I need to print a full sized aero engine

I was asked yesterday if I could print up an aero engine. It needs to be full size, but I have no details as of yet as to which engine it is, so we just have to imagine something along the lines of an engine found in an airplane between of 1915 to 1920, with maybe with a V6 or V8 configuration. I just got a glimps of the original before the question was sprung on me, and it is fairly big.

Never having done anything of that scale before, I am stumped as to what to respond.

I suppose I would have to obtain or build a new, bigger better printer....!

I might be able to take photos tomorrow, or at least get the exact make and model of the engine. From what I can tell, their request is quite serious!

Anyone have any comments, suggestions, or frame of reference for me to start with?

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Yvan

Singularity Machine

have you thought about outsourcing the printing?

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+1 on outsourcing print. expect it to be expensive. shapeways is one of many choice vendors. or you could try parts sourcing. break down your print to components and have volunteers print out parts.

what is the size of each piece, ie how large is the largest piece?

Wow that's a big job is it just a external mockup of engine or is it every piece internally and externally of an engine either way very large job

I would think an early airplane would have 2-4 cylinders

Thank you for all the replies!

I just found out the engine is a Curtiss OX-5. It is a rather massive V8 dating from around 1917 or so. Overall length is over 50 inches.

I had not thought of outsourcing it. Does anyone have the faintest idea what kind of price range we might be talking about? Just the other day someone told me about a 11 inch long by 3 inch wide nylon part for a Bombardier snowmobile that cost them $1000. I can't imagine how much it would cost for a V8 engine.

This would only be an aesthetic mockup, it would be in an airplane hanging from the ceiling once done.

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Yvan

Singularity Machine

I don't think 3D printing is the right tool to use for this job--at least not all of it. You'd be better off trawling airport graveyards for broken engines you can scavenge for parts, or building a full-size replica using odds and ends, and 3D printing only small components that you can't easily fabricate out of something else.

How about printing a car in parts
[www.telegraph.co.uk]
Or
[www.independent.co.uk]

Don't listen to the nay-sayers who think that it is not the right thing for 3D printing on smaller machines. If you think in terms of theater set designing, it can look very convincing from a distance. Another reason why it would be good is that if it is being hung from the roof they will not want an 800lb monster engine on it
The cylinders and cylinder heads and other small parts could be done on something like a Rostock. The crankcase would be your biggest problem, it may have to be done in sections and may need gluing and filling. Some parts may need to be done with "vitamines" such as aluminium sheet etc..
Drawings of old engines such as the OX5 can be found in old copies of Jayne's All the Worlds Aircraft (1919 should be good) I think that they may be available from other sources like serious model engineering publications.

It will still be a huge job, but I think that it can be done cheaper than other mock-up methods -and should look muck better as well.

Best of luck, I envy you this job

Mike

Pointedstick, the same kind of thoughts have been going through my mind. They already have an OX-5, but since they want to suspend the circa 1917 airplane it would be mounted in from the cieling... the thought of a 400lb V8 in a plane made of popsicle sticks gets kinda scary!

Myles, wow, that guy's project is just amazing. Very good choice of car to copy too, although I lean towards Jaguars myself.

Mike, thanks for the encouragement! I think you have identified the heart of the matter. Thanks for the tip about the drawings. I will soon find out more detailed technical information about this project, such as maximum weight, time frame and so forth.

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Yvan

Singularity Machine

As they have an OX5, perhaps they could remove components such as cylinder heads for 3D scanning - this would save a lot of CAD time.

Mike.

I think Shapeways cheapest material is $1.75/cm3. I estimate the print volume around 250,000 cm3 so doing the math that = expensive.

Unless time and money is no object, then printing does not sound a great option. If all that is required is a lightweight mockup to be viewed from a distance, materials such as foam and balsa would seem like a cheaper option.

Strangely enough, it was the thought of gluing tugether several slabs of balsa to make a tube and then turning it to make one of the water cooled cylinders of the OX5 that convinced me. compare the time and materials for a 7 inch dia by 9 inch tall (vague memory/guess) cylinder with a 4 layer thick printed vase and there is no contest. the cylinder head in 10% fill will need a left hand and a right hand model. Various techniques for other parts, some of which won't be easy to 3D print, but identical to the non-3D printed versio, so no worse.
The clincher is that I know on no balsa/polystrene/papermache etc., model that still looks good a few years down the line even when they looked really good when just done

Wow that is a the big Job I think you going to have to use various methods some printed some wooden some Styrofoam printed parts for a rocker arms odds and ends the biggest problem I'm assuming they're going to put a real prop on this so you still need a good steel shaft and a way to support it in the block say going to have to have some sturdy wooden components inside block in fact block might be made out of plywood except for prop end printed maybe PVC pipe for cylinders copper tubing for water cooling lines probably print the heads too a lot of filler sanding and painting a big job for any model maker

Something like this from the Makerbot booth at NY Inside 3D print show 2013

[www.thingiverse.com] has the stl files. i think it is 1/10 or 1/20 scale. i have no clue as the the actual size. would be fun to group together a few people and build it though...

if they already have that engine, and it just need to look the same from the outside, can't you just vacuum form it from some sheets of plastic and then paint it?
this seems to me the fastest and easiest way to do it.

