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Post by Johansson on Oct 31, 2023 12:24:33 GMT -5
Hi guys! Long time since I visited here, I sort of lost my steam when the JU-02 engine was installed in the turbine bike. Working all day with steel construction and welding didn´t exactly increase the urge to spend my evenings in the workshop... I´ve spent my years since then raising a pair of girls and a bunch of chickens, growing a mustache and competing my way into the Open division IPSC handgun Swedish national team. Anyways, with a new job that is more paperwork than construction I am starting to feel like I want to build something again. I have a very interesting book about Germanys jet engine development during the war years, and one thing that struck a note in me was the first experimental engine that Hans von Ohain built out of sheet metal.  My plan is to build a LARGE engine with both compressor and turbine home made, a 500mm diameter Schreckling style centrifugal compressor wheel, an matching axial turbine wheel, high pressure spray nozzles, ball bearings and a minor swimming pool with kerosene for running the bastard. I am in the middle of the "driving the kids to practice 5 days a week" years so don´t expect the same blinding build pace I had during my bike building years, having passed the 40 year mark I have started to appreciate a full nights sleep.  This will be FUN. Best regards /Anders |
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Post by andym on Oct 31, 2023 12:41:02 GMT -5
Hi mate.... welcome back..... going to make my little 130 mm look , well..... silly :-) let the fun begin
What happend to the ice yacht
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Post by turboron on Oct 31, 2023 13:03:27 GMT -5
Anders, good to hear from you. Good luck with the new build.
Thanks, Ron
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Post by Johansson on Oct 31, 2023 13:58:13 GMT -5
Hi mate.... welcome back..... going to make my little 130 mm look , well..... silly :-) left the fun begin What happend to the ice yacht Thanks! I will do some calcs from the Schreckling FD3/64 book and try to figure out a rough design, much of the engine will be made from laser cut sheet metal including the compressor wheel so the revs will be kept deliberately low. Probably not higher than 10.000rpm. The curse of joined efforts struck it I guess, both Olov and I have our days filled with work and kids so it is practically impossible to find time to work on it together. Anders, good to hear from you. Good luck with the new build. Thanks, Ron Thanks Ron! I will enjoy having a long term project to tinker with again, I have missed it. |
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Post by andym on Oct 31, 2023 17:11:48 GMT -5
Looking forward to seeing things start..... have or do you use fusion 360.... has good sheet metal section Do you have any plans to take the bike out with the new engine.... I cut mine up, sold parts and put money into the new project Man your build will be epic |
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Post by Johansson on Nov 1, 2023 1:01:28 GMT -5
Looking forward to seeing things start..... have or do you use fusion 360.... has good sheet metal section Do you have any plans to take the bike out with the new engine.... I cut mine up, sold parts and put money into the new project Man your build will be epic Hi Andy! I am using an older Fusion version at home but I have used 360 at work, really neat sheet metal functions as you say. No plans to go race the bike, there are no races that I am aware of in Sweden and if I have to choose I rather spend the few weekends away from home shooting IPSC. Building stuff is more fun than using them. |
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ripp
Veteran Member
I'm sorry, I don't speak english, so I torment you (and myself) with a translation program,Sorry
Joined: January 2013
Posts: 230
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Post by ripp on Nov 1, 2023 1:28:41 GMT -5
Hi Anders,
I'm glad you're active again!
Ralph
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Post by Johansson on Nov 1, 2023 3:12:24 GMT -5
Hi Anders, I'm glad you're active again! Ralph Hi Ralph, Me too, feels great to have the urge to build something again. |
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Post by andym on Nov 1, 2023 6:21:37 GMT -5
Hi, yes i know what you saying, some times you build a thing, over come all the issues in the build..... once its done, you are looking for the next thing..... I do think apart from putting two of these engines in the kart chassis..... going to do some improvements on the van, and travel around... perhaps make it to your part of the world.... in the summer clearly
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Post by turboron on Nov 1, 2023 9:25:39 GMT -5
Anders, rpm will be limited by the tip speed of the covered compressor impeller. The tip speed should be held to 900 feet per second (fps) or below initially. A tip speed of 1100 fps may be achievable if the design has a good stress pattern. A aqick formula for tip speed is pi x D x N / 720 = fps where D is in inches, N is in rpm.
