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Mistral proceeds toward certification

R

Rotary10-RV

Well Known Member
Mistral Engines posted to the ACRE site recently that they are approaching certification on their G300 3-rotor (300 HP) and are seeing very good Hp and BSFC numbers. They have changed the desination of their G190 engine to G200 because they are now producing a consistant 200+ HP. They posted the HP curves and BSFC curves for the engine. Their redundant EMS is configured to take advantage of the rotaries ability to run LOP safely and they have posted the numbers in both the ROP (max power) and LOP (best economy) configurations. Both engines use the same PSRU a purpose built 2.8:1 reduction planetary. All the G200 numbers have been logged in-flight on their Piper Arrow with the rotary installed. Looks like there will be at least 1 more certified possibility in the near future. I've linked the performance graphs
Bill Jepson
 
The ACRE is Paul Lamar's email list that deals with Rotary engines in aircraft. Here is the link to the subscription page. It's called the Aircraft Rotary Engine Newsletter on his home page but it comes through the email labled ACRE. Not sure why. He also has some interesting articles listed on his main webpage, here.
 
Fuel numbers and ACRE

kcameron said:
Thanks, Bill. I've been watching Mistral for years hoping they'd finally show fuel burn numbers. I can't find it on their site though: http://www.mistral-engines.com/index_files/Page423.htm

Maybe that site is outdated? Also, what is "the ACRE site"?
Click to expand...

No, Kevin the site is not outdated, but Mistral has been holding the numbers until finishing on the G300. Francois the CEO has a good relationship with ACRE, (Aircraft Rotary Engine) newsletter and did something of a "pre release" of the happenings.
I have the excell spreadsheet of the G200 which looks great. I'm trying to figure how to put it on here. Max power rich of peak (ROP) on the 2 rotor is 200 HP at a BSFC of .57. The real suprise are the LOP cruise numbers. 75% power running LOP which the rotary is totally SAFE with BTW, are showing 168HP at a BSFC of .44! that is in there with the best them when running gasoline. Mistral is incorporating the LOP operation into their EMS which will really help the cruise and range numbers. Francois said that the G300 3 rotor is making the design 300 HP very easily they are control limiting the engine to 6200 RPM. That is on Mogas too, 95 RON (90 US) regular or mid-grade unleaded gas. The Mistral guys are out front about everything saying they wanted to get the NA engines done first because they are the easist. The 230-240 turbo 2 rotor will follow. They are working on turbo sizing and being sure the turbine wheel is tough enough to endure the high temp exhaust of the rotary. He commented that the turbo 2 rotor could easily make 300+ but they felt that they needed to limit it so bad gas wouldn't cause detonation problems. the same type of problems experienced by regular aircraft turbo engines.
Bill Jepson
 
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Excellent. I'm glad Mistral has stayed with it. It has been a long journey. Those are really good numbers and tend to support what Tracy Crook has been saying for a long time- LOP, Wankels are pretty good.

The next step will be getting them out there are seeing how they really do in use.

I like how they have had a test airframe for some time and can validate in the test cell as well as in actual flight. They have seemed to do it right on not a massive budget and haven't posted a lot of unbelievable information- rare indeed.:)
 
Posted test flight

rv6ejguy said:
Excellent. I'm glad Mistral has stayed with it. It has been a long journey. Those are really good numbers and tend to support what Tracy Crook has been saying for a long time- LOP, Wankels are pretty good.

The next step will be getting them out there are seeing how they really do in use.

I like how they have had a test airframe for some time and can validate in the test cell as well as in actual flight. They have seemed to do it right on not a massive budget and haven't posted a lot of unbelievable information- rare indeed.:)
Click to expand...

