you truly are an Ironman fan

Quote from: asperised on June 24, 2020, 01:35:20 AM
you truly are an Ironman fan

Hahaha, Yes big fan. All my stuff is having that logo. Bike helmet laptop walls profiles etc.

Update:

As the shaft failed, got the new round and will start machining soon.

Designing the shaft and the diffussor gave me the clue that 80mm will be difficult to make at this point of time. The parts become really small and the compressor wheel might not be able to drive the turbine wheel. The current compressor wheel selected is 5+5 with exuder 54. Need better GT compressor wheel to deliver. May be need to experiment.

So I am switching to 90mm diameter. Everything else remain same. Will machine the new shaft tomorrow if time permits.

Meanwhile, I got some parts from US and Spain. The turbine wheel and NGVs. It took almost 2 weeks to reach me after custom clearance (pandemic thing). The customs was cleared fast. To my surprise & dismay, the Indian customs has charged 80% & 90% total duty on the declared amount on the respective shipments under the code 9965. One came through DHL and other through UPS. Both shipment was not opened.(went through x-ray screening). Now this is astounding. Did they thought its coming from China? Such a heavy charging. Usually they use to charge around 42-43%.

Was thinking of ordering some parts from China for some projects. If that's the duty they're gonna charge then whoops, the plan goes down the drain.

Its tough to get anything from China now. DHL and FeDEX both have halted the shipping from China given the Indian custom is not clearing stuffs. I don't know the point of this. This is hurting our own industries and the global companies assembling or manufacturing here. This is not the way one reduces dependency.

Charging double as duty is not the way.

But I think this won't last longer.

That's just stupid and pointless. What do they think they'll achieve out of this?

Update:

So after the first shaft failed. I started with the new one. I have been machining it 2 days now (some 8-9 hours).It was about to finish. But today luck betrayed at the last moment. I delayed a fraction of sec in detaching the lead screw and it screwed me up. The shaft bent a bit. This one also goes to the grave. 

Time to machine the 3rd one. Small parts are not that easy machine it seems. 
Fun continues.

Update:

The week has past without much progress on machining front. The city is under lock-down and I can't get the shaft material till 12th.

Meanwhile I took a chance to investigate the 1st shaft failure which looked like a caliper being misread. careful investigation revealed that my lathe machine was cutting taper and off center. This week I disassembled the head to align the offset. Now it is aligned. I will check the center alignment tomorrow.

The reason of this was change of place and over the time head do tend to get misaligned. Once set I will proceed with the shaft machining next week.

The other team is working on the control electronics for the engines. A PIC IC based controller is being worked upon. He is the circuit board in 3D.

Update:

The tail stock was misaligned by 1 mm. This would never let the shaft be concentric. I removed the offset last Sunday and also got the shaft round machined. The shaft is ready now.

Update:

Its been a while I posted here. Last couple weeks were consuming.

Now following parts are ready.

1. Shaft
2. Shaft tunnel
3. Diffuser system
4. Compressor nut
5. Turbine nut
6. Turbine wheel (German make, machined it to tolerances)
7. NGV (german make, Needs machining)
8. Compressor wheel (ready stock from Garrett)

Next in line will be diffuser outer. As this project is agile one, the diffuser dimensions will be calculated and drawn in CAD. Will surely post some pic soon.

Cheers!!

As promised, Here are some pics of the parts made so far.

You can spot the completed diffuser, shaft tunnel in making and the front shaft nut.

Newbie here,
Why don't you get the parts manufactured by some machining shop that has CNC lathe ?
I guess that will speed things up right ?

Nice progress ... Looks like the ECU board is being designed in Ki-CAD , the wrong 3D design of the SMD Resister/Capacitors gave me illusion that your board is using this many (tall)  Boxed Poly Caps (WIMA type) ... Let me know if I can help from ECU / Board side ..

Power with you ...

We require more Innovative Individuals like you in this Hobby.

Quote from: theweblover007 on August 06, 2020, 05:40:29 PM
Newbie here,
Why don't you get the parts manufactured by some machining shop that has CNC lathe ?
I guess that will speed things up right ?

I would think twice before giving amateur suggestions to professionals...

Quote from: theweblover007 on August 06, 2020, 05:40:29 PM
Newbie here,
Why don't you get the parts manufactured by some machining shop that has CNC lathe ?
I guess that will speed things up right ?

There are many reasons for this. I will try to explain it here.

R&D are agile in nature. When you are creating something from scratch, many component go over many phases of development and iterations. Consider this example, You start with one design, mid way you come to know you need to modify this or change this or scrape this and built a new one altogether. All of this would require readily available resources (man machine materials) to materialize the change. Jumping to CNC now-n-then will take your prototype cost way higher.

There are many inherent challenges.

1. CNC setting up time is high, its one time effort and so its good for mass production, not for a single component which might subjected to change.
2. Getting one off part is made from CNC is costly.
3. You can't just have CNC so easy, most of the workshop won't even consider your order if its less then MOQ of 10. (still cost will be high)
4. And off-course you can't buy a CNC when you have multiple source of cash outflow and no concrete product yet.

If you have easy access to it, it definitely a boon. The above reasons are in context to a cash strapped self funded startup. If you are sitting on a pile of cash, well there is no reason not to head to the CNC room.

