Assembling My Home Made Jet Engine
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- เผยแพร่เมื่อ 14 ต.ค. 2024
- Some video I took while I was assembling the parts of my engine made to the design in the book by Thomas Kamps.
Everything was machined on my 7x14 mini lathe (except the compressor wheel which was bought in as a spare part for a turbocharger).
Added 11th April '22:
The book is "Model Jet Engines (3rd Edition)" by Thomas Kamps. ISBN 978-1900371933
www.sarikhobbi...
There's a build diary on my website: misterg.org.uk...
such fantastic work and attention to detail; cheers my friend
Thank you very much indeed!
You have finshied everthing that I have dreamed. I wated to make by hand every thing related with rc jet engine. You alomost showed that except electronics like control unit. But I love it. Great!!
Thank you very much! At the moment there is no electronics, but I'm trying to make a better RPM sensor which might mean an Arduino, so I may as well have that display EGT as well... And if it knows about those things, it may a well control the fuel, too... (You see how these things snowball :D ). Thanks for the comment, and thanks for watching. :)
Very detailed and well understood simple assembly video. Is cheaper building kit turbine than buying fully built one great work mate
Thank you very much indeed for the kind words. 🙂
really nice job on machining and finish.
Thanks very much! 😊
(I still haven't tried it on kerosene yet, but it's close.)
You are amazing and wonderful
Thank you very much. I feel warm and fuzzy inside now, ☺
مدهش
👋🇰🇼
Nice job , love your work.
Thank you very much, indeed! 😀
Hello
I'm enjoying the video
Is the bearing lubrication in the shaft housing on the compressor side by drilling a hole in the intake cover and connecting the copper pipe?
Don't you need to lubricate the bearings on the turbine side?
Hi, and thanks, glad you are enjoying it. If you pause the video at 3:20 you can see that the small pipe fits into one of three slots in the front of the engine. A small amount of air from the compressor flows through these slots into the bearing tube, through both bearings and out of the back of the engine. A small amount of fuel/oil mix is pumped into the small tube and this forms an oil mist with the air that lubricates both bearings before being burned off as it comes out the back of the engine.
@@Mister_G thank you for your answer.
I have one more question
As far as I understand, 1spool consists of an impeller, a shaft, and a turbine
After securing the bearing to the housing, the outer diameter of the bearing is fixed with the shaft passing through the inner diameter of the bearing, and the shaft rotates as the bearing rotates the inner wheel.
In the video, the inner diameter and axis of the bearing don't fit tightly and there's plenty of room
Does the axis spin without tight tolerance between the axes of the bearing?
@@wjstk1725 The inner diameter of the bearing is supposed to be a very close sliding fit on the shaft (it could probably be tighter than shown at 15:50). The inner race of the rear bearing is clamped to the shaft when the nut holding the turbine is tightened, and the front bearing when the nut holding the impeller is tightened - the shaft can move at 15:50 because the impeller (and the spacer behind it) have yet to be fitted and tightened down. Does that answer your question? If not, please ask again 🙂 There's a cross section of the engine on my website which may help things make more sense.
@@Mister_G Thank you for your explanation😉
Love the way it looks,feels and
Also ,
Can you tell me the reason you did this 😮😮😮😊😊😊
Thank you very much! 🙂
Why? - I don't know, really. I saw Kurt Schreckling's original design in the 1990s, and have had a hankering to build a jet engine for myself ever since. Only recently have I had the necessary equipment & time.
Good job MisterG. I saw your test run video. The engine runs very smooth and looks well balanced. I appreciate if you could share the brand of the hybrid bearings that you are using? I'm also developing a small turbine but I'm facing high level of noise and vibrations.
Hi, Thank you very much for the kind words :)
The bearings are full complement hybrid bearings - I could not find any ready made at a price that I could stomach, so ended up buying some generic, caged, hybrid bearings (from ebay / Alibaba). I took the balls out of these and machined away one side of the inner race so they could be reassembled with a full complement of balls (the extra balls taken from another bearing of the same type). This is not my original idea, but it works well because the bearings are pre-loaded against the un-machined side of the race. There are some photos here:
misterg.org.uk/turbine-html-10/
Others suggested doing the same thing, but buying Si3N4 balls of the identical size to the originals but every type of bearing I took apart seemed to have very slightly different ball diameter.