Quite true Ross!
Paul Lamar visited Mistrals florida location where they are working with Embry Riddle on the Piper Arrow. He was given a ride in the plane and was very impressed. His site has a link to the video of the flight. ACRE is www.rotaryeng.net I believe. Paul often run down some odd tangents but there are many people colaborating and there's frequently some good information there.
Bill Jepson
 
FLAME ON! (or not)

I would suggest that most of gmcjetpilot's comments are true...up until electronic engine management and continuous high load operation are considered.
His friend with an RX-8 will never benefit from the rotary engine's true advantage, which is continuous high engine load economy @ LOP.
The rotor path geometry is inferior to a traditional piston, true. However the wide open exhaust and intake ports don't have the throttle losses incurred by Piston Engine's old poppet valves which never get out of the gas path. I say the results could be a wash with computerized fuel injection and LOP.
Also; the fuel is thrown centrifugally toward the spark plugs because the intake charge is carried around from the intake side to the combustion side. The resultant stratified charge is easily lit by the plugs even though it would be too lean to light in a piston engine.
As for noise, some rotary powered aircraft are quieter that thier piston powered siblings, mufflers have been a problem in the past, but now better mufflers have been developed that can withstand the high energy exhaust pulses.

The Rotary Engine community is growing, and the results look pretty good.
 
Comparing the CO2 emmisions (EU standard for cars) of the Mazda RX8 with the state of the art Wankel, the RENESIS engine, to the similarly powered BMW 325 (stright 6), they are 267 and 225 g/km respectively. This means that the RENESIS uses approximately 15% more fuel on average. For the sake of completeness, the much stronger BMW 3.0L diesel with 500Nm of torque only has 174 g/km of CO2 (35% less fuel compared with the RENESIS).

However, the EU standards for car CO2 emmisions is made for average car operation incl city driving, highway and so on, and not for peak power operation. At high load the Wankel can operate with a much leaner mix than a gasoline piston engine, so no one should be surpriced if a state of the art Wankel would actually be more efficient than a similarly powered gasoline piston engine.
 
Does anyone know why Mazda has not embraced LOP operation at part throttle on the Renesis using wideband O2 sensor feedback? The other OEMs have been doing this for years now, some running 17-20 to 1 AFRs in cruise.

The Renesis has a deserved and real reputation for poor fuel economy. I'm thinking Mazda has very smart people working on this. Is this an emissions issue?
 
SvingenB said:
Comparing the CO2 emmisions (EU standard for cars) of the Mazda RX8 with the state of the art Wankel, the RENESIS engine, to the similarly powered BMW 325 (stright 6), they are 267 and 225 g/km respectively. This means that the RENESIS uses approximately 15% more fuel on average. For the sake of completeness, the much stronger BMW 3.0L diesel with 500Nm of torque only has 174 g/km of CO2 (35% less fuel compared with the RENESIS).
Click to expand...

Incorrect.

You cannot compare the CO2 output of the engines when they are running different fuel (Mogas versus diesel) as the Carbon/Hydrogen ratio for the two fuels is different. It's close, but it's not the same. To make an accurate cross-fuel comparison, you would have to look at oxygen content before and after combustion, since the oxygen is used to combust both the hydrogen and the carbon of both fuels. Even then, different blends from different areas of the country will contain varying percentages of compounds with single versus double bonds within the carbon chain, which changes the chemistry further - not to mention oxygenate additives. It's not apples to apples.
 
It's not apples to apples, but close enough "for government work", literaly :) The point I was trying to make was that a modern Wankel only use 15% more fuel than a modern otto engine for similar cars with similar hp (Mazda rx8 vs BMW 325). This is much less than the fuel consumption of old Wankels and nowhere near the 40% difference reported on RVs.

The CO2 emmisionn is a standardized procedure, and a better measuree than factory reports on fuel consumption, which is more affected on driving habit thaan most otther things (CO2 is of course also a result of driving habit, but the procedure of measuring it is not.
 
Well, I put my apples in the Wankle bucket so now...

