December 29, 2020

3D Printing - tips

13 Things I wish I had known

A guy has a video entitled "13 things I wish I had known". Here is my outline of his tips:
  1. Bed leveling and first layer squish (piece of paper just pulls with some friction).
  2. Print on clean glass or a good bed
  3. (maybe obsolete) Hairspray or glue stick to get first layer adhesion.
  4. Skirts, brims and rafts
  5. understand support and bridging
  6. Octopi and Octoprint revolutionizes everything.
  7. Keep an eye on things (he uses a camera for remote monitoring long jobs).
  8. Know your materials (PLA for most things, TPU for flexible things).
  9. Help from friends - forums and the 3D printing community
  10. Ironing (running the bare hot end over the top layer for a smooth surface).
  11. Print profiles for different materials, printers, quality settings
  12. Slicing matters (tune your settings)
  13. It is a hobby, be patient, have fun, expect some failures, get better.

Dave's Tips

These notes began when I found out that my friend Dave had a 3D printer and began giving me suggestions and lots of valuable advice that I wanted to preserve somehow. It began with him saying in an email:

"Tomorrow I’m going to print out a box ..."

For someone like you, I would compare having a lathe. It’s more about what you can do that you couldn’t do before.

I recommend getting the cheapest Ender 3 3d you can. You won’t regret buying it because the critical parts are the aluminum extrusions. So long as the frame is solid and the build plate moves nicely, everything else can be replaced if need be. $40 or so for a new power supply. $40 or so to upgrade to auto level. Better servo motors, blah blah… By the way, I have done none of those things. My printer works great. There are little inconveniences; I have to baby sit the first layer to make sure it’s going well. Tweak the head offset mostly.

From what I’ve seen there are two kinds of 3d printers, cheap, expensive. There seems to be this binary threshold of $100’s of dollars to get “cheap” quality and $1000’s of dollars to get great quality (no user intervention). So $100-$500 are the same $500-$xxx0000 printers to get varying better quality. My point is the $100-$500 produce similarly.

What printer

Dave began with a Troxy X5S that was loaned to him. That got him started. That printer is big, expensive, fancy, and near as I can tell no longer available.

He now has a Creality Ender 3D, which is more or less a $200 printer and is serving him well even in the stock configuration. Most of what follows are his comments pulled out of a series of emails.

One of the things that got my attention in working with the Troxy was the idea of improving your printer by printing parts on your printer. So you can buy a cheaper printer and make the modifications yourself that some of the more expensive printers have. In the beginning, I made a ton of modifications for the Troxy to stabilize and make it print better. On my Ender3 3d I didn’t have to do as many, but I did some.


Great for making custom boxes and broken parts. I made some knobs for our stove.
Parts can be very strong if over 10mm thick. (I’m not sure if I could make a water pump coupler but maybe. I made some hinges for an Igloo cooler)
You don’t need to worry about asphyxiation if you are using PET. I use mine in my house. ABS should probably have ventilation, though I have printed it inside under a box.


Not fast. Takes about 6 hours average to print a 4" x 5" x 2” box. I usually just let it run all day. Sometimes over night.
Not air or water tight. I made a shower head that water comes out of the pores. I could have made it from ABS and used acetone to melt/seal it but that was my first water project.
Not very strong when making small parts. Almost always any standoffs that I’ve made for mounting circuit boards on break off very easy if they are not over 10mm. I normally just use screws now.
I rarely use ABS because it’s very susceptible to warping (temperate changes make it shrink while printing). That can be overcome with an enclosure. I just throw a box over it when needed.

I asked what else I would need besides the printer to get going:

To start printing, nothing else but filament. It will probably come with a small roll so you technically don’t need anything else right away. You will no doubt want to print, add modifications, but they are not expensive. I bought a piece of glass (Home Depot, cut myself) for the bed because I like printing on glass the best and use Aquanet hairspray. First layer is everything. If you can get a good first layer, you pretty much are done. Auto level is nice but not absolutely necessary once you figure out how. It was worth the $40 to me to upgrade to auto level but you have to modify the firmware and hardware which voids warrantee because you have to splice wires. Other than that, nothing else necessary.

All in all, I’m glad I got it and find it very useful.

I wouldn’t spend a lot of money for your first printer or buy a big one.

It’s about $15 for a spool of filament and lasts a long time. The Ender 3 is by no means one of the best but for hobby stuff it's fine. It can make about 8” square stuff but I’ve never made anything over 8”x8”x2". I bought the Ender3 3d thinking in the future I might buy a bigger one and have never had the need to upgrade. It just takes too long to print and there is nothing more depressing than coming in the morning to see $5 worth of spaghetti sitting on the build table.

I will say, I’ve learned how to work around little bugs over time so it’s not just throw a design at it and out comes a thing. There are a million little things that you learn over time. I’m pretty good at it so if you get one, I can help you with the snags. I like my printer but it’s 3 years old so there may be something else better for the same price range now.

