MakerBot Industries

First draft on the left, second draft on the right

I’d like to address some comments to the prior two posts.  The first post was essentially about identifying a problem that could be solved with a 3D printer.  In this case, it was the cracked plastic case for my mom’s car key fob.  The second post was about one method for measuring and documenting measurements in a meaningful way.  Basically I trace out the parts on a sheet of paper and draw in arrows indicating the dimensions.

@Mark wanted to know why I was breaking up the posts.

Well, originally I had intended to live-blog the process of identifying, measuring, designing, and printing the solution.  This was not to be for a variety of reasons.  Instead I opted to break what would be a very very long post into discrete sections. ¹²

@Alex Guichet wanted to know when you’d get to see the results and if this was just going to be a teaser.

I’ve broken the entire saga into four posts.  You’ll get to see the finished product at the end.  Promise.

Draft, the First

From the photo above you can see the first attempt on the left.  There were a number of deficiencies in this draft that I didn’t really think about until I was actually holding the part in hand.  In my zeal to measure the electronic-beeper-thingie and the metal key, I had completely forgotten to measure or design the less critical part that allows you to put the darn key on a keyring.  Next, the metal part that is the actual key is quite a bit thinner than the electronic-beeper-thingie.  As such, there needs to be a raised section that is only “key”-width rather than “beeper”-width.  In this first version you can see that there is no such raised section.  I also failed to include a hole for the small screw that holds the key in place and both sections together.  In this draft the two parts do not actually fit together, they are both just flat pieces that do not interconnect in any way.  I also noticed that I made the entire enclosure slightly too big vertically.  Just one more thing to tweak in the next version.

Once it was in my hand, I decided that the next version would allow a portion of one part to fit into a section of the other.  Just looking at the finished product was enough to help me realize all of these deficiencies – that’s why I didn’t even bother to clean the part up. 

Onwards and upwards!

Draft, the Second

From the photo above you can see the second attempt as the two parts on the right.  While these parts were much more suitable than the prior, there were still some issues to work out.  I included a section for the keyring, a hole for the screw to hold the key in place, a lip on one side and a bevel on the other so they would fit together, and I reduced the interior height by 2mm to reduce the extra room.  The parts fit together well – but came apart relatively easily.  I decided the next version would have an even larger lip.  It turns out that a reduction in 2mm was too much, since the electronic beeper just barely kept the parts from fitting properly.  Increase by 1mm.  I decided all of the buttons needed just a little more clearance on each side, so I gave them all 0.4mm more space.  I made created a recessed section for the screw head to disappear flush into the top section once installed.  Lastly, I also widened very slightly the two walls on either side of they key, since it was a very tight fit.

The benefits of drafting

Imagine you had to program by punch card.  Get one punch wrong and that card was toast.  Get one punch card wrong and your whole program was toast.  Sure, you could double, triple, and quadruple check your program by inspecting every punch and the order of every card…  But it’s not a very efficient use of time.  For modern programmers there is little penalty for just taking a chunk of code and firing it up.  The most common worst case scenario is an error code directing you to where the problem might exist.

Now, if software guys can try out a draft of code without any significant penalty, why not hardware guys? ³  I don’t need to get everything exactly right the first time – and I might even find a few improvements along the way.  With an investment of about 20 minutes of unattended printer time and $0.20 of plastic each I got to try out two interim designs – and improve my final design.

Up next:  The final results!

Posts in this series:

• MakerBot Hero:  Car Keys I
• MakerBot Hero:  Car Keys II
• MakerBot Hero:  Car Keys III
• MakerBot Hero:  Car Keys IV
• MakerBot Hero:  Car Keys Epilogue

1. Like Dave Durant long post. [↩]
2. Dave, I kid because I love! [↩]
3. And, for that matter, why not tinkerers, makers, hackers, repair people, and dads? [↩]

I like laser cutters. I like MakerBot Operators who modify their MakerBots. I LOVE this amazing hack by iliis. Knowing what I know about laser cutters, I can’t endorse this awesome modification, but wow, just wow. Much respect!