Thanks, Ron
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Post by Johansson on Nov 7, 2023 16:25:45 GMT -5
I´ve talked with a friend who is a laser CNC operator, and he will help me to cut the parts out for the engine. It feels great not having to use the angle grinder since precisely cut parts will make balancing the finished compressor much easier. The first step is to get the compressor drawings made and get the parts cut out, John has helped me with some number punching and combined with some scaling up from the FD3/64 design I think I have come up with something that will work. The main ball park figures for the JU-03 is 10kg/s massflow, 10.000rpm and 450lbs of thrust. I will try to make as much as possible out of sheet metal to keep the weight and complexity down, the JU-01 diffusor plate almost gave me a tennis elbow from turning the darn rotary table on the mill so I will try an easier way of making things this time. Action pics will come once I start cutting some metal, stay tuned guys! /Anders |
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Post by andym on Nov 9, 2023 17:24:29 GMT -5
I´ve talked with a friend who is a laser CNC operator, and he will help me to cut the parts out for the engine. It feels great not having to use the angle grinder since precisely cut parts will make balancing the finished compressor much easier. The first step is to get the compressor drawings made and get the parts cut out, John has helped me with some number punching and combined with some scaling up from the FD3/64 design I think I have come up with something that will work. The main ball park figures for the JU-03 is 10kg/s massflow, 10.000rpm and 450lbs of thrust. I will try to make as much as possible out of sheet metal to keep the weight and complexity down, the JU-01 diffusor plate almost gave me a tennis elbow from turning the darn rotary table on the mill so I will try an easier way of making things this time. Action pics will come once I start cutting some metal, stay tuned guys! /Anders Hi Anders Yes laser cutting is a game changer.......being able to use it for some time has helped no end Looking forward to seeing your project come together 450lds nice.... think you will be able to mount it on something ..... or afterburner..... what type of bearings will you be running, 10,000 normal bearings will handle that Take care, all the best andy..... do wish you could make it over here with the bike..... but them again we have had some big changes, rules insaurance |
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Post by Johansson on Nov 11, 2023 4:42:18 GMT -5
Hi Anders Yes laser cutting is a game changer.......being able to use it for some time has helped no end Looking forward to seeing your project come together 450lds nice.... think you will be able to mount it on something ..... or afterburner..... what type of bearings will you be running, 10,000 normal bearings will handle that Take care, all the best andy..... do wish you could make it over here with the bike..... but them again we have had some big changes, rules insaurance Hi Andy, I have access to a cnc plasma cutter at my old job but for a build like this I want everything laser cut, the crappy surfaces from plasma makes welding difficult without grinding and that would upset the balance in the parts. Plus it looks like shit. When the engine is finished it will be a very simple affair to fit it to a vehicle since it has ball bearings and won´t need the whole arrangement with oil tank, cooler, pumps, battery etc. A secondary goal with the project is to make it run 100% mechanically, so no electricity once it is up and running. With only 10.000rpm max I can gear the main shaft down a bit and run a fuel pump off it, perhaps even a small alternator to recharge the start battery. |
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Post by Johansson on Nov 11, 2023 9:57:01 GMT -5
To get some feeling of the sizing of the parts I will 3D-print the engine in 30% scale, first off is the compressor hub.  I've modelled it 12mm thick with a beefy centrum hub that will hold the cone clamping element I plan to connect the compressor to the shaft with.  These are really neat, there are premium models that keeps the center alignment perfect when tightened.  Here is a preliminary drawing of the compressor wheel arrangement, so you can get an idea if what it will look like.  The compressor front wall will be cone shaped so the duct area will be kept the same all along the blade length. Anyone who knows how to make a flat pattern out of a 3D model so I can cut it out and roll it into a cone? As fas as I can tell Fusion 360 can't do sheet metal cone patterns, only straight walled ones.  Cheers! /Anders |
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Post by pitciblackscotland on Nov 11, 2023 14:42:36 GMT -5
Hi Anders, i have use www.conelayout.com you print out all the segments on A4 paper and cut a long the lines stick them onto the sheet metal and cut to that shape and roll. Cheers, Mark. |
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