# Fully 3D Printed DIY electric car



## schelle63 (Jan 3, 2018)

Buenos dias Gonzalo,
this is an interesting project, and a very nice design and concept. I would like to know more about your inspiration (from NZ...?), too.
To be honest, I doubt that your concept to print all the structural parts, too, will work. I feel that axles and suspension will need some metal (or at least good fibreglass or carbon fibre) to make them last longer than a couple of moments. Anyway, appears to be a very nice idea to me.
I must have an old CATIA-instllation somewhere in my desk, so we could share some ideas.
Do You intend to make it street-legal, some day? I assume that this would be a huge (if not impossible) task, especially in Spain. By the way, where do you come from, there?
Markus


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## brian_ (Feb 7, 2017)

schelle63 said:


> To be honest, I doubt that your concept to print all the structural parts, too, will work. I feel that axles and suspension will need some metal (or at least good fibreglass or carbon fibre) to make them last longer than a couple of moments.


True, but I suspect that the "etc" part of the off-the-shelf parts list in this statement:


_GonZo_ said:


> It is Designed to be made with standard hobby printers and easy to find/work PLA, and/or maybe PETG plastic. Some small parts printed with Nylon. And some off the shelf components like motor, battery, lights, screws, etc.


... will include hubs, bearings, spindles or hub carriers, all braking system components, and many suspension components.

All that would be printed would probably be body parts. And yes, I agree that's a problem for anything structural: polymers are generally not adequate for structure in a vehicle without some sort of reinforcing fibre. It is possible to "print" with a polymer filled with short carbon fibres, although that's not likely within the capability of "standard hobby printers", and is not a common material.


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## pickmeup (May 8, 2018)

Hey Gonzo this looks like a really interesting project, im a great fan of using additive manufacturing and have been luck enough to work in the industy on and off for the last 10 years. I was recently helping my previous workplace look at large scale additive manufacturing for producing composite mould tools and components for aircraft.
Ive done a fair few projects on using FDM printingto make parts and bodypanels, you should check out the guys at Scaled3D they have just completed printing a full electric vehicle, the bucket seat sat on top was made using one of our combined projects.


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## pickmeup (May 8, 2018)

PROJECT CHAMELEON


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## _GonZo_ (Mar 23, 2009)

schelle63 said:


> this is an interesting project, and a very nice design and concept. I would like to know more about your inspiration (from NZ...?), too.
> To be honest, I doubt that your concept to print all the structural parts, too, will work. I feel that axles and suspension will need some metal (or at least good fibreglass or carbon fibre) to make them last longer than a couple of moments. Anyway, appears to be a very nice idea to me.
> I must have an old CATIA-instllation somewhere in my desk, so we could share some ideas.
> Do You intend to make it street-legal, some day? I assume that this would be a huge (if not impossible) task, especially in Spain. By the way, where do you come from, there?
> Markus


Thank you Schelle63 for your words. Answering to your concerns and adding more info:

The shape of the body (But just the shape) was greatly inspired by the Velopetta fromhttps://www.velectric.co.nz designed by Peter Vullings. I asked permission to him, and I have to attribute as it corresponds. As well I was inspired by more vehicles, you can see them in this video I made: 




The project is quite experimental and risky. But I am not fool enough to print things like axles, bearings, hubs, motor, etc. That will make no sense at all because it is not job for a 3D printer at all, and most of them are just commodities.
In a few days (maybe weeks) I will "open" the documentation including 3D files so you will be able to see it in more detail, you are really welcome to give ideas and help.
I will like to make it street legal, but as you Spain is a no go way for that. Anyway I plan to use it with peddling system, so it may pass like an e-bike...
Malaga


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## brian_ (Feb 7, 2017)

_GonZo_ said:


> The project is quite experimental and risky. But I am not fool enough to print things like axles, bearings, hubs, motor, etc. That will make no sense at all because it is not job for a 3D printer at all, and most of them are just commodities.


That makes perfect sense, although some of those components (metal structures such as suspension arms, hub carriers, and brake calipers) are quite producible with additive manufacturing (or "3D printing")... just not hobby-grade printers that can only deposit thermoplastic. So why call it a "Fully 3D Printed DIY electric car" instead of what is really is: a "DIY Electric Car with Fully 3D Printed Body"?


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## _GonZo_ (Mar 23, 2009)

brian_ said:


> True, but I suspect that the "etc" part of the off-the-shelf parts list in this statement:
> ... will include hubs, bearings, spindles or hub carriers, all braking system components, and many suspension components.
> 
> All that would be printed would probably be body parts. And yes, I agree that's a problem for anything structural: polymers are generally not adequate for structure in a vehicle without some sort of reinforcing fibre. It is possible to "print" with a polymer filled with short carbon fibres, although that's not likely within the capability of "standard hobby printers", and is not a common material.


Yes brian, you are right, As I commented before: I do not pretend to to print things like axles, bearings, hubs, motor, etc. That will make no sense at all because it is not job for a 3D printer at all, and most of them are just commodities.

But all the rest will be 3D printed as it is a self supported structure, I mean it is not a body bolted over a metal frame as manny have done already before.

As you say plastic itself is not so stiff and strong as other materials like composites or metals.
But with 3D printing it is possible to create internal structures in the parts that are impossible to do with other manufacturing systems. So it is possible to get final parts quite strong if properly designed.
As well I am using other tricks in order to enhance the unibody strength. Starting from the "egg" shape...


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## brian_ (Feb 7, 2017)

_GonZo_ said:


> Yes brian, you are right, As I commented before: I do not pretend to to print things like axles, bearings, hubs, motor, etc. That will make no sense at all because it is not job for a 3D printer at all, and most of them are just commodities.
> 
> But all the rest will be 3D printed as it is a self supported structure, I mean it is not a body bolted over a metal frame as manny have done already before.


Right... so it's a fully 3D-printed *body* (or unibody, since it is a unitized body and structure), not car.



_GonZo_ said:


> As you say plastic itself is not so stiff and strong as other materials like composites or metals.
> But with 3D printing it is possible to create internal structures in the parts that are impossible to do with other manufacturing systems. So it is possible to get final parts quite strong if properly designed.
> As well I am using other tricks in order to enhance the unibody strength. Starting from the "egg" shape...


Actually, components with internal structure can be made by other methods. Composites with cores (typically honeycomb or foam, in metal, composites, or polymers) have been common in race and custom vehicles for many years; even some travel trailers have cored composite construction now. 3D printing may be a way to produce them more easily and less expensively - which is good  - but it's not the only way to get internal structure.

The egg shape is cute, but not structurally useful unless it is a complete shell - with an open top and doors, it's no longer an egg.


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## Duncan (Dec 8, 2008)

You CAN make a car body using hundreds of small 3D printed parts
But why in the name of the wee hairy one would you want to???

Use the correct tools for the jobs!!

Don't hammer in nails with your micrometer


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## _GonZo_ (Mar 23, 2009)

Duncan said:


> You CAN make a car body using hundreds of small 3D printed parts
> But why in the name of the wee hairy one would you want to???


Well, because I like to try new things and new ways. In other words, I like to research.
Same as many other people here and worldwide.


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## _GonZo_ (Mar 23, 2009)

brian_ said:


> Actually, components with internal structure can be made by other methods. Composites with cores (typically honeycomb or foam, in metal, composites, or polymers) have been common in race and custom vehicles for many years; even some travel trailers have cored composite construction now. 3D printing may be a way to produce them more easily and less expensively - which is good  - but it's not the only way to get internal structure.
> 
> The egg shape is cute, but not structurally useful unless it is a complete shell - with an open top and doors, it's no longer an egg.


Yes, there is other ways to create internal estructures but not with the control and in the shapes that can be done in a 3D printed part. 

It is not a full egg shape as its "broken", but still better than a boxy shape.


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## _GonZo_ (Mar 23, 2009)

pickmeup said:


> PROJECT CHAMELEON


Whoaaa...  
I was not aware of that project, thank you very much for posting it.


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## Duncan (Dec 8, 2008)

_GonZo_ said:


> Well, because I like to try new things and new ways. In other words, I like to research.
> Same as many other people here and worldwide.


Use the correct tools for the job - and experiment
But don't use your micrometer as a hammer!


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## schelle63 (Jan 3, 2018)

This is going to be an interesting project anyway. I am looking forward to see the files.
Which 3d program do you use?
Markus


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## remy_martian (Feb 4, 2019)

Speaking of using a vernier caliper (much better than micrometer for balance) as a hammer, there are some belt printers on Kickstarter right now (and another coming on the 18th), so your longerons and formers can now be printed in one piece...maybe carbon-reinforced nylon would be a good choice?


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## brian_ (Feb 7, 2017)

remy_martian said:


> Speaking of using a vernier caliper (much better than micrometer for balance) as a hammer...


But a micrometer has a much more massive "hammer head" portion. 



remy_martian said:


> ... there are some belt printers on Kickstarter right now (and another coming on the 18th), so your longerons and formers can now be printed in one piece...maybe carbon-reinforced nylon would be a good choice?


That makes sense, but are we going from common home 3D printer to Kickstarter promised products, and from common media to carbon-reinforced? Then I would suggest moving the rest of the way to a different construction method...


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## remy_martian (Feb 4, 2019)

Carbon fiber reinforced filament (it's chopped, not oriented strands, so far from coming close to a real composite) is common - you can get it from a number of vendors and sellers where you get other filament. Kickstarter's a risk, but printing a car out of PLA _will_ fold up, lol

The constraint here is "3d printed". Can it be done, more whimsical than reality. Some of you are missing that. 

Not the right, or optimal way to do build a car, but one where you're on a small desert island with a 3d printer and a box full of axles & wheels and you want to cruise for chicks and get to the grocery store (yes, I know what I just wrote).


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## _GonZo_ (Mar 23, 2009)

schelle63 said:


> This is going to be an interesting project anyway. I am looking forward to see the files.
> Which 3d program do you use?
> Markus


Thank you Markus.
I use Onshape.


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## _GonZo_ (Mar 23, 2009)

As remy_martian says it s not the right or the optimal way to build a car. I am very aware of it.

Provably the most reasonable way to build a vehicle like this, will be using a fibre glass/carbon body and reinforce it with internal ribs or a metallic chassis underneath, or may be both. Been there done that.

Even if going throw the 3D printing way, to use just hobby printers is not the right or optimal way. I am aware of that as well.
The most reasonable way of 3D print a car like this, it is probably to use a huge 3D printer and print it all at once or may be in some big parts. But I do not have the resources or access to a printer like that. AND IT IS NOT CHALLENGING, it has been done already by many.







And as stated in the description: _"This is an experimental project that aims to explore the limits of hobby 3D printing.
This project does not aim to reproduce a standard vehicle construction. Many things can go wrong, but I am sure we will enjoy and learn through the process."_


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## brian_ (Feb 7, 2017)

_GonZo_ said:


> Provably the most reasonable way to build a vehicle like this, will be using a fibre glass/carbon body and reinforce it with internal ribs or a metallic chassis underneath, or may be both.


True... and that's a BMW i3. It's practical as a home build, if you use a simple frame as a base with a composite (or even just thermoplastic) body on top.



_GonZo_ said:


> Even if going throw the 3D printing way, to use just hobby printers is not the right or optimal way. I am aware of that as well.
> The most reasonable way of 3D print a car like this, it is probably to use a huge 3D printer and print it all at once or may be in some big parts.


Speaking of size... with actual hobby printers (not some product that isn't even available yet) what are your maximum part dimensions? Some hobbyists have built quite large 3D printers, but those are not "standard hobby printers". It might make sense to open up the constraints a bit, and consider using a larger printer that can be built from a readily available kit.


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## brian_ (Feb 7, 2017)

remy_martian said:


> The constraint here is "3d printed".


It's actually this, which is substantially different and far more restrictive:


_GonZo_ said:


> ...to be made with standard hobby printers and easy to find/work PLA, and/or maybe PETG plastic. Some small parts printed with Nylon...





remy_martian said:


> Can it be done, more whimsical than reality. Some of you are missing that.


I'm not missing that. I'm just looking for some reality in the description - 3D printed body (not 3D printed car) - and in expectations of what the material can reasonably do, particularly when building a large object from small pieces.


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## _GonZo_ (Mar 23, 2009)

brian_ said:


> Speaking of size... with actual hobby printers (not some product that isn't even available yet) what are your maximum part dimensions? Some hobbyists have built quite large 3D printers, but those are not "standard hobby printers". It might make sense to open up the constraints a bit, and consider using a larger printer that can be built from a readily available kit.


I have already cut the parts to fit printers with a build volume of 220x220x220mm that is actually quite standard for hobby printers. The one I own now is 220x220x230mm
The actual tendency in hobby printers is going to bigger build volumes 300x300x300mm and up.
If I am able to gather enough economic resources I plan to buy one printer with that bigger sizes and then cut the parts to fit in that larger printers.
And obviously use that bigger printer for the job.

I think by tomorrow I will have ready some sample parts files to publish so you will be able to see how its made.


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## _GonZo_ (Mar 23, 2009)

As commented I just created today a project in Prusa printers and Thingiverse because I will be releasing the Open Source in a few days (maybe weeks…) and needed the links for the documentation.
And because in some forums people wanted to see more and see how the parts are, and if they can print them.
So I just uploaded in the projects a couple samples pieces of the body, anyone can print them with the printing suggestions and profiles detailed and check if they like the idea.
Please post your prints and please give some feedback.

Link to PrusaPrinters: https://www.prusaprinters.org/prints/46 ... ellybean3d
Link to Thingiverse: 3D PRINTED DIY ELECTRIC CAR, The Jellybean3D by GonzaloChomon
Any suggestion and help is welcome. Feel free to comment.


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## brian_ (Feb 7, 2017)

I assume that the colour patchwork is just to show the shape. Do you have a version yet that shows how the body is divided into 300 mm x 300 mm x 300 mm parts?


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## _GonZo_ (Mar 23, 2009)

brian_ said:


> I assume that the colour patchwork is just to show the shape. Do you have a version yet that shows how the body is divided into 300 mm x 300 mm x 300 mm parts?


What you can see on that image are the different parts. Now cut to fit 220x220x220mm printers (I own one about that size)
If I gather enough resources, I will get a larger one (300x300x300mm+) and will perform the cuts for that printers size.
The colour patchwork is made in order to see better the different parts.
A sample part image:


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## pickmeup (May 8, 2018)

I would add some features like a key way or slot to allow for better mechanical attachment to each other, also what material are you looking at for bonding the parts together?
A good structural adhesive like 3M DP490 works very well on PLA


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## brian_ (Feb 7, 2017)

_GonZo_ said:


> What you can see on that image are the different parts. Now cut to fit 220x220x220mm printers (I own one about that size)


Okay, thanks. The patchwork just looked a little random to me to be a plan for parts... for instance, wouldn't you make the headlight housing as one part, and the concave area in front of it as another part, to avoid the most obvious seams? Wouldn't you overlap rib sections over body panel sections, rather than having their joints line up?



pickmeup said:


> I would add some features like a key way or slot to allow for better mechanical attachment to each other...


Absolutely! Just ending parts with butt joints would be a structural nightmare, especially in those ribs. They need to mechanically interlock or at least have joints which provide suitable adhesive bonding surfaces. To illustrate this, take a plastic model of a vehicle, saw it into a checkerboard of pieces, and see if you can glue it back together into anything other than a fragile mess.


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## _GonZo_ (Mar 23, 2009)

pickmeup said:


> I would add some features like a key way or slot to allow for better mechanical attachment to each other


I will love to do so, but I have not found a way to automate that kind of features in the CAD software. Doing them by hand is almost imposible (over 2000 features) and if it is not automated (like a pattern or so) the CAD files provably colapse with so many operations.



pickmeup said:


> what material are you looking at for bonding the parts together?


The final construction material has not been chosen yet. So final bonding method has not beed decided either..
But I have done some previous tests on PLA with different glues including different structural epoxies and the one that works best is Cyanoacrylate, even the cheapest one bonds better that the best epoxy.
But cyanoacrylate does not produce strong permanent bondings on things that are going to be exposed to moisture, sunlight and temperature differences.
So I will provably will use chemical welding instead of glueing, but I still didn't have time to test this method.



brian_ said:


> Okay, thanks. The patchwork just looked a little random to me to be a plan for parts... for instance, wouldn't you make the headlight housing as one part, and the concave area in front of it as another part, to avoid the most obvious seams?


It is not easy to perform the cuts as many things have to be taking in account:

Printer size, so the parts fit in the printing volume.
Printing orientation, in order to get the most strength in the directions that are more need in the part and make them coincident with the XY printing plane.
Cut in the appropriate orientations and locations in order to avoid the use of supports when printing.
Avoid or enforce the cuts in determinate areas in order to strengthen or not weaken them.
That is why it looks a bit random, but actually it is not random at all.



brian_ said:


> Wouldn't you overlap rib sections over body panel sections, rather than having their joints line up?


Sorry, do not understand this question.


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## brian_ (Feb 7, 2017)

If the 3D printing software can't handle making the pieces so they can be joined properly, I don't see much point in using it. You might as well carve the shape in foam and lay fiberglass on it, as has been done for decades, and have a lighter and stronger shell... probably with less manual effort than piecing this together. I understand that the idea is a 3D printing challenge, but doesn't that mean you should solve the joint problem as part of that challenge, rather than just ignoring it?

If you look at a brick wall, they are never (unless they are purely decorative) built with all of the vertical joints lined up, the way you have lined up panel joints and rib joints. Bricks in each row overlap the joints in the rows above and below, so the wall isn't so likely to just fold at a vertical joint. These patterns of bricks are called bonds; while you're not working with masonry, the same idea of avoiding problems at joints applies.

If you can find the right adhesive, you might be able to make those patchwork ribs actually useful by printing them as two half-thickness pieces, bonded together, with staggered joints. Far more effort and material than just putting a couple of bends in an aluminum strip with a brake to make a stronger rib, but still 3D printed...


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## _GonZo_ (Mar 23, 2009)

I made a printable 1/10 scale model of the Jellybean3D, let me know what you think.
You can download the file parts for printing from: PrusaPrinters
Check this short video for printing, assembly instructions and other details: *



 *
.