I'm admittedly not an impartial observer.
I'm building an RV-8 with a turbo 13b. I'm using Tracy's engine controller and reduction gear. Hopefully the first engine start will be in a few weeks.
Tracy's engine controller allows manual leaning up to 15% of the standard value you set. You observe the O2 sensor while performing baseline tuning, and 'drivability issues'.
Based on Tracy's comments, the naturally aspirated 13b and Renesis engines can be run quite a bit lean of peak, with fuel consumption 'approaching' that of a lycoming equipped RV-4. I understand that this is a bit vauge and still higher consuming.
My goal is to get 200 Hp, so I know a turbo is required. I want a high sustained climb rate and to reach high alititudes. The Cascade Mountains are nearby and drive this desision.
Likewise, a fast dive for home once I get west of the mountains favors the rotary which should have no shock cooling issues.
The possibility of using auto gas would hopefully make the higher fuel burn a financial wash.
I enjoy the work. It has added years to the building process, and I don't reccomend it. You have to want to do it. But that's just me...and many of us.
Here's a link to the EAA326 site, and my most recent pic. http://gallery.eaa326.org/members/semery/DSCF0985.JPG.html you can kludge around from there and see the others, plus EAA326 members projects as well. A neat bunch of guys, and very active RV builders and fliers.
 
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Possibly Oxides of Nitrogen problems

rv6ejguy said:
Does anyone know why Mazda has not embraced LOP operation at part throttle on the Renesis using wideband O2 sensor feedback? The other OEMs have been doing this for years now, some running 17-20 to 1 AFRs in cruise.

The Renesis has a deserved and real reputation for poor fuel economy. I'm thinking Mazda has very smart people working on this. Is this an emissions issue?
Click to expand...

There have often been Oxides of nitrogen emissions trouble when running LOP. The newest rotary is finally exploring direct injection which should allow LOP and stratified charge operation, both of which will work well with the rotary.
Moose did us the favor of posting the pictures of the Mistral power and fuel consumption numbers. Despite George's adversion to wankel combustion chamber shapes those numbers look very good. I hadn't been able to do it (post the charts) from work. I hope that Mistral will do side by side flights so everyone will be able to see how well they have the engine working. In an aircraft they don't have emission troubles so they are able to get much better LOP numbers. Tracy Crook has been telling everyone that the rotary works great there and Mistral seems to be verifying what Tracy has been saying. The higher the needed output the better the rotary works. If that wasn't true Mazda would never have won LeMans outright in 1992 durring a total fuel available limited year. That engine was NOT turbocharged.
Bill Jepson
 
An RV 111.1 NM Race took place 5 April 2008. Lycoming parallel and angle valve 360s with Constant Speed props and one MAZDA Rotary RV-6 with Fixed Pitch. I witnessed the fueling BEFORE and AFTER the race. I did the timing. The Mazda rotary was right in the middle of the pack with the 200 HP and 180 HP RVs and had a similar fuel burn. Fuel burn on the Rotary was a LOT LESS than what I tought it would be.

See RESULTS:
http://www.rvproject.com/race.html

Results are near the bottom of the page. Photos of the racers should be up on the site tomorrow.

I am the one that collected and processed all the RAW DATA. I created the master spreadsheet that calculated the results.
 
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What Fun!

That race was very interesting. I'd sure love to participate in something like that.
It looks like a well run, safe and inexpensive event that the 'average rv builder' :rolleyes: would enjoy.
The data is encouraging for a rotary builder like myself. There used to be so much negative feedback coming from the conventional engine group. Now I notice a bit of a change. Our group is also getting larger and doing some flying. (that's right, in the not to distant past very few actually flew)
I'm alittle averse to the prepackaged alternate engine (sorry Jan) because I am of the opinion that the builder should have an intimate relationship with his expirimental power plant, and think out, then build it. Of course there are levels of commitment. I don't mean cast your own pistons and build your own connecting rods and cylinders ala Burt Munro.
I fall pretty much in line with the Rotary Engine builders I've come in contact with, buying the few parts available, and fabricating the rest, mostly everything that hangs from the engine or the engine hangs from. So maybe it's just a matter of degrees of ability and commitment, as well as resources.
Anyway, I'm always interested in advancing the art.
 
The question I have about the runoff:

2 lycs were specifically ran for fuel economy, 2 for top speed- George claims that both extremes were representative of the entire group as a comparison to the single rotary. I[m not so sure that approach is valid given other differences.