My makerbot now serves me since quite some time and I have to say, it’s one of the coolest (and most useful) toys I’ve ever had. Besides Lego maybe I experimented a bit with my Laser”pointer” (a 1W Spider III Arctic from http://www.wickedlasers.com/lasers/S3_Series-105-37.html) and the Unicorn-scripts. While this laser is not nearly strong enough to cut wood, it draws very nicely into it. And you can cut paper. This gives way to some pretty cool applications

Tbuser promptly noted that it looks like this movie poster!

Tracing the key fob

The last post covered my decision to remake/repair my mother’s car key. Frankly, I’m surprised I haven’t been fired from this job for not having fixed this problem immediately. In my defense, from the moment I learned of this issue I dropped everything to begin working on it.

A critical step to printing a replacement part is measuring your existing parts to make sure the replacement components will fit well.  I find the easiest way to start doing this is to simply trace the existing parts on a white sheet of paper.  Once this has been completed, I flesh out the “sketch” a little and draw in all of the measurements.

Marking the dimensions of the key fob

Once the measurements have been taken down and associated with the relevant areas on the existing parts, I like to create a digital representation of these parts.  Doing so allows me to use those existing components as a basis for developing the replacement parts.  With printing tolerances, a little ooze, and some very minor Z axis wobble I find that 0.5mm – 1.0mm room on all sides is sufficient to develop parts that print and fit together nicely.

Next up:  A first draft

Posts in this series:

• MakerBot Hero:  Car Keys I
• MakerBot Hero:  Car Keys II
• MakerBot Hero:  Car Keys III
• MakerBot Hero:  Car Keys IV
• MakerBot Hero:  Car Keys Epilogue

Key fob, apart

My mom had been a public school teacher for all of her working life until she retired several years ago.  It was just before she retired that she bought herself a nice new car.  Yesterday she came to visit and she handed me her car keys to grab something from her trunk.  I was horrified at what I saw.  Her car keys, which have a built in electronic car lock/unlock remote, was wrapped in cheap packing tape.  On top of that, it was old packing tape.  So old that it had become stringy and oozey.

I asked what happened only to be told that while at her school she had dropped her keys which immediately cracked at the point where the metal key met the plastic housing for the electronic guts.  The school maintenance worker had kindly offered to fix it up the only way he could – with public school¹ packing tape.

This conversation ensured:

• MakerBlock: “How long has it been like this?”
• MakerBlock’s mom: “Oh, a looong time.”
• MakerBlock: “How long?”
• MakerBlock’s mom: “About two years.”
• MakerBlock: “Two years?!  Mom, you do know I have a machine in the other room capable of just making you a new plastic housing for your keys, right?”²
• MakerBlock’s mom: “Oh, that never occurred to me.”
• MakerBlock: “This is just unacceptable!  You can’t live like this.  I’m making you a new one.”

With the careful application of a utility knife to remove the packing tape and precision screwdrivers to take out the one lone screw, the key fob revealed its secrets, as depicted above.

Next:  Designing the replacement

Posts in this series:

• MakerBot Hero:  Car Keys I
• MakerBot Hero:  Car Keys II
• MakerBot Hero:  Car Keys III
• MakerBot Hero:  Car Keys IV
• MakerBot Hero:  Car Keys Epilogue

1. Read: cheap [↩]
2. 3D printers has essentially been all I can talk about, or write about for that matter, since hearing about them for the first time in April of 2008. [↩]

Thing-O-Matic shipments are delayed. Here’s what’s going on:

Thing-O-Matic shipments are currently delayed until we get a package delivered to the Botcave that is currently being held in transit because of the recent mail bomb scare and the new procedures put in place to make us more safe.

