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Discussion Starter · #1 ·
Right. Have I got this right.
Basically, you would be able to 'scan' say, a 1/43 Volvo estate, increase the size to 1/32, print it, then depending on the quality and maybe with a bit of prep', some of you clever guys out there would be able to produce a Racing shell.....

Sounds like a scratch builders dream !!!
 

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There is a guy on this forum called Choc-Ice, he is into the CAD/CAM and 3D-Printer stuff why not PM him?
 

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I've done some 3d printing and usually you provide the 3d printer with a file that someone has created in a 3d program as 3d scanners are quite expensive at this point. Luckily, there are people out there willing to sell you 3d models of cars they have created as there is a pretty high learning curve to learn 3d programs, especially well enough to model a car accurately in 3d.

Heath
 

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Yes.
So you need a 3D scanner, a suitable vector drawing package (and the ability to use it) and a 3D printer.
That adds up to a significant amount of money.
These things will inevitably get cheaper but, at present, I can't see too many slot car scratch builders rushing to switch from more traditional methods.
I'm still trying to persuade the school I work at that they 'really need a 3D scanner and printer' but no luck so far. 'No money' they say.
Cheers.
****.
 

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Not sure yet about how good scanners actually are. You should be wary of scaling up a 1/43 to 1/32 as you may find errors not seen at 1/43 would show up at 1/32. Better to scan big and scale down. I guess thre are places that would scan items for you at a price. Armed with a scan odds are you would need to hollow out the scan using a cadds package and add some stengtheners, fixing posts etc before printing. From Shapeways (google them) who will print a CADDS model it costs about 1$ per cubic centimeter (cheapest we have found but if anybody knows better please tesll uds) so you need to have thin walls. Shapeways will tumble polish but not well enough to paint and you would have to hand finish the model if you want a mirror finish.
 

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Alfie Noakes
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Hi Jonboy,
Within our workshops we teach and use rapid prototyping/3D printing. We have starch, plastic and ABS/PLA extrusion printers, a 3d scanner, and teach Rhino, Solidworks and ProDesktop programmes. Technology always promises more than it delivers, and 3D scanning and printing is no exception. You still need a skilled operator, with experience and an understanding of how things are made to get the best from it, and even then it has limitations just like any other making tool.

If it was as easy as you hoped, everyone would be doing it. Every week there seems to be a news story about the potential of 3D printing, for making guns, houses, more 3d printing machines, etc, but it's just easy headlines. I think we're being lead to believe that once prices fall we will all have one in our houses next to our inkjet printers, and at the press of a button it will churn out stuff for us, but it won't happen.
The cost of consumables and equipment maintenance, and the ability to generate good quality 3d files either from scratch or via a scanner will be the reasons why 3d printing won't provide the solution that we all want.

I've got access to all this great stuff, and it's still easier (and more rewarding) for me to convert a saloon 850 to an estate 'by hand'. Which I WILL finish and post at some point!
Cheers,
Richard
 

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Phil Kalbfell
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Richard Thanks for the feed back from someone with experience with scanners as well as printers. I have seen one of the mid range printers in action and was impressed BUT the product produced still needed a lot of "finishing" certainly would not compare to what we now want from Resin casting today.
Maybe the next generation of scratch builders will produce bodies this way!
 

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Discussion Starter · #8 ·
Hey guys, thanks for the replies. It just shows what a wealth of experience is lurking on this site !!

Greg K; I was hoping more for the finished article as my modelling skills are about as much use as a chocolate Teapot !!

Flag slot Racer; It is still a lot more complicated than my brain can handle.

****; I'll get in touch when I win the lottery !!

Ushcha; good point about the up scaling. I just thought that there would have been more choice of cars to reproduce in the 1/43 scale as opposed to say 1/18 or 1/24.


Richardtheforth; I think I may have been thinking five years or so into the future !! But I would love to see the finished 850..... should you get around to finishing it !!