As far as cad. I recommend to start. Very easy. Just add and subtract primitives. I’ve made some crazy stuff. I made the hardware for my automatic curtains.

If you do get one, I can save you a ton of time because there are common issues that I had to learn by experience. Things like how to get a good first layer, build surface, and bed leveling. I recommend getting something with auto bed leveling if you can. The best version of leveling is a touch pin not capacitive or inductive. Temperature makes a big impact and is almost as bad as manual leveling.

Various tips.

Glass bed: I like it because of all the other ways to print, this one worked the best. I tried tape, the included build mat and both gave me trouble either not sticking or sticking too much. Glass was the baby bear for me. The problem with glass is you HAVE to use a physical touch sensor for auto leveling. I tried both inductive and capacitive and both don’t work through glass well. They seem to become ineffective over 2mm from the “surface” since glass isn’t a surface it bounce off the metal which gives erroneous results.

Having said that, there are many anti glass (I think they also believe in flat earth, but not sure) folks. The key though is Aquanet hair spray. I haven’t had problems with sticking too much or too little ever since I started printing this way. Search about first layer adhesion and 3d printing and you will see. It’s similar to how Thomas Edison invented the light bulb. People are trying everything. Ex glue stick. For comic relief (for you) I tried using gaff tape. It definitely was a gaff. Not only did it not work it made a mess of the build plate because of the heat. I had to take the build plate off and scrub it with goo gone over and over to get rid of the goo.

As far as leveling, you can add on auto level later. The best is the BT-Touch. I got a knock off version to save $10 YMMV. If you can get a printer that already has that fine, but for the above reasons, don’t bother with a non touch sensor. Auto leveling is not perfect but does make things easier. You have to use a modified firmware, but the firmware is open source on the ender 3 which is nice. It is a little complicated for flashing as you need an Arduino to flash it the first time as there is no boot loader. Read up on firmware modding for the Ender as it relates to auto leveling. Manual leveling takes some practice. When you get there I’ll tell you more. It’s a little lengthy to explain in text. Bottom line, everyone tells you to do certain things but I’ve found that you can’t really know how well you leveled the bed until you actually start a print so I added code to my startup script (not firmware, gcode) to run an outline a few times around the print and tweak it as it’s going. Oh… the other thing about glass which is nice is glass is normally not bumpy or warped like aluminum. My first bed was warped and had to get a replacement, which was warped as well but not as bad. Clamping a piece of glass to the top makes that go away.

Leveling -- you have to do it for every print. The bed is on springs, servo motors aren’t that accurate, belts slip, changes in temperature, humidity, gravitational anomalies, star alignment, life is unfair, etc. Glass bed - If you want to trim off some money, you can just by a piece of glass from Home Depot and cut it yourself. I had never cut glass before but I was able to cut it. If you haven’t the two keys are #1 you only get one chance to correctly score the glass so make it count. #2 Make sure you are on a nice smooth surface. I did it on my dining room table on one layer of cardboard. I’m not sure how much the glass costs anyway.

Don’t forget Aquanet hair spray for the win!

Look up manual bed leveling. This is the tricky part because the thing to avoid is the nozzle being too close or too far away. Too close and you get to listen to the nozzle scratch a grove in your build plate. Hence the springs on the build plate. Too far and your 3d printer becomes a plastic spaghetti maker. If the bed is lopsided you get the added possibility of being able to do both at the same time! Normally this is never fatal, fortunately. My recommendation is to just use a piece of paper doubled as a gauge on your 4 corners and center, then use the knob to tweak it once you start the print.

For your homework:

I asked some questions about drilling (and tapping) things and got:

Because it is printing in layers, you have to careful cutting or drilling so the layers don't split. Beefing up the thickness would help. Another thing you will need to learn about is infill. I have never liked this because most of the things I make need to be beefy or have thin walls (like boxes). The idea of infill is making a hollow shape with just a skin of some thickness. It saves print time and filament. You DON’T want to drill through stuff like that obviously because the hole will only have a skin around it. If you drill bigger than the skin then the hole becomes an opening into the internal hollow. Think of drilling 10mm hole through the center of a 20mm cube with a 2mm surface and a honeycomb (or triangles, squares, whatever) matrix inside. Once you drill through you will have a 10mm diameter by 2mm deep hole, a cross section of honeycombs with a hole drilled through it and another 10mm by 2mm exit hole.


You can use PLA, PETG, or ABS. ABS stinks and is toxic. But it can be smoothed with acetone, which seems to be the only reason to use it. PLA will melt in a hot car in Tucson, Arizona, so it may be fine for some things, but not all -- but it is the easiest to work with. PETG solves the heat problem, and is non-toxic, so it sounds ideal for me to use for things that may be exposed to Tucson Heat.

