Does any one know how do cast this out of inconel.. ?

Eddie Weeks

Hey Eddie.
I'll ask around here at work, but I bet the answer I get is sure; all it takes is money.

Hi Eddie,

Have you looked at the stress you would get in that middle ring?

The top speed is around 45,000 RPMs, and have not
checked the middle ring.

I did check the stress on each thrust fan blade
witch was only 2-3000 psi.


Eddie

Hello Eddie,

I find this very interesting as I am working on something very similar. Looking at you CAD snapshot you will run into a few problems. To cast this you first need a wax pattern. This would be a complicated tool with possible undercuts. The tool would not only have to split, but also rotate all while not damaging the pattern. Also, depending on the diameter of the internal blades, you may run into problems with the ceramic dipping process. You would more than likely have to close the center hole for gating purposes. One way out of this is to create each pattern as a prototype created by either sterolithography or in ABS plastic with Fused Deposition Modeling (I have one of these machines). There is another prototyping machine that makes very accurate wax patterns, but it is painfully slow. A casting house may be able to create these from a prototype pattern, but will charge you an arm and a leg and won’t take responsibility if all the patterns fall out (guess how I know that). Also many casting houses are hesitant to work with prototype patterns, as the thermal expansion is much greater than wax and could possibly crack a shell. If the shell cracks, you can lose all your patterns in one shot.

It’s a nice design and I see exactly what you are trying to accomplish. Right now I say no it’s not possible, but you need to work closely with a casting house to brainstorm on what may work. If I get any ideas, I will send them your way. Good luck!

-Eric

Hi Eddie,

As Eric stated, It would be best to create a wax master for the ceramic dip/investment.

I own/operate a rapid prototyping firm. I can offer my services to you for the investment process. I have the following equipment... SL-250 Stereolithography, FDM (we can run polystyrene, ABS, nylon 6/6, etc.), 3D print - which by the way is set-up for investment masters (wax). We can also create soft tools for mass casting of investment masters in a wax of your choice.

If your interested, PM me for more details, file requirements, etc.

Craig

I agree with Craig. SLA might be a good way to go with this, depending on the casting firm. The SLA part will require some cleanup work before sending to the casting company. Make sure you get some radiuses at the vane/hub/ring junctions, to relieve stress and to get better flow of the metal through the ceramic mold. We've worked with Howmet before for casting Ti nozzle parts, but I've never played with Inconel.

You'll most likely have to deal with scaling factors, due to part shrinkage during cooling (on order of 1-2 percent), and multiple shots, since the first casting is usually scrap (learning curve).

Not familiar with the wax systems... That might be even better than SLA for this.

Let me get this straight, you can creat wax plugs with soft tools?

I thought "SLA" type processes only produced plastic parts?

We need the same process for my real job, to create a prototype bezel for a consumer electronic device

Hi Matt,

Sure can...

The wax plugs/masters would be created from a soft tool.

We would make an SLA/FDM/3DP/LOM part from your files. This part would be benched (cleaned-up, polished, etc.) and a soft tool would be made from the component.

We would then cast as many wax masters as you need from the soft tool.

We would need to discuss the final component material and the process to be used for the end product. This would provide the information necessary for shrinkage, etc.

We've done quite a few investment masters for the toy/hobby industry.

Craig

Hey Eddie,

Are you using SolidWorks 2003? It has an integrated FEA tool apparently. It supposed to be a 'light' version of Cosmos, the full on FEA package commonly used with SolidWorks.

Kelly

SLA, FDM, etc… usually makes the final part. Soft tooling is basically silicone molding created from the final part. Typically it works great and will pick up every detail, but I’ve run into problems injecting wax into soft tooling. Pouring with only gravity usually doesn’t work. I think a very small, enclosed turbine wheel would be nearly impossible with silicone molding from a pattern, but you never know. Another method is to take the CAD model and design the Mold from the CAD file. Then you build the Mold from one of the above methods and inject the wax. This really produces a very nice pattern, but is time consuming to say the least and requires some high-end CAD program (Pro/E, Solidworks, CATIA) and skills. I’m actually doing this right now for castings with Stellite and Inconel. Good stuff, great technology!

Hi Eric,

Silicone is one type of Soft Tooling. There are also vulcanized (as used in spin casting) tools and resin tools. Actually, Aluminum is considered a soft tool -or- bridge tool as well.