Everything for the Thing-O-Matic launch was supposed to arrive at the beginning of November. We know from experience that everything takes two weeks longer than expected to arrive so we gave ourselves an extra 3 weeks lead time to iron out any last minute delays. Electronics have been our biggest challenge in the past and so when they turned out to be two weeks late in getting to us and we felt all smarty pants and high fived when they arrived last week. Then, like a cruel slap to the face, we learned about the shipping delay on our super awesome custom Z-stage motors. Our super special custom made Z-stage motors are currently being held somewhere between Hong Kong and customs in Cincinnati. Sam, our supply chain manager, is working hard to find out when that shipment will be released to us, but we don’t have any hard information at this time.

I hate it when I order things and they come late. Because we have a little extra time, we’ve organized a little treat to go in each box for each Thing-O-Matic Customer. It’s not much consolation, but it’s all we can do as we wait for the final parts to reach us so we can send them on to you!

We’ll keep you updated here on the MakerBot blog and on twitter so you can know the exact second when the machines start to ship out.

Thanks for your patience. As soon as we get the final parts in, we’ll go into double time to get them out to you. The first Thing-O-Matic order will be the first one out the door and we’re going to be putting all our resources into getting all of the pre-orders in the mail in the order that the order was placed so that you can put your machine together and start printing with your beautiful new machine as soon as possible!

- Bre Pettis, CEO MakerBot Industries

One Leg Articulated Frog by Benjamin

Okay, maybe it isn’t intended as an actual prosthetic, but this is still super cool articulated frog leg by Thingiverse citizen Benjamin.

I can see a lot of potential with this part.  You could print up four and a frog body that connects all of them.  You could design a telescoping frog tongue using a similar mechanism.  You could design a rabbit leg for some robot-rabbit-ribbit action.  It resembles a piston or plunger for potential use as a component in another toy as a linear spring.  From just the right angle it resembles a key from an old school typewriter. ¹  On a larger scale, these could be spring loaded walking boots/stilts.  A similar set up could be used as shock absorbers – perhaps for a printable RC car?

1. Who is up for the challenge of designing a printable typewriter? [↩]

Tricks for measuring with a digital caliper

A digital caliper is one of the most useful accessories to a 3D printer.  With a caliper in hand you can ensure you’re going to end up with accurate replacement or upgrade parts.  Some Skeinforge guides even suggest using calipers to assist in calibrating your printer.  The guys over at Buildlog.net have put together a short guide with some tips and tricks for using your digital calipers.

Dave Durant’s latest guide to configuring Skeinforge is probably the most valuable post so far.  This post tells us more about the nuts and bolts of his method for dialing in Skeinforge settings to get the best possible prints.  What I like about Dave’s method is that although he’s using some counter-intuitive methods and assumptions, he’s clearly thought all of this through and got the results to back it all up.  Once again, Dave!

This article’s the second of two on making up a new profile. If you didn’t read the first one, you probably should do that before reading this one. Or at least scan through it. Even if you’re not making up a new profile and are just trying to get an existing one to make nicer prints, you might find this useful.

WordPress.com tells me I’m close to 2000 words here - yikes! – but if you’re having problems getting nice prints and aren’t sure what to do about it, I think it’s worth wading through. You’ll be amazed at how much quality a Makerbot is capable of – I know I was, once I started understanding the calibration process.

The key to just about every aspect of dialing in a profile is being able to recognize when you’re getting too little plastic or getting too much plastic.

I’m going to try to avoid using actual profile numbers here because I’m using a 0.35mm MakerGear bighead nozzle instead of a stock 0.5mm MakerBot nozzle. Profiles with this nozzle are a bit different and if I just spit out numbers and you try to use them, you’re probably not going to get the same results that I get. That’s not to say, not even a little, that you can’t get fantastic prints from a 0.5mm nozzle – you absolutely can.

Enough talk! Here’s a picture of two 20mm calibration cubes taken from two different views:

On the top half of this picture, notice how the threads aren’t touching – you can even see down to the previous layers. The profile that made this cube isn’t putting down nearly enough plastic to make a solid print. If you put any stress on this cube, it’d likely crumble.

