The One Man Turbofan

[wannabebuilderuk]

Man that is a beauty, can't wait to see it run

[dieselguy86]

Hi Monty,

Model looks beautiful, looks like it'll be a beast of an engine.

Here's a wheel I just picked up, although I got it for MUCH cheaper, but it is huge. 126mm exducer, 10 blade, mixed flow, looks like it would favor high flow...
www.ebay.com/itm/224526404234?_trkparms=amclksrc%3DITM%26aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160908105057%26meid%3D5a7e74a8d2e149ff837497b8cab42a3b%26pid%3D100675%26rk%3D2%26rkt%3D15%26sd%3D383785149541%26itm%3D224526404234%26pmt%3D0%26noa%3D1%26pg%3D2380057&_trksid=p2380057.c100675.m4236&_trkparms=pageci%3Af802a93f-104e-11ec-9372-ee13f68e0220%7Cparentrq%3Ac34cb5c117b0a45b096bebc8fff4a6a6%7Ciid%3A1

-Joe

[monty]

Hi Joe,

That mixed flow turbine would be great for a regular turbojet with the combustor around the center section. I think it's a little big for my use! The TF15 wheel is more in the ballpark.

I still want to look at whether changing everything is worth all the work.

Monty

[monty]

The amount of changes to put the new turbine in the design are just too great. I think I'll just keep going with the current design and see how it works. Turbofan 2.0 can use the bigger one if necessary.

Monty

[monty]

Progress...and hopefully a casting for Christmas.

I received the gas generator outer case. You can see it here with the mid-frame casting form. I just got this off the 3D printer.  Hope to get this and fan case cast soon.

Monty

[racket]

Hi Monty

Very nice :-)

Christmas presents coming early ;-)

Cheers
John

[monty]

Made a little progress today. I made the flask for the mid frame casting. Used an acrylic base screwed to the PLA form as the bottom of the flask. Before this I coated the form with propylene glycol water mix to prevent air bubbles from sticking. You can also use a couple of drops of dish washing liquid/water mix. I apply with a spray bottle and wait for it to dry.

Then I made a hardware cloth flask to keep the plaster of Paris investment together.

The entire thing is enclosed in aluminum sheet and held together with packing tape.

Hopefully tomorrow I can pour the investment.

[monty]

Christmas casting is upon us....Investment poured during a tornado warning tonight once started...you gotta keep going storm or not!!...Now I just have to finish work next week and then I should be able to cure the investment and cast the metal!

[dieselguy86]

Monty,

Hope all is well there, not sure where your located but hopefully no where close to that monster last night.

[monty]

Dec 11, 2021 8:00:32 GMT -5 dieselguy86 said:

Monty,

Hope all is well there, not sure where your located but hopefully no where close to that monster last night.

Nothing bad here, just a front with a lot of wind and lightning. It was over in about 20 min. All the bad stuff was East of me. While I was mixing the plaster I was thinking "I hope the lights don't go out!!" I had a plan to use my car lights if the power went out. It only blinked a couple times.

Monty

[racket]

You guys took a hammering , it was on the news here in Oz , poor old Kentucky copped it bad :-(

[monty]

Dec 11, 2021 16:55:21 GMT -5 racket said:

You guys took a hammering , it was on the news here in Oz , poor old Kentucky copped it bad :-(

Yes, not good at all...

The weather here is "dynamic". We have a saying "If you don't like the weather, wait a minute." I remember one day in particular before weather apps or even the weather channel... I woke up to a beautiful fall day. It was clear skies, 70 deg. F. No wind. Perfect!. I started to leave my apartment for the day wearing a tee shirt and jeans. Then I thought....better get take a jacket. By mid day we had clouds and rain. By late afternoon we had a tornado, and a thunder-blizzard. Don't know what else to call it. When I got home there was 6 inches of snow on the ground and the temp was in the 20s.

Fortunately where I am is on a plateau. Most of the bad weather goes North or South. It can be exciting at times though!

Monty

[racket]

Hi Monty

Where you live sounds like Melbourne here in Oz , 4 seasons in a day .....no worries ,.......... stinking hot desert wind one minute , freezing Antarctic winds the next , thankfully a lot more benign where I am on the coast :-)

Looking forward to seeing how the casting turns out .

Cheers
John

[monty]

Fresh hot alumuffins and a mold in the oven for Christmas!!

I got my burnout oven wired up so I can operate it outside. Much better!

Mold went in the oven this AM. I put a thermocouple in the mold so I can monitor when the bulk water is all gone (over 100 C) This will let me know for sure when to start ramping up to the burn out temp of ~320 C.

I couldn't source any 356 ingots for some reason. My usual supplier must be on vacation or out. So I had to melt down a bunch of old failed castings and make some ingots. Not ideal, but it will work. Also melted down a bunch of pistons and failed piston castings for making the diffuser. Hope to cast the mid-frame tomorrow.

Monty

[monty]

Merry Christmas Everyone!!

I must have been a bad boy. The casting gods sent me a lump of coal. I have been experimenting with different things to seal and smooth the 3D printed casting forms. PVA glue being one of them. I used ModPodge on this one. It is mostly PVA glue, but has some other stuff in there. I think Acrylic. It all burned out cleanly where the air could get to it. Unfortunately the Acrylic residue stayed in the top of the mold. When I poured the casting it started producing gas defects. It's not a total loss. I can use this casting for proving out my CNC code for machining. Next one I'll put some vent holes in the top so air can flow from top to bottom within the cavity. I'm also going back to strait PVA glue thinned with water.

Monty