Author: Replicat3d

image courtesy of Printrbot inc

I know we had seemed to go past this already, but with the announcement from Printrbot about the imminent release of their Metal Printrbot Simples into the wild, I just wanted to touch on the awesomeness of Brook and his 3D printing vision.   He went from Kickstarter to incredibly successful company in a few short years…  Brook, I just want to say, congratulations and keep it up.

Now, as most people will look at the picture and think ‘I want one!’, lets start a little closer to home.  The Printrbot Simple (wood version) is available now and is, in my opinion (and Make magazine), the best value 3D printer you can buy.

I’ve looked at quite a few, some cheaper, a lot more expensive.  The one thing I feel about this new technology, and I love it, no mistake (I will happily talk about this stuff for hours!), once you start you will want to print a lot of stuff.  Most of it may be junk, a lot of the first ones will probably look like it was made by a spider on speed, but you made it, yourself, on such a cool little machine.

So, did you buy it assembled?  did you make it from a kit?  Is it your first go with a printer or just your first own printer.

My though would always to build it yourself.  The reason for this is that it is leading edge technology.  We want it to work every day, without fail, but it doesn’t always go the way we like.  If something happens, we know how we put it together and we know how to take it apart if we need to.

If we just took this out of the box, it will always be ‘the printer’, like your desktop printer.  you don’t know how it works, it’s just the thing that you click print with and see what comes out.  Don’t get me wrong, however you get your printer, you will love it, it’s the process and the output that is awesome but, for the day something goes wrong, being able to fix it gets you printing quicker.

So what printer do you want?  When people tell me they want a 3D printer, my first question is ‘what do you want to print?’  If their answer is, ‘I don’t know yet, I just want one’, my answer is ‘Do you really want one?’.  People look at 3D printers as gadgets, fun tech toys to play with, still awesome, but more likely to be dropped when the next toy comes along.

If someone tells me why they want to print and what they want to print, then we can start the serious conversation.  Size of print area, what sorts of filaments they want to print with.  You can see in their eyes the passion they have for design and how they can turn their ideas into things they can hold in their hands.

And that is what all this is about.  We are taking an idea, a thought, a sketch on a napkin and turning it into something we can touch, in our own homes, using 3D printing.

Okay, so the first thing people ask me about 3D printers is, “so what do I do with it now?” and my answer is normally “anything you can imagine”.

There are websites, such as Thingiverse.com that have loads of useful (and a lot more not useful) designs for you to download and print.

Did you get your printer as ‘I must have one of those’ or more of a ‘If I had one of those I could….’?  If it was the former, maybe you have more money than sense, or maybe you have a designer hidden deep inside that was controlling your inner self.

If it was the latter, then this is where you come into your own!  You have Tinkercad or Sketchup or for the more numerically inclined, OpenSCAD.  If you have money, a lot of money, then you will need something like Solidworks.  There are so many design tools that you can call on to bring those idea to life as a piece of plastic.

Over the next few blogs, I will try and give you some ideas for turning ideas into real things to play with.

So we’ve got our printer, we’ve got a load of nice colourful filament, so what are we going to do with it?

The first thing we need to do it to print something.  Anything really, we just want to see for ourselves, what this 3D printing thing is all about.  This may not be your first printer, but indulge me a little.

A successful 3D print really just comes down to a couple of key points.  You want the first layers to stick firmly to the bed and you want the filament to flow smoothly and constantly on demand.

The first is, to be quite honest, a bit tedious but, if you don’t do it, you will probably regret it.  We need to level the bed and set the Z-zero (Z0) height.

So, with our printer connected and powered on, we tell it to send all axis home.  This should be to a position of 0,0,0 (we always give such coordinates in the order of X, Y and Z).  With the bed in this position, we should just be able to fit a piece of paper between the tip of the nozzle and the bed.  If not, adjust the Z Home screw to make sure you can.

Once Home is sorted, then we send the printer to the maximum X extent.  And then, when it’s there, we adjust the bed levelling screw (there should be one in each corner) to make sure that we can still only fit our paper there.  Once that’s done, we go to Y extend and do the same and then send X home (Y is still at maximum) and do the same.  Finally, we go to the centre to make sure that all is still okay.

You may find, half way through the process, that you don’t have enough bed levelling movement to compensate.  In this case, we go back home, adjust Z home down a bit and then correct with the corner screws again.

Once that’s all completed, we need to look to the filament flow.  There are 2 main extruder types (if you have another type, I apologise, but you are probably in the minority).  These are a Wades type extruder, it has a smaller gear on the motor, driving a larger gear with a hobbed bolt (this is a bolt with teeth in the middle).  Or a direct drive extruder.  This has a small hobbed drive gear directly on the motor.

In both cases, there will be an idler bearing that pushes the filament onto the hobbed part on the drive train.  This idler should be adjusted so that the pressure is firm, but not too much.  If you tighten it too much, it will tend to flatten the filament, which will then make it more difficult when it comes to enter the hot end.  On the other hand, if it’s too lose, it won’t provide the pressure needed to make it work as it should

In order to check this, heat the hot end to the working temperature of your filament.  For PLA I normally use about 195 and ABS about 220.  This will vary between manufacturers and even colours, so you will need some trial and error.  Try and extrude 50mm and watch the gears turn.  If they turn but nothing comes out, tighten the idler.  increase it in small increments until the filament comes out smoothly and then I give it an extra 1/2 turn on the screw (this is optional and you may not need it).

Finally, load up something like this 25mm calibration cube, slice and print.

Hopefully it will look as you expect, you will have printed something and you are well on the way to playing with this fantastic new toy.

Next time we’ll look at some open source control software and where to get things to print.