On the bottom half of the picture, it’s blob central. This object is supposed to be a nice, square cube (or 1/2 a cube anyway.. it’s 20x20x10mm). On the left side of this one, you can see how the threads aren’t nice and straight – they’re sorta wavey – because the extruder is pushing too much plastic into too little area and shoving the existing lines around. On right right side, you can see how this eventually makes the top bulge up. If you used this profile to print an object that required nuts & bolts or multiple pieces fitting together, you’d get pretty frustrated, pretty quickly.

(note that if you’re using a stock MakerBot nozzle, it won’t look like this – those nozzles, when the profile is wrong, tend to scape up and push around the extra plastic so you sorta get little chunks of goop in random places. It’s a bit of a trade off – the MakerGear hot ends are rock-solid and more tolerant of blobs but the MakerBot ones make a slightly smoother finish on top, when they’re really dialed in nicely. Both are good but they do produce different results. )

Test & Tweak

I had wanted to do a bunch of pictures for this article, showing a gradual quality improvement and ending with a beautiful print. Sadly, these really didn’t show up well. Black ABS in particular never seems to show up well for me.

So, instead of a series of pictures, here’s the end result you’re looking for. It’s not perfect but it’s not bad at all:

The big thing to take note of here is that the infill lines are nice and tight against each other without any plastic blobbing up between them. There is a small dip between each line which I could lessen by dropping the feed rate by another 0.25 or 0.5 mm/second but this is pretty good as it is. There are some gaps between the infill and perimeter noticeable on the right-side cube but that’s because my build platform is overdue for leveling – you can see it’s just fine on the left side.

The whole “Test & Tweak” thing is really easy to do. From the previous article, you should have a target layer height and width over thickness (“w/t”) that you’re aiming for. You should also have at least a general idea of the feed rate that you’ll be using.

To do the test & tweak thing, pick a starting feed rate (and, again, aim high here – better to aim too high than too low) and print out a cube. Once you’ve got the cube, take a look at the top of it and decide if the feed rate is too high or too low.

If the cube seems blobby, the feed rate is too low - raise the feed rate a bit; if it’s looking anemic, the feed rate is too high - drop it a bit. Print out another cube at the new feed rate, take a look at the top and tweak the feed rate again. Keep doing this until you’ve got yourself a cube that’s really, really nice.

How much you should tweak the feed rate each time totally depends on how far off the print is. If it comes out like the pictures up near the top of this article, the 2 views of 2 cubes, you’re going to want to change the feed rate by 10; those cubes are way off.

• Add to the feed rate if too much plastic is being laid down
• Subtract from the feed rate if too little plastic is being laid down.

I usually go by halfs when I adjust feed rates.. If it’s horribly off, I tweak by 10. Once I think I’m within 10 of the right value, I tweak by 5. Once I’m within 5, I tweak by 2 or so. Then 1 then 0.5.

You can go down to tweaking it by 0.25 if you want but any more than that is overkill, IMO. Other variables (ambient temperature, filament inconsistencies, how well X/Y rods are oiled, etc) can effect the print more than tweaking that much. If you can get it to 0.25, you’re going to be really happy with the prints.

Oooo.. Shiny!

This is another one I wanted pictures of but they look a lot better in person than in picture so you get words instead of photos. While the 20mm cube is printing, keep an eye on the surface of it.

If your feed rate is perfectly right or too high, the surface of the print (even if it’s still in the middle of the print) will look uniformly shiny.

If the feed rate is too low, it will not be uniform – there will be parts that look shiny and parts that look sorta dull.

This makes perfect sense, too.. Go back up and look at the 2 view of 2 cubes near the top of this post. On the top-right one where there’s not enough plastic being laid down because the feed rate is far too high, if you were to look in from the front of your ‘bot while this is printing, each of those identical lines would reflect light the same way and it would be nice and uniformly shiny.

On the bottom-right part of the picture where it’s blob city because the feed rate is far too low, it’s not consistent. Because too much plastic is being laid down, extra plastic is pushing up from semi-random places which causes the light reflection of those places to be different from the more normal parts.