I am no expert on turbines, bit I would say to check that the shaft is straight after fitting the turbine - I was very, very surprised how easy it was to send the shaft out of true when the turbine nut was tightened - just a slight burr or speck of dirt on the mating faces will cause a runout on the shaft. A sensitive indicator will tell you. Runout on my assembled shaft was ~0.004 mm TIR.
(Feel free to contact me via my website if you want to discuss further).
Good luck! 🙂
Dear MisterG,
Thank you for your attention.
I agree with you that the shaft parts concentricity is critical for turbojet engines. I need to improve the machining process of my shaft and shaft tunnel to achieve better alignment. I found some misalignments in the shaft and due to this the balancing of rotor parts assembled is affected too. After that I will check the quality of the bearings too, if necessary.
Congratulations to your website. There is a lot of good information.
Thanks
@@Fabioaw No problem - let me know i I can help.
This is a reeaaally good looking engine.
Nice work mate 🙂
I have been reading much into micro turbine jets as I want to build one myself, and you are setting standards with your build.
Some remarks though.
You shouldn't oil up the ID and OD of the bearings. The are suppose to stay put and if snug it won't really improve the assembly.
The other thing: I also been reading dissertations and scientific stuff to this topic. And I recall I've read somewhere the wave washers or springs should be locate at the front to the compressor not at the turbine.
Unfortunately I do not recall if it was because of thermal issues or for another reason.
But your build is made in a way that a preload in the front makes no sense.
I would love to see more from you and the engine
Thank you very, very much for your kind comments. I hope to post another video with some thrust measurements soon (another project got in the way - a desktop CNC 🙂).
Re: the bearings - the inner races of both bearings and the outer race of the front bearing (in this design) are held tightly. The outer race of the rear bearing floats inside the shaft tunnel and must be able to slide freely enough to accomodate differences in thermal expansion between the (steel) turbine shaft and the (aluminium) tunnel whilst maintaining bearing preload, but not so freely that it spins in its housing (it's a bit of a kludge, but it's a well used one!).
The direction of the preload depends on the direction of any axial force that builds up on the rotor as the engine speeds up. The important thing is that the preload is in the same direction as the axial force. If it isn't, the bearings can become unloaded (due to the axial force overcoming the preload) resulting in vibration / scuffing and potential damage. The direction and magnitude of axial forces seem to be design dependent, and (from what I can gather) are not easy to predict. I just followed the design in the book 😄.
From what I have read, KJ66 derived designs benefit from the bearings being preloaded forwards (rather than backwards as in this design), but this is by no means universal. If you're thinking about alternative preload arrangements, bear in mind that it's also beneficial to be able to hold a tight tolerance on the clearance between the compressor wheel impeller and its housing, so whether backwards or forwards, it's better (IMHO) to apply preload to the rear bearing - can be difficult to achieve a forward preload in practice, though.
Thanks again for your interest, and for taking the time and trouble to comment.
@@Mister_G do you have a video of how you made the exhaust stators?
@@FirstLast-tx3yj Thanks for watching - I don't have a video for the exhaust stator (NGV) but there is a description and photos on my website -
misterg.org.uk/turbine-html-5/
misterg.org.uk/turbine-html-6/
Happy to help if you have questions (either here, or get in touch via the website)
@@Mister_G thank you for the response
The links did not work but i navigated in the site.
So the only parts one is obliged to buy are the compressor and the turbine wheel the rest can be made!! With enough skill
Did you have a custom pcb made for control or how did you control the rpm and whatnot?
@@FirstLast-tx3yj No worries! Glad you found the info. I only bought the compressor wheel - the turbine was also home made. The main reason I went with the Kamps design is that it is mild enough to use a DIY turbine wheel. It you can get hold of a commercial cast inconel turbine, then the KJ66 would probably be a better design - more powerful for the same size. Some waffle on how I made the turbine wheel on another video: th-cam.com/video/ZvoJ1ksTRlo/w-d-xo.html
The only control is the speed of the fuel pump at the moment (which is just an ebay PWM motor controller). I've had difficulty getting a reliable RPM measurement, but I hope that is now sorted, and another run (video) will be coming soon.
Thanks for the interest 🙂
Ohh Ohh.. This is brilliant! Could you tell us the ISBN of the Thomas Kamps book that you used to build this engine pls?
Thank you very much! 😊
The book is "Model Jet Engines (3rd Edition)" by Thomas Kamps. ISBN 978-1900371933
www.sarikhobbies.com/product/model-jet-engines-3rd-edition-by-thomas-kamps/?page&post_type=product&product=model-jet-engines-3rd-edition-by-thomas-kamps
There's a build diary on my website: misterg.org.uk/turbine-html/
(I've added these details to the description now - thanks)
What will happen if a used pla for making that compressor inlet and the cover of this inlet?