My friend Dave recommends "Hatch Box" filament:

A 1 kilo roll of HatchBox is about $20 on Amazon and I’ve had good results. I wouldn’t buy a lot though. One roll goes a long way. I’m sure the stuff sold by Creality would be good if it comes in at the same price, fine. I find white handy for things I mount on walls and black for stuff that sits on desks. Other colors are up to you. I’ve never printed anything in another color I recommend one white, one black to start. If you really want to save, Get one white. You can always spray paint it if really needed.

Crappy filament will sour the experience for sure. I’ve had some that was so stringy that it just made a mess. Having said that, I’ve never had to throw away a roll but it’s a real pain to have to adjust and I did have failed prints and hours of frustration. The main issue is handling so the moisture is controlled. I was recommended to use Hatchbox by the guy I mentioned who works at a company that uses 3d printers for prototyping. It works, it’s constant from roll to roll so what the heck why change. As I said, I did try to be cheap and buy $15 rolls… Not worth saving $5.

PLA - Super easy to use but not high temp. You live in Arizona, soexpect things that are out doors to warp made of PLA. Look up temp specs for sure. Nothing in your car would survive.

ABS - Biggest plus about ABS is you can melt it with Acetone so you can seal it for water, even airtight purposes. But it REQUIRES you to put a box over the printer while it’s printing because any free moving air will more than likely cause warping (Good 3dprinting warping). It’s also a little toxic so it needs to be in a ventilated area, which causes warping. ABS is higher temp.

PETG - My (and many people’s online) favorite. It’s PLA 2.0 Higher temp, easy to use like PLA, technically non toxic (verify), less fussy, no warping (I’ve not printed anything really tall so YMMV).

The printer may come with a small test roll of PLA. I’ve tweaked my settings for PETG and for the most part, as I said, except for babysitting the start of the first layer, my prints are normally problem free.


Have a look at when you get time, that will be step one. Also, download Ultimaker Cura and have a look at that. L earn how to export sty from Tinkercad and import into Cura. Just a few mouse clicks. Here are my setting files as a starting place. I’m using Mac version so I don’t know where the settings are. I recommend backup the ones that are there and then just drop the whole thing in place. There may be an option to import/export settings but I haven’t looked.

My settings are years old now. Perhaps try just using Cura’s settings first. They have direct support for the Ender printers.

Design and CAD

For 99% of what I made, I used Free and works well, and is very easy. I recommend trying it to see how easy it is. Once you are done modeling, it exports to an .stl file which is imported into Utilmaker Cura (free). There are others, some pay, I use Cura because it works the best for free. I’ve even tried the pay ones and found that I just needed to tweak settings in Cura to make it do the same thing. If you start with my settings, more than likely all you have to do is import it, click slice and save as .gcode. (You can learn all the settings in Cura later, not that complex once you know the terms.) Put the .gcode file on an SD card, push it into the Ender 3d and chose print from SD card and off you go.

If you give yourself a solid day to create a shape, fiddle and play, you probably will know 70% of what you need to know. The other 30% will be in drips and drabs over weeks of “how do I get that to print better”. Truth is, I will probably be able to just tell you the answer because there aren’t that many things to go wrong.

Here is a link to my latest boxes that I made. I recommend selecting them and click the ungroup to get to the original pieces and you’ll get an idea of how easy it is. This is my classic box style because I don’t need screws.

One thing I should add is if you want serious tolerances don’t bother. Basically a 2mm hole will be about 1.8mm. These are things I have gotten used to in my designs. If I need an exact 2mm hole, I’ll make it about 2.2-2.5mm. With small things like that, I’ll usually try to put together some quick test print to see how it prints. Vertical holes are different then horizontal holes as well. Just the nature of the cheap beast.

Might as well give you things to research because they will happen at some point: Warping (ABS problem mostly), stringing, first layer problems (this one is #1). These are the first problems you will encounter.

Another tip. Don’t be afraid of going over the “recommended” temperatures. I print PETG at about 225-250c. I found that less didn’t give me very good layer adhesion, but the by-product is stringing, which is countered by using more retraction; basically it sucks in the the filament and then squirts back out between movements to kind of cut the filament flow during movement, which is where the stringing occurs. There are a number of test prints available that you can run for optimizing temperature, stringing, alignment, wall thickness and various other problems that are worth looking into. Best bet: start with Cura default settings for Ender3 3d as a base and then tweak slowly from there measuring results.

You are probably already familiar with this but Thingiverse is a great place for finding stuff that others have already made that can speed up your production time. I found that I’ve learned some things by viewing how others have compensated in their designs for real life 3d printing.


I wondered if I needed a spare, if they wear out or get jammed. Dave says no ...

I rarely change mine but they do wear out. In the future you might want to experiment with different sizes. The guy in church just started printing with a huge 4mm hole and he says his prints are much faster and the resolution isn’t that much of an issue. It’s interesting for him to say that because he prints things like helmets and Thor hammers where small details matter. I think the default is 1.75 if I remember correctly.

Have any comments? Questions? Drop me a line!

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