Small engine dyno

[Bentwings]

I have only some sketches as my double vision makes doing much else. I’ll make some cad models and take pictures as I go . I have a bunch of parts coming . I may lay them out and take pictures just to show this is a bigger project than meets the eye. Try reading a micrometer with magnifying glass then seeing two views at the same time. Closing one eye helps sometimes. I’m using a stylus to help typing but I still make mistakes . I think I’m going to use two heaters. I have to check the home circuits to see what I use. I could pull the stove out snd make a y extension cord so I could use 220 but it’s a lot of work. I can use two separate circuits with a bit heavier extension cord. If it doesn’t work I’ll just break down and go with the quiet air compressor. I was already committed when I started the boiler build or I could have just scrapped it. But we’ll see how it turns out. It’s a new hobby for me so plenty of room for mistakes and misdirection. Something I learned in football I think. LOL
Byron

Here's a "Small Engine Dyno" that I built years ago and is still working - built as a "Rolling Road" braked dyno for testing slotcars and is capable of measuring from 0 to 300W output.
View attachment 132240
I started with the idea of using a DC motor as a generator and loading its output - using motor parts scavenged from dead cordless tools.
Below the GA for the rolling road - the roller drives a smaller motor as an analogue tacho where Volts equals (calibrated of course) rpm.
And the larger motor is the "generator" to be loaded up by applying increasing loads (multiple 12V x 50W downlighter lamps) such that Amperes equals torque (again obviously calibrated).
View attachment 132241

Well even dead short it did not produce enough torque to do the job - I nearly wrote the whole thing off as a failure but then I thought - what if you force the brake motor in reverse ? - with nothing to lose I tried it - only now forcing the load via the surge lamps - as in the diagram below.
View attachment 132242
Using the original drive components out of the donor cordless drill as a power supply
Eureka it worked - Current was still proportional to torque.
Note optional loading of 50W, 100W & 150W - giving a range of 0-300W in 50W steps.
It's only major shortcoming was specifically the problem with slotcar motors is that they cannot output maximum power for more than a few seconds without cooking them so your test has to be done very quickly - this should not be a problem for motors capable of continuous output.

The point I am making here is that you can get a torque reading via the amperes and calibrate it against a torque arm and spring balance - using nothing more than scavenged parts from a cordless drill.

Hope this is of some use to someone.

Regards, Ken

Edit: The DC Wattmeters are an 8 component dead simple (and accurate) idea off the internet if anyone is interested.

that’s interesting. I’m setting my “power plant model up so I can experiment as you have done
I had slots too as a kid
It was pretty serious stuff for a few years. There a number slot houses here the end of my involvement can rather violently . There was money on the table when big fist fight broke out I tossed all my stuff in my box and ran out the back door just as the cops arrived. I ram as fast as I could. Funny now looking back . Fortunately it was a night game so my own kids were not there. I done even go into that section of town anymore it’s in the center of where the infamous riots were.
Byron

 

[Bentwings]

I’ll try and take pictures as we go . As I noted my vision is not good especially after reading all day . I’m so fortunate to hav the boys that can work from my verbal instructions. I tried sketching but I now found that my drawing pencil that was supposed to have 2B lead is like 2ahard as rock graphite. No wonder I can’t see the lines I do have som sharply ordered. I’ll try and redraw somethings. Maybe I can take pictures of drawings. If I can get the cad computer up I might be able to print or save drawing output One way or the other get something. I woke up early today and got my trusty sketch pad out I had a thought for a boiler fill pump. . I could make a gear pump and there are a couple products on the market . I had not put ports for a pump feed in the unit yet so I made a couple circles and noted them fo water pump feed I’d like to have an automatic level control . I have some ideas but I’ll have to investigate a little more I also saw a shiftable model transmission yesterday. But I only filed it away in my head. I had planned on just changing what gets drone by the steam enginge and what gets driven by the turbines just change belts as needed. There is even a model of the line shaft mill shop that you can make belt changes in the fly. I’m not that old so I don’t remember how they worked. At the farm show we try to go to in the spring they have a complete saw mill driven by a big steam tractor . I know it has a big line shaft so I hope we can go this spring. Mean time I’m thinking …… my mind is a jumble right now. I have an Rc radio that still works so I could rig up a servo to control a shifter transmission. The model rail road guys have such a device for layout control. They may have something. I know a couple of them so I’ll ask. My little dynamo and stepper motor are still in transit so it will be weeks before I see them

it’s breakfast time and I think I heard Amazon a few minutes ago .

