And who says that home 3d printing can't do detail?

[Rabs]

I realised that I've done this whole thread showing only end results and not the printer or the raw prints as they come off it.  I've not got any pictures of the printer available at the moment but here are a couple of the latest raw print.  These are a batch of parts to complete the first Foden lorry and then enough to build one more.  This print took about 4 hours.  I particularly like that the tyre tread came out, as did the very, very small holes in the wheel hubs although you can't see them from the angle of these photos.

The top corner of one of the decks failed because I missed a support, I'll have to reprint this one part.

 

 

 

It's worth clicking on the photos to open them up full size.

 

As you can see, the parts are printed with small, conical support struts.  Next I'll snip off the supports to release the individual parts.  I print everything diagonally to because this gives best results with fewest supports.  I also try to orient them to make the supports attach onto a face which won't be visible when the model is built so that I don't have to be too fussy about cleaning up the little 'pips' after snipping the supports off.

[Rabs]

As there's been a fair bit of interest here I thought I'd go through an example print.

 

So, from a set of .stl files I import them into the software and add supports:

The supports are added manually but the software is very easy to use.  This build took about 10 to 15 minutes to get ready.  The software then processes the complete layout ready for printing which takes about 10 minutes while I have a cup of tea.

 

There's a bit of fiddling to set up the print, position the various bits and add the resin.  This takes about 5 minutes.

 

After this I start the print and go and do something else.  This print took about 4 hours.  I check it occasionally to make sure that it hasn't broken/caught fire/eaten my cat.

 

When the print finishes it lifts the platform clear of the resin and we get our first clear view of the print.

 

I detach the platform and clip it at an angle to drain the excess resin off.

 

I then scrape the print off the platform with an old credit card.

 

The print still has a layer of excess liquid resin all over it at this point, so you can't see how well the detail has come out.  You can tell if it's basically got all the right parts though.

 

The print goes into a warm ultrasonic bath of isopropanol for 2 minutes to clean off the excess resin.

 

It then goes into a UV curing box with a little turntable for about 30 minutes to fully harden the print.   After this it is ready for painting.  And yes, I do usually put a lid over this.

 

Here are some parts with two thin coats of halfords grey primer.

 

Oh, and proof that the tiny holes in the wheel hubs have come out:

 

 

It's taken a long time to get the process to the stage where I'd back myself to get a successful print more often than not.  It's now 6 months since I bought the printer.

 

I've had a high success rate since switching to the new resin and this has helped a lot but there's also been a lot of learning about how to support models, how to clean them up, how to maintain the machine and so on since the Eiffel tower back in the OP.  Looking back I can see how lucky I was to get such a good result on my first print given how many things I accidentally got right which could (and later did) have ruined it.  I'm only now at the point where I'm beginning to feel confident that if something goes wrong I'll know why it did. I'm not yet at the point where I'm confident that it won't go wrong! 

 

A teaser for next time:  A couple of Mink F vans from Richard.  I'm not happy with the surface finish where I've had to remove the supports so I'm experimenting with a different approach to building these but the good bits are just as good as the beetle with all the rivets present and correct.

 

BTW Julia, a kit of parts are in the post for you.  I left the supports on because I've found it convenient to leave them on for painting and remove them as late as possible.

[Rabs]

And here is the (almost) finished lorry.  Just needs some matt varnish and glazing in the windows.

 

The total time to build get to this stage (but excluding the CAD time, as that was done by Missy) is about 2 hours work.  Not bad for a scratch built model!  Please excuse the poor painting - it's my first attempt since a crude airfix kit about 10 years ago.

[-missy-]

That looks brilliant!

 

A few things though. The first is the bit of 'sprue' sticking out from the fuel tank on the back is to hold a spare wheel (one of the front wheels). The recess in the front grill was to fit a bit of fine mesh to simulate the grill. Finally the intention was to fill the headlights with some clear resin to simulate the headlights.