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## remy_martian (Feb 4, 2019)

That forthcoming printer I mentioned is now sitting at $1M worth sold, at about $600 a pop. People have printed next-to-useless, lol, 20 foot I-beams on the prototypes. Unlike many Kickstarters, this is being used as a sales channel (Kickstarter used to be strict about funding creativity, then they basically turned themselves into whores, IMO) by one of the largest printer makers in China. The carbon fiber filament makes the print stiffer, but does next to nothing for strength. You can pause the printer and add rods,hardpoints, nuts, etc, to embed them into the plastic. 

Severely compromised way to do it, more challenging than doing it the "right" way...which seeds innovation.


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## remy_martian (Feb 4, 2019)

^^ What you could do is "Crowd print" the pieces. 

This was done for a hobbyist get together where everyone pitched in with printing a piece of a very large project a few years ago and got to be part of it. I don't recall the details as that part of my brain is still in "longhauler" Covid fog. Might have been Adam Savage for an Ironman suit, maybe.

As far as joining, good old dovetails works, as would using rods on the inside threaded through surface "eyelets" in the part


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## brian_ (Feb 7, 2017)

remy_martian said:


> As far as joining, good old dovetails works, as would using rods on the inside threaded through surface "eyelets" in the part


But either of those would require features on the edge of each piece which are apparently too difficult to do.


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## remy_martian (Feb 4, 2019)

He can probably attach the eyelets while in assembly. Think piano hinge.

There are other tricks you can do on the solids with Booleans while it's in assembly...maybe.


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## brian_ (Feb 7, 2017)

remy_martian said:


> He can probably attach the eyelets while in assembly. Think piano hinge.


Then why use what is effectively a hinge? Why not just use plates? This is patching the pieces together... I suppose that could look steampunk if done right


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## remy_martian (Feb 4, 2019)

Plates wouldn't reinforce it, though I suppose you could rivet half-thickness plates together for double the print-time fun and to get your repurposed steam-boiler look.


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## _GonZo_ (Mar 23, 2009)

Thank you for all your comments. Very helpful and had make me think and improve.
To have some kind of interlocking system will be very helpful when assembling the parts, and obviously will make the joints stronger. But actually tho make the joints stronger is not necessary because they are already stronger than other areas of the parts. Let me explain:
The parts are almost "hollow" they only have a internal structure at the mesoscale level, while the edges and faces are solid. So when glueing/welding the edges, the joint are stronger than other areas of the parts, so they will never be the point of failure, so to make them even stronger is not necessary.

But this comment from Brian (Thank you) made me think...


brian_ said:


> If you look at a brick wall, they are never (unless they are purely decorative) built with all of the vertical joints lined up, the way you have lined up panel joints and rib joints. Bricks in each row overlap the joints in the rows above and below, so the wall isn't so likely to just fold at a vertical joint. These patterns of bricks are called bonds; while you're not working with masonry, the same idea of avoiding problems at joints applies.


The bricks wall are made that way for several reasons one of them is because usually the joints are weaker than the bricks, but in this case the "bricks" (parts) are weaker than the joints. So it let me thinking that instead of misaligning the joints, it could be good to align them, in a short of a web pattern, in order to create an estructure in the macro-scale level, with the joints pattern. Certainly this is a constrain that I do not took in consideration when performing the cuts.
Maybe I decide to recut again the body taking in account this in order to improve strength.



remy_martian said:


> ^^ What you could do is "Crowd print" the pieces.


That is great idea and will love it to do it that way. But I see a big problem with it.
The project has already too manny variables and possible problems, adding the issues of different material brands, tolerances, different print setups, etc. may turn it into a nightmare...


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## Duncan (Dec 8, 2008)

The limit on the size of a 3D printer is simply the length of the actuator rods SO
Either make some longer rods or change the mechanism
This is a diy CNC wood cutter that takes 8 x 4 sheets





It would be easier and more useful to try and adapt something like this to print the body in a small number of parts rather than use lots of little bits


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## _GonZo_ (Mar 23, 2009)

Duncan said:


> It would be easier and more useful to try and adapt something like this to print the body in a small number of parts rather than use lots of little bits


Yes it will be easier to have a huge 3D printer and do it in just a few parts. 









But I do not have access to one of those or resources to make/hire it.


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## Duncan (Dec 8, 2008)

Its probably easier to make a bigger 3D printer than to make a car out of little bits !
The limiting factors are the two base actuators and the up/down actuator
They are basically threaded rods driven by a stepper motor - you can make a threaded rod 2 meters long
It would take a very long time to print something!


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## remy_martian (Feb 4, 2019)

While you could do that, Duncan, you trade finishing labor for printing speed. 

Tasking 50, $150 printers gets the job done at finer layer heights, vs one $7500 behemoth that needs monstrous nozzle sizes and layer heights (which you can see in the pic in this thread) to get the job done in reasonable time.