 

[L98fiero]

that’s interesting. I’m setting my “power plant model up so I can experiment as you have done
I had slots too as a kid
It was pretty serious stuff for a few years. There a number slot houses here the end of my involvement can rather violently . There was money on the table when big fist fight broke out I tossed all my stuff in my box and ran out the back door just as the cops arrived. I ram as fast as I could. Funny now looking back . Fortunately it was a night game so my own kids were not there. I done even go into that section of town anymore it’s in the center of where the infamous riots were.
Byron

That kind of racing is still big in Europe, a friend of mine builds some of the most winning armatures for the top end slot cars and showed me some of the races on Youtube, the cars are just a blur on the track. I think the cars he builds armatures for are 1/32 scale, the races are an international series, speeds are unbelievably fast.

 

[Bentwings]

That kind of racing is still big in Europe, a friend of mine builds some of the most winning armatures for the top end slot cars and showed me some of the races on Youtube, the cars are just a blur on the track. I think the cars he builds armatures for are 1/32, the races are an international series, speeds are unbelievably fast.

I don’t know if you have seen the drag racing slots. You can’t even see the blurr.going down the track. The cars are so hot at the end you have to use gloves to pick them up . The electric Rc planes are the same. Batteries get hot catch on fire. You have to use as much cooling ducting as a gas motor. The connecting wires would do a good welding machine justice . Two Tesla’s burned up at the local drag strip last summer.
byron

 

[L98fiero]

I don’t know if you have seen the drag racing slots. You can’t even see the blurr.going down the track. The cars are so hot at the end you have to use gloves to pick them up . The electric Rc planes are the same. Batteries get hot catch on fire. You have to use as much cooling ducting as a gas motor. The connecting wires would do a good welding machine justice . Two Tesla’s burned up at the local drag strip last summer.
byron

The friend is just starting to make wheels for the drag racers and to that end has built a track in his shop for testing, I've got to get over and see that.

 

[lohring]

And how many fires were there in the nitro cars that were present at the srrip in much smaller numbers? Do you actually race electric model or full size vehicles? I own a Tesla and have raced RC boats for a long time. I was a partner in the full size electric boat that still holds the UIM kilo record as the fastest electric boat in the world. All these vehicles use lithium ion batteries. I have also raced gasoline fueled RC model boats. The gasoline boats are the only ones that actually had a fire that I needed a fire extinguisher to put out.

Any medium that stores a large amount of energy is dangerious. Gasoline is the king of high energy storage in small vehicles. Its vapor is explosive. As the safety director of my national ganization, I spend a lot more time convincing people not to smoke around gasoline than anything else. When lithium polymer batteries were new, I spent a lot of time educating modelers about how to handle them safely.

Properly charged and stored lithium ion batteries are safe. If you don't believe that, throw away your cell phone, notebook, and lap top immediately. Next, go out and convince all your friends to do the same. You certainly don't want to be around them when these highly dangerious devices explode in flame. I felt very comfortable around the batteries pictured below because we followed the manufacturer's directions in our high power application. We pulled 840 amps peak during the kilo run. The brushed motor, required at the time, was actually a bigger concern.

Lohring Miller

 

[74Sprint]

Bentwings are you going to use the emersion heaters dry or wet?

A few years ago I almost bought a business called "Red Devil Heater" which made heating elements of enclosed tubular and open elements. I learned how to make all kinds a heater elements before I got a chance to look at the books to find out the business wasn't viable. The emersion heaters we made were of custom design or OEM style and usually made with stainless steel tubing, nichrome wire, and manganese powder. We used various mandrels of different lengths and diameters to coil the nichrome to the size and resistance we wanted. We then crimped the nichrome to steel ends we called the cold ends which, the wires attached to. These steel ends were held in place with plastic cups (temporally). They had a 15' deep hole in the floor which we put the tubed element, capped end first into the hole and filled it with the manganese. The nichrome wire stayed in the center. Once it was filled we capped off the remaining end and took the heating element to the swagger and squeezed it down to the size we needed. Needless to say the manganese went rock hard. After this we put it on a custom made rig and annealed the element to make it soft and easier to bend. For emersion heaters and trash incinerators the elements depending on voltage used and wattage needed we could make them into series, series-parallel, parallel, delta, or wye. These type of heater elements went through a bung or a plate and were silver soldered into place. It would take a hell of a lot of pressure for them to leak or fail. The boiler will fail before the elements fail.

The bad:
For trash incinerators we used mostly Inconel tubing because of the heat they made.
For emersion heaters we usually made them to run hotter because they would be immersed in water. Unfortunately if the water ran out the element usually melted.

The good:
you can use say 2 x 220 volt 1,500 watt heaters wired in parallel to reduce the resistance and run them on 120 volts but, doing this means that the total amount of heat is halved. So you get 1,500 watts and not 3,000. Wired this way the amperage will be the same as a single element on 240 but because the voltage is halved the wattage is halved.

Ray

 

[Bentwings]

And how many fires were there in the nitro cars that were present at the srrip in much smaller numbers? Do you actually race electric model or full size vehicles? I own a Tesla and have raced RC boats for a long time. I was a partner in the full size electric boat that still holds the UIM kilo record as the fastest electric boat in the world. All these vehicles use lithium ion batteries. I have also raced gasoline fueled RC model boats. The gasoline boats are the only ones that actually had a fire that I needed a fire extinguisher to put out.

Any medium that stores a large amount of energy is dangerious. Gasoline is the king of high energy storage in small vehicles. Its vapor is explosive. As the safety director of my national ganization, I spend a lot more time convincing people not to smoke around gasoline than anything else. When lithium polymer batteries were new, I spent a lot of time educating modelers about how to handle them safely.

Properly charged and stored lithium ion batteries are safe. If you don't believe that, throw away your cell phone, notebook, and lap top immediately. Next, go out and convince all your friends to do the same. You certainly don't want to be around them when these highly dangerious devices explode in flame. I felt very comfortable around the batteries pictured below because we followed the manufacturer's directions in our high power application. We pulled 840 amps peak during the kilo run. The brushed motor, required at the time, was actually a bigger concern.

Lohring Miller

View attachment 132300 View attachment 132301

I ran my fuel injected 57 chev early on there was only one other one in the mid west area I had just about everything written about the Rochester mech fuel injection. I held the track record for years with it not nationally but it was the model to beat then . We then ran the motor in our first dragster. We won enough the first year to pay for the car and motor. Later we wet to top gas which was supercharged gas dragsters. The twins took over . I had another complet motor and coupler ready to g when Nora cancelled the class. So I went to top fuel funny cars I did ok on the match race circuit there was still money in the bank and each crew person was paid I even got a cut then we went to alcohol funny car . Ram that for about 5?years very successfully . Costs were getting out of hand so it was time to move on. I just go wing boy occasionally . My son takes car of scnostalgia funny car but they didn’t even go out this year started it up once. West coast they are pretty popular but here in the mid west they attract spectators but there are only a few cars track insurance makes it hard to get much for the racers. The old days are long gone.
ByronAlong the way I flew some hot rod model planes I’d still like to do that but eyesight just wot let me my very younger son is getting big on big Warbird he has a big me 109 a faker tri plan and working on a realy nice big p 51 B so I’ve been helping him best I can . All my hobbies have gone away so that why I’m going steam as I can do it at home . I can get out to the shop but it’s easier and safer to have the boys Mae stuff I need. I got a bunch of stuff from Amazon to day a new digitaltachometer, heat gun and digital multi meter. I’m still waiting for the turbines. The quad steamer will be here by the end f yam it was -10 deg F for my after noon walk so I’m trying to warm up now it’s going to be -17 tonight I hope my water doesn’t freeze. It did twice last year by it was much colder. I have a nice electric blanket. Kitty sleeps righ next to me on it.

 

[Bazzer]

I was a partner in the full size electric boat that still holds the UIM kilo record as the fastest electric boat in the world.

Lohring

I done the composite engineering on the Jaguar electric World speed record boat. It had Williams Formula E batteries and Yasa pancake motors for 300hp

Jaguar Vector Racing | Electric Powerboat World Record - YouTube

B.