 

I am really pleased how that looks (and I havent even seen one yet!) How did you paint it? Airbrushed acrylics? Brush painted?

 

Missy

[Rabs]

1) Ah, ok.  I've got some spares so I'll add the spare wheel tomorrow.

2) I guessed as much but I don't have any material suitable for a grille at the moment.  I'll see what I can rustle up.  Next time we could try incorporating it into the CAD.

3) Yep, got that.  I've just put some Krystal Klear in them at the same time as doing the glazing for the windscreen

 

Painting was a bit of both.  The base colour for each part is airbrushed.  Other colours were added with a normal brush except for the metallic steel which was put on with a 0.1mm lining pen.  Paints were all acrylics (some vallejo and some humbrol) on halford's grey primer.

 

I also need to add some number plates.  I've been meaning to try some DIY etching, so this might be a good opportunity.

[queensquare]

That looks superb. I can see the end of the laborious task of carving the shapeless lumps of white metal that have passed as 2mm road vehicle kits coming to an end, this is a really exciting advance. Clever sticks like yourself and Julia are really pushing the boundaries - brilliant.

 

Jerry

 

ps. so when are you going to have a go at those Alchin wheels then

[Rabs]

As soon as somebody sends me a CAD file

[Rabs]

[Posted in response to a post which has since been deleted]

 

You're right, technically stereolithography (SLA) is when a pair of lasers are scanned through a material causing it to solidify.  However, it's come to be used to describe any additive manufacture/rapid prototyping/3D printing technology which uses light to harden a polymer.  In this case I'm using a digital projector which isn't technically SLA but for most people we're into hair splitting territory at that point.

 

On your second point: CAD = modelling, it's just one of many skills that can be used.  In my opinion it's simply wrong to think of certain skills as a 'valid' part of our hobby and to discount other skills as 'invalid'. It does take skill to produce a good design which can be printed.

I'd be willing to bet that the same argument was made when the first injection moulded plastic kits were introduced:  "They're not real models, real models are diecast".  Or when miniature electric motors became available in the 50s: "Where's the skill in just buying a motor? Real modellers wind their own!".

 

It's a tool like any other.  You can choose whether or not you want to use it.

[Etched Pixels]

CAD is a modelling skill!  8)

[-missy-]

As soon as somebody sends me a CAD file

 

Thats weird. They were attached to the email I sent last week.

 

M.

[andygif]

CAD is a modelling skill!  8)

yes and its also an art as is modelling with real materials.

 

I was crap at art in school(unless you count my isometric diesel loco drawings), but ok at Tech Drawing. 

I can just about fly Autocad Inventor '13 now to point it does what I want(most of the time), but give me an art package or 3d sculptor tool and I'm lost.

[Rabs]

Thats weird. They were attached to the email I sent last week.

 

M.

 

So they were.  That was your polite way of calling me a numpty!  I'll have a go at them sometime this week.

[justin1985]

Really amazing looking results there Rabs! Now you've worked out the best ways to set the machine up, your results look WAY better than Shapeways FUD! Is there much chance of additive 3D printing improving to these standards, or SLA the "technology of the future"? I seem to remember the very early talk of 3D printing back in the late 90s and early 2000s talking about SLA type processes, so it struck me as surprising that it was additive systems that led the breakthrough of the past few years. Quite literally seems the same as the old inkjet v laser printer price\quality question.

 

Looking at the B9 website, it doesn't seem at all cheap, especially with $200 shipping, and I'll imagine you got stung quite a bit for import duty and VAT. Do you have any plans to sell printed kits on a cottage industry basis? 

[Rabs]

Thank you very much.