I can imagine the diffulcities trying to gravity cast wax into silicone tool. Especially with a geometry like Eddie's wheel.

No... we would use a 'soft tool' made of High-temp, filled epoxy. That way we could inject the molten wax into the tool under moderate pressure, insuring complete fill and regulated density.

Oh the joys of RP!

We currently operate with SolidWorks 2003, AutoCAD 2000 w/M-desktop and Rhino.

Craig

Hi Eddy

Jacques here from Belgium. Perhaps Dieter Albisser from Switserland is willing to help. He makes inconel turbinewheels up to 70 mm. I Send you his coordinates

His email

( [email protected] )

He surely will give you an adequate answer. I am buying NGV's from him at this moment.

ALL the best Regards
Jacques

Maybe it can be done by EDM, i think some of the inconel turbine wheel of our small turbine are made that way by now.

EricJ : SolidWork is not an High-end cad prog It's an entry level one, like Inventor. ProE, CatiaV5, Ideas or UG are high-end integrated cad progs

I was thinking EDM sinker would be the way to go if you wanted a extremely close tolerance part just find a EDM shop and give them a call see what they could do for you.Paul

Ahh, epoxy tooling. Still very difficult and an art in itself! I think the only accurate wax pattern for this one is from RP directly. Soft tooling is just to complicated on that geometry. Wire EDM is a good method, but I'm not sure if you could hit all the angles. EDM burning with CNC electrodes would be great, but the price of one turbine stage would be the cost of an entire turbine. It's a tough call, but lets keep kicking it around.

Glorfindel : You crack me up! I'm a Pro/E guy to the core, 8 years. I still can't deny the quality of designs I've seen from Solidworks. Basically it depends on the end user and not the tool, but I know what you're getting at!

Thanks for all the help. Modelman is going to make
the part out of wax and we will on our way
to getting it cast...

I want to thank everyone for their input, without
RCU and your help I would still be stuck.. thanks

I put the biggest fillets I could.. Is there anything
else.. ?

Eddie Weeks

So Eddie - are yougonna keep us in the dark, or are you going to tell us what project this part is going to be used for ?

Gordon

I would show the CAD file to a casting house before you start the pattern making. Keep in mind that not all IC houses can handle inconel. Maybe a 2-D drawing showing cross sections and minimum wall thickness (blade thickness) would be helpful. Although the Wax pattern will be pressure injected, the casting will be gravity poured. They may request a different or multiple gating locations. Gating can have a dramatic affect on the shrinkage rate. Shrinkage could also vary in X,Y and Z directions. Gets complicated but it is an inexact science. Good luck and keep us posted how it works out.

-Eric

Dude... I have no idea... My only goal right now
is to sping that thing over 40,000... If that happens
then 2 x Turbofan Jetcat P80 could fly a 120 lb DC-10.

Eddie

Eddie,

Here's my two cent's worth. It seems that casting this is going to be difficult due to the undercuts. I don't know exactly what this is for or why it was designed the way it is, but what if you were to eliminate one or two blades so that none of them overlap each other. Then you'd get rid of the undercut and make casting this (as well as prototyping it) a lot easier.

Do a search on google for inconel casting. I do know that unless you plan on dumping a load of cash into this process, it's expensive. So is EDMing it unless you have a buddy who can do it for you.

Anyhow, just my input.

Russ

Likes like only one thing TURBO FAN

Turbulence

IF this thing works, and works well, it is very possible
to fly a plane with over 40 lbs of thrust that burns
6-10 oz min...

That a big IF because the last two we built did not work.!!!

Maybe this one... ?

BTW.. its a 5.8 inch dia fan

Eddie Weeks
http://www.corpcomp.com/weeks1/

Eddie I checked with our people here at work and I was right the cost would be in the tens of thousands of dollars for doing the tooling and first one then the price goes way down as all production items do.

EDDIE....SOUNDS LIKE YOU HAVE HIT ON SOMETHING AGAIN...GOOD LUCK MY FRIEND....THE JET MUD DUCK IS FINISHED..AM WAITING ON ENGINE....IT IS CALLED THE "MUD-DUCKTED FAN".........SEE YA IN WINONA IN MAY......