 

[Bazzer]

Being a long time auto racer the first thing that usually comes up is how much power does the engine make.
So we are talking steamers down a ways. How much torque and rpm do thes little engines make ?

there have been a number of home small engine synod built over the years . So what’s involved. Usually the first is the brake dyno this I’d a measured length bar with some kind of braking agains a flywheel. The bar rests on a scale and measures pressure usually pounds against a scale. There is some means of forcing the flywheel to beare on the arm. Various means of causing the arme to try to slow the flywheel a brake shoe. I’m sure many of you have seen these at farm shows with big tractors huffing and puffing . We go to one every year and it’s surprising just how much those big old steam tractor can put out . There are a number of you tube links for small engine synod often directed at go kart engines. But thee are just to big for our little bench steamers . I saw one years ago at the farm show that was based on an old hyra magic transmission fluid coupling or fluid drive it was pretty primitive but it works well . I’ve given some thought to a model dyno but load cells re still pretty expensive so I’ve started lookin at reflux’s coupling . I think a small coupling could be made that you bleed water into or out of. That’s the principal that many really powerfull engine synod work on . Actually Pratt & Whitney used this type to test the big radial engine during the war years. Today car engine synod are electric but some do use the water idea. It’s measuring the torque that is the tech issues so anybody interested in a desk top dyno?

I quite extensively used Mike Billintons torque reaction dyno, this was a very precise device and was finely tuned over many years.

A torque reaction dyno like Mikes uses crude props to provide the load on the engine, these are not calibrated as there is no need. You just measure the RPM and the torque and hey presto you have the BHP. The torque was transferred by an arm to scale system and was extremely sensitive.

Kavan also made a series of finally calibrated power absorption props (see page 32 of attached PDF), these were used extensively by engine manufacturers such as K&B and Irvine, the Italian manufacturer OPS had a brake dyno but did not use it very much, they also preferred known test props.

 

[lohring]

Even with newer technology the Jaguar electric boat is still 10 mph slower than Mike Bontoft's record set in 2008. The UIM created a new class to make the sponsors feel better, but it still isn't the fastest official electric record. See Union internationale motonautique under records "circuit electric 144 volt hydroplane".

Lohring Miller

 

[Bentwings]

That electric boat is amazing . A friend is into big power boating he had me over to see it one day. It was beautifully done. I told him I couldn’t afford to walk up the ladder to even look at it. It must have taken an army to do all the chrome and polishing. He showed me his gas bill to go from the marina to his home marina across the bay $600 but I suppose if you go 140-150 mph you use a little gas. I’ve only gone 100 once in a boat. That’s once too many for me.LOL

 

[Bentwings]

Hi Byron, I guess you have confirmed the pressure the electric elements can withstand inside the boiler.
Also hoop stress calculations in you boilershell, and boiler end design?
Any chance you can post some drawings so we can see the design? And details of the electric heater units will be interesting! I know a few friends who would like this!
K2

Yes I don’t have my Roarks book handy so I looked up a neat hoop calculator I’m good on the tube , I don’t have the gear tube thickness but using thin shell I should be ok even at 100 psi we are going to make a test set up to test the end cap screws. If I use #8 24 button head hex socket in stainless I think they will be ok . The clamp load that they put on the tube is hard to really calculate. If it was just the screws I think it will be ok. The test fixture will prove that I’ll do one side with loose screws and one side with tight screws. Raw aluminum against raw aluminum has pretty high friction I didn’t look that up but I will see if I can find something the screws won’t pull out as there will be plenty of length. It would be more likely to shear the tube but even that is pretty high. I think there will be more than a diameter of tube for each screw. I’m hoping to get my solid works up on my other computer. It has a pretty easy to use stress analysis feature. I haven’t used it for quite a while but I can simulate loose bolts by allowing just a little clearance between the tube and end cap . It will show a wavy deformation on the display indicating slip I can’t remember but I think there is a way to allow for slip as a coefficient of friction if the parts are just mated, it will consider it solid which will be incorrect. There will be a few fittings but I don’t think any wil pull out . I’ve seen so pretty rough explosions in the race cars. The lines rip apart #bevfore fittings pull out in going to use #3ans#4 AN FITTINGS EITH TEFLON braided HOSE. For pretty much all connections. It’s actually not super expensive in these sizes you can get either black or blue and red fittings stainless is available too. I could use hard stainless line but it invariably gets bent and looks bad. You can get aluminum too but accidentally touching steam heated aluminum would not be good the braided line dissipate exterior heat pretty well in this case. I looked at the filter and lubricator but I’ll have to get something better. I don’t really like these. I missed the reviews and they are not good I’m not even going to send these bak. I may use them on the boiler feed pump to filter incoming water. More to keep the kitty fur out than any thing else. I’ll get after the oils tomorrow. Both are frozen solid now. It’s -18 F out side now. There was a little breeze on my walk so - 28 wind chill. Dangerous cold to be out side. Colder tomorrow. Hope my water doesn’t freeze to night I’ll stay up late and wash blankets or something to keep the hot water going. The pipes are really small diameter they froze twice last year and it wasn’t this cold this long. The next 3 day are well below I a couple COVID masks so I’ll put them to good use .LOL I Wasn’t thinking about gages looking for temp gage but I found a temp vs pressure chart so I see if I can print it out. Once I study it I think I’ll be able to tell temp by pressure. I just got a new infra red temp gun so I’ll be able to confirm easily . I saw an interesting video of the Tesla turbine it not a hard build but tedious. Save it for later in the winter.
Byron