You question didn't surprise me. Many a time I get such recommendation to go for CNC or get it 3D printed. What I believe is in ladder of progression. There is no easy & fast way to success. A balanced approach would be to get the basics right and  your foot deep into roots and then take a leap. (yeah contrary to what Tony Stark said: "Sometimes you gotta run before you can walk"   ).

Once the design is proven, CNC is the way.

Quote from: ujjwaana on August 06, 2020, 06:12:09 PM
Nice progress ... Looks like the ECU board is being designed in Ki-CAD , the wrong 3D design of the SMD Resister/Capacitors gave me illusion that your board is using this many (tall)  Boxed Poly Caps (WIMA type) ... Let me know if I can help from ECU / Board side ..

Power with you ...

The software used is "Design spark PCB". Yes the 3D impression of SMDs are wrong, but I didn't bother. It makes everything looks gigantic and far from reality.

I will definitely sought help here when require. It is one of the objective of keeping things open in the forum. 

Quote from: tonyStark on June 19, 2020, 10:36:00 PM
3D printing won't help in such design given the amount of strength and pressure they come into.

@tonyStark Skyroot has recently 3D printed their rocket engine. They said it reduced the weight by 50% and significantly cut the lead time.

Isn't it possible to 3D print the jet engine as well?

3D printed rocket engine not something new. SpaceX superdraco engine was 3D printed and tested in 2014. The most critical engine part is the combustion chamber which was printed using DLMS method in inconel. All other parts are relatively easier to print with normal alloys and metals. Printing inconel is a challenge. "Relativity" a company formed by x spacex employee is also 3D printing rocket parts.

But serious congratulations to Skyroot, they did it. This is a positive development in 3D printing technology.

Regarding jet engine (model ones), its not impossible. Only critical component here is the NGV and Turbine blade both are steel alloy and mostly made in Inconel. You need such machine to print these part and test it. Infact a company in Russia has recently printed a complete jet engine and tested it too. A company in Europe are also testing these methods. Even you don't have to look far, Intech DMLS (An Indian company) has also printed and tested model jet engine.

Welcome to Industry 4.0.

Only if I could understand all your verbiage 
Having said that, do you guys have any plans to build turboprop/turbofan engines too?

very good progress tony subscribed 

Quote from: themaverick on August 12, 2020, 08:50:55 PM

Quote from: tonyStark on June 19, 2020, 10:36:00 PM
3D printing won't help in such design given the amount of strength and pressure they come into.

@tonyStark Skyroot has recently 3D printed their rocket engine. They said it reduced the weight by 50% and significantly cut the lead time.

Isn't it possible to 3D print the jet engine as well?

A correction is needed here. According to their twitter, post they have used 100% 3D printed injector. Injector is a part of rocket engine essentially where the fuel mix happens and then it is pushed towards the throat and then to thrust cone.

They have not printed a complete rocket engine, just a part of it. The Indian media couldn't understand this and trimmed the injector from their tweet and they printed the entire rocket engine......just ...like....that...

Update:

Its been a while I posted here. There has been a lot of progress on the engine development and so this is going to be a long post.

Combustion chamber:

The combustion chamber was designed and has been manufactured now. The prototype is made from high temperature SS sheet. The main combustion chamber body has been cut, drilled and then rolled. It was then spot welded in place at appropriate current. The side faces were round cut from the same material and then initially cold rolled and then hot rolled to relieve stresses to make the end flanges. All were assembled and spot welded together. Central section has been brazed for additional strength at high temperature.

Diffuser outer and compressor cover

After milling the diffuser, the next step was to make its outer and then the compressor cover. Making the diffuser was relatively simple only the inner curve should match the diffuser end curve to fit perfectly.
The compressor cover is very tricky as you first need to find the radius of the compressor wheel and then follow the same radius on the cover inner. Once the radius is found, the same is carved out diligently on the cover inner and then some tolerance is added to it for the desired gap between the two. The efficiency of a compressor is dependent on this tolerance. too short and you risk ramming the compressor into its cover while running, too high and the compressor won't be able to develop req. pressure.

Once done all parts are fitted together to check the clearance and mating accuracy. All parts are required to be perfectly concentric to avoid any misalignment. Mis-alligned parts has bad ramification which must be avoided.

Once all parts are fine tuned and clearances are checked. I final assembly was done to check the fit. I shaft is given a spin to check if anything is obstructing the rotation. Initially I kept 0.1mm gap at the turbine end but I figured out that the starting temperature gradient may cause the wheel to jam against the NGV or it may even break it. I have increased the gap a little to safe standard.

Balancing:

It is needless to mention the importance of balancing for the rotor system. A well balanced system will produce less sound, will be hazardous free, the bearing will last more, free from cyclic stresses etc. When you are going to run a machine at 1 lac rpm, it becomes imperative.

So I kept the shaft assembly on the balancing cradle. The balancing cradle is completely in-house designed. It can detect a flee size imbalance in the system. But this level of precision is not required usually. There are two method to balance the component. either you go part wise balancing or you just balance whole assembly at once. I prefer the second approach. After reaching a satisfactory results, the assembly is taken off the cradle and will not be disturbed till final assembly.

Fuel ring:

Some progress on fuel line has also been made. The fuel line is made of Brass. The tube has been rolled in appropriate size and is ready for taking the injectors.

You can find all these in the attached photos.

Some more pics: