Gary Jefferson

My Feedback: (167)

Your right it has nothing to do with being a competent pilot, but as long as it remains a little expensive I think people who do still have issues with cashing on a regular basis will be a little more hesitant to spend money, because they have more to lose. That was my point and from that perspective it is sort of self regulating to people that have the neccessary skills. Gary

josecilurzo

Hi ,
in my opinion, the proposal of JET JOE, is not to compete with the turbines ( JETCAT, RTI, AMT,FTE, WREN and others ) of the market, and yes, an alternative of low cost and with good value aggregate technician, it is a home buid turbine most attractive.

Joe comes gradual improving its turbine since the launching.

I just do not find to criticize or to compare at this moment the JETJOE, is a turbine proposal different.

jose [8D]

dw_crash

My Feedback: (6)

How many people in this thread have actually owned and run a JetJoe engine?

I have one. It was a very early one with teething problems. But, it runs fine now. I also have a Wren. It too runs fine. Again, it took some fiddling and learning to get it up and going....I have seen every engine have it's cranky day. Expensive or cheap engine. It comes down to learning what you have.

This power comment bothers me. Power is a factor of a number of things. I have had fantastic power on a cold day and a slug on a hot day. Same engine. fly at sea level or in Denver, the same affect.

My two bits,
DW_Crash

AndyAndrews

lol Busted!

rorrock

I understand the difference between a good turbine and a poor one, this is the very reason I only run well know brands in my larger models. albeit glo prop engines.

And i hate to tell you, from my experience the amount of money that somone has and is willing to spend has very very little to do with their ability, particular in this hobby.
Some of the best pilots I know cannot fly turbines because of the amount to purchase the components. However I have met the odd idiot pilot who can, and if you really want to see something scary watch some of the morons on you tube.

Perhaps instead of comments which sound so elitest such as "My biggest fear is that someday everyone will be able to afford to buy turbines because there are people that cannont even fly prop planes w/o crashing every week", You as a rep should put more time into education and helping to keep the safety of this area up there.

Given JJ's history I have no doubt they are an underperformer, my big question was what are you guys going to do when a serious lower cost competitor hits the market, trash them just the same?

Rob

growingupisoptional

Sarah Parish, what did wren do when you found out Jet Joe copied you?
How did you find out, have you proven it or taken them to court?
Didn't they break your patent. Should be a cut and dried case?
Wren should be able to get compensation for each and every turbine engine sold using your design.
Jet joe would also be forced to pay royalties to wren for continue use of the design.

Have these options been taken up?

afterburner

My Feedback: (18)

Believe me, only the reps for the big players in the micro turbine arena will be trashing them. The rest will be getting in line to buy a cheaper, reliable turbine that has a good track record.

Marty

JET FX

Hmmm try taking the Chinese to court for copying now thats funny.....maybe Judge Judy could sort em out

Boomerang1

If multi billion dollar companies like GM & Honda cannot do much about blatant copies being produced by the chinese what can a small team of ordinary people working in a small factory in middle England do about it? Waste hard to come by money employing lawyers to chase people from a culture that does not recognise intelectual property rights? Get real!

Google Cherry cars & Daewoo Matiz (Daewoo is controlled by GM) & you will get just a small picture of what the chinese are up to. One GM official commented that the chinese had even copied the mistakes made in the original design.

To answer my question Wren, Jetcat & all the other quality turbine manufacturers can only hope people put a value on quality, value, customer support, service & business ethics. All these concepts seem alien to the chinese copycats for whom the bottom line in business is, well, ........the bottom line. - John.

WrenTurbines

We did exactly what John has just said - we haven't wasted time or effort trying to pursue JetJoe in any way but concentrate on quality, value, customer support, service & business ethics.

Sara Parish
Wren Turbines

growingupisoptional

Well business is business and if you decide not to protect your intellectual property (because it's too hard/too expensive) then that's the companies choice.
Maybe GM should take a leaf out of apples book. Seeing as you don't see any copy ipod click wheels their lawyers are clearly better.
Having said that even if you patent your design they can still buy your jet and change just 10% of the design which they obviously did as you say they left out components they did think they needed, then as far as patents are concerned they have not done anything wrong.

Continuing on and providing excellent customer service etc etc is the best you can do.

For jet joe owners it's interesting to note that their engines are based on a well known and respected brand.
Because after the slagging they have received you'd be surprised they were based on a wren.

