3D printed V8 air powered

[lozpeters]

Hi all,

I thought it was time I post up some info about my latest project! dont know if this is the right place but you guys have given me lots of inspiration

A bit about me and the project.
I am a design engineer for a well known vacuum cleaner company based in the UK. I have always loved building and making model and using engineering machines to make precise parts

So recently I have wanted a project that is a bit more involved than buying a plastic kit from the shop to assemble, this combined with my desire to get a classic American V8 muscle car (but no money ) has led me down this path! With no engineering machines at home to use and not currently having the skills to machine this all from billet aluminium. I have used my knowledge of modern CAD and 3D printing.

This is a scale V8 engine that I have modelled it up on CAD the idea is that it can be compressed air powered. I have had all the parts 3D printed from nylon and I am now in the assembly/tinkering phase to get it working

CAD screenshot






The supercharger/blower is all for show, no go hopefully the engine will be powerful enough to turn the supercharger. But I couldn't design the V8 without a supercharger

My idea was to get the engine running of compressed air to prove it works, If I can't get it running I will at least paint it up and have a nice display piece!

I thought I would post it up here in its current state so I can get feedback and advice from all you knowledgeable people

A big thanks to Chuck Fellows, Steve Huck and other members who have helped me with ideas with their fantastic design and skills.

More pictures to come and the progress so far
Hope you like it
Loz


Arrival day of the printed parts  it took 3 weeks of waiting!


1st main part assembly


all holes drilled out and tapped


pistons & con rods assembled


valve liners pressed in


all was going well until i slipped while reaming out the rotary valve which put it off center so i decided to drill the valve out larger and cast in a brass tube of the correct dimensions using a 2-part polyurethane


so this is where i am currently, the timing gears from the crank to rotary valve are too tight so awaiting 2 new slightly smaller gears to try out otherwise i may go for a belt driven timing connection. Hopefully the rotary valve will work in the new brass tube but it might be too small diameter and leak so i think i need to get back on the lathe at work and turn a new one up

[b.lindsey]

Very interesting project Loz. Good looking parts too, any idea what type machine they were printed on and the resolution?

Bill

[lozpeters]

Very interesting project Loz. Good looking parts too, any idea what type machine they were printed on and the resolution?

Bill

it was an EOS P110 SLS machine with a accuracy of 0.1mm, we use the same at my work but i got these sent out to a company in London as i couldn't claim it was a "work" project!

[crueby]

Will the other bearing surfaces, like con rods to crank, crankshaft to block, all have metal liners? Seems like plastic to plastic rubbing would tend to weld each other.

Very neat project, will be following along!

[lozpeters]

Will the other bearing surfaces, like con rods to crank, crankshaft to block, all have metal liners? Seems like plastic to plastic rubbing would tend to weld each other.

Very neat project, will be following along!

I have 2 roller bearings on either side on the crank but the middle journals are plastic to plastic and the same for the con rods to crank. i did it this way as i wanted to see if i could get it running 1st then work out exactly what parts need liners etc, at least i can cut away material easier than adding it on! I don't need it to rev much just wanted it to idle and show some sort of increase of revs!

i also wanted to see if the leaking compressed air would cool some of these parts so would have less on an issue but i imagine i will need to make up some sort of liners for these parts

[Brian Rupnow]

Very nice. There was somebody on this forum a week or two ago searching for information on exactly what you have done. (I think). I tried to find the post so I could direct him here, but couldn't find it. Maybe someone else can find it and direct the guy to your thread.---Brian

[crueby]

Very nice. There was somebody on this forum a week or two ago searching for information on exactly what you have done. (I think). I tried to find the post so I could direct him here, but couldn't find it. Maybe someone else can find it and direct the guy to your thread.---Brian

Just posted a link there, it is over in Your Own Design subforum.   

[lozpeters]

thanks for all the positive comments

Had a bit more time today to check over bits, the air valve is too small so i need to order new material and turn up a new one when it arrives. in the mean time i checked to see if the pistons move



each of the silicone tubes connects to the valve in the head an to the pistons, i went through the firing sequece blasting in compressed air and each one moved perfectly so now i know that bit works its all about the valve now

[Art K]

Very nice project you've got going. As Brian mentioned someone else has the same idea. Maybe somewhere down the road we can print metal parts.
Art

[lozpeters]

Very nice project you've got going. As Brian mentioned someone else has the same idea. Maybe somewhere down the road we can print metal parts.
Art

I was looking into metal printing have a look at these guys (there are many other too now)

http://www.3trpd.co.uk/dmls.htm

I think you could do a very similar process to cast parts that would require a lot less post finishing. If you designed it so the main block etc could be printed in ally, then ream/bore out the pistons and line them you could quite easily have an engine that could run off petrol. At the moment this metal printing is expensive but expect the cost to drop dramatically over the next few years!

[stevehuckss396]

At the moment this metal printing is expensive but expect the cost to drop dramatically over the next few years!

Doesn't seem to be expensive. I just ordered 2 gears to be printed in steel for 42 bucks. That seemed cheap to me.

[b.lindsey]

I doubt you could buy manufactured gears for that Steve. That's not bad at all.

Bill

[lozpeters]

That's a good price, what size of gears were they? If the resolution is there in metal printing will be fantastic for some of the more complicated engine parts as you just don't need to worry about undercuts or internal ducting

[cfellows]

Stock Drive Products has a huge assortment of machined gears in brass, steel, stainless, aluminum, and plastic.  They sell spur gears, worm gears, helical gears, bevel gears and others.  Their prices seem pretty reasonable.  I think they have a $25 minimum order policy, but two gears will probably meet that requirement.

http://www.sdp-si.com/

Their web site is a little tricky to navigate, obviously designed by someone who wanted to make it flashy.  But it's manageable.

Chuck

[stevehuckss396]

That's a good price, what size of gears were they? If the resolution is there in metal printing will be fantastic for some of the more complicated engine parts as you just don't need to worry about undercuts or internal ducting

One is 1.710 OD and the other is .425 OD. I'll post a few pictures in the chevelle thread when I get them.

[stevehuckss396]

Stock Drive Products has a huge assortment of machined gears in brass, steel, stainless, aluminum, and plastic.  They sell spur gears, worm gears, helical gears, bevel gears and others.  Their prices seem pretty reasonable.  I think they have a $25 minimum order policy, but two gears will probably meet that requirement.

http://www.sdp-si.com/

Their web site is a little tricky to navigate, obviously designed by someone who wanted to make it flashy.  But it's manageable.

Chuck

These were Skew/Bevel gears for the ring and pinion in the little ford rearend. Not something I could get off the shelf.

[Pete49]

While not in the same class or taking away from your great design I saw a very Subaru boxer engine on http://www.thingiverse.com that uses a electric motor to turn it over. While it cheats it was very detailed and is a great way to understand the mechanics of these things. He also had a Toyota motor and I believe a gearbox as well. I am wondering on the feasibility of printing them in PLA and casting the motor block and head in aluminium and making it a runner though my skills are well below what would be needed.
Pete