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## Duncan (Dec 8, 2008)

remy_martian said:


> While you could do that, Duncan, you trade finishing labor for printing speed.
> 
> Tasking 50, $150 printers gets the job done at finer layer heights, vs one $7500 behemoth that needs monstrous nozzle sizes and layer heights (which you can see in the pic in this thread) to get the job done in reasonable time.


Why would a bigger printer need to use bigger blobs?
Could it not use the same size - same resolution - as the smaller printers?
It would take a lot longer to print each layer - but it would be in one piece
Why would it cost more?
A pair of 2 meter long threaded rods would be what $40 ??
You may need the next size up stepper motors
The change would be in the software - and that would be a one off cost
The Maslow CNC cutter is about $400
replace the Cutter head with a plastic extrusion nozzle - and you are half of the way there

I keep thinking about buying a 3D printer and/or a Maslow - but I don't have a project for them that I can't do with my current tools


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## remy_martian (Feb 4, 2019)

The major cost/hassle is in the heated bed.

One of his pieces is likely to take a few hours to print. One. So a year or two to print the car 24/7, lol.

So the only solutions are larger nozzle or multiple printers or both. In the picture, you see the layers of spaghetti, which means one of my most abhorred activities....sanding. After bondo, maybe.


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## Duncan (Dec 8, 2008)

If you make the printer big enough for a car then it will take the same amount of printing time as many smaller printers - which means much LESS overall time as you don't have all of the setup for each part and time to glue the thousands of individual parts together

Heater pads are about $20 each - so a 100 of them would be $2,000 for a 2 meter by 2 meter heat pad - but you would use a metal base with a smaller number of heat pads underneath - I assume the pads are controlled to a set temperature so you may end up with a large power bill but not a HUGE one

I'm intrigued by the idea of a large 3D printer - I may well buy a small one and see what's involved in making a huge one


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## remy_martian (Feb 4, 2019)

I bought an Ender 5 Plus and am doubling the print bed size. 15x30 inches when done. Two heated build platforms for it were $160

If you increase your print volume from 0.3m cube to 2m cube, your print time for a solid cube will go up by a factor of 300. What took a day to print will now take a year (with no jams, skips, running out of filament, power loss, etc). So, you _have to_ up the layer thickness, which is what they did in that large print pic earlier in this thread.

With 50 small printers, you're done in a week with fine layer lines.


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## _GonZo_ (Mar 23, 2009)

That is the question.
What is better, use a big printer or a myriad of small printers?
I find similarities of this discussion as the one we had about Tesla car batteries long time ago.
What is better, use large size cells or a myriad of small cells?

And the answer is the same: Due to actual available resources, the best is: to use small printer/s.


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## Duncan (Dec 8, 2008)

_GonZo_ said:


> That is the question.
> What is better, use a big printer or a myriad of small printers?
> I find similarities of this discussion as the one we had about Tesla car batteries long time ago.
> What is better, use large size cells or a myriad of small cells?
> ...


If you are restricting yourself to using commercial machines then yes 
But this is a DIY forum and once you have a 3D printer it does NOT appear to be that difficult to simply increase the size of the table


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## brian_ (Feb 7, 2017)

_GonZo_ said:


> Yes it will be easier to have a huge 3D printer and do it in just a few parts.
> View attachment 120968


But hopefully with finer resolution than that ridiculous thing, which almost looks like it was built from Lego.


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## brian_ (Feb 7, 2017)

_GonZo_ said:


> I find similarities of this discussion as the one we had about Tesla car batteries long time ago.
> What is better, use large size cells or a myriad of small cells?
> 
> And the answer is the same: Due to actual available resources, the best is: to use small printer/s.


First, this isn't about battery cells. Second, most EV manufacturers use relatively large pouch cells, not small cylindricals... and even Tesla moved to 50% larger cells years ago, and they changed from 16 modules (in the S/X) to 4 (in the 3/Y). And they never made a module by soldering together a dozen sub-assemblies of cells because they couldn't work with a suitably sized bus plate. But you're right: Tesla only used laptop battery cells because that's all they could get.


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## brian_ (Feb 7, 2017)

(sorry, accidental duplicate post)


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## brian_ (Feb 7, 2017)

remy_martian said:


> If you increase your print volume from 0.3m cube to 2m cube, your print time for a solid cube will go up by a factor of 300. What took a day to print will now take a year (with no jams, skips, running out of filament, power loss, etc). So, you _have to_ up the layer thickness, which is what they did in that large print pic earlier in this thread.
> 
> With 50 small printers, you're done in a week with fine layer lines.


No, the object printed with the larger printer isn't more solidly filled, so the print time doesn't scale up as the cube of the fragment linear dimension.