 

[Steamchick]

Hi Byron,
The biggest disadvantage of the Tesla Turbine is the speed for EFFICIENT running. an 8" turbine made by Tesla was doing 30,000rpm... and he stretched the discs.... I saw a video of a 3" turbine, with a huge flash boiler, doing 100,000rpm. The efficiency was demonstrated by the "struggle" to get enough steam to get to over 70,000rpm - but then it accelerated to 100,000 rpm VERY quickly, as the true working of the turbine was achieved. The bearings were super-high-speed ceramic I think? Not sure of disc material, but has to be burst resistant at 1.5 x the max speed of design. Do the sums first!
And then you need a worn/wheel arrangement to get the speed down to generator speeds... (Most commercial electric motors and belts stay below about 16000 rpm (driving pulley), so a 10:1 reduction from the turbine is a good idea!).

 

[Ken I]

There are huge problems in gearing down from ultra high rpm's.
Any kind of belt or chain drive can't handle the pitch circle velocities or centrifugal forces.
Gear drives also cannot handle the pitch circle velocities without special consideration to lubrication.
Lubrication and cooling for high speed gears - NASA Technical Reports Server (NTRS)
Typically it has to be forcibly sprayed into the meshing contact points in exact misted quantities - otherwise it can't get out of the way quickly enough and can literally break teeth off.
Quite often such gears are run with a larger clearance or modified and even vented dedendums to allow the lubricant to do its job without behaving like a solid or non-Newtonian fluid.
IIRC the British Navy had a standing award for anyone who could come up with a better take off gear arrangement for the turbine drives as this was the least reliable point in the entire drivetrain requiring frequent maintenance and replacement.

Regards, Ken

 

[Steamchick]

Hi Ken,
A similar problem existed on CVT transmissions, that led to the development of special transmission fluid, that was like regular Auto Transmission Fluid until it "felt" the extreme pressure developed between the drive belt and pulley faces, when it changed "tribology" into glue = high friction solid. This then became a light fluid viscosity as soon as the extreme pressure was released. And CVT fluid was developed that is NO GOOD in regular A/T, just as ATF is NO GOOD in a CVT.
I don't know what "Torotrak" use in their infinitely variable transmissions, but the rotational speed of their transfer drive discs inside the larger input and output discs suggests a need for CVT fluid or something? They also have replaced sun and planet gears with rolling elements so that at the contact point the extreme pressure is developed to have "zero shear losses"... Perhaps this is the technology required to take a small disc rotating very fast onto a much larger disc ? Instead of by gears?
K2

 

[Bentwings]

Hi Ken,
A similar problem existed on CVT transmissions, that led to the development of special transmission fluid, that was like regular Auto Transmission Fluid until it "felt" the extreme pressure developed between the drive belt and pulley faces, when it changed "tribology" into glue = high friction solid. This then became a light fluid viscosity as soon as the extreme pressure was released. And CVT fluid was developed that is NO GOOD in regular A/T, just as ATF is NO GOOD in a CVT.
I don't know what "Torotrak" use in their infinitely variable transmissions, but the rotational speed of their transfer drive discs inside the larger input and output discs suggests a need for CVT fluid or something? They also have replaced sun and planet gears with rolling elements so that at the contact point the extreme pressure is developed to have "zero shear losses"... Perhaps this is the technology required to take a small disc rotating very fast onto a much larger disc ? Instead of by gears?
K2