Since the rotary fell into the middle, and it was the only fixed pitch prop in the bunch, it is probably a bit premature to make an across-the-board assumption other than it performed as well as the others in economy and power, just as we've been saying for the last two years, and a little cheaper to operate. I dare say any fixed prop 180hp Lyc would have also fallen into the middle performance-wise, given that buch of planes...
 
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Mistral? Thread drift?

rtry9a said:
The question I have about the runoff:

2 lycs were specifically ran for fuel economy, 2 for top speed- George claims that both extremes were representative of the entire group as a comparison to the single rotary. I[m not so sure that approach is valid given other differences.

Since the rotary fell into the middle, and it was the only fixed pitch prop in the bunch, it is probably a bit premature to make an across-the-board assumption other than it performed as well as the others in economy and power, just as we've been saying for the last two years, and a little cheaper to operate. I dare say any fixed prop 180hp Lyc would have also fallen into the middle performance-wise, given that buch of planes...
Click to expand...

I find it interesting that whenever someone points out that a rotary does well on fuel burn everyone says, "can't be or say isn't so." I am familar with David Leonard's RV-6 configuration and he admits himself it is no where near a "cleaned up" configuration aerodynamically. The engine is turbo-normallized with the Turbo modified to prevent too much boost. The point here is that Dave showed well and got BETTER MPG than some of the Lycs. They were flying fast. David said in another forum that they were averaging 190 knots or 218 mph over the course. It has proven to be true that the higher the needed output the better the rotary does in terms of both P/W and BSFC. It has been shown that in the "tuned" output areas at high RPM the rotary does well on fuel and power. Interestingly everyone mentions the cars, and this is understandable, but as so many people mention the duty cycle, and power requirements in an aircraft are always higher than a car. I have long believed that the rotary was BETTER SUITED TO AIRCRAFT THAN TO CARS.

Now I need to mention that this has as usual started to veer far afield from what I started the thread about. Mistral Engines is certifing the rotary is both 2 and 3 rotor configurations. They have posted excellent power and efficiency numbers. These numbers will need to be proven out in an non-factory unbiased environment to be accepted by the conventional engine contingent. I would love to see a side by side comparison with another Piper Arrow for instance. Mistral has done the grunt work to truly bring the rotary up to a competitive engine on both power to weight, where it has always looked good, and on a fuel efficiency basis as well if their numbers prove out. They are a truly professional and top drawer group from everything we have seen so far so I expect they will do well in independent tests. We simply have another manufacturer of engines that will help to provide us with a really nice way to fill our engine needs if you might like something different.
Bill Jepson
 
My 2cents about the Mistral- that intake manifold is a thing of beauty and Im jealous. Other than that, the package is overpriced just like Lycomings and Eggs, imho. I couldn't care less if it (or any other engine for that matter) is certified or not when the certification is not required and it only jacks up my price.

As nice as the engine package is, it doesn't really offer anything special beyond the basic Mazda setups available for a small fraction of the price these days- thanks to Tracy Crook and others who have produced bolt-on parts and figured out the bugs for the rest of us.
 
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ONLY PARTIALLY TRUE

rtry9a said:
My 2cents about the Mistral- that intake manifold is a thing of beauty and Im jealous. Other than that, the package is overpriced just like Lycomings and Eggs, imho. I couldn't care less if it (or any other engine for that matter) is certified or not when the certification is not required and it only jacks up my price.

As nice as the engine package is, it doesn't really offer anything special beyond the basic Mazda setups available for a small fraction of the price these days- thanks to Tracy Crook and others who have produced bolt-on parts and figured out the bugs for the rest of us.
Click to expand...

