Lets print something ….
Lets print something but how do we do it?
You may have read about how 3D printing has helped us with our prototyping. How we had switched over to printed skids on our chassis kits a couple years ago. Or seen our Shapeways store where you can get some replacement pieces for our chassis and pick colors.
3D printing has come so far in the last 5 years its with out hesitation that many of us use them. There is a difference though in technology between commercial and hobbyist. The two main types we see are SLS (Selective Laser Sintering) and FDM (Fused Deposition Modeling).
SLS sounds cool, its got lasers. SLS is more of the commercial grade we see from companies like Shapeways and i.Materialise. These machines are in the price range of triple digit price tags before the decimal point is seen. With that price tag comes some things an FDM cant do. Part detail, just the overall look of the parts is incredible. Part integrity, the strength in the materials they use is much higher then an FDM machine. And the materials they can print from.
Basically a SLS printer uses lasers to melt a powder material together in the form of your design. One layer at a time. Check out this little video on Youtube, you can basically find a ton of videos showing SLS Printing.
Now outside of commercial use we have the hobbyist machines, the FDM types. These have drastically come down in price and increased in quality over the years. From the software to run them to the hardware on them. Dont take that wrong though and think you can run out for 200$ and get a great machine. You get what you pay for! But thats not to say you cant turn a 200$ printer into a 400+$ work horse.
FDM printers are more of what you see on desktops or in print farms. They are inexpensive, have become reliable and the software (and firmware) has come so far. FDM printers use what we call ‘filaments’ its basically just raw plastics (lack of words) that is melted into a small string thats wound up on a roll. Normally about 1.75mm in diameter but you can find 3.0mm stuff too. The filament is heated up in the hotend from 180* up to 250* depending on what type of material it is.
Your normal material like ABS, PLA, PETG, TPA you can find in the heat range of 180 up to 240. Then you have your more exotic and picky stuff like nylons and other composites that like the 230-260 range. But each manufacturer usually gives you a heat range of +/- 10 degrees they recommend.
Its FDM strong? Yes – depending on design, material and print orientation though. Print orientation is something not many people talk about. It can be the least important thing or the most important thing next to the type of material.
Lets say you are making something for your mother, lets say its a vase or a key chain. Something like ABS or PETG would be ideal and you could spiral the vase or lay the key chain flat. It wouldnt matter because structurally its not doing anything.
Now lets go to the RC world we are in. Lets say you want a receiver box, again its not structurally doing anything. Drop it into your slicer and print away. But lets say that receiver box is in a truggy and your body mounts to it or its part of your shock mounts. Basically something is going to be screwed into it and you need strength.
FDM printing is layers, layers on top of layers and theyre all flat. Now if you print flat and drill a hole to tap it, you are probably gonna split your layers. The part has no strength between the layers. Ideally you would want to print it so when you do tap that hole you are perpendicular to your layers. Your screw would essentially beholding your layers together.
Theres other tricks when designing, slicing and printing too that can help with strength. Try designing in radius’s when you can, even a little .03” radius can help add support to a piece. The easiest and most common thing we hear people say is just increase the infill. Well yes and no for us.
Increasing your infill yes makes the part more solid. Again though if you are going against the layers you can gain strength but all that extra infill isnt helping if you try going into the layers. The other thing is now your print part got heavier and you used twice as much material.
You have screw holes in your part that you need to thread into? Heres a little trick that can help. Increase your wall count. Walls are stronger then infill and can be as strong as 100% infill with out the weight gain. Designing a skid? Up your wall count to 6 and leave your infill at your normal. See how tough it feels after that. You are not just increasing the exterior wall count, you are also increasing the wall count on your holes.
The other thing to be mindful of is what type of material are you printing? Different materials will react with the environment differently and need different printer settings.
ABS for instance is easy to print, runs around the 200-220 heat range but requires an enclosure of some sort. It does not take well to temperature changes such as a draft blowing on your build plate. But ABS is strong and resists well to UV light and warping. Think Lego blocks and you think ABS.
PLA is a hydroscopic material meaning it will absorb moisture so you need to keep the raw filament dry. Most of the time you can hear and see that moisture as its printing. You will hear little hisses or pops and see what can look like air bubbles in the material. PLA can be the easiest thing to print but can also bring head aches. Always have your unused rolls kept in a air tight bag and having a pack of silica in there can help. There are tricks to baking your rolls before use. Pre heat your oven roughly around 125* and put the roll in there for 30-60 minutes before using. We use a food dehyrdrator on our material. You will notice a difference if your role sucked up moisture.
Nylons are the same way except nylon will suck the moisture in while youre printing. Its very hyrdroscopic and you would benefit from having a heated enclosure for it while printing. Nylon is also one of the strongest materials to print too though.
