Thursday, 29 January 2015

Do you want to build a lightsaber?

OK enough exposition and technical background for the moment. Let break this up with an actual build in a couple of parts. This is about one of the coolest, most satisfying things you can do with your 3D printer: Build a LIGHTSABER!



Cool no? Entirely 3D printed. Obviously this is the end result after painting and whatnot but lets go back to the start. I didn't design this model, far from it. It was released as part of the May the 4th celebrations in 2014 by the very skilled Jacky Wan. and can still be found here here .

I see now that I look at the page that there are now 2 versions of this for you to print, a 4 piece version (which is the one I printed) and a 14 piece version which is more accurate and takes advantage of printing direction better.  If I were doing it now again, of course I would make the more complex one, but to be honest you will get more out of doing a nice paintjob than you will in printing an accurate model. but more on that in part 2.

The creation of the 14 piece model raises a good point on printing direction though. Printers are great at creating cylindrical objects built up gradually in the Y axis. However any part that is cylindrical that does not align that way will suffer in quality (Such as the control buttons). This is detailed very well on the above article on the light saber above.

Anyway so we built this thing seen here before painting.




A Few of key points.  We used white filament because that's all we had at the time, if I were doing it again I would do it black as it makes painting a bit easier.  Secondly the model was actually JUST to large for the UP! printer. this meant that we scaled the parts in the UP! software to about 95% and then it fit no problem within the build depth.  In all honestly the Lightsaber still feels the right size and no one could probably tell. Thirdly we wanted to tax the printer as a test so we tried to print ALL the parts in a single build!  So that means all 4 parts in one build surface! 

Which in total was a 22 hour print time and at the time we were feeling confident leaving the printer on overnight so that's what we did.  In the morning it was clear something had gone terribly wrong as one of the parts was on the floor and there was a large amount of white spaghetti over the build surface (I wish I took pictures). 

So what happened? well if you have any printed object where the print head leaves part of an object to go print elsewhere (As with the multiple parts) occasionally the printer will leave a little tail of filament sticking up. When the print head comes back to that part it may snag that little tail and in our case, because the model was so tall with such a small base, it had enough torque to unstick that part and dump it on the floor! 

So lesson learned there, I probably wouldn't go for printing the parts all at once again but a valuable lesson was learned! The faulty part was reprinted and all was well. 

another problem with this model and 3d printing parts in general is that using twist - fit components are a gamble. again because the model is built up in layers, too much torque when you are fitting / unfitting parts can snap off the locking part, which i also did.   

The final assembled body above was actually securely glued together and for extra strength and a little heft I put an aluminum rod inside it which is also glued at either end.    and the next step was onto paint!







Wednesday, 14 January 2015

Which filament? PLA or ABS


This is an interesting topic, one which has many articles scattered throughout the 3D printing community and a lot of information either way. if you are just reading quickly to try and get an opinion then let me give my oppinion quickly from our 3D printing perspective:

We use ABS and thats it.  ABS wins.

But perhaps that's a bit inflammatory, there are merits to both, and perhaps I should have added "for our uses".  I should also point out that we have NEVER even tried PLA!  So how can I form such an opinion or give advice on this?  easy, let me explain why.

There are many basic limitations and material factors which are totally different on paper between the two materials, so doing a back to back test was never something we sought to accomplish its easy based on requirements to see what material wins for our needs.  Lets look at some points and address them in turn.


1: ABS smells bad!  PLA smells good!  Whats wrong with you?  you just bought a 3D printer and ancillaries probably spending at least the best part of two grand and the smell bothers you?  Are you putting it in your kitchen?  Personally I don't find the smell offensive in any way, shape or form. It does NOT smell like burning plastic, we have experienced that enough to know the difference. It does have a smell but its nothing even close to the smell of soldering, welding, woodwork etc. So if you are putting your printer in the garage or whatnot, I wouldn't even factor the smell as an issue.

2: ABS is stronger,   Fact,  the material holds up to abuse more (on paper) .  For us it was important to build strong things when needed.  Thusly ABS won this easy

3: Better thermal resistance,   PLA has a lower melting point so exposing it to heat will cause models to warp.  Again why we went with the ABS.

4: Warping / Lifting. We did have some issues with models lifting, but this turned out to be a error with out use of the printer.  If PLA is less prone to warping then cool,  but we now have no warping on our setup at all.

5: Cost:  its much the same.

6: The printer CAN do PLA,  but its designed and optimized for ABS.

Will we ever try PLA?  probably not,  because folks, for our needs at this time ABS does the trick and the number one rule in engineering is: IF IT AINT BROKE, DON'T FIX IT!


Sunday, 4 January 2015

2015

Happy New year to all!

Looking forward to some pretty cool projects in 2015 and I have a whole massive backlog of posts for you about the past years adventures!

Monday, 29 December 2014

Should I buy a 3D printer?

This is a difficult question, and one that no doubt many people ask themselves as they paw over the latest roundup of the latest and greatest printers.

Which one should I get? What build size do I need? What filament is best? Which is most reliable etc etc. It goes on and on.  Should I buy one?

Well possibly, but allow me to answer a different question first. Do you NEED a 3D printer?  Nope, you probably don't.  Don't try to justify it this way. If you are a hobbyist or simply curious, you don't need one so don't bother, particularly if you are trying to convince someone else that its a sound investment.  Your significant other is right to raise sceptical eyebrow while you describe the rich array of coat hooks and other useless crap you will be able to conjure from thin air.

Its an expensive thing, and certainly a luxury item unless you have a specific repeating need to make tiny plastic objects as a part of some other hobby or work need.

I sat watching the evolution of 3D printers with glee and when the Makerbot "Replicator 2" printer came out: DAMN I wanted one so bad!  I could do so many amazing things! All my minor engineering problems would be over finally free from the chains limiting the imagination.  I actually began to consider that I could splash the cash for it and it would justify itself just out of sheer usefulness!   Thank god I didn't! Because I found out the reality is a little different.

I am lucky that while this was going on, my work bought a 3D printer for the engineering dept! So I have been able to access the benefits of the printer without the initial outlay but what happened was interesting. I honestly couldn't think of anything to print! Certainly nothing I needed! So I was really glad that I didn't splash out or I would have felt pretty silly with the printer just sitting there.

Things are a bit different now, the 3D printer has changed the way I do projects and think about design but that's taken over a year and its still just making non-essential "hobby" stuff for me. Otherwise its purpose is fulfilled by a never ending slew of engineering builds whenever its not printing lightsabers or arc reactors :)

so remember, unless you are a day to day engineer, or constantly needing bespoke plastic parts, a 3D printer is a LUXURY item.  If you have the cash to burn then go for it! Its a fascinating bit of kit that will bring you pleasure, impress your friends and is great for producing personalised Xmas gifts. Otherwise I would wait till the price crashes a lot more to bring it into the budget level.

Sunday, 21 December 2014

How to print Dreams.

This blog is going to be about 3D printing which it seems has become a hobby of mine but is lacking in material out there about some aspects of the "craft" of 3D printing.

Sure if you want a 3D printer you can read some reviews and decide what's best, buy something and get going, but reviews only get you so far. How practical actually is it?  How difficult is it? What can you make? What's it like REALLY working with a printer over a long period of time? 

Over the past year I have been lucky to have access to an UP! plus printer from pp3d and I have made all kinds of things,  some worked, some didn't. I have printed objects from thingiverse to my own scratch built designs and I believe the things I learned about the machine and about the craft of 3D printing will be of use to some of you out there so stay tuned and I will endeavour to enlighten.

3D printing is here to stay and its so exciting to be riding the initial wave of technology.