very nice work. Try and get some 608 highbred full complement ceramic bearings as they will last a long time compared to steel caged bearings which only last a few runs before the cages start to expand like they did in my KJ66
I have some full complement ceramic bearings in my as per book Kamps engine but don't know if it's worth it with this KJ66/Kamps engine unless I can get the power up with my home made soft turbine wheel .
I am watching your TH-cam with interest. In the diffuser introduction scene, there are two tubes, one seems to be a tube that supplies lubricant to the bearings, and what does the other tube do?
Hi Young not sure which tubes but here goes . At 2.30 there are aux gas line pipes at 12-6 c clock position feed into the two vaporizer tubes these feed pipes are shown as a Y pipe at 2.54. At 3.10 you can see the oil pipe in front of the front bearing this oil/fuel lubricates/cools the front bearing and caries on down the alloy bearing tube to cool/lubricate the rear bearing.at 3.20 the snaking pipe is the oil pipe going out to the front face. At 3.21 about 11 o clock position is a U shaped pipe for pressure take off to monitor case pressure. hope I got the right pipe, case pressure I think ,it would have been ok on the outer case I have it into the airflow exiting the diffuser as it was used for pressurizing a oil bottle but now is teed off from the fuel line so it's at fuel pressure now which is always well above case pressure..
Is it possible to show how you made the lubrication of the bearings please? . I don't understand how that part works. A bit confused. And also how did you get the patterns of the holes in the combustion chamber?
th-cam.com/video/bRSvcSpn_Bg/w-d-xo.html Hole pattern above Umar and I have found that the hole pattern works better if you add 2mm to outer combustor at front moving all holes in pattern to back of engine. you will need to remove 2mm from back of combustor . also take 1mm off front of the inner tube moving all hole pattern forward 1mm.
Lubrication and preload was one of the early problems causing bearing failure which becomes more noticeable when flying as you have to operated at higher revs for longer. Ceramic and steel bearings both need lubrication and also it aids cooling, steel bearing should only be lightly loaded kamps states how much in his book. Angular contact ceramic bearing need more preload as only one shoulder to push against. Steel are better lubricated with a small bottle of thinned oil pressurized from the compressor when engine running. use 5% Oil in paraffin for ceramic teed off from fuel line which should be restricted to 5% of the flow going to main injectors. The fuel/oil mix is at the front of the front bearing which it then pass's down the bearing tube to lube the rear and then helps cool the turbine wheel and gets burnt in exhaust. To help pressurized the area behind the compressor wheel the gap between the edge of the compressor and the diffusor can be increase a little then the air trips over the edge and help take the air/oil down the bearing tube ,people have also drill holes in the diffusor to pressurize the area but you can run into problems with rear preload and the front ceramic bearing becoming unloaded that's why most are front preload now. Sorry about long reply hopefully I've covered all the problems but i don't have all the answers.
Hello... i appreciate your comments and suggestions even in other channels... pls tell me why the diffusor wedges and blades are pinned/glued? can't they be made as a single part in CNC(5 axis)? If not is that made without CNC? Is it possible to make an entire jet engine without CNC? Also i'm thinking of making an annular combustion chamber (since i use radial turbine), so can you suggest some materials which have calculations and drawings, i couldn't find anything proper. I only have the rotor assembly-(comp, shaft friction welded with radial turbine)- so can i make an NGV suitable for this? or should i direct combustion chamber exit radially to the turbine- like Heinkel HeS3 engine- but this gives poor thrust even in real plane so i'm not sure if i'll get satisfactory amount of thrust....so is it possible to create an NGV for this? The KAMPS book by thomas kamps suggests a PAL model engine in pg 22 but i can't get that drawings or calculations too....and the book doesn't have calculations for radial turbine too... Kindly help me out as i took this as my project this semester and due to COVID restrictions i also have limited sources for fabrication too... i would highly appreciate if i could get your point of contact for further doubts (as i cannot ask all doubts in this comment section)... i'm giving my mail id tharhitrovesh2018@gmail.com kindly contact me there... pls be assured that this is legit and no spam messages will be sent.Thanks for your help in advance. P.s:- I take your suggestions at my own risk
A lot to answer there so here goes, a quick answer which is in Kurt's book ,he only had minimum machinery 30 years ago so all early engines only used a lathe so fabricating the parts was necessary and the only way to make the NGV apart from casting. The cnc machinery was not available for home use 30 years ago which is the reason the diffuser has the vanes glued on in the Kamp's engine only a lathe needed. It is worth reading Kurt's and Kamp's books they explain why they choose a axial turbine wheel vs radial turbine wheel quick answer is rotor is very heavy and gives problems mounting the bearings and the accuracy has to be higher as the for and aft position has to be fixed to maintain the clearance on both wheels. The GTBA members did design/ build gas turbines using radial turbine wheels but tended to be bigger heavier engines very few are made commercially now all the engines 66mm wheel diameter and under use axial wheels .