Sorry can't see a whole lot wrong here.
Business is business and if the jet joe engines were even half as bad and has been said on RCU alone surely jet joe would be out of business by now.
Instead they have resellers in many countries and seem to be expanding.

Interesting isn't it.
(just before the Sara supporters get on here and completely derail this thread, I am not attacking her and have nothing but praise for someone who gets some awesome feedback for her excellent jet buyers support)

rolsen12

If you want some advice from someone with 50 years of R/C flying.
Don't go CHEAP on this purchase.
I spent 12000 dollars on CHEAP and did not get one flight for it.
Buy the best engine you can.
In the long run it will be CHEAPER>

davo580

amt are the best micro turbines in the world byt they are exxo

mikedenilin

My Feedback: (67)

Hi Guys,

I believe that there are markets for expensive turbines or low cost turbines.

I don't believe that JetJoe is doing anything illegal. These turbines have no patents. Even so, they've expired. Just like generic drugs, once the patents expires there are a lot of drug companies (American and European) copying the drugs immediately. If we can do it, why can't the Chinese companies do the same? There is not thing wrong ethically or legally when you are making the same products that can't be patented. I say this because I am in the same shoes in my business. There are companies in China, South Africa making products identical to ours and even use our "expired" patent numbers on their products. What can I do? I don't blame them. Instead, I set up factories in China and compete with them head on. Better quality, better price, better services help us win the battles. There is no whining, just competition.

I hope JetJoe, Wren, JetCat, Artes, and many others come in and compete so we all can enjoy better products, better prices, and services. Competition brings out the best.

As long as JetJoe continues improving and have the passion to be the best, I will buy a JetJoe, even though I still love my Wren, Jetcats and Artes. Please give the freshman a chance to compete.

Mike

JohnMac

Gordon Mc

My Feedback: (11)

Ummmm...... What ????

The patents that you say they DON'T have, have expired ?

If there is no patent, how does it expire, and how were you personally able to check that it has expired ?
(e.g. what patent # did you use to verify that the patent is expired ? )

erazz

Legal? Illigal? Who said anything about the legality of their operation? I always questioned the ethical nature of what they're doing.

AndyAndrews

Patents can be looked up online. Hell if they actually copied one and it worked that would be great. The problem is that they copied it, and substituted critical parts with inferior metal materials. This is the same scenario in a lot of crap coming out of China. But when they do get it right it is usually a very nice alternative that can be quite useful. The only thing keeping China out of my business market (food service equipment) is the cost of freight overseas. If it weren't for that 99% of the factories here that produce ranges, fryers, griddles, etc. would be out of business.

Gordon Mc

My Feedback: (11)

You are missing my point. WHICH patent did he look up, to find out that it was expired ? He says they have no patents, so how does a non-existent patent expire ?

AndyAndrews

I guess there is nothing wrong is someone with WIDE OPEN eyes buys one knowing what potential pitfalls there are with these turbines. What IS wrong is telling people who ask if they are good that they are when they are not as indicated by the vast majority of people in this very prolific forum regarding turbine jets.

It is also, in my humble opinion, very wrong to sell something that is sub par and tell people that there is no problems with them. This borders fraud. And don't give me that "well you paid less than brand XYZ crap, so you should have known". When I first got into this hobby I had not idea of what types of turbines existed in the market. I almost made the mistake of buying one of these and it was completely based on PRICE. Because I told myself, wow, these turbine things are really expensive. Why would JJ engines be so much less money and have the same thrust ratings etc..etc? According to their literature and info on their web they are made to the same exacting standards that all others are made to and ..even a little better in some areas. Oh and the statement on their info online at the time, "we had problems in the past but these have all been addressed" - is bunk. I thought to myself, man these other ones are REALLY more expensive. Why are they so much higher? The other thing that almost got me to buy was their warranty statement. Well a warranty is only as good as the company behind it. Lots of things go through a guys head when contemplating dropping several thousand Washingtons on a toy engine. I sure glad that I DIDN'T take the advice of the REP who was selling them in my area and buy one. I actually ran across this forum for the first time doing research on them. It's a good thing that I did to otherwise I might have been one of those poor suckers that got stuck with another POS turbine.

The thread, asked the simple question, "Are Jet Joe Turbines Good"? My question back would be, that depends. Good for what? Eduacation on how NOT to buy turbines - how to rebuild a turbine -how to understand what it takes to make a turbine run - a study of the fine elements of the negotiation on getting it replaced? Pfst!

pappy35

If you KNOW it's copied, doesn't lack of action on Wren's part imply consent?