Phil; Next generation of builders it is.

Cheers guys.
 

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Hi jonboy,

The same drive that is pushing you to look at these machines is with us too.

As another member quite rightly said you do need skills, I am living proof that those skills can be learnt.
Yes it took a while, but with determination, it is possible to achive much more than we at first determine.

The fears expressed above are all valid and despite techniques to improve the finish, the output your looking for is still a way off. So for now id say hold on to your moolar


One point about scale I would like to make, is that when you try to resize models to fit a restricted length ie. a slot car chassis, you often get squashed or distorted sizes of result. Something quite noticeable in larger scales like RC.

I wish you much luck with your path and offer any advice I can (for what my self taught methods ar worth)
 

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At the risk of "jumping the Shark" on this subject let me offer one more real life example that
may indicate where the world is eventually going to converge in this area.

Richardtheforth is using 3D printing, scanning and CAD software such as Rhino to
teach and produce these models. And he is reporting that they (at least the printing and
scanning) are not quite that precise yet.

My experience as an engineer with Dupont (25 years ago or more) came from the opposite
end. I was using Finite Element Analysis software (Nastran and Patran) which creates an
image of a model (similar to what evolved into CAD) and then layered on top of that material
properties, loading, constraints etc and actually simulated the response of the part (stress, strain,
natural frequency etc). After that, we often rapid prototyped the part for the client. So for
example when I designed the plastic intake manifold for the Quad4 engine for GM, we sent them
several nylon prototypes to look at, and attempt to position on a motor etc before final
approval.

Now those parts were highly precise copies (and much larger than the limits of current
printers), needing no reworking whatsoever...but instead of a printer they were build up from
lasers being shot into a pool of liquid nylon. This was extremely expensive equipment...many
millions...but undoubtedly getting cheaper over time.

My only point is that there's going to be some "happy medium" eventually...the quality level
is out there for fine scanning and rapid prototyping, and has been for some time. it's not
so much a matter of printers getting better as finding some convergent technology halfway
in the middle...in the middle of both quality and pricing. I wouldn't be surprised if we see
a service such as the current private printer companies, but with higher quality technology
sometime soon. Perhaps 5 years out as jonboy suggested earlier.

John

PS that's the optimistic view...the pessimistic view is that companies in the West aren't
investing in new technology and research like they used to. So the real question may be
whether someone in China sees a need for such equipment...sadly.
 

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I'm also a bit supprised by comments on accuracy. Using Shapeways who have some serious kit, accuracy seems more than acceptable, I got a scaley rear wing drawn up (bit thiker on the wing due to wall thickness limits). Olsd one out new one in. The home 3D using extrusion are not quite there without too much fuss for me but are getting close for some jobs. I have seen pictures of barriers done well with a simple printer and a bit of surface clean upo. The "Just for fun" thread I think has a 3D printed shell.
 

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Just to add my two pennyworth. I've been working, drawing cars in CAD for 18 months now and am 16 years in a job where I use CAD every day. (I'm an architect).

The problem as I see it is not so much the 3d printing which, yes does need tidying up, but in the ability to draw in 3d in a computer which can't 'fudge' anything, something which by and large you have just a few photos and a hand drawn set of model plans of.

What a bit of sandpaper and filler can do SO easily a computer cannot!

It needs EXTREME skill to work with complex curves and attempt to match them to a real existing car. We are talking 100's of hours work here..... Then if you imagine the frustration when for some unknown reason your (simple) computer program doesn't do what you want it to and multiply that by a factor of 1 million due to the complexity of the model and CAD programming, because the object is in some way 'not correct', you get close to knowing how I feel most of the time.