@@reedy93 tq for replying, I'm reading the books... but i've already got a compressor wheel of 78mm dia(exducer)- It was a sponsored by a service station- so i couldn't get a smaller one... and for tubine i feared i would face balancing issues... so i planned to use radial itself- as it's balanced and in best condition....so even though i saw what you said in the book : MOI-is high and even accl the wheel is tough i still preferred to use radial...But as u said since mine is bit large and heavy at 508 g- (total rotor assembly-compressor wheel shaft and tunnel as a single part-mould/friction welded) now i fear bearing issues -so now i'm reconsidering... I asked CNCs for checking feasibility of making axial turbine with one...since i fear balancing issues and angle accuracy if made manually...since i need those calculations. But after asking many places i couldn't find anyone having 5 axis CNC and even for 3 axis the machining cost is higher (anyways it can't do the job)... so i have to manually make the tubine or stick to the radial one i have as a turbocharger rotor assy. Anyways i'll read both books and contact you again for any further clarifications... thank you for your help...greatly appreciated. I would highly appreciate if i could get your point of contact for further doubts (as i cannot ask all doubts in this comment section like sending pics for reference)... I'm giving my mail id tharhitrovesh2018@gmail.com - so you wouldn't need to publicise yours...kindly contact me there... pls be assured that this is legit and not a spam and i'll only contact if i have further doubts.btw sorry for the lengthy msgs each time... Thank you.
@@tharhitrovesh1397 It is very hard to buy a commercial axil turbine wheel now that was one of the reasons the GTBA was looking at designing a turbine using car radial turbine wheel and shaft but it is not easy most people who do it us the whole turbo charger and add a combustion chamber as Thomas Kamps did for his first engine which glowed yellow ,not recommended. The shafts on radial turbine wheels have very short shafts trying to fit a combustion chamber between them is very tight you need to do a reverse flow chamber makes a large diameter heavy engine . You need to look at designs for radial turbine wheels there was a GTBA guy who designed engines using radial wheels with the drawing in GTBA but only overall view he did sell them but that's all a long time ago I think one of them was called panther. The more parts you buy makes it very expensive soon gets to the point were it's better to buy a new engine which i would recommend if you intend to fly it, It is worth making one yourself for the fun of it and gives you experience in running and maintaining them. You are right in saying balance is a big problem but not because of self made axil turbine but to balance it must be fully assembled axial turbine radial compressor wheel on shaft in the engine for final balance all fits must be perfect, alloy compressor wheel must be a tight fit warmed up to fit shaft shaft must be true with no bend at all. A radial compressor wheel must be balance at both ends or can whirl /bend the shaft at high rev,s which pulls the front bearing off it's contact area and will make it the bearing fail this is more likely with angular contact bearings as they must be correctly preloaded. the smaller the wheels the better the balance must be.
@@reedy93 thank you brother that was very informative i'll keep everything in mind, i appreciate your patient and detailed explanations...i'm just planning it as a stationary model not flying but this is for my college project so calculations and derivations matter that takes lot of time ... i'll read the books completely and i'll comment if any doubts persist, thank you.
I took one off the pt35 there is still the compare between fd3 and pt35 it's not a practical design for home build when in production it was supplied with all the metal spinning's and cast turbine wheel machined alloy compressor wheel it was a kit for home assembly . The drawing do not have all the sizes drawn as parts are supplied finished.to be honest it would be easier to make the kj66. The NGV design/build method is same as the Kamps that i have on this engine.
Thanks, first time insides have seen the light of day since i made it I thought the diffusor would be in pieces but looks like the glues held up. I was surprised how clean the combustor looked must have run 2-3 gallons though it.
Hey attempting to design my own and had a few questions, sorry if they've already been asked previously and I just missed them. 1. What type of can did you use for the outer casing? Is it just a normal gas canister and if so what are the dimensions? 2. Did you 3d print the inlet cone? 3. Having gone through the process how would you recommend constructing the diffuser while staying on the cheap? (Should I attmept similar to how you did?) 4. Did you fabricate or purchase the combustion chamber?
Hi Josh I made everything, when made there was no home 3d printing or home NC machining, The gas can is 107.4mm i/d some cans have a 0.30mm wall thickness some are thicker /heavier 0.40mm i have also used a double walled wine cooler which is stainless steel 0.5 mm. KJ 66 is not an easy engine to home construct with minimum machinery . the engine in this video is half kamps /kj66. The KJ66 was designed for production using castings for the NGV/turbine wheel and NC machining for the diffusor.
@@reedy93First of all thank you so much for the response! I have some follow up questions then if you wouldn't mind answering. I have a cnc lathe and a plasma cutter and can borrow a mig welder so I'm not exactly on minimum machinery. -I've just finished reading through some of Kamp's work as well as scouring the internet, and I can't find any of the recommended compressor wheels, all I find are things on allibaba and ali express that I'm to weary of to buy. Do you know of any places to look for a recommended compressor wheel that has some quality? -Do you happen to remember which brand of gas can you used? All the ones I could find were around 3.75" in diameter or 95.25mm. -With the tools I described above would it be better for me to try and make the diffusor myself or get it machined by someone with a 5d cnc machine?
