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Old Jul 20, 2005, 07:02 PM
Up and Dowwwwnn
Tampa, FL
Joined Jul 2004
411 Posts
I am kinda sad to hear that...but its ok, it was just a oddball though.....Oh Timfly check this out....

http://www.plans-kits.com/plans/jets.html

Its the U-22D plans...

Mcjustis, dont remember where I saw it but I know there is a person out there that designed a lil turbine, homemade ofcourse. I used to have a picture that showed his lil engine on a lil version of those Bob-Cats. I will try to find the pic and pos it here.

Virat
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Old Jul 20, 2005, 10:58 PM
Registered User
Columbus, Indiana
Joined Nov 2004
324 Posts
Virat,
Interesting link. Probably some good learning plans on there. The ramjets they talk about making I would have some serious questions as a ram jet need to be (I think...) at or near supersonic speeds to work. Not too practical for a model airplane. The pulse jets can be made pretty easily, but they have some drawbacks. First they run on gasoline, very flammable. Second they are not throttleable, all or nothing. Lastly, they are EXTREMELY LOUD. Your ears will bleed if you are near them without hearing protection.
As for the FD3/64, you could probably make that one in your garage on simple machines. In the book 'Gas turbine engines for model aircraft" Kurt Shreckling does a great job of explaining the principles of how the turbine works and how they are made, and his design the FD3/64 was a good practice turbine. I only say practice because it really isn't good for actually flying. I know he had pics in the book of the motor in a F-100, but realistically when it just starts to work efficiently you've maxed out the rpms. It was originally made with a wooden compressor and a stainless steel turbine wheel. Only good up to about 60,000 rpm. If its a new design with an aluminum compressor and inconel turbine wheel you would probably have a nice engine when done. Also in his book, he has a funky combustion chamber setup. Apparently it didn't work too well. But if you have a chance to get this book it is a good starter course on turbine work. Anyway, after all that, it looks like it might be an interesting set of plans.
Later...
Martin
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Old Jul 21, 2005, 09:42 AM
Registered User
Newhampshire USA
Joined Jun 2003
69 Posts
Yes mcjustis.
Justin at JET JOE USA is getting in some spun cases $25.oo with shipping. These should fit perfictly I dont think I can beat that price anywhere not even at walmart. The id. is 88mm.
Tim
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Old Jul 22, 2005, 09:41 AM
Registered User
Newhampshire USA
Joined Jun 2003
69 Posts
jet engines

I had a dyna jet pulse motor when I was 16. That thing was loud, fast on 90' steel braided control lines.
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Old Jul 22, 2005, 12:43 PM
Registered User
Joined Jan 2005
12 Posts
QUOTE "I finished the turbine I checked the thrust and was getting right at 11 pounds.

What RPM or C/P were you getting at 11 pound of thrust.
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Old Jul 22, 2005, 11:04 PM
Registered User
Columbus, Indiana
Joined Nov 2004
324 Posts
Unknown,
I don't know what rpm exactly I was getting, but best guess from the junky tach I was using at the time I was right around 105,000. The canister pressure was at 10 lbs. I know that's not the highest rpm's I could get, but like I said before the turbine wheels aren't hard to make, but I don't want to make another. I had a caged bearing in the rear end when I first made it and it lost the cage at about 90,000, stops real quick and just sits there burning throwing flames out the back end. Do you have a turbine you've made? Love to see some pics if so.
Later...
Martin
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Old Jul 22, 2005, 11:09 PM
Registered User
Columbus, Indiana
Joined Nov 2004
324 Posts
Tim,

$25.00 sounds like a heck of a price. Is that the only piece you need to finish your mk54? Should be a nice engine when finished.
Later...
Martin
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Old Jul 22, 2005, 11:39 PM
Registered User
Edmonton
Joined Dec 2004
36 Posts
Tim, check out Wren for the Mk 3 case.. Also, checkout your local hardware store for propane and camping fuel canisters- you might find one the diameter you need. But...it might be hit and miss. The welded case is a very tight fit over the diffuser, and it is also used to hold the combustion chamber in place with the two glow plugs (Mk 2).

Best case out there is the TJT (way too big for a mw54). It is CNC machined with grooves for the mounting staps, and is very attractive...compared to what all the other manufacturers are using...