Let me state up front that I'm a TOTAL noob in RC jets but know a lot about the physics and engineering of GT engines from working at Pratt & Whitney and now GE Aircraft Engines for the last 18 years (commercial and military design, analysis, repair, flight test, control systems, and finally instrumentation engineering). Please don't take this the wrong way, I mean it only as a staement of fact, but the technology in these engines is pretty crude - comparable to Whittle's and other early GT designs and only the advent of miniturized FADEC's' is what allows the use of GT engines in small models. I guess my point is that the relevant technology's patent's expired decades ago so I'm not sure there's a legal basis for a lawsuit.

These engines use single-stage centrifugal compressors, single-stage axial turbines (cast or forged, I'm not sure but they are blisks - blades and disk forged from a single mult - with surface finishes that lead me to believe they are cast), no oil flow control, no boundary-layer cooling, 'normal' IN718 hot parts, and titanium or stainless steel cold parts. Let's face it, they're pretty simple machines whose basic operating parameters can be calculated in a week of evenings by anyone that paid attention in Thermo and Fluids. The compressor design could be tricky, I've never worked a centrifugal design, but they don't need to be very efficient to operate.

The real trick in getting them to operate reliably is the control logic, secondary flows control/design to ensure the bearings get lubed, and turbine airfoils designed for the Reynold's numbers, mass-flow, and pressure. The fact that the turbines are solid blisks really limits the *** (T4) which really sets the max possible thrust.

I guess I agree that if the JJ's are an identical replica of a Wren, that's cheating but I can't believe the statement that "they don't know anything about how jets work". There's a lot of specialized materials engineering, rotor-dynamics, and control system knowledge that needs to come together to get a bunch of parts to work together to make thrust. I can't believe a group of idiots with a furnace and a lathe are going to get it to work (though their success does seem questionable given the comments).

I for one hope they can reach an acceptable level of reliablity. With all the time I've spent working in this industry, it just makes sense that I should own a GT-powered model but I won't spend outragious sums of money to make it happen. This is what I love about a free-market, you wanna stay in business, innovate. Even in the face of cheaters you still need to meet the requirements of the market.

This is my first post on this subject and I am VERY interested to learn more about the technology. If I am totally off-base, please let me know or point to somewhere that explains the technical details of the better products. I really love jet models and would love to be able to buy one soon!

erazz

Hello Al,

Welcome to miniature jet engines

I think that inadvertantly you actually illustrated exactly what's wrong with JJ.
You're absolutly right. These engines are really simple. That's the point. The initial design considerations by Kurt Shreckling and others was to make these engines simple enough to build. Boundary layer control, oil cooling, multiple stages etc... would not only be incredibly difficult to implement but very cost prohibitive.

So on the one hand these engines are SIMPLE. That makes it easy to copy them. Which is exactly what JJ did.
Because on the other hand, the design of these engines is anything but simple. The design challanges are pretty big. The paths in the compressor and c.c. are very very short making for some very interesting solutions. Herein lies the ehtical issue. While it's easy to copy it's hard to design. Wren's engine is a VERY optimized design. They had to do a lot of experimentation in order to get their engine to perform as it does. JJ simply skiped that R&D stage and copied Wren's design.

Well I guess I should stop. In the other thread I got childed for bashing. (geez, I though I was expressing a valid opinion based on facts and what my eyes see).

If you're interested in these engines I heartily suggest you become a member of the GTBA. I think the fee is around $20 and for that you get a LOT of info in these engines.

causeitflies

While the type of engines we use is simple in overall design, the translation to miniature causes many problems. Tolerances and materials become critical and as stated the Reynold's numbers make it more than just shrinking a larger engine down in size. Just as a model P-51 is different than a full scale and a 1/2A is different than a giant scale, the smaller you try to make it the more problems you encounter.

WrenTurbines

As John (Boomerang1) said, why "waste hard to come by money employing lawyers to chase people from a culture that does not recognise intelectual property rights?" We make it clear to anyone who wants to know that the JJ1200 and 1400 are poor copies of the Wren 54 Mk 2 and 3, but it would be a waste of time and money to try to pursue a Chinese guy with several different names and at least two addresses.

When "Joe" bought the Wren kit in 2003 he had never run a manual start turbine. I still have copies of the emails we exchanged:
"I hv problems to start my new assemblied MW54.

The Glow plug are very difficult to light up the
gas.
pls adv what is the best way to ignition?

