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Joined: Apr 2019
Location Auburn, WA, USA
Some questions:
How large of a print area do you want (and please don't say "as big as I can get for the budget" ;-). This will be more about the things you expect to print. Figures and chassis can fit on pretty much any printer, but buildings? Non-slot car things of any kind?
What kind of