PETG is probably the second easiest in our opinion. Very low hyrdroscopic rate, less prone to warpage, and some great colors. It does need a little higher printing temperature then PLA but its strength is right up there with ABS.
Long story short check manufacturer’s recommendations for their filaments. Not all brands are alike.
Back to the you get what you pay for part. You can find them cheap but be ready for upgrades. Spend now or spend later as some say but if you are like us, you are not afraid to tinker later. Plus you learn so much about the machines and printing.
Our first machine was a Anet A8, an Amazon knock off of the early Prusa’s from what we understood back then. Price was great, roughly 250$ at the time and it printed right after assembly. As we got into looking for ways to make it better we found Thingiverse.com. Theres plenty of free sites to find 3d files on and Thingiverse seems to be the bottomless hole for all of them.
So first we tackled some hardware items like a bigger power supply, went from stock 15amp to a 24v 30amp. From there we jumped onto some heat related items. We opted in for the Mosfet mods for both out hot ends and our heat bed. One of the things we read often was how the stock boards these machines come with tend to be weak. We figured if we can help take some strain and heat off the board it would help longevity. These would help supply a more consistent power so our temperatures would be more stable.
I will say the stock board that came with our Anet is still running and going on its 4th year for us. We do plan to upgrade the board soon but not because its a problem. Again its just technology with them has come so far and prices are very low on them.
Well after the Mosfets we chose to upgrade out heated bed to a thicker one and our hot end to a more heavy duty type. Being that we were planning on printing carbon fiber materials we didnt want to worry about wearing the tips out quickly. Carbon Fiber material is very abrasive on hotend tips.
With those mods done we looked at strengthening the frame. Our Anet came with an acrylic frame. Not the sturdiest thing when put together but Thingiverse to the rescue. We printed every support we could find for it. After taking it apart a bunch of times and re-squaring things up for assembly we had a pretty tough machine.
Bed leveling was always a hard spot for us. Luckily you could tell when it was off. With a little re-calibrating of spring tensions on the bed we would quickly fix it. That got tiring though so we went after auto bed leveling. Our first one was an inductive type sensor. Basically would come down, sense the metal bed and know its limit. It worked but we couldnt print on glass, the sensor wasnt strong enough. Knowing the sensor worked we just printed on painters tape on the hot bed and it worked well.
Recently though we did upgrade the sensor to a BLTouch v3 and LOVE It! Our next upgrade will be a new control board and an all aluminum frame for this machine but its definitely been a great work horse along the way.
Our second machine was again another Amazon knock off of the popular Creality Ender-3. It was about 200$ when we got it 3 years ago and well worth it. All aluminum frame, sturdy and right out of the box was printing great. Again we started making our mods to it pretty much in the same order.
First a 30amp power supply followed by a Mosfet mod for the hot end. We also upgraded our hot end to a Micro Swiss with heavy duty 0.4 tip for extra assurance in our prints. One thing to note was a definite needed upgrade was the rollers our axis’s were on. Factory ones were a bit soft and we started to see some variations in prints. We traced it back to the gimble (Z axis) moving and our Y axis not staying aligned. We upgraded to some tough POM (Delrin) style ones and noticed the improvement again.
This machine was the first to get a BLTouch v3 probe added to it for auto bed leveling. Thats where we fell in love with the simplicity of them. After all these mods were done it became our production machine for many of our produced printed parts. The reliability was top notch to where we could hit start and watch the first layer. Once that was down the machine would just print away.
We upgraded the board about 2 years ago for one with more options and better circuitry, it was an MKS board we read good reviews for. About 3 months ago it did die on us so we were forced to upgrade again. Not that the board was bad, it gave us 2 solid years of flawless printing. This time we went with a 32bit board from Big Tree Tech and upgraded our firmware to the newer Marlin 2.0 version.
The best thing about this board is its a direct drop in for the Ender-3 printers. This meant we could just drop it right in the same spot as the stock board, plug our wires, flash the firmware and go. Not us though, we saw it as a time to mod and tidy things up. Thingiverse to the rescue again for sure.
The Ender-3 has a spot in the front for the control board and all the wires are under the hot bed. We wanted to tidy and enclose much of our wires just to create a cleaner look. We found a mod that enabled us to enclose the board in the back under the bed and tie all our wires in neat and clean. This mod also leaves us the ability to add a Pi Raspberry to our setup for more improvements and mods. Things like installing Octoprint and wifi printing as well as a wifi camera interface. Virtually letting us create a suitcase printer that is all self contained. Super excited about venturing down that road.
After rebuilding and the new firmware update its back to our production printer for in house parts. Its no Shapeways level of work but its perfect for our concerns.