***

Martin.... I can see the result of a lot of work there. Getting it to run at all is a major accomplishment. More power will come with refinment and patience. That big one is a monster.....what are you expecting from it in the thrust department????
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Old Jul 23, 2005, 01:53 PM
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Columbus, Indiana
Joined Nov 2004
324 Posts
Nony,
I really don't have any idea what kind of thrust to expect, but I would be real happy with hundred pounds or so. I know on the little one I could get more out of it with cast wheel, but that takes a lot of the fun out of it for me...not too mention I don't have the cash to buy a cast wheel. I don't even know where to get a 60mm wheel.
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Old Jul 23, 2005, 03:01 PM
Jet and arena blimp guy
Kelly W's Avatar
Vancouver, Canada
Joined Sep 2004
64 Posts
Heward Microjets manufactures a 60mm turbine wheel / NGV now and use it in their 'wasp' kit engine, here's a Link. It was announced a couple months back and has some pretty impressive stats for thrust vs. KJ-66 derived engines.

Good luck!
Kelly W
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Old Jul 31, 2005, 08:32 PM
Registered User
Columbus, Indiana
Joined Nov 2004
324 Posts
Kelly,
I checked out the site and it looked pretty good. I didn't see anywhere that said it was a 60 mm turbine though. Maybe I just missed something...anyway, that looks like a nice setup.
Later...
Martin
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Old Aug 01, 2005, 12:19 AM
Jet and arena blimp guy
Kelly W's Avatar
Vancouver, Canada
Joined Sep 2004
64 Posts
Martin,

I just remembered where I read it now. The 60mm spec is quoted on the GTBA web site at the following link.

with regards to customs fabricated wheels, I'd recommend against it. A good friend scratch built a wheel from solid inconel and did achieve a good running engine, but it was likely nothing close to an optimized wheel from any of the major casting providers. He made his wheel with a complex rotary table setup on a manual milling machine, and destroyed many cutters in the process. After calculating the cost of the inconel and SS for the NGV, and the hardware required, a custom made set only turned out to be marginally cheaper in the long run. It certainly wasn't worth it when you consider the increased performance and safety factor due to the fillets around the blade roots. He's currently flying his 4th generation turbine, all of which were based on the KJ-66 with some modifications to the combustion chamber and beating preload/alignment system. The 1st was thew only one to use a manufactured wheel and, replaced by a cast GTBA wheel / NGV relatively quickly.

Kelly
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Old Aug 01, 2005, 06:54 PM
Registered User
Columbus, Indiana
Joined Nov 2004
324 Posts
Love the GTBA site.
I know the cast wheel is going to put out more RPM's than the one I made, but right now I just don't have the cash. I have never had a problem with a wheel I made. I spent about an hour turning the blank, about ten minutes slotting it and about two hours bending and forming the fins. There is no need for a complex rotary table setup. Mine has the fillets around the edges just like a cast wheel. As for the NGV, mine is made of stainless and I have not had a problem with it. I know if I were flying this engine daily I would probbly be making another in a year or two. The NGV really wasn't that bad to make. I'm sure an inconel NGV would last longer, but that wasn't the intention of making this engine. Anyone with some money can buy most every part of a turbine nowadays and just assemble a kit, so what... I have been very happy with the wheel I made. I know I have a good running engine. If you use the correct cutters and correct feeds and speeds you will not wear out the cutters terribly bad. They don't last as long as they would if you were cutting aluminum. As for the cost, I can't argue that one... a few of my buddies went in on the material together and even split several ways the inconel blank was about $18.00. Metal suppliers and their pesky minimums...Actually the aluminum for the front is really expensive too. Especially with the bigger turbine.
This engine was built as a challenge and was actually a lot of fun for me to make, I have already gotten the enjoyment out of it that I was looking for and if it does see flight (hopefully get some $$ soon) all the better. I doubt I'll change anything on it as far as putting prefab parts on it. Then I can't say I made it myself...
Later...
Martin
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Old Aug 18, 2005, 08:32 AM
Registered User
Columbus, Indiana
Joined Nov 2004
324 Posts
This is kind of a bummer, I thought more people would be posting their pics. Oh well,
Later...
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Old Sep 27, 2005, 01:09 PM
Registered User
Columbus, Indiana
Joined Nov 2004
324 Posts
Surely someone out there has some pics....c'mon guys...
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