Watching the print while it’s printing, especially once you get down to tweaking feed rate by 1 or less, is going to be enormously helpful in figuring how where to go next on the feed rate - if you get to the point where it’s all nice & shiny up until the last couple layers, you’re within 0.5 or 0.25 of it being perfect. If it’s fine until around mid-print, you’re probably within 1 or 2.

All that said, I generally ignore the first 5 layers or so unless they’re hugely, painfully obviously off. It’s hard to get the Z stage perfectly positioned at the start of a print and that can throw things off a bit. Once you get 5 or so layers done, it will have worked out any of those types of issues.

Take notes!

One thing I learned pretty early in my calibration cube printing days is that with each cube taking 10-15 minutes to cycle through, from starting the print to starting the next print, plus eating and sleeping and answering the phone and maybe a tasty adult beverage in there too, it gets hard to keep track of what’s what.

The easiest & simplest solution to this, at least for me, was to use a razor to carve a roman numeral into the side of each cube when it finishes printing and notes on a piece of paper (or some text editor) the details for each cube.

You don’t have to use roman numerals if you don’t want to but it’s a lot easier to carve I, II, III, IV, etc into a cube than 1, 2, 3, 4. Or use a Sharpie, as long as you’re sure it won’t smear or fade or anything like that.

This doesn’t need to be anything fancy. When I dial in a profile, I just scribble the layer height and w/t at the top of the paper then have lines under that like “I = 33″, “II = 34″, etc, noting the cube number and the feed rate it was printed at.



Once you get close to being dialed in, this will make things a lot easier. You’ll be able to just check out the top of the cubes for too much or too little plastic and make a quick decision on how much the feed rate needs changing.

Infill Solidity = 1.0??

Any time I suggest printing calibration cubes, I say they should be printed with Infill Solidity set to 1.0, which is 100% solid. Fairly frequently, people look at me funny (yes I can tell, even when it’s via text) and say that they never print over .15 or .25 solidity so why waste time & plastic turning it up to 1.0?

The bottom 2-views-of-2-cubes cube shows a bit of an extreme example of why these cubes should be printed at 1.0. If I had printed this one at a lower infill, skeinforge would have left hollow bits in the object and those would have given all that extra plastic somewhere to go – it still wouldn’t have looked great but it wouldn’t have been as horribly wrong as what you see in this picture.

On the surface, that might sound like that’s a good thing – if it hides problems, why not turn the infill down and be happy? The answer is that it probably is fine if you’re never going to print anything more complicated than a calibration cube.

Once you tried a more complicated print like something with some large flat areas and some smaller/narrower areas, you’d run into trouble – you’d either get too little plastic (like the top picture) on the big open areas or you’d get too much plastic (bottom picture) on the smaller areas. Only with a profile that puts out the correct amount of plastic will you be able to handle both types of features in a single print.

So, moral of the story, set Infill Solidity to 1.0 when you’re printing calibration cubes. The goal is not just to get a little cube that looks good – it’s to find the right combination of values that will work at any infill setting…

Done.

I know that’s a lot of words and hope you didn’t “tl;dr!” this and jump here to the end. I also know it’s a fair amount of work to dial in a profile but once you go through it a couple times, it really does go pretty quickly. You’ll also, hopefully, get a better feel for skeinforge, which isn’t nearly as complicated as it seems, once you get a handle on the basics.

I really can’t over-state how much your prints can improve if you’ve never really sat down & worked on a profile and go through this test & tweak process . The time & plastic investment you make here are well worth it. Really.

Thanks Dave!

Peacefrog's instant platform leveler

Thingiverse user peacefrog posted a super simple and elegant method for leveling  the build platform.

You can try to shim or shave the build platform or the XY stages that support it.  One problem with this method (besides the shaving/sanding being permanent) is that you can’t have the platform on the XY carrage while you’re working.  The result is you spend your time shimming/shaving/sanding, placing the platform back on, checking to see if it is level, and repeating.

