamaha.  Never put these paper estimates of his to a test.

The same is true for a line of sprag clutches he recently came out with.  He came up with TBO estimates with the same engineering slant (this time slanting towards his product) of thousands of hours TBO and a limetime guarantee from Mohawk Aero.

Real world testing on those sprag clutches showed: 2 tested and entirely destroyed within 2 hours each.  Copro's testimomy in the post above describes this.  Greg sent these clutches out (to people I know and talked with at the time) UNTESTED. The worst part of that sprag clutch debacle is that he didn't even notify other customers that the failures had occured.  I actually had to contact one of them (overseas customer), who planned to fly the clutch soon, and I advised him to stay on the ground because there were problems.

So what were dealing with in these engineering calculations is plain and simple:

 "Garbage in..... garbage out"

Like Akflyer says... proof is in the pudding (real world empirical test data).

Edited by MN Kitfox 2

Share this post


Link to post
Share on other sites

Posted (edited)

Remember here guys, I'm just a Yamaha enthusiast.

I have no alterior motives here.  I don't make money in this business.  I am just a guy that enjoys helping others who have an interest in Yamaha power options.

I have tried to support Greg and REALLY WISH that I could continue to do so, because the more good people who help develop Yamaha power in aircraft the better!

But he has forced my hand here, and I do not like it a bit.  You guys see what I normally post!  I am the positive easy going and supportive guy!

But when someone puts out bad, slanted, and fake news that doesn't help anyone.

When someone says their part will last thousands of hours, doesn't test it, and then doesn't warn others when a problem is found!!!  Then continues to pick on the other guys product that has been working virtually flawlessly..

Really?

Not cool... and not good for furthering Yamaha power.

Edited by MN Kitfox 2
I suck at spelling
1 person likes this

Share this post


Link to post
Share on other sites

Posted

You folks are turning this into a yahoo forum :wacko:

1 person likes this

Share this post


Link to post
Share on other sites

Posted

You folks are turning this into a yahoo forum :wacko:

I don't like it either.  Just trying to counter some bad info.  Somebody had to say something.

But I'll sign off on this one now.

I've said my piece.

 

Share this post


Link to post
Share on other sites

Posted

Greg, I talked to you on the phone one time and that was to try to get Jodys Skytrax adapter to work with your one way clutch and your clutch wouldnt work purely dimensionaly. I could of went online and posted to everywhere that looky here everyone his stuff doesnt work it was dimensional incorrect but i didnt just because i figured you werent familar with my adapter and you needed to work out the bugs. Now looking back on this situation thats exactly what you would have done. We never discussed all the things that you supposedly "taught" me. I shared with you my plans for the future (Apex gearbox) and some of my thoughts and you shared some of your insights. I kind of that at the time that we were sharing knowledge to collectively make this yamaha redrive thing better for everbody. Now that you have out right lied about multiple things on our correspondence among other things i will never talk with you on the phone or work with you to solve somones redrive problems. I am reluctant to do this because everone suffers but I can not allow you to slander my reputation and not for fear that i wont sell somthing to someone. I have met so many great people just making these little parts as a side hobby and there is no reason that someone should make up such things about me. You have allready started talking bad things on my new Apex gearbox and i havent even started the testing phase yet. I have high hopes for it but who knows testing could reveal all kinds of flaws and i could end up with a pile of scrap for the metal bin but one things for certain I wont be offering any for sale until i prove that they are a good alternatve. I am very interested in who had any failures of my adapters. To my knowledge there has been none with the exception of a oil weep on a few adapters and I am aware of one rotax c gearbox bearing failure (Steve Henry) that happened after 100 hours and it was not catostrphic he noticed excessive play in the clutch drum on preflight. We attributed this failure to the type of lubrication used and possible damage during a gear change out. He is now up to about 350 hours many of which flying at wot during competitions and 180 hp for take offs using nitrous. I am aware of his rubber rotax hardy disk coming apart but thats not to say one cant use the these ive used one my plane for over 200 hours now with no issues. Plus that is not a catostrophic failure either since the c box is design to eject the rubber pieces out the large holes in the side and continue to drive the 2 couplings by direct contact. I am not making any claims that this setup will go for thousands of hours because its an unkown  and I am unwilling to make up fake facts but at this time but it seems to be working pretty good so far. I would be happy to discuss any and all failures that you know here on this forum. We owe it to anybuilder considering one of our PSRU options. I however wont get in a debate with you on your skewed engineering data. I hardly have enough time as it and i dont want to use what little i have in negative arguments its not productive for anybody.

 

4 people like this

Share this post


Link to post
Share on other sites

Posted

Well said Teal. I have a jealous person in my line of work as well, he is my biggest advertizer:BC: 

2 people like this

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now