The actual inlet (before the compressor wheel) would probably be OK. The compressor wheel / diffuser cover would probably get too hot for PLA - the theoretical temperature rise across the compressor is ~~100°C, so the compressor exit temperatures could be pushing 120°C - it is on the limit for the epoxy used to glue in the diffuser vanes. From what I understand, PLA will start to soften at 50-60°C
Thank you so much 🌸
@@Mister_G i found a compressor wheel for kj66 which is has the same excducer and height but differs in inducer diameter, instead of 46.1mm it became 39.7mm what do i need to change in the inlet bell dimensions ?
kkk 2038 dimensions
K26 Turbo parts compressor wheel
Inducer "ØA"=46.1mm
Tip Height "B"=5.9mm
Exducer "ØC"=66mm
Hub Length "D"=33.5mm
Bore "ØE"=7mm
No. of blades:6/6
kkk 2036 dimensions
Nose diameter:13.53mm
Inducer:39.71mm
Exducer:65.94mm
Tapered tip exducer:69.92mm
Tip height:4.47mm
Superback:0.00mm
Overall height:30.88mm
Blades height:26.47mm
Trailing angle:55 degree
Bore size:7.02mm
bore type:through
Cutback:0.0
Splitter height:18.50mm
Sp height angle:-7.00
6+6 blades
Forward rotation
Tapered tip angle:30 degree
@@yousefashry2897 You'd need to make the intake diameter smaller to suit the inducer diameter of your wheel, and also you'd need to figure out what the profile of your wheel is, and adjust the radius of the intake profile to suit (not easy to measure this).
@@Mister_G i will use car's fuel pump because i can't find any suitable pump here but this, how can i adjust it to suit this engine ?
❤🎉 thnx bro
Thank you
Осталось отбалансировать и проверить.👍🏻🤓😎
Thank you - the rotor was balanced before assembly 🙂
@@Mister_G я и не сомневался, что все вращающиеся детали, были отбалансированы перед сборкой, но после сборки, они должны быть отбалансированы совместно.
Поэтому купленные двигатели, нельзя разбирать, если не хочешь потерять балансировку.
@@aleksandrkargin1978 True - I am relying on the compressor wheel being well balanced from the factory. This engine only runs up to 100k RPM so not quite as critical as commercial engines. Thank for the kind comments 🙂
This engine was build using mini lathe ? In terms of turning operations ?
Hi - yes, it was. (The compressor wheel was bought in though).
@@Mister_G For KJ-66 did you recommend mini lathe or bigger lathe for project or mini lathe is fine ?
@@MrCzarnm KJ66 is roughly the same size as this engine so it should be possible on a mini lathe, but a bigger lathe is always better! The diffuser on the KJ66 is usually milled from solid (as far as I know) which would require access to a milling machine of some sort. (The diffuser on the Kamps is made with sheet metal blades, so only turning is required). Also, I think the KJ66 uses a cast inconel turbine - I'm not sure if they are still available and at what cost.
Im quite confused how you created a good oil seal, it seemed like that feed tube just kinda is pancaked in the mating for the center shaft housing, does it leak oil?
Hi. Yes, you are correct in your observations - The lubrication system is a "total loss" oil mist - A small amount of pressurised air from inside the engine blows through the slots between the diffuser and the shaft tunnel and into to the inside of the shaft tunnel (which is open at the rear end). The pipe is just clamped in one of the slots (not tightly enough to close the pipe off though) and any oil that comes out of it is carried away by the stream of air. This produces a stream of air and oil droplets flowing down the inside of the shaft tunnel and through the bearings which cools and lubricates them. When this stream comes out of the rear bearing, the oil just gets burnt up with the exhaust from the engine (a bit like how a 2 stroke petrol engine is lubricated). Thanks for asking!
Wow, I never saw a combustion chamber built with thick steel plates, usually builder builds with thin steel plates, which i'm familiar with.
Is a thick or thin steel sheet compatible for sustainable performance ?
Hi - the combustion chamber is made from 0.5mm thick 304 stainless steel. I suspect that commercial engines might use 0.3mm, but 0.5mm was quite thin enough for me to work with!🙂. Thanks for watching and commenting.