Peacefrog’s method is devestatingly simple.  Put the bolts holding the platform on upside down and add 3 nuts.  One between the XY stage to hold the bolt tight, one above that to level the platform, and one on top to hold the platform tight.  To level the platform, just remove the top nuts, adjust the middle nuts on the four corners until the platform is level, then replace the top nuts.

David Durant had recent published another amazingly readable guide on working with Skeinforge.  He’s also published an index of his articles on configuring Skeinforge so far.  This latest article is particularly interesting because he suggests a new method for dialing in your latest Skeinforge settings when creating a new Skeinforge profile.

It’s very useful to have multiple Skeinforge profiles – for different equipment¹ or different materials² .  Another excellent reason for having multiple profiles is so that you can optimize one profile for speed and another profile for high resolution prints.

So, without further ado or gilding the lily, I am pleased to present David Durant!³

Next up is actually creating a new profile.. I’m using Skeinforge 33 for this, dated 10.11.10, but any version close to that should work pretty well.

I know 2 ways to dial in a new skeinforge profile. One, the one this post is not about, involves picking layer height & feed rate then printing a thin-walled object and measuring the wall width. You do a little bit of math to figure out the width over thickness (“w/t”) then plug that into skeinforge.

There’s nothing ‘wrong’ with this method - lots of people use it - but I don’t like it. I’d rather pick layer height and w/t then tweak the feed rate until it comes out right, which is the other way. The way this blog post is going to talk about…

The reason for my preference here is that layer height has a lot to do with resolution – how ‘fine’ the object is printed. Similar, the w/t values say a lot about the strength of the object. Basically, layer height and w/t are characteristics of the finished object.

Feed rate and flow rate, on the other hand, don’t really tell you anything about an finished object - they’re more about the process of how the object was printed than about how the object ends up.

Because of this, layer height and w/t are values that I want to choose. Within reason, I’m not too concerned about where the feed and flow rates end up – I’m more interested in the resulting object.

All that said, on with making up a new profile. I think the basic process has 2 big parts: The Setup and The Test & Tweak. This post is about The Setup, the next one will be on Test & Tweak.

The Setup

The plan goes something like this:

1. Decide on your target layer thickness and w/t values
2. Clone an existing profile and give the new one a descriptive name
3. Plug your target values into the new profile
4. Take a guess at what the feed rate should be for the new profile
5. Make gcode and feed it to your ‘bot
6. Examine the result, tweak the feed rate
7. Back to step 5

1: The first step is to pick some reasonable values for layer height and w/t. By reasonable, I mostly mean something your hardware is actually capable of printing; probably a layer height in the 0.20 to 0.50 range with w/t values of 1.2 to 2.0.

If you’re shooting for a profile that’s a lot different than one of your existing ones, I strongly recommend doing a series of profiles and working your way towards your goal. This may seem like a lot of extra work but once you do it a couple times, you’ll find that it goes pretty quick. Similar, if you’re changing both layer height and w/t, it’s probably easier to concentrate on just one of those parameters until it’s pretty good then go back and do the other one.

If you don’t actually have a decent profile to start from, don’t worry – below are some combinations I’ve used before. Some of these are better than others but all should at least be in the right ballpark. If you haven’t done a lot of printing before and are picking one of these combos below, you probably want to start with one that’s got a feed rate under 45 or so. Moving faster is certainly possible but takes a bit more work & care – start slower, work up to it.

Layer Height	Width/Thickness	Feed Rate	Flow Rate
0.25	1.8	49.50	255
0.25	1.6	60.00	255
0.28	1.8	44.00	255
0.28	1.6	49.75	255
0.28	1.4	54.25	255
0.28	1.2	61.50	255
0.32	1.6	34.25	255
0.32	1.4	42.25	255
0.32	1.2	51.75	255
0.32	1.0	60.50	255
0.35	1.4	34.25	255
0.35	1.0	46.25	255

(yeah, my HTML table-fu stinks.. )

2: Clone an existing profile and give the new one a descriptive name.