Don't think either that 'buying' a model from some company like Turbosquid is going to help much. By and large they are made in software to look good in renderings. Making renderings and making 3d objects are completely different arts. Renderings can to some extent be fudged since if an object 'goes inside' another it doesn't matter as all you need is an external 'shot'. For a 3d object instead IT MATTERS. Plus you cannot just take a surface mesh and make it solid in most programs as the complex geometries will 'coincide'..... So 'buying' a model (even if it is accurate which in my experience it wont be anyway), is not an answer either....

You CAN make slotcars in 3d printing, I did but can't mention it here, but they do then require a lot of finishing. If you want to do a production run (professional etc. costing 10.000's of euros) its worth it, if you want to make a single scratchbuild, better buy a block of wood and some tools you'll get better results quicker even if you have no carpentry skills.

This process by the way is actually how all the companies prototype their models but they have access to funds and professionals which most of us hobbyists will never achieve....
 

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QUOTE (Slotz101 @ 23 May 2013, 19:13) <{POST_SNAPBACK}>One point about scale I would like to make, is that when you try to resize models to fit a restricted length ie. a slot car chassis, you often get squashed or distorted sizes of result.
True enough if you choose to use some existing chassis, or are building to a set of regs that pushes you to a particular (not necessarily scale) size.

But there is no need to do it that way.
A slot car chassis can be any size or shape.
Scratch built chassis are built to whatever size the builder chooses.
3D printing can be used to produce a plastic chassis whatever size you choose. Once the motor locating parts and axle bearing locations are drawn adjusting the wheelbase etc. to suit the body is a simple task with CAD.
 

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If you have a look at this thread you can see how I did most of these things (except the 3D scanning).

The 3D scanning is still the very expensive part, not just for the equipment but because it produces data points in a cloud, you then need these to be made into surfaces which must be joined (made watertight) and then shelled out for 3D printing.

But most of the technology is out there and usable now, my resin shells were produced so I'd try and break even after selling a reasonable quantity.
 

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I keep looking at prices and quality, for me I think te only time I would buy a 3D printer is if and when the fine powder printer drops in price as it seems to be the ont method for reducing very fine detail.

If I win the lottery I will let you all know how god it is.

I dream of te day I can scan in a body of a car and tweak the design as if adding a custom body kit. Create modified spoilers etc. ahhh the dream.
 

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Not quite 3D printing I know but Trevor Crout uses Rhino 3D software and CNC milling to create moulds for vac-formed bodyshells: http://www.3axisltd.com/page6.html

As the resulting bodies are for BSCRA racing they are (deliberately) not accurate scale models - but they incorporate much finer and sharper detail than is generally possible in vac-forms produced from hand-carved moulds:

 

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QUOTE As the resulting bodies are for BSCRA racing they are (deliberately) not accurate scale models - but they incorporate much finer and sharper detail than is generally possible in vac-forms produced from hand-carved moulds:
Actually David I have to disagree with that statement.
I do have a fair amount of experience of using a 3D CNC milling machine, of vac forming and of making vac form moulds.
CNC milling is excellent for producing dimensionally accurate masters, and in being able to do it time and time again, but it is limited by the need to use a round tool which means sharp internal corners are not possible in every plane. Undercuts also present particular problems, even with a very expensive 5 axis machine. I believe Trevor has to do a fair amount of 'finishing' after the masters come out of the machine.
It is perfectly possible to incorporate at least as much detail when making a mould by hand and Trevor used to do just that when making all those superb GT Models masters.
The limiting factor with all this kind of technology, apart from the cost of the hardware which will come down in time, is the ability to use a suitable 3D drawing package.
I can see a time when a 3D printer will be cheap enough for home use and it will be possible to download pre-drawn designs for common objects and reproduce them in your printer but, and it's a big but, something as complex as a slot car body is unlikely to be easily available or cheap.
Cheers.
****.
 

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QUOTE (**** Kerr @ 25 May 2013, 22:25) <{POST_SNAPBACK}>The limiting factor with all this kind of technology, ..................... is the ability to use a suitable 3D drawing package.

Cheers.
****.

Exactly what I said in my post then.
 
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