I’ve seen the mini Tesla turbine build. Looks easy enough but pretty tedious. I may try it after I get my system up and running . I’m working on the bulkheads that hold the tube bundle. I was going to lightly knurl the of dog it would be a light press fit in the boiler tube but I think I’ll just use spacers to position the assembly. And let the end caps hold then in. I think it will be easier to disassemble for cleaning.
byron

 

[Steamchick]

Hi Byron,
I thought you had decided upon Compressed air as a preferred source to run indoors?
But as you are progressing with a boiler, do you have any sketches/drawings of your design?
Ta,
K2

 

[Bentwings]

Hi Byron,
I thought you had decided upon Compressed air as a preferred source to run indoors?
But as you are progressing with a boiler, do you have any sketches/drawings of your design?
Ta,
K2

Originally I did plan on air compressor. I may still do that. The boiler has had a couple set backs the main being the original tube turned out to be tapered inside. This actually was drive shaft material. It was probably done for vibration issues. So I now have new tube ordered. I was planning on .25” wall thickness. However that wasn’t available locally so I had to settle for 3/16”. ThicknessThat’s ok but I had to redesign the ends and the super heat tube bulkheads. Then I had what I thought was the perfect heater with 1/2” threaded end. So had to re do the end caps again. Then found an even better heater slightly higher wattage. More larger wattage more redesign. Then I thought I could simply use bot or two smaller ones more redesign. Now I’m planning on both with the option of doubling up. All this caused rearranging the super heat tubes again. So I thing I’m fixed now. I redid the hoop stress and end cap stress. I think it’s ok. I have plans on an ultimate test as we just got a new porta power hydraulic unit. I’ve done this type of test in industry so it will be safely done I just got the copper tube fore the supervhet tubes. My cutter disappeared so I have a new one coming today I got the end cap aluminum bar stock last week. I’ve made rough sketches, but because my vision isn’t good. Only I can read them. I just got the cad program up last night so I’ll try and get started on better modeling . Along the way children came out with two new electric boilers but they said neither would be sufficient for the 4 cyl engine. So scrap that plan. Chasing materials and parts is easier than searching Thomas registers of old it still takes time. Shipping over the holidays has been slower than usual too. I wish I could post some sketches but they just aren’t good enough. It’s hard to just draw anything. Frustrating. I have resorted to descriptive notes. I can understand them but it would be hard for others. I’ll take pictures as we get under way. Holding the aluminum bar stock pusses our lathe to capacity. I have a good friend who would come and get the bard and cut it for me if I ask but he is 35 miles each way so I just can’t do that. It will be a full day at the shop when I get out there. The boys will help with the chip making. We have figured out the process. I like to have a plan a,b and c before starting so we can make best use of time. I’m ordering the engine kit today less a couple small items. There are some things coming today as it is. Over all it’s been fun so far. I’m learning stuff I never really gave much thought to. It a whole new hobby for me. Of course we have had snow and some realy cold weather ther. I’ve still got my oil test to do. Maybe today I’ll get to it. I did find steam oil but not in combiner qty. 5 gal would be a lifetime supply .LOL I also have a plan for the connection kinesiology think I can use AN FITTINGS AN THE STANDARD HOSE WE USE ON HOT RODS IS STEAM RATED. Fittings can be either aluminum blue red or black as well as stainless. Some one noted corrosion. So I did a little research and found zinc and magnesium anodes the same as used on my boat. So I’ve located raw material which I’ll order today. It’s not too expensive as size is much smaller. We have done magnesium in the shop so we’ll aware of dangers. At another shop a sander actually caught fire from magnesium and steel being used on it without cleaning. Well it’s been recycled by now. LOL. It wasn’t funny at the time. Mag fires are serious. Anyway I’ve been very busy. It’s been years since I did much cad but I’m glad I was able to get it running. I’m going to try it out today after I get the big order in. I’m pretty excited as children has been just excellent to deal with.
Byron

 

[Toymaker]

There are huge problems in gearing down from ultra high rpm's.
Any kind of belt or chain drive can't handle the pitch circle velocities or centrifugal forces.
<snip>

Regards, Ken

The simplest solution to mating an electric generator to a turbine is to connect a high RPM generator directly to the output shaft of the turbine. More than a few "spindle motors" used on CNC routers are rated at 200,000 rpm; these motors make very good alternators when driven by a turbine. NASA did this years ago with a small residential solar electric generator.