Next up is creating a new profile. Fire up skeinforge and, near the top, click the Profile button then click the Extrusion button below that. At the bottom, there will be buttons for Add Profile and Delete Profile with a list of your existing profiles above that.

You should give your new profile a descriptive name. I usually use names like “0.5mm, 0.32mm, 1.6, 3.0mm” which means it’s for a 0.5mm nozzle, 0.32mm layer height, 1.6 w/t and 3.0mm filament. Use whatever you want but if you call it something like “asdf” or “test”, you’re probably not going to remember what that means, a couple months down the line.

In the list above the add/delete buttons, single-click the profile you want to clone, type the name of your new profile in the area to the right of the Add Profile button then click the Add Profile button. That’s it – your new profile is started.

At least for me, I need to exit and restart skeinforge at this point. If I don’t, it gets a little bit weird and doesn’t let me use my new profile. No big deal – just close skeinforge then start it back up.

Near the top of the skeinforge window, make sure the Profile Type is set to “Extrusion” and the Profile Selection is set to your new profile then click the Craft button, just below those.

3: Plug your target values into the new profile.

Unless you’ve done this a few times before, now would be a good time to wander through all the pages in skeinforge Craft and compare them to my previous post. You don’t need lots of things enabled at this point; you’re really not going to be looking for the perfect print here - you’re just looking for the right combination of the Big 4 (or 5) Settings.

In addition to plugging in the Big 4 (or 5) Settings, there are a couple other things you should set while you’re in there. Here’s my checklist for when I’m printing 20mm calibration cubes:

• Carve\Layers From = 0
• Carve\Layers To = 10000  (or any really big number)
• Carve\Layer Thickness = your target layer thickness
• Carve\Perimeter Width over Thickness = your target w/t
• Fill\Diaphram Thickness = 0
• Fill\Infill Width over Thickness = your target w/t
• Fill\Infill Solidity = 1.0 (yes, really.. set this to 1.0 for calibrating)
• Fill\Infill Perimeter Overlap = some value under 0.25
• Temperature\All Settings = 210 (or whatever value you extrude at.. usually 210 or 220)
• Speed\Flow Rate = 255
• Speed\Travel Feed Rate = 50
• Speed\Feed Rate = your best guess..

Since you’re starting with values you chose for layer height and w/t, and since I said to just peg the flow rate at 255 (full speed on the extruder), the only one of the Big Settings left is feed rate. For that, you really do just have to take your best guess.

That said, you can make it a fairly educated guess by looking at various combinations of settings that should work and comparing them to the combination you’re trying to make work – the correct feed rate should go up or down based on if you’re raising or lowering the layer height and if you’re raising or lowering the w/t. In general:

• Lower layer height or lower w/t = higher feed rate
• Higher layer height or higher w/t = lower feed rate
• Change feed rate by 3-4 for each 0.01mm change in layer height
• Change feed rate by ~5 for each 0.1 change in w/t

So, if you’re going from 0.32mm layer height to 0.30mm layer height, you probably want to start by adding 8 to the feed rate. If you’re going from a 1.4 w/t to a 1.6 w/t, you should subtract about 10 from the feed rate.

Forget about fractions here – just use whole numbers – and when in doubt, aim a bit high with the feed rate.

If you’re stressing over get this wrong, don’t worry about it – unless you guess really, really low on what the feed rate show be, nothing bad will happen. If that doesn’t decrease your stress level, just do your best on getting it about right then add 5 to it. Don’t worry.

The Setup is almost complete.. The only prep left to do is to head over to Thingiverse and grab the 20mmbox.stl file from Spacexula’s Makerbot Calibration Set. The other pieces he’s done are also good but I’m just going to be using the 20mmbox object.

That’s it! Next up will be printing the 20mmbox and dialing in your profile.

Thanks Dave!

1. Such as a MK4 versus a MK5 extruder, with/without heated or automated build platforms. [↩]
2. Such as PLA versus ABS. [↩]
3. I really wanted to preface his introduction with this quote, but it seemed a bit much. [↩]