Edited 1 time(s). Last edit at 08/10/2013 05:18AM by possenier.

but if a group of people print an entire engine, would that not be greatness?

I woudl vacuum form the block and rocker arm covers and all the sheet metal parts, and print the carbureters and cylinder heads/cylinders and exhaust manifolds etc .

pics if this gets printed

DIY 3D printers, mine anyway, spend most of their time printing vases, busts of Yoda and parts for yet more 3D printers.

Then, a couple of days ago, Yvan told us that he had been approached to do a full scale 3D print of an aircraft engine. After the normal ( for me anyway) dismissive hrumphs etc., I though about it and realised that this was almost perfect for the FDM type of 3D printers which most on these forums have.

In evidence I submit a photograph of a Curtis OX5 cylinder and head assembly that I have just come across.

Plenty more of the valve gear etc. - just google for images of Curtis OX5.

Mike

There is a video of one running on Youtube [www.youtube.com], plus some other vids of OX5 stripped down.

Each cylinder has a bore of 4 inch and a stroke of 5 inches, to give an idea of size.

Wow, lots of good suggestions from everyone! I was in there workshop yesterday and I'm still in awe at everything I saw. I'll be there again next week and will ask if there are other smaller things they would like me to print. Once they see what I can do it could ease the way to the more challanging stuff like the OX-5. Talk about a cool 3D printing demonstation piece. And yes, it would be very cool if it was a community created project. I will keep that in mind.

I'll also ask if they have extra OX-5 parts, that would be good for scanning or measuring up.

Bobc, if we printed it up though, we could leave most of it hollow. In the end maybe the entire engine would be 50lb or so. Costs for ABS wouldn't be that insane then.

Leadinglights, that is an interesing point. I'll ask what they think of balsa, and why they are looking into 3D printing. I've done a fair share of model making with all sorts of materials. Durability is important.

cncdick, yes, the prop! It would look silly without one. I could weld a simple steel frame for that...

possenier, yes I wonder why they haven't done something like vacuum forming already? There is more to this than I know at the moment!

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Yvan

Singularity Machine

I don't see why you can't do this but you will want to let your customers know about the limitations of current 3d printing technology. Will you be painting the parts? Have you considered the time it is going to take to scan, catalog and model every part in 3d? You may also want to consider cncing some of the parts as that may be a better tool depending on each parts design.

BTW this sounds like an awesome project, I can't wait to see if this works out.

Yes, I have to question them much more as to why they have not already obtained a lightweight model of the engine using traditional means, and what leads them to think 3D printing is the solution.

I assume I would be painting everything to look authentic. I have never done something exactly like that, but I have a good amount of experience applying paint to plastic models, and canvas(back when I used to think I was an artist!).

I have to say I am not too intimidated by the 3D modeling part, I've been doing that on and off for almost 20 years now. Some projects were a bit complicated like a full blown steam locomotive, so this in not too challenging for me. Scanning technology is something I know nothing about, but it looks like it could be a real time saver.

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Yvan

Singularity Machine

Okay, so the most important aspect of this print would obviously be a knowledge of engines and of course indepth research on this particular one. The engine wasn't manufactured in one piece, so it shouldn't be printed in one piece.

That means the largest piece of this or any engine will be the main block where all the parts bolt into. From the pictures, it looks to be a 2 piece affair, with the bottom piece holding the oil, covering the lower end, and being larger than the top.

You could probably break the upper and lower into 3 or 4 pieces lengthwise and still have it be structurally sound. I would say a build area of 26 by 26 by 26 inch would probably be large enough to complete the engine. Otherwise would would need a printer capable of 56 by 30 by 40 or so, which would be silly.

Break the block into 8 pieces, 4 upper, and 4 lower portions. Then do all the parts that bolt up to that individually. The valve gear will be the toughest, the cylinders ought to be the easiest. I wouldn't worry about any internal or moving parts unless you would going to do cutaways, then of course this project would take months of build time instead of weeks.



Edited 1 time(s). Last edit at 08/12/2013 10:21PM by Snarky.

Snarky, you are correct. Those engines were built in multiple pieces. I've been thinking that would make this much easier. The crankcase is the only piece that is massive. I might have a 12 x 12 inch build platform if my latest printer works out. Print and glue, print and glue...

I've been swamped with distractions lately, and that big OX-5 project got drowned out by tantalizing leads to much, much bigger projects!

They will probably all blow over though, and I will soon be able to get back to building my new printer and then thinking of printing an engine with it.

Just waiting for the swirling madness to stop...

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Yvan

Singularity Machine

So this is what you need a 12"x12" printer for Hey, Nylon parts are pretty strong so you could probably use them to build several components of a real functional version of this engine

I wish you luck with this ambitious project!

Eric

Unless you need the inside of the motor to be a copy of the real thing, I would look for a foam milling workshop equipped with a CNC machine. Volume recreated with the milling operation will need to be finished and painted by an artist. Much faster, cheaper and likely lighter (the latter may be bonus if it is to be hanging from the exhibit ceiling) than 3D printing.