 

SLA is a type of additive manufacture, you are still building a model up rather than cutting it down.  If you are thinking of rep-rap or makerbot type machines then those are usually referred to as FDM (Fused Deposition Modelling) machines or Extrusion printers.  There are people out there who insist that the best FDM printers can be as good as optical methods.  I personally have never seen any FDM machine that can get close to these results (I have one as well).  There's a lot of nonsense bandied about about 'resolution' for FDM machines becasue some people think that being able to position a nozzle to within 10 microns matters when you are squirting goop out of a 200 micron hole.  They always advertise 'resolution' (by which they mean positioning resolution of the motion system) and not the minimum printable feature size, which is what actually matters.  I think that your analogy of inkjet vs. laserjet is quite apt.  There are pros and cons for each approach.  It's easier to build a big FDM printer than a big SLA printer and the printed materials are generally a lot cheaper.

I'm sure that both technologies will continue to improve rapidly and that FDM may, in time, equal the current SLA crop.  However, at a fundamental level, I simply don't believe that a robotic miniature glue gun (FDM) can be as accurate as an optical system (SLA).

 

In industry FDM is relatively uncommon, Objet is the only one that springs to mind.  It gained popularity for hobbyists mostly because it's cheap to make and the materials are very safe and easy to get hold of.

 

Cheap is a relative term.  Compared to the competition and measured on the specific specification points that matter to me the B9 is very, very cheap (the machine that Shapeways use costs ~£250,000).  But you are right, I'm a 3D printing enthusiast and can also make use of the printer for my business (I'm a freelance engineering consultant) so I'm prepared to spend a lot more than a typical modeller.  The B9 is definitely for 'early adopters'.  In a few years machines like this will likely be <£500 and easier to use then it really will be game on.  Although, when HP start selling resin cartridges ... £££

 

I actually got my machine second hand in the UK from one of the original batch.  Also, the original units were lower cost through kickstarter because at that point it was unproven so anyone buying was taking a bit of a risk.

 

As for selling parts, I'm afraid not.  I'm happy to make the odd bit here and there, particularly if the prototype is of interest for my layout, but as a business it's just not how I want to spend my time.  I've already got one new business on the go at the moment!

[Rabs]

Finished the Foden this evening.  I found some suitable mesh for the grille and had a play with some mud splatter and powders for weathering.  Followed by some dullcote and finally the glazing.

 

Sorry for the poor photos, I only had my mobile to hand in bad light.  This is now as good as my current painting ability is going to get it and I'm happy with how it has turned out.  More practice will no doubt improve on this first attempt at model painting but I'll be happy to have this on the layout as it is.

[-missy-]

Excellent Rabs!

 

I got mine through the post yesterday so thank you very much. It was all intact and everything. As a result I have a couple of quick questions before I make a start on it...

1. What is the best way of breaking/cutting off the supports?
2. What is the best glue to use when sticking the parts together?

Thanks

 

Missy

 

P.S. If you ever do anymore then I am more than willing to take them off your hands, even faulty / incomplete ones! There are a few variations that I would love to do...

[Rabs]

Excellent, I'm glad it survived.  I wasn't sure how best to pack it up.

 

1) I use a pair of flush cutters like these: https://www.google.co.uk/search?q=flush+cutters&espvd=210&es_sm=122&um=1&ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi&authuser=0&ei=zKdKUu6jIYX80QWs_oDgBQ.  If they are nice and sharp then hopefully it shouldn't need much cleaning up.  If it is needed I use a scalpel and/or a small file.  The only supports which are really visible on the finished model are the ones on the top of the rear wheel arches and the ones on the front bumper.  The material files quite nicely but it is brittle so be careful with the very thin parts. I found the leaf springs to be particularly vulnerable.

 

2) Cyanoacrylate glues work well.  I use Loctite 431 and 495 depending on the shape of the parts (one is thick and can cope with larger gaps between parts, the other is thin and good for wicking into small gaps). For visible joints I use Microscale Krystal Klear. I've not tried anything else yet but I'm sure that lots of other glues would be fine.  I generally use the supports as test material for everything (glues, primers, paints) before I go at the main model.