-When I do the ignite. should I turn on the gas
first or turn on the glowplug power first?"

These mails were exchanged only 6 months before he started selling engines. His first engines had no preload and when one of his dealers, who knew something about turbines, queried it "Joe" said "the spring is only there to keep the bearing in" and that it wasn't necessary.

For a long time, the JJ turbine wheels were balanced by grinding into the middle of the hub. It was very clear that he had no idea why the sacrificial balancing ring was there. In fact, he had copied the balancing ring but made it too small to be much use. Incidentally, one of the criteria needed for turbine wheels to pass the aerospace certification is that there is no damage to the hub, yet "Joe" was grinding into the hub, invalidating the certification (if he ever had any) and weakening the wheels.

I could give several more examples but I think you get my drift.

People don't realise just how much information Wren have on the JJ turbines. We've been watching him since he started, our friend and colleague Gaspar has a lot of information, a number of disillusioned JJ dealers have contacted me with information and we have received engines here that claim to be Wrens but are in fact JetJoes, so we have seen things with our own eyes. The parts are close enough to be interchanged with ours - but of course the engines don't run very well. So a guy sends his engine to us "I bought one of your engines, secondhand, and there's something wrong with it ..." and we look at it and find that half the parts, including the turbine wheel, are Chinese copies.

We are a reputable, hard-working company who spend over 30,000 GB Pounds (60,000 USD) every year on research and development. When, after a lot of work, we found a new compressor which gave 2 pounds more thrust, we upgraded the MW54 engine. We were selling these compressors for customers to retro fit, so one guy bought one and sent it to Joe (yes, I know who the guy was). Within weeks, JJ was using the new compressor and claiming the 2 pounds extra thrust.

I know the JJ supporters will say "That's life" and "Everybody does it". But that is their only answer. Nobody can claim that what he is doing is right, and by producing a substandard product he's cheating customers out of their money and possibly endangering people in this hobby.

Sara Parish
Wren Turbines

mikedenilin

My Feedback: (67)

Wow, Nice response,

I would like to clarify my statement.

1)Patents:
I mean that turbine technology might have patents in the 50s or earlier, but they have longed expired. If Wren has a new, valid patent on their engine, then they should have put the patent number(s) on their engines. These patents can be used to go against JJ even in China or even dealers who are trying to sell JJ in the Western World.


2.) The basic technology is very simple on our model model engines, yet the manufacturing process requires a lot of experiences, precision and skills. JJ won't be able to compete with Wren in performance or quality because they can only "copy" the shapes, not the skills, precision, or experiences that Wren has accumulated over the years.

3.) Ethical issues versus legal issues:

Are we all unethical when we are copying or modeling after the scale aircraft? F-16, F-15, etc. Don't the scale builders get awards or money for building highly scaled "copied" models. If we can do that? Why can't other engine company copy competitors if there is no legal issues?

4) Wren or JJ:
I own 3 Wrens and I got great services from Sarah. I like to buy Wren because of the service, quality and performance. I have not owned a JJ. I am very tempting to buy one because of the price is only 60% of Wren, but I held that thought because when we equated the services, quality, price, performance, JJ turned out to be not a great deal. I hope that Wren can compete by building their engines in China or somewhere that their cost is only 10% to 20% more than the copycat's.

5)JJ:

The biggest problem in China is that "in general, not all" they are in for the money as the top priority. They will find things that seems profitable then they jump into it. They can careless about the quality, the reputation or performance, as long as there is money to be made. After reading Sarah's comment, I won't buy a JJ any more because they don't show their passion for excellence. They just act like a copy machine. If they can't beef up their RND or understanding of turbines, then they will never catch up in the making quality products. A lot of Japanese companies moved their factories to China to cut cost, but they did not cut the quality. I hope that Wren can build their turbines in China. There are many quality factories in China (mostly run by non-Chinese owners) that can really achieve the high quality standard. Maybe the RND should still be kept in England, but the purely manufacturing part of Wren should be in China. They will have better margins, better quality, and better price to compete. I kept RND in the USA for my company, but manufacturing in China. In the past 2 years, we have wiped out our copycats from China because we are standing on the same playing field in cost.

I hope to see a $1200 turbine engines from Wren, Jetcat, etc. If Wren, Jetcat or other quality brands can have their products built in China, I will buy them in split second. We will be able to buy more jets, more turbines, twin turbines for my F15s, F14, etc. Bring the cost down, we will come.

Mike