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## _GonZo_ (Mar 23, 2009)

Duncan said:


> If you are restricting yourself to using commercial machines then yes
> But this is a DIY forum and once you have a 3D printer it does NOT appear to be that difficult to simply increase the size of the table


Yes, I am going to restrict myself to comercial hobby printers with small modifications to print big parts. I am not going to build printer/s.
Don't you think that designing from the ground up a fully electric vehicle is enough DIY?




brian_ said:


> First, this isn't about battery cells. Second, most EV manufacturers use relatively large pouch cells, not small cylindricals... and even Tesla moved to 50% larger cells years ago, and they changed from 16 modules (in the S/X) to 4 (in the 3/Y). And they never made a module by soldering together a dozen sub-assemblies of cells because they couldn't work with a suitably sized bus plate. But you're right: Tesla only used laptop battery cells because that's all they could get.


I used the Tesla battery thing just as an example, of why sometimes things are not made in the optimal way, but they can work.

A bit about it:
I was involved in the definition of that first battery design, many many years ago when Tesla was not even Tesla.
There was available larger cells in the market at that time, Actually by that time Wiston started to sell the first big Lion and Life cells to the market, that before were restricted only to military Chinese uses, mainly submarines. But they were very high priced and they were not reliable, and Wiston didn't want to sell few units, etc.
So we decided to build the battery for the prototype with 18650 cells. It had an advantage; some dead cells out of some thousands makes almost no difference in performance. But it was a night mare to build.
The reason why Tesla is still using that monstrous I don't know, but I can imagine that they had spent several hundreds of millions in the manufacturing engineering of that kind of packs and that is something you can not throw away...


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## _GonZo_ (Mar 23, 2009)

Back to the topic:

I always promise myself that when designing a vehicle the first area is going to be the front steering/suspension geometry, but always I break my promise .... 
So the front end knuckles have been ones of the lasts parts I have designed.
It was not in my mind to 3D print them and provably use CNC aluminium parts or similar.
But I was given the opportunity to test the nTopology platform for 7 days. Although it is a quite complex software due to its enormous capabilities, I was able to perform topology optimisation to the knuckles.
The people of nTopology liked the project and gave me some extra time to further work in them.

And here is what come out. It still may need some refinement but they will be something like this:


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## Duncan (Dec 8, 2008)

_GonZo_ said:


> Yes, I am going to restrict myself to comercial hobby printers with small modifications to print big parts. I am not going to build printer/s.
> Don't you think that designing from the ground up a fully electric vehicle is enough DIY?


Naahh - thats not that difficult! - mine has been on the road for seven years now


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## _GonZo_ (Mar 23, 2009)

More info about the DIY 3D PRINTED CAR. Today components, components and more components.


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## _GonZo_ (Mar 23, 2009)

I knew that this project was going to take me to unexplored places... 🤣
In order to join the different parts I need a good "glue" that is able to create bondings that are strong, reliable and durable on PLA or PETG.
The best result I have got are with Cyanoacrylate (CA) or Gloop but both have some issues:


*CA* while the bondings are very strong they are not durable under moisture and UV light, and it is a quite expensive glue.
*Gloop* it is even stronger than CA as it is a chemical welding, but it cures/dries too fast. What I mean is that the parts are big and it dries up before I am barely able to apply it to both parts surfaces to be bond. Also it happens that as soon as the surfaces get in contact they weld so strong that is imposible to reposition them in the case of misalignment. (Similar to contact glue)
So after testing the Gloop I decided that that was the path to follow; to use a similar chemical welding as it is used for ABS or PVC.
And I have good news, after dusting off my organic chemical knowledge, I think have found the right mix of solvents and fillers to create a similar product to be used in PLA (It looks like it can work as well on PETG).
It still needs some refinement in order to get the right proportions of solvents/fillers, and the right fillers in order to get the right joint elasticity. But it actually works, and the first tests looks very promising.

More info in following days.


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## _GonZo_ (Mar 23, 2009)

I managed to design a glue for PLA that actually creates stronger bondings than epoxy ones.
More than a glue is a chemical welding product. It is made with a solvent (Dichloromethane) and PLA+ as filler.
It really works well in PLA, PLA+ and PETG but need some more test in this last one.
I am now working in the proportions (Filler/Solvent) in order to get the best results and easy to use.
Made a vido comparing different bonding systems:


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## _GonZo_ (Mar 23, 2009)

First parts just come out of the printer (door parts+), all looks good so far.
Next step chemical welding.


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## brian_ (Feb 7, 2017)

I assume that the first image shows the door parts in the orientation that they were printed, except perhaps the centre and right parts on the bottom (closest to the camera) row.