 

For other variations, it's probably easiest to just draw them up in CAD and print them from fresh.  The material isn't very easy to adapt because it tends to snap.

 

For the future I would suggest that we add some additional details to the model in relief on the surfaces.  Representations of door handles, hinges, wing mirrors, steering wheel and indicator lights would probably all be possible.  Also, the trailer side panels might have some strapping or bolts in.

 

I'm also interested to try printing it in one piece.  Painting might be a bit harder but it would be fun to try.  Would it be possible for you to send me some STP or IGES files? That way I can import them into my CAD and have a play.

[-missy-]

Thanks Rabs.

 

For other variations, it's probably easiest to just draw them up in CAD and print them from fresh.  The material isn't very easy to adapt because it tends to snap.

 

Thats certianly a possibility. It wouldnt take that much effort to produce variations now that bulk of the model has been done. I was thinking about a LWB model with maybe a flat bed. Have you got any other suggestions / thoughts?

 

 

For the future I would suggest that we add some additional details to the model in relief on the surfaces.  Representations of door handles, hinges, wing mirrors, steering wheel and indicator lights would probably all be possible.  Also, the trailer side panels might have some strapping or bolts in.

 

Its a bit ironic really. Much of that detail you suggest has been left off the model as the original intention was to shapeways it. The idea was to add that after sanding and smoothing of the body but now its not really needed the sensible thought would be to add some detail back. That it of course, if the model was to be printed lots of times in the future. As I now have a copy of it (and so do you) is it worth the extra effort? What minimum thickness do you think is possible? Things like wing mirrors would be very fine and thin. 

 

 

I'm also interested to try printing it in one piece.  Painting might be a bit harder but it would be fun to try.  Would it be possible for you to send me some STP or IGES files? That way I can import them into my CAD and have a play.

 

I tell you what, I will send the next variation as close to a single piece as possible. I do think that the cab will need to be a seperate piece though so you can paint the inside easily.

 

Missy

[Rabs]

Well, I had some freestanding parts the other day that were about 0.1mm thick (scale bench legs).  The worst case is that they don't come out and we end up snipping them off and get the same as we do now.  I can probably excuse another variant on my layout, perhaps the LWB that you suggest. I'd be happy to try adding the details before printing it.

 

I agree that the cab will need to be separate.

 

I'm looking forward to how your build goes together. Please do post pictures because I've got a lot to learn about assembly, painting and detailing.

 

I've now learnt that STLs are a bit of a pain to work from because it's really awkward to modify them if any small features need to be thickened slightly to get them to print.  I can if I have to but STP or IGES makes it much easier for me.

 

I should have photos of the traction engine wheels tonight.  They seem to be printing well but it's hard to tell until I clear the excess resin off.

[-missy-]

Thats interesting to know Rabs, thank you.

 

Looks like there could be a reason to carry on with that traction engine then. Now if you want fiddly small bits that would be a good tester!

 

M

[billbedford]

1. What is the best glue to use when sticking the parts together?

 

 

Original resin and UV light?

[Rabs]

Yep, it's a good option, but only before you put paint on it. Unfortunately I'm pretty sure that Missy doesn't have any of the printer resin.

[queensquare]

I should have photos of the traction engine wheels tonight.  They seem to be printing well but it's hard to tell until I clear the excess resin off.

 

Now I'm really getting interested. These modern lorries are all very well but.............

 

I have plenty of traction engine castings in stock with horrible lumpy whitemetal wheels so if you're looking for somebody to do a test build using the wheels........

 

Jerry

[Rabs]

Ok, here they are:  Some teeny tiny traction engine wheels.  All the spokes, the tread and the little rivets in Missy's design have printed correctly.

 

Now we're on a roll (groan)

[-missy-]

Hmmmm, thats interesting!

 

I think the front wheel has too many spokes (my fault), the back one looks good so far. Its difficult to see how they have come out, any chance of putting a bit of primer on them and taking some more piccies please?

 

Thanks.

 

M