@@joshtopliss8878 www.ebay.co.uk/itm/164220776557?epid=2255306289&hash=item263c52306d:g:bFwAAOSwG8tezgRG Kamps and KJ66 used KKK flat back compressor wheels both were 66mm exducer inducer was about 42 on kamps with 5mm working tip height the KJ66was larger at 46 inducer and 6mm working tip height you are best finding a turbo rebuilder they sometimes have second hand wheels. Try AET Engeering ltd wakefield in uk the KKK wheels used the same casting to make many sizes .
@@joshtopliss8878 Yes even on steel it's best to preload, I can't remember the figure but it is covered in Thomas Kamps book,i did run the same size bearings front and back at 22mm o/d . i recommend testing at low rpm 50k with steel bearing first as you need more preload with ceramic and if not balanced good enough can come unseated and will scrap the front bearing. I would not fab a diffuser again like the KJ66 wedge diffuser . The diffuser in the Kamps book is easier to make and could be downsized to fit 107.4 i/d can ,make the blades seat on the front face of diffuser for 2-3 mm to stop them from pushing through the sawn slots when tightening the bolts that hold front cover. all above can be ignored if you have n/c milling machine.
it was standard practice early on with home built engines to not weld the front combustion chamber . 1/ if you do weld, use spot welding, tig or mig will distort badly. 2/ I am only using 316/310 stainless for the fuel vaporizer tubes/sticks these tend to burn away at the ends this was also common on early commercially made engines with better material such as Inconel (very expensive). 3/ the outer body of the combustion chamber can burn /blister and I have seen the last big holes on outside increase in size /burn away . 4/ having it wired together means i can remove /repair any 1 part and easier to check if everything is burning correctly. 4/ with the KJ66 all has looked good but not done a great deal of hours on engine flying will degrade the sticks a lot faster having seen Rob Wardale's (early engine builder) engines after much flying. 5/ if you notice I have spot welded the back pressing to the outer combustion chamber and the front pressing is welded to the inner combustion tube if the sticks burnt i could grind the tabs off and replace the sticks. not easy to spot weld when all together at the front outer.
@@reedy93 Hello, Thank you again for your effort. Your the Only one that answeres me. I have now Most of the Parts. And you said something about „sliding fit“ Ablout the axle hub and the NGV, because of the Expansions. I dont find the Word for „Sliding fit“ in my Language so i dont Know exactly What you mean. Do you mean that the axle hub should be able to „slide“ through NGV? Or do they have a gap After everything is Installer? This is very Important for me, Thank you because right now my Axle hub does not slide through the NGV! Thank you very much!
@@mola2646 At 3.18 the ally bearing tube is a sliding fit /push fit in the stainless steel NGV . The whole alloy assembly bearing tube and diffusor push's into the outer body and into the NGV centre hole and is only screwed/fastened at the front to the outer body this allows for any different expansion between the two.
Once again i have a question After You helped me a lot! Does The NGV + welded flange has to be installed from outside to the housing and the second flange from the inside or is it the other way around? Kind Regards
@@mola2646 Yes the welded on flange on NGV is clearance on the screws the second ring fitted inside the body has tapped holes, the gas can body has clearance bolt holes. once fitted i leave it on as the NGV hole is a sliding fit on the alloy bearing tube To dismantle the engine first unscrew the compressor nut, slide out the turbine and shaft backward. Then undo the front outer screws and slide the outer case back off the diffuser and bearing tube .
Hi Jacob check in my video's i did a video on how i made it you can use an old electric battery drill or buy spare triggers and motors 550 size off ebay you need a motor that does over 20k .no lathe was used in making of the starter
@@reedy93 thank you sir. God bless. You have lots of videos, do you mind, at your free time, share the link to that video sir? . Thank you once again. I have design a smaller version but fabricating is where am stuck. Especially NGV. Very confused about that part
@@jacobokpara7618 th-cam.com/video/7DkJ9IdD5SU/w-d-xo.html does not show it in the linked video but I used a rc electric prop adaptor that fits on with grub screw{collet type will not work} on the motor shaft then just used some rubber tube on you can see it in this video.
Hello my friend, my Last step is the Installation. I Need to Know the Gap between combustion chamber and NGV? Is There even a gap or did you slide in the NGV Into the combuster? Thank you, i Hope this was my Last question
it's a slide fit the inner combustor tube fits inside the inner NGV and the outer combustor fits over the outside of the NGV as per book, it needs to be a good slide fit .