Any way I can get a parts and measurements list
Hi, the design is all described in Thomas Kamps' book (details in description). Cute monkey, btw! :)
How did you balance the turbine wheel dynamically because usually the hand work has a lot of errors
I only did a static balance - the compressor wheel should be balanced as supplied and is a shrink-fit on the shaft. I worked hard to keep the shaft true when everything was assembled (keeping the spacers parallel and the dirt out), so the only part that should be out of balance is the turbine wheel itself. After assembling it to the shaft, I did the initial balancing by 'rocking' the shaft in its bearings to find the heavy point and grinding metal off the wheel. Final balancing was done by touch - you can feel the out of balance forces if you hold the back bearing between finger and thumb and spin the turbine gently with compressed air. if you stick a small piece of tape (e.g. 3 x 3 mm) to the wheel it will make the vibrations feel better or worse. Find the place where the vibrations are the least, then remove a small amount of metal from the opposite side of the wheel and try again. You eventually get to a place where you can't feel any vibraton at all - it is really noticeable! Then you can call it done :)
Some more description on my website :misterg.org.uk/turbine-html-20/
Thank you 🌸
could you remake this video some time with the changes you made please you are a verry talented engineer i dont mind how you do it i subscribed btw :D
Thanks very much - The engine is pretty much as per the book, so no real changes.
If i want to make it from scratch, do you have 3d printing files of these ????
Pls can u share me everything. Btw i looked the description yet i want a direct way to achieve what you have
Pls share if u have any🙏🏻
Sorry, I don't have 3D printer files. The design belongs to Thomas Kamps, and the drawings are in the book.
@@Mister_G oh, thanks alot for the guidence
@@Mister_GThe book that you mentioned in the description does not ship to India and the only option i have is to search on Amazon cuz Amazon had this book but it costs ₹42.8k INR that is £406 ($517 USD)💀💀💀, No way i can afford it
Do u have the pdf of the book😶🌫️ any chance?
@@dakumangalsingh1384 I don't but I believe you may be able to find one on the internet...
How many pieces of this started as cookware?
Ha ha! None of it in this case, but I did prowl the stainless steel aisle with a tape measure,,, Just couldn't find anything suitable :)
Either way very pretty, looking forward to preformance figures and personal evaluation.
SHOWWWW!!!!
How about the bearing lubrication system
Hi - it is a total loss system using a small amount of fuel/oil mix that is bled into the front of the shaft tunnel from the main fuel supply.
@@Mister_G Oh, nice. Actually does it have a negative effect on the fuel economy and what if I use a full hybrid bearing, thanks
@@demoaccount2392 The feed to the bearings is only about 1% of the main fuel flow. (have a look here for more details: misterg.org.uk/runing-on-kerosene/ ). Fuel economy is not high on the list of priorities for this engine :)
I am using hybrid bearings.
@@Mister_G Thanks
How much does it costs, to make all of these?
Hi, I do this as a hobby, so my costs are just the raw materials.
@@Mister_G What about the machining cost of the blade? Is that a single piece?
@@shewagdhanush1391 The compressor wheel (at the inlet) is a turbo-charger part from a car (cost 30GBP from ebay). The turbine wheel was made from an offcut of Hastelloy X sheet - see misterg.org.uk/turbine-html-7/
@@Mister_G What was the max RPM and efficiency? Thank you.
@@shewagdhanush1391 I don't have a reliable way of measuring RPM yet (I am working on it! :D ). Design maximum is ~100,000RPM. I will measure thrust, etc. once I have a reliable RPM reading.
Sir, may I get the cad drawings please?
Hi, the drawings are all in Kamps' book :) See misterg.org.uk/turbine-html/ for the link.
I like to buy how much for that engine uncle
Not for sale yet, sorry!
Hi
Hi - Thanks for the comment 🙂
Absolutely bad perspective of the assembly to be able to see the details, small and out of frame image.
I did try and warn you in the introduction! 😅 Thanks for watching and commenting, anyway,
I think its made by a company, not a home made. Sorry
Thank you! that is a very high complement 😂
You can check out the build here: misterg.org.uk/turbine-html-2/
Please watching my new rotary engine....
Advise me...!!!???!!! 🙁🙁🙁
I have watched the last 2 videos, but I can't understand what you're trying to make, sorry!
You can send an email to me
Did you scale up the size of the kj66 Turbine?
Hi - No, this is a slightly different design, although very similar to the KJ66. The turbine is the same, 66mm diameter.
What is the name of this design please?
@@yousefashry2897 It's usually called the 'Kamps' engine because it comes from the book by Thomas Kamps. (Link in description, I think.)