As shown in post #26, the individual pieces of the door panel are the same thickness at the edge as in the middle, as if a complete physical component were just sawn apart into small enough pieces to fit the printer. With these actual pieces, this is confirmed and the thickness becomes apparent... and the door panel appears to be incredibly thick, and apparently solidly filled (no honeycomb or similar structure with voids, due to the part orientation in the printer). How thick is this panel (ignoring the reinforcing rib and edge)?


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## _GonZo_ (Mar 23, 2009)

brian_ said:


> I assume that the first image shows the door parts in the orientation that they were printed, except perhaps the centre and right parts on the bottom (closest to the camera) row.


Yes most of them are in the printing position but not all. I cut the parts in order to avoid using supports. All this parts print with no supports.



> With these actual pieces, this is confirmed and the thickness becomes apparent... and the door panel appears to be incredibly thick, and apparently solidly filled (no honeycomb or similar structure with voids, due to the part orientation in the printer). How thick is this panel (ignoring the reinforcing rib and edge)?


The panels that compose the unibody and door have a thickness from 10mm to 20mm depending on how much stress that area has to handle.
The parts are almost hollow (See picture) with an internal gyroid estructure. The walls of the parts varies from around 1.2mm to 3.9mm and the infill from 9% to 15% of the volume again all depending on the stress of the area.
So parts are quite light and strong.


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## brian_ (Feb 7, 2017)

_GonZo_ said:


> The panels that compose the unibody and door have a thickness from 10mm to 20mm depending on how much stress that area has to handle.
> The parts are almost hollow (See picture) with an internal gyroid estructure. The walls of the parts varies from around 1.2mm to 3.9mm and the infill from 9% to 15% of the volume again all depending on the stress of the area.
> So parts are quite light and strong.
> 
> View attachment 121623


Thanks. The visible surfaces didn't show the internal structure, so they appeared to be solid. The thickness makes a lot more sense at 9% to 15% fill volume! The gryoid structure is interesting.

With the high void volume I can see now how the bonded part edges could be thought of as a structural rib array as described in post #38.

Have you calculated the weight penalty of including the solid part margins necessary to use multiple parts (even ignoring the glue) compared to a single-part component which just continues the internal structure without interruption? I'm guessing it would be a few percent.


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## _GonZo_ (Mar 23, 2009)

brian_ said:


> Have you calculated the weight penalty of including the solid part margins necessary to use multiple parts (even ignoring the glue) compared to a single-part component which just continues the internal structure without interruption? I'm guessing it would be a few percent.


Good thought Brian,
I have not calculated it. If you want to do so I can give you access to the files and do it, it will be very interesting to know.
Anyway I bet it is a quite big number >10% at least.
Never thought of that point, so it certainly will benefit quite a lot if a bigger printer is used, not only in the reduction of parts number and assembly complexity, as well there will be a weight reduction.

Thank you for your inputs @brian_


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## _GonZo_ (Mar 23, 2009)

OK, here are the schematics for the lights and such of the vehicle.
Please, can you have a look to it and let me know if it looks OK to you?


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## _GonZo_ (Mar 23, 2009)

After a long stop in this project, I was able some weeks ago to retake it.
I finished the development of the chemical welding for the 3D printed parts. And it certainly works quite well.
If you are interested here is a video about it, make sure to see the end of the video...


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## _GonZo_ (Mar 23, 2009)

I just managed to finish last video about this 3D printed electric vehicle project. And finally I was able to test my ideas on a real part. Looks like it holds quite well, I am very happy and proud. 
It is just a 2 min. video. Hope you enjoy it.


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## schelle63 (Jan 3, 2018)

Interesting.
I still believe you will need the essential structural parts to be made of steel/aluminium, but I will be happy to learn I am wrong. Every day is a schoolday.
Markus


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## remy_martian (Feb 4, 2019)

Seems you missed the point - he's out to prove you don't need steel or aluminum for the structure to not fail.

If you've ever stepped on a Lego brick, barefoot...


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## piotrsko (Dec 9, 2007)

Other than the physicals are different so parts should be thicker and possibly heavier or much more expensive, should be possible to make a vehicle that would pass inspection at least here in Reno. Dont know about the engineering you have to present.


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## remy_martian (Feb 4, 2019)

They might get upset over fire barrier, but if you can show it's ablative or has fire retardant additives (not regular PLA) they might let it slide. 

Should have a Plan B to be able to attach sheet metal in those areas.


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## _GonZo_ (Mar 23, 2009)

Thank you @schelle63 remy_martian piotrsko for your inputs.
There is some metal reinforcements brackets included at the design in order to distribute stress of the load and at suspension attachments.
If it is not enough I always have the possibility to add a layer of fiberglass on top of the full body.
But after the testings on the door I am quite confident in it, time will tell if I am right.
*







*


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