My outer can/body is the full length of the can approximately 126mm i have even left the seam on the bottom if you check the pictures. i had checked it was totally empty of gas and punched 3 holes with a sharp 3mm masonry nail around the top screwed fitting then fill it with water .Use 3 nails and leave them in until you have punched all 3 that stops air getting in then remove them and put can in a bucket of water to fill. To remove the bottom i ground about 0.5mm off the end you will see a line appear as you grind the seam of the can then lightly tap it in on one side and twisted it round 90 degrees to pull it out ,i did this with the can full of water. The can fits over the outside on my engine like the Kamps engine and because of this needs to be longer than the KJ66 which is 112mm as you say. Hope that makes sense and you do it all at your own risk !
Hello Brother i have a question, did you only Use the 6 wires to fix the front part to the outer part of the cumbostion Chamber? Or did you also did do some welding There ?
just the six wires in the front to hold it together and sealed it ok ,some people had the sticks burn away so leaving it two piece i could check and repair but sticks did ok, no burn.
I have two More question if its okey: 1. did you welded the flange to the NGV? Or did you got it like that? 2. how did you connect the axle hub to the NGV? Only by pressing? Or also screws? You would help me a lot! Thank you!
@@mola2646 on the combustion chamber it is important to only having the air enter by the holes ,when i say seal i mean no air gaps to much air at the front will upset the combustion .
@@mola2646 1.I welded the flange to the NGV outer tube but it does tend to distort the flange and the outer NGV tube, this is how Kamps did it .allow 025mm for remachining of flange and the turbine housing inner after welding 2.The NGV inner diameter ( 1.26 time ) is a slide fit over the bearing tube at( 3.28 ).this is how the KJ66 is and allows for expansion. .
Hi, very nice job, i'm trying to build one. I have a question, in the original drawings there are two tubes to lubricate the front and rear bearings. You only have one in the front bearing, is this enough to lubricate the rear one too?
Most people went with single front lube, the same as Kurt's latest design's a needle in front of the front bearing the air also comes in that way no other holes in the bearing tube the air lubes and cools both bearings . the problem with the early fd3/64 was the centre air hole in the bearing tube soot/carbon contaminated the bearings and on the kj66 THE front bearing it could run dry . The oil is in the fuel 5% and is Teed off the main fuel line with 5% metered down going to the bearings.
@@reedy93 Thanks for the reply, very exhaustive. I still have another question for you, on the works plan they say to use a CV 470 cartridge for the external case which is made of steel. For practical reasons, I purchased a gas cylinder cover of the same size but in aluminium, can it still resist the temperatures?
@@MarcoFormentin I don't have any experience with aluminum outer body ,I know commercially made turbines use them the NGV can reach over 650c at start up aluminum melts at 660c and looses a lot of strength at over 200c your first turbine will have heat issues unless you get everything right first go also corrosion may become a problem unless you anodize the aluminum .steel can is zinc plated inside and is not a problem ,the case gets plenty of oil/fuel on start up /shut down so no rust problems inside, the original gas can Kurt used is only 0.3mm thick and is very light even the paint holds up well to temperature. Most other disposable gas cans with screw on fitting are slightly thicker at 0.5mm but still light but these will not Z bend as Kurt shows for fixing the NGV on . If you notice on the outer body of mine ( 1.15)still has the swaged end on the can ,I just ground it away on the bottom till you can see the lines of the can appear ,about 0.5mm off then tap the dished bottom inward it will twist round then pull out clean, it even leaves a chamfer lead to fit the front diffusor ring in .
@@reedy93 Thanks I'll keep that in mind. my last question is about the hypodermic needles that inject the fuel. Can I also make them straight? Or is there a reason if they are curved like the ones you made or as they are represented on the drawings? Also, do they have to be perfectly in the center of the vaporizers?
The kj66 combustor I made to fit the FD3/64 was passed to Umar to try in his FD3 ,he's been busy with his No 2 engine but the original fd3 combustor that he fitted in No 1 engine was very near to working ok with the walking sticks added he may try correcting the faults and retry that engine. making your first engine is a steep learning curve and you do start to realize what matters.
![กิโลเมตรที่ 0 เดินทางรอบโลกไม่ใช้เครื่องบิน [Around The World Ep. 1]](http://i.ytimg.com/vi/toJG9oofLFY/mqdefault.jpg)
very nice work.
Try and get some 608 highbred full complement ceramic bearings as they will last a long time compared to steel caged bearings which only last a few runs before the cages start to expand like they did in my KJ66
I have some full complement ceramic bearings in my as per book Kamps engine but don't know if it's worth it with this KJ66/Kamps engine unless I can get the power up with my home made soft turbine wheel .
I am watching your TH-cam with interest. In the diffuser introduction scene, there are two tubes, one seems to be a tube that supplies lubricant to the bearings, and what does the other tube do?
Hi Young not sure which tubes but here goes .
At 2.30 there are aux gas line pipes at 12-6 c clock position feed into the two vaporizer tubes these feed pipes are shown as a Y pipe at 2.54.
At 3.10 you can see the oil pipe in front of the front bearing this oil/fuel lubricates/cools the front bearing and caries on down the alloy bearing tube to cool/lubricate the rear bearing.at 3.20 the snaking pipe is the oil pipe going out to the front face.