The one BIG difference is that the PSRU is designed for use with a HYD/CS from the start. That is a big deal if your building something like a RV-10 where the load will vary tremendously. Not so important in a RV-6 or 7 where a fixed pitch will work fine. The purchase price includes a extensive Fadec system with full redundancy, and the rear plate includes a parafocal mt and pads for alternator, (spare), and a prop governor drive is built in. If you want to build cheaply there is nothing wrong with doing it yourself. Tracy's drive and PSRU are much cheaper, so if you are capable by all means, do it yourself. I will be! I may buy Mistrals PSRU though because my RV-10 will perform much better heavily loaded with a constant speed. The Mistral PSRU is costly, around 7K which is twice what I paid for my engine, a 20B 3 rotor, but I'll save half of that by not needing to buy a super expensive electric cs prop. If you don't have the engineering know how though and still want something different it is a good way to get a finished engine package. Mistral has been very friendly with the homebuilt community and has been willing to sell parts to homebuilders, which certainly helps me out. I could probably even design a good PSRU myself, (I a mechanical engineer), but I'd spend more than that by far before finishing a 1 off design. FWIW
Bill Jepson
 
Bill, Any reason why you are not going to use the 3-blade IVO Magnum air adjustable? It seems to work as well as the MT and is much cheaper and not affected by ridiculous exchange rates these days:cool:. Just needs a larger spinner.
 
I don't favor the IVO blades

rtry9a said:
Bill, Any reason why you are not going to use the 3-blade IVO Magnum air adjustable? It seems to work as well as the MT and is much cheaper and not affected by ridiculous exchange rates these days:cool:. Just needs a larger spinner.
Click to expand...

I'm not a great fan of the IVO prop. I don't like the way they twist rather than rotate the blade. I am not claiming there is anything wrong, just not what I favor. I am also influenced by a guy I worked with that was too ham handed and cracked something and threw a blade while I was watching. Totally his fault, but bad mojo anyway. I believe you also have your choice of used props if you can use a hyd/cs. I also may want to tweek the 20B later, and Tracys drive is going to be working pretty hard in the 300 HP range.
Bill Jepson
 
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Rotary10-RV said:
The one BIG difference is that the PSRU is designed for use with a HYD/CS from the start. That is a big deal if your building something like a RV-10 where the load will vary tremendously. Not so important in a RV-6 or 7 where a fixed pitch will work fine. The purchase price includes a extensive Fadec system with full redundancy, and the rear plate includes a parafocal mt and pads for alternator, (spare), and a prop governor drive is built in. If you want to build cheaply there is nothing wrong with doing it yourself. Tracy's drive and PSRU are much cheaper, so if you are capable by all means, do it yourself. I will be! I may buy Mistrals PSRU though because my RV-10 will perform much better heavily loaded with a constant speed. The Mistral PSRU is costly, around 7K which is twice what I paid for my engine, a 20B 3 rotor, but I'll save half of that by not needing to buy a super expensive electric cs prop. If you don't have the engineering know how though and still want something different it is a good way to get a finished engine package. Mistral has been very friendly with the homebuilt community and has been willing to sell parts to homebuilders, which certainly helps me out. I could probably even design a good PSRU myself, (I a mechanical engineer), but I'd spend more than that by far before finishing a 1 off design. FWIW
Bill Jepson
Click to expand...

What are the prices for the vareous Mistrals?
 
Not showing on the site right now.

SvingenB said:
What are the prices for the vareous Mistrals?
Click to expand...

They aren't listing the latest prices, but they were running just under a Lyc of the same power ie the G200 (200HP 2 rotor) was running mid-high twenty Ks. (New to new parts) Full airplane prices, to be sure. The web site is www.mistral-engines.com they are requesting an e-mail to put out the prices. I'll try e-mailing Francois and see if he'll publish. FWIW these guys have never claimed they would be cheap. They are pushing toward a finished product without a lot of tall tales. They aren't twisting up an engine to get big numbers. They are looking for something more permanent that that. I sent an e-mail to the web site and hopefully they will get back to me as soon as possible.


Bill Jepson
 
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I saw the site, but couldn't find any prices. I looked at the dimensions, and the G-190 should fit in an RV-4 engine mount. They are using standard dynafocal mounts as I understand. The difference is that it will be longer than a 320/360, this could cause problems with COG and possibly also some structural issues. But maybe the COG of the engine is roughfly the same as a Lyc, then this will be no issue at all.

