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Post by Johansson on Feb 11, 2024 12:22:47 GMT -5
I think we are talking about the same thing, when I said a belt clutch I meant a CVT transmission just like in a snowmobile. Those are cheap and easy to adjust for the characteristics that the engine need.
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Post by Johansson on Feb 11, 2024 9:29:43 GMT -5
Use the whole snowmobile clutch/cvt assembly? Gives you gearing and control then That is the idea.
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Post by Johansson on Feb 11, 2024 7:31:47 GMT -5
I Ve worked with "JB Weld Steel" epoxy Around 3000 psi strength Quite strong as long as surfaces are clean and rough. Don't go for 5 minutes epoxy Its faster but never gets as strong as regular epoxy. Bare minimum of 24 hours curing time double that before you try to tear it apart. Now about your snowmobile / car gearbox idea. How will you be able to shift the gear box unless the centrifuge clutch is disengaged. I mean won't you have to bring the engine to idle to do that That means a long spool down / waiting time before you can change gear .. But again I might be wrong I´ll let it sit a couple of days before I try to break the pieces apart. No gear shifts while running, the gear choice will mostly affect the top speed. I will probably find a gear that is best depending on the track conditions and stick to that, the ability to reverse is a big bonus.
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Post by Johansson on Feb 11, 2024 7:12:37 GMT -5
Another decision I have made is that the turboshaft engine that will power the formula car will be a single shaft engine.
I will use a snowmobile belt clutch fitted on the rotor shaft in front of the compressor wheel, and couple it to a manual car gearbox somehow to get a reverse and ability to choose gearing.
So the turbine wheel will be set up to absorb as much energy as possible, not like a jet when it just needs to power the compressor and make thrust out of the rest. A bit more twist to the blades is needed in other words.
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Post by Johansson on Feb 11, 2024 4:30:23 GMT -5
It seems like the gorilla used for this particular glue batch was unhealthy somehow, perhaps some tropical disease? The glue strings (I didn´t put glue in between the parts, only along the edges) didn´t stick very well, that much is a fact.
I will try their epoxy glue next, hopefully they used a new and healthier gorilla for that batch.
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Post by Johansson on Feb 10, 2024 5:58:08 GMT -5
The printer has 22 hours of work to do now, I will try a solid PLA+ blade press jig reinforced with steel plated sides and M5 screws. I will make the plunger later if this turns out ok. I am also reviving the glue experiments, I bought a new kind of glue that might do the trick. I mean, since gorillas are strong like crazy a glue made out of gorillas has to be strong as well. Simple logic, it is a shame there are so few of us who actually use it nowadays. /Anders
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Post by Johansson on Feb 10, 2024 4:09:05 GMT -5
Dam...... that looks epic.... It is pretty massive yes. I am sitting and trying to draw up a blade press jig in Fusion 360, hopefully the PLA+ is hard enough when held together by screws.
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Post by Johansson on Feb 9, 2024 15:06:43 GMT -5
The last piece of the puzzle, had this been the final stone layed in a church I might have praised the Lord. Had it been the final stone layed in a synagogue I might have sacrificed a child. Being what it is I will just make a cup of tea and watch the last part of the Tucker/Putin interview. An overview. Have a nice weekend! /Anders
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Post by Johansson on Feb 8, 2024 16:49:27 GMT -5
And a big, fuel thirsty, sheet metal behemoth as well. A small efficient gas turbine whistling along under the hood wouldn´t suit it at all. With only 50% of the revs perhaps the fuel consumption won´t be quite as terrible as John calculated, 12.5 L/min at full throttle was what he predicted. It might settle for 5-6 L/min which is pretty ok, a 60 liter fuel tank will get me to the nearest village and back.
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Post by Johansson on Feb 8, 2024 16:02:25 GMT -5
I have been thinking about the future of the engine and I have decided that once (if?) it is running properly I will build a 1940 style Indy car with spoked wheels and leaf spring suspension around it. If I can get 150hp out of the engine it will be plenty enough, John calculated the engine to produce >400lbs of thrust at 10.000rpm which translates roughly to 400hp from a freepower coupled to it. So I really only need half of that power, which might not be very far away even with the RPM restrictions that these rotor parts put on the engine. Heck, 100hp and leaf springs is probably exciting enough on a gravel road. After all this is a steam punk project, if I wanted max power I would just build two JU-02 engines and feed the massive freepower turbine that John sent me a couple of years ago. 500++ hp easily. /Anders
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Post by Johansson on Feb 8, 2024 15:22:58 GMT -5
I got half way through making the diffuser cover when I called it a night, when it is finished and welded I will clean up the edge and make a thinner mild steel compressor cover. /Anders
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Post by Johansson on Feb 8, 2024 12:56:21 GMT -5
Thanks a lot for the link to the program! Unfortunately I don´t own a PC but I will save the zip file and try it out when I can get my hands on one.
This is really interesting, I had no idea that there were such forces involved in the rotary parts we use.
I am waiting for the registration to an IPSC handgun match to open in 3 minutes, then I am heading out to the workshop to cut aluminum for the diffusor housing!
Cheers! /Anders
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Post by Johansson on Feb 7, 2024 0:29:59 GMT -5
Is there a program that doesen´t cost an arm and a leg for making these calculations? It would be interesting to try different materials and shapes and see if it is possible to make a rotor that can survive decent revs from stacked sheet metal. I might abandon the sheet metal rotor idea at some point but I am not fully convinced just yet.
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Post by Johansson on Feb 7, 2024 0:17:15 GMT -5
There is very little information to be found about his early engines, but you are right in that the numbers are for the HeS2. My book mentions it being made from rivets and sheet metal but that is probably only the outer casing and not the rotor. Guess I´ll be the first to make one then. I will figure something out, making tapered steel discs is an option.
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Post by Johansson on Feb 6, 2024 16:46:27 GMT -5
Perhaps, but I like the idea of being able to slide the turbine wheel onto the shaft and clamp it down. Hopefully I will be able to make a sturdy enough turbine wheel without having it boreless.
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