At 3.21 about 11 o clock position is a U shaped pipe for pressure take off to monitor case pressure.
hope I got the right pipe, case pressure I think ,it would have been ok on the outer case I have it into the airflow exiting the diffuser as it was used for pressurizing a oil bottle but now is teed off from the fuel line so it's at fuel pressure now which is always well above case pressure..
Hello my friend,
Can you tell me how much fuel/oil mix runs through the bearing per Minute ? Any suggestion?
Thanks €
Is it possible to show how you made the lubrication of the bearings please? . I don't understand how that part works. A bit confused.
And also how did you get the patterns of the holes in the combustion chamber?
th-cam.com/video/bRSvcSpn_Bg/w-d-xo.html
Hole pattern above Umar and I have found that the hole pattern works better if you add 2mm to outer combustor at front moving all holes in pattern to back of engine. you will need to remove 2mm from back of combustor .
also take 1mm off front of the inner tube moving all hole pattern forward 1mm.
Cris I don't see lubrication pipe to rear bearings? Is lubrication not required for ceramic bearings?
Lubrication and preload was one of the early problems causing bearing failure which becomes more noticeable when flying as you have to operated at higher revs for longer.
Ceramic and steel bearings both need lubrication and also it aids cooling, steel bearing should only be lightly loaded kamps states how much in his book.
Angular contact ceramic bearing need more preload as only one shoulder to push against.
Steel are better lubricated with a small bottle of thinned oil pressurized from the compressor when engine running.
use 5% Oil in paraffin for ceramic teed off from fuel line which should be restricted to 5% of the flow going to main injectors.
The fuel/oil mix is at the front of the front bearing which it then pass's down the bearing tube to lube the rear and then helps cool the turbine wheel and gets burnt in exhaust.
To help pressurized the area behind the compressor wheel the gap between the edge of the compressor and the diffusor can be increase a little then the air trips over the edge and help take the air/oil down the bearing tube ,people have also drill holes in the diffusor to pressurize the area but you can run into problems with rear preload and the front ceramic bearing becoming unloaded that's why most are front preload now.
Sorry about long reply hopefully I've covered all the problems but i don't have all the answers.
what will happen if increased the overall diameter of the shaft tunnel 4mm?
Hello... i appreciate your comments and suggestions even in other channels... pls tell me why the diffusor wedges and blades are pinned/glued? can't they be made as a single part in CNC(5 axis)? If not is that made without CNC? Is it possible to make an entire jet engine without CNC?
Also i'm thinking of making an annular combustion chamber (since i use radial turbine), so can you suggest some materials which have calculations and drawings, i couldn't find anything proper.
I only have the rotor assembly-(comp, shaft friction welded with radial turbine)- so can i make an NGV suitable for this? or should i direct combustion chamber exit radially to the turbine- like Heinkel HeS3 engine- but this gives poor thrust even in real plane so i'm not sure if i'll get satisfactory amount of thrust....so is it possible to create an NGV for this?
The KAMPS book by thomas kamps suggests a PAL model engine in pg 22 but i can't get that drawings or calculations too....and the book doesn't have calculations for radial turbine too...
Kindly help me out as i took this as my project this semester and due to COVID restrictions i also have limited sources for fabrication too... i would highly appreciate if i could get your point of contact for further doubts (as i cannot ask all doubts in this comment section)... i'm giving my mail id tharhitrovesh2018@gmail.com kindly contact me there... pls be assured that this is legit and no spam messages will be sent.Thanks for your help in advance.
P.s:- I take your suggestions at my own risk
A lot to answer there so here goes, a quick answer which is in Kurt's book ,he only had minimum machinery 30 years ago so all early engines only used a lathe so fabricating the parts was necessary and the only way to make the NGV apart from casting.
The cnc machinery was not available for home use 30 years ago which is the reason the diffuser has the vanes glued on in the Kamp's engine only a lathe needed.
It is worth reading Kurt's and Kamp's books they explain why they choose a axial turbine wheel vs radial turbine wheel quick answer is rotor is very heavy and gives problems mounting the bearings and the accuracy has to be higher as the for and aft position has to be fixed to maintain the clearance on both wheels.
The GTBA members did design/ build gas turbines using radial turbine wheels but tended to be bigger heavier engines very few are made commercially now all the engines 66mm wheel diameter and under use axial wheels .
@@reedy93 tq for replying, I'm reading the books... but i've already got a compressor wheel of 78mm dia(exducer)- It was a sponsored by a service station- so i couldn't get a smaller one... and for tubine i feared i would face balancing issues... so i planned to use radial itself- as it's balanced and in best condition....so even though i saw what you said in the book : MOI-is high and even accl the wheel is tough i still preferred to use radial...But as u said since mine is bit large and heavy at 508 g- (total rotor assembly-compressor wheel shaft and tunnel as a single part-mould/friction welded) now i fear bearing issues -so now i'm reconsidering...
I asked CNCs for checking feasibility of making axial turbine with one...since i fear balancing issues and angle accuracy if made manually...since i need those calculations. But after asking many places i couldn't find anyone having 5 axis CNC and even for 3 axis the machining cost is higher (anyways it can't do the job)... so i have to manually make the tubine or stick to the radial one i have as a turbocharger rotor assy.
Anyways i'll read both books and contact you again for any further clarifications... thank you for your help...greatly appreciated.
I would highly appreciate if i could get your point of contact for further doubts (as i cannot ask all doubts in this comment section like sending pics for reference)... I'm giving my mail id tharhitrovesh2018@gmail.com - so you wouldn't need to publicise yours...kindly contact me there... pls be assured that this is legit and not a spam and i'll only contact if i have further doubts.btw sorry for the lengthy msgs each time...
Thank you.
@@tharhitrovesh1397 It is very hard to buy a commercial axil turbine wheel now that was one of the reasons the GTBA was looking at designing a turbine using car radial turbine wheel and shaft but it is not easy most people who do it us the whole turbo charger and add a combustion chamber as Thomas Kamps did for his first engine which glowed yellow ,not recommended.
The shafts on radial turbine wheels have very short shafts trying to fit a combustion chamber between them is very tight you need to do a reverse flow chamber makes a large diameter heavy engine .
You need to look at designs for radial turbine wheels there was a GTBA guy who designed engines using radial wheels with the drawing in GTBA but only overall view he did sell them but that's all a long time ago I think one of them was called panther.
The more parts you buy makes it very expensive soon gets to the point were it's better to buy a new engine which i would recommend if you intend to fly it, It is worth making one yourself for the fun of it and gives you experience in running and maintaining them.
You are right in saying balance is a big problem but not because of self made axil turbine but to balance it must be fully assembled axial turbine radial compressor wheel on shaft in the engine for final balance all fits must be perfect, alloy compressor wheel must be a tight fit warmed up to fit shaft shaft must be true with no bend at all.
A radial compressor wheel must be balance at both ends or can whirl /bend the shaft at high rev,s which pulls the front bearing off it's contact area and will make it the bearing fail this is more likely with angular contact bearings as they must be correctly preloaded.
the smaller the wheels the better the balance must be.
@@reedy93 thank you brother that was very informative i'll keep everything in mind, i appreciate your patient and detailed explanations...i'm just planning it as a stationary model not flying but this is for my college project so calculations and derivations matter that takes lot of time ... i'll read the books completely and i'll comment if any doubts persist, thank you.
Have you deleted a video about pt35 plans? I remember I had watched a video showing turbine ngv all diagram of pt35 in your channel. 🤔🤔🤔
I took one off the pt35 there is still the compare between fd3 and pt35 it's not a practical design for home build when in production it was supplied with all the metal spinning's and cast turbine wheel machined alloy compressor wheel it was a kit for home assembly . The drawing do not have all the sizes drawn as parts are supplied finished.to be honest it would be easier to make the kj66.
The NGV design/build method is same as the Kamps that i have on this engine.
Beautiful Chris
Thanks, first time insides have seen the light of day since i made it I thought the diffusor would be in pieces but looks like the glues held up. I was surprised how clean the combustor looked must have run 2-3 gallons though it.
Hey attempting to design my own and had a few questions, sorry if they've already been asked previously and I just missed them.
1. What type of can did you use for the outer casing? Is it just a normal gas canister and if so what are the dimensions?
2. Did you 3d print the inlet cone?
3. Having gone through the process how would you recommend constructing the diffuser while staying on the cheap? (Should I attmept similar to how you did?)
4. Did you fabricate or purchase the combustion chamber?
Hi Josh I made everything, when made there was no home 3d printing or home NC machining,
The gas can is 107.4mm i/d some cans have a 0.30mm wall thickness some are thicker /heavier 0.40mm i have also used a double walled wine cooler which is stainless steel 0.5 mm.
KJ 66 is not an easy engine to home construct with minimum machinery .
the engine in this video is half kamps /kj66.
The KJ66 was designed for production using castings for the NGV/turbine wheel and NC machining for the diffusor.
@@reedy93First of all thank you so much for the response! I have some follow up questions then if you wouldn't mind answering. I have a cnc lathe and a plasma cutter and can borrow a mig welder so I'm not exactly on minimum machinery.
-I've just finished reading through some of Kamp's work as well as scouring the internet, and I can't find any of the recommended compressor wheels, all I find are things on allibaba and ali express that I'm to weary of to buy. Do you know of any places to look for a recommended compressor wheel that has some quality?
-Do you happen to remember which brand of gas can you used? All the ones I could find were around 3.75" in diameter or 95.25mm.
-With the tools I described above would it be better for me to try and make the diffusor myself or get it machined by someone with a 5d cnc machine?
@@joshtopliss8878 www.ebay.co.uk/itm/164220776557?epid=2255306289&hash=item263c52306d:g:bFwAAOSwG8tezgRG
Kamps and KJ66 used KKK flat back compressor wheels both were 66mm exducer
inducer was about 42 on kamps with 5mm working tip height the KJ66was larger at 46 inducer and 6mm working tip height you are best finding a turbo rebuilder they sometimes have second hand wheels.
Try AET Engeering ltd wakefield in uk the KKK wheels used the same casting to make many sizes .
@@reedy93 thank you so much for your help! Did you preload your bearings?
@@joshtopliss8878 Yes even on steel it's best to preload, I can't remember the figure but it is covered in Thomas Kamps book,i did run the same size bearings front and back at 22mm o/d .
i recommend testing at low rpm 50k with steel bearing first as you need more preload with ceramic and if not balanced good enough can come unseated and will scrap the front bearing.
I would not fab a diffuser again like the KJ66 wedge diffuser .
The diffuser in the Kamps book is easier to make and could be downsized to fit 107.4 i/d can ,make the blades seat on the front face of diffuser for 2-3 mm to stop them from pushing through the sawn slots when tightening the bolts that hold front cover.
all above can be ignored if you have n/c milling machine.
Hey Brother, im curious why would you Not Weld the back part and Front Part of the combustion chamber? Is There a Benefit? Would it work if i Weld it?
it was standard practice early on with home built engines to not weld the front combustion chamber .
1/ if you do weld, use spot welding, tig or mig will distort badly.
2/ I am only using 316/310 stainless for the fuel vaporizer tubes/sticks these tend to burn away at the ends this was also common on early commercially made engines with better material such as Inconel (very expensive).
3/ the outer body of the combustion chamber can burn /blister and I have seen the last big holes on outside increase in size /burn away .
4/ having it wired together means i can remove /repair any 1 part and easier to check if everything is burning correctly.
4/ with the KJ66 all has looked good but not done a great deal of hours on engine flying will degrade the sticks a lot faster having seen Rob Wardale's (early engine builder) engines after much flying.
5/ if you notice I have spot welded the back pressing to the outer combustion chamber and the front pressing is welded to the inner combustion tube if the sticks burnt i could grind the tabs off and replace the sticks. not easy to spot weld when all together at the front outer.
@@reedy93 Hello, Thank you again for your effort. Your the Only one that answeres me. I have now Most of the Parts. And you said something about „sliding fit“ Ablout the axle hub and the NGV, because of the Expansions. I dont find the Word for „Sliding fit“ in my Language so i dont Know exactly What you mean. Do you mean that the axle hub should be able to „slide“ through NGV? Or do they have a gap After everything is Installer? This is very Important for me, Thank you because right now my Axle hub does not slide through the NGV! Thank you very much!
@@mola2646 At 3.18 the ally bearing tube is a sliding fit /push fit in the stainless steel NGV .
The whole alloy assembly bearing tube and diffusor push's into the outer body and into the NGV centre hole and is only screwed/fastened at the front to the outer body this allows for any different expansion between the two.
Once again i have a question After You helped me a lot! Does The NGV + welded flange has to be installed from outside to the housing and the second flange from the inside or is it the other way around?
Kind Regards
@@mola2646 Yes the welded on flange on NGV is clearance on the screws the second ring fitted inside the body has tapped holes, the gas can body has clearance bolt holes.
once fitted i leave it on as the NGV hole is a sliding fit on the alloy bearing tube
To dismantle the engine first unscrew the compressor nut, slide out the turbine and shaft backward.
Then undo the front outer screws and slide the outer case back off the diffuser and bearing tube .
May I know the brand or the hand held motor you used to start the engine and what is the RPM please? .
Thank you.
Hi Jacob check in my video's i did a video on how i made it you can use an old electric battery drill or buy spare triggers and motors 550 size off ebay you need a motor that does over 20k .no lathe was used in making of the starter
@@reedy93 thank you sir. God bless. You have lots of videos, do you mind, at your free time, share the link to that video sir? . Thank you once again.
I have design a smaller version but fabricating is where am stuck. Especially NGV. Very confused about that part
@@jacobokpara7618 th-cam.com/video/7DkJ9IdD5SU/w-d-xo.html
does not show it in the linked video but I used a rc electric prop adaptor that fits on with grub screw{collet type will not work} on the motor shaft then just used some rubber tube on you can see it in this video.
@@reedy93 thank you so much sir. Will watch now.
Hello my friend, my Last step is the Installation. I Need to Know the Gap between combustion chamber and NGV? Is There even a gap or did you slide in the NGV Into the combuster?
Thank you, i Hope this was my Last question
it's a slide fit the inner combustor tube fits inside the inner NGV and the outer combustor fits over the outside of the NGV as per book, it needs to be a good slide fit .
@@reedy93 Thank you, how deep does it slide in your case ? There is Not much Space for the immer NGV, so i think its like 2 - 5 mm ?
How can someone contact you? Kindly advise
Reed can you tell me what is the can length? Is it 112mm or 120.3?
My outer can/body is the full length of the can approximately 126mm i have even left the seam on the bottom if you check the pictures.
i had checked it was totally empty of gas and punched 3 holes with a sharp 3mm masonry nail around the top screwed fitting then fill it with water .Use 3 nails and leave them in until you have punched all 3 that stops air getting in then remove them and put can in a bucket of water to fill.
To remove the bottom i ground about 0.5mm off the end you will see a line appear as you grind the seam of the can then lightly tap it in on one side and twisted it round 90 degrees to pull it out ,i did this with the can full of water.
The can fits over the outside on my engine like the Kamps engine and because of this needs to be longer than the KJ66 which is 112mm as you say.
Hope that makes sense and you do it all at your own risk !
@@reedy93 ok thanks for the information
Hello Brother i have a question, did you only Use the 6 wires to fix the front part to the outer part of the cumbostion Chamber? Or did you also did do some welding There ?
just the six wires in the front to hold it together and sealed it ok ,some people had the sticks burn away so leaving it two piece i could check and repair but sticks did ok, no burn.
What do you mean by seal? Sorry my english is Not so good, and thanks for the reply even tho the videos is old, greetings
I have two More question if its okey:
1. did you welded the flange to the NGV? Or did you got it like that?
2. how did you connect the axle hub to the NGV? Only by pressing? Or also screws?
You would help me a lot! Thank you!
@@mola2646 on the combustion chamber it is important to only having the air enter by the holes ,when i say seal i mean no air gaps to much air at the front will upset the combustion .
@@mola2646
1.I welded the flange to the NGV outer tube but it does tend to distort the flange and the outer NGV tube, this is how Kamps did it .allow 025mm for remachining of flange and the turbine housing inner after welding
2.The NGV inner diameter ( 1.26 time ) is a slide fit over the bearing tube at( 3.28 ).this is how the KJ66 is and allows for expansion. .
Hi, very nice job, i'm trying to build one. I have a question, in the original drawings there are two tubes to lubricate the front and rear bearings. You only have one in the front bearing, is this enough to lubricate the rear one too?
Most people went with single front lube, the same as Kurt's latest design's a needle in front of the front bearing the air also comes in that way no other holes in the bearing tube the air lubes and cools both bearings .
the problem with the early fd3/64 was the centre air hole in the bearing tube soot/carbon contaminated the bearings and on the kj66 THE front bearing it could run dry .
The oil is in the fuel 5% and is Teed off the main fuel line with 5% metered down going to the bearings.
@@reedy93 Thanks for the reply, very exhaustive. I still have another question for you, on the works plan they say to use a CV 470 cartridge for the external case which is made of steel. For practical reasons, I purchased a gas cylinder cover of the same size but in aluminium, can it still resist the temperatures?
@@MarcoFormentin I don't have any experience with aluminum outer body ,I know commercially made turbines use them the NGV can reach over 650c at start up aluminum melts at 660c and looses a lot of strength at over 200c your first turbine will have heat issues unless you get everything right first go also corrosion may become a problem unless you anodize the aluminum .steel can is zinc plated inside and is not a problem ,the case gets plenty of oil/fuel on start up /shut down so no rust problems inside, the original gas can Kurt used is only 0.3mm thick and is very light even the paint holds up well to temperature.
Most other disposable gas cans with screw on fitting are slightly thicker at 0.5mm but still light but these will not Z bend as Kurt shows for fixing the NGV on .
If you notice on the outer body of mine ( 1.15)still has the swaged end on the can ,I just ground it away on the bottom till you can see the lines of the can appear ,about 0.5mm off then tap the dished bottom inward it will twist round then pull out clean, it even leaves a chamfer lead to fit the front diffusor ring in .
@@reedy93 Thanks I'll keep that in mind. my last question is about the hypodermic needles that inject the fuel. Can I also make them straight? Or is there a reason if they are curved like the ones you made or as they are represented on the drawings? Also, do they have to be perfectly in the center of the vaporizers?
@@reedy93 Please can you explain me this last thing for the epidermic needles about the position of them in the vaporizer and the shape?
plans ?
see book KJ66 in my other video.
@@reedy93 Which one can you give a link?
@@emirhndrk17 th-cam.com/video/O_nDGzPY4mU/w-d-xo.html
Have you tried this combustion chamber in your fd3 64? Would it work ?
The kj66 combustor I made to fit the FD3/64 was passed to Umar to try in his FD3 ,he's been busy with his No 2 engine but the original fd3 combustor that he fitted in No 1 engine was very near to working ok with the walking sticks added he may try correcting the faults and retry that engine.
making your first engine is a steep learning curve and you do start to realize what matters.
Eliuos jou Soon I gona post video fd3 64 engine with kj66 combustion. We 'll see how Is going to work in fd3
@@Umarzaman8400 . Ok umar waiting for video.