The good points with this engine in my opinion:
* It will look cool in a -4 :cool:
* Water cooled
* Lots of power
* Probably high quality (but uncertain with very few, only one? flying)
* No issues whatsoever using mogas
* Better cruising performance ??
* Less vibrations
* Geneve is much closer than Seattle (or wherever the Lyc clones are made).
 
Removed prices

SvingenB said:
What are the prices for the various Mistrals?
Click to expand...
They had prices and delivery dates four years ago, but they took that and performance data down? Humm

I recall their entry level engine, with the claimed 190HP, atmo engine, was about $31k. That is sans engine mount, radiator, prop and other goodies. Just write them. I recall someone just wanted the PSRU and it was about $6k to $7k!? They really did not want to support the experimental market I also recall, going for the certification market, at least at the time. It seems that is still the plan.
 
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Actually supportive of experimenters now

gmcjetpilot said:
They had prices and delivery dates four years ago, but they took that and performance data down? Humm

I recall their entry level engine, with the claimed 190HP, atmo engine, was about $31k. That is sans engine mount, radiator, prop and other goodies. Just write them. I recall someone just wanted the PSRU and it was about $6k to $7k!? They really did not want to support the experimental market I also recall, going for the certification market, at least at the time. It seems that is still the plan.
Click to expand...

George,
I would say that you have their ORIGINAL business plan nailed. Mistral had a re-think after they started an e-mail forum through the ACRE newsletter. They found that there would be many takers for parts to start with, but not as many for complete engines. Their prices are high, but they are really doing the research rather than a cut and try operation. The PSRU is at least 7K right now. That sounds super expensive, but there are several things to remember about it. The unit is designed to run hydraulic constant speed propellers from the start. The nose of the gearbox has a built in drive for a governor. (for a hyd/cs) All the internals of the Mistral PSRU are purpose built as a continuous duty aircraft PSRU, and the entire gearset is custom straight spur gearing for low losses. The entire case is a magnesium casting to save weight. I looked at it honestly and now think that the Mistral PSRU at $7000 may be the best buy a rotary engine experimenter might get.
They have been willing to sell parts to the homebuilder. That was a major change in their thinking a while back. There are several builders on the rotary newsletter that have purchased their parts and they say that they are things of beauty. They also say that they look good enough that they can ALMOST forget the hole they left in their wallets:D
Bill Jepson
 
I got a reply from Mistral today. An experimental G-200 (there will be no more G-190) costs 27,200 ? with a delivery time of 3 to 6 months. A certified version will be available next summer at earliest.

27,200 ? is exactly twice as much as a Mattituck IO 360 at 180 HP (22,200 US$), even more than a 200 HP 360. I guess this answers all my questions :)
 
Weak dollar bummer

SvingenB said:
I got a reply from Mistral today. An experimental G-200 (there will be no more G-190) costs 27,200 € with a delivery time of 3 to 6 months. A certified version will be available next summer at earliest.

27,200 € is exactly twice as much as a Mattituck IO 360 at 180 HP (22,200 US$), even more than a 200 HP 360. I guess this answers all my questions :)
Click to expand...

The wonderful effect of the current weak dollar, 43K by my current conversion calculator. Too bad, it will hurt their sales for certain.

B, was that EURO? OR Swiss Francs? I assumed Euro. It makes a huge difference as in Francs it would work out to $27,148.00 which would be more in the ballpark, Probably wishful thinking on my part. I had a chance to buy a 2 rotor real early for super cheap if I could have brought the RV-10 to Osh the next year. Couldn't do it curse the luck.

Bill Jepson
 
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Ouch

SvingenB said:
The mail said Euro.
Click to expand...
27.5k Euro is $42,822.50 USD! Ouch :eek: That makes more sense, since the projected price of a G-190 was over $31,000 in 2004. Just the PSRU was $7k in 2004, if they would sell you one. Pretty sure it did not get cheaper. Of course you still need and engine mount, radiator and other goodies to make it work. I see the cost thing being a hindrance to sales.
 
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too bad really

gmcjetpilot said:
27.5k Euro is $42,822.50 USD! Ouch :eek: That makes more sense since the projected price of a G-190 was over $31,000 in 2004. Just the PSRU was $7k in 2004, if they would sell you one. Pretty sure it did not get cheaper. Of course you still need and engine mount, radiator and other goodies to make it work. I see the cost thing being a hindrance to sales.
Click to expand...

Hindrance, heck that is more of a showstopper. Yea that number is just wrong, (not incorrect just wrong), and that is comming from a rotary supporting guy. They just won't sell at that price. Too Bad. If everything is even including the price you will have trouble getting people to change. Unless the thing PRODUCES gasoline I don't think they will do well at that price.
A minor point in their favor is that the two rotor has an integrated dynafocal mount on the back so you can use a conventional engine mount. I believe the 3 rotor is going to accept the engine mount for a 6 cyl Continental, the bed mount style. I hope the currency sorts out so the prices can be realistic.
Bill Jepson
 
BED mounts are cool

Rotary10-RV said:
I believe the 3 rotor is going to accept the engine mount for a 6 cyl Continental, the bed mount style. I hope the currency sorts out so the prices can be realistic.
Bill Jepson
Click to expand...
I love the Lyc dynafocal, but from an engineering stand point the BED mount, 4-corner method is really great for tuning vibration and deflection characteristics. Lets face it cantilevering ++300 lbs of spinning gyroscopic prop, engine and stuff off four points has pros and cons. If you need help designing a mount, shoot it by me. I use to analyze stuff like that. A good place to start is just look at a Continental mount. Other engines, like the in-line rangers had bed mounts I recall. Sounds like a fun project. Get some tubes and start welding.

You know who really does good tube work now a days, are the off road, truck, rock crawler and race guys. They make steel tube roll bars, frames and all manner of tubing. Tube technology and skill has been kind of lost in the Aviation world. My point is a hard core tube shop for the Off Road/Race crowed might be a good place to help fab it. They use top quality ("aerospace") steel tubes and have all manner of special tools to fab tube structures easily and very accurately. They also tend to make nice welds, since they are out in the open. It has to be way cheaper than going to some Aviation shop for a custom deal. If you get it on CAD, they can make duplicates. Usually a steel Jig needs to be made, but with the computer aided stuff and accurate ways they have to cut tubes now, you might get away with out? You might make several down the road and sell them to other three rotor RV'ers for the Dash 10?
 
I'm interested in products

gmcjetpilot said:
I love the Lyc dynafocal, but from an engineering stand point the BED mount, 4-corner method is really great for tuning vibration and deflection characteristics. Lets face it cantilevering ++300 lbs of spinning gyroscopic prop, engine and stuff off four points has pros and cons. If you need help designing a mount, shoot it by me. I use to analyze stuff like that. A good place to start is just look at a Continental mount. Other engines, like the in-line rangers had bed mounts I recall. Sounds like a fun project. Get some tubes and start welding.

You know who really does good tube work now a days, are the off road, truck, rock crawler and race guys. They make steel tube roll bars, frames and all manner of tubing. Tube technology and skill has been kind of lost in the Aviation world. My point is a hard core tube shop for the Off Road/Race crowed might be a good place to help fab it. They use top quality ("aerospace") steel tubes and have all manner of special tools to fab tube structures easily and very accurately. They also tend to make nice welds, since they are out in the open. It has to be way cheaper than going to some Aviation shop for a custom deal. If you get it on CAD, they can make duplicates. Usually a steel Jig needs to be made, but with the computer aided stuff and accurate ways they have to cut tubes now, you might get away with out? You might make several down the road and sell them to other three rotor RV'ers for the Dash 10?
Click to expand...

Yes George, I'm interested in doing several products for -10 installs, or simply 3 rotor installs. I won't advertise until I have something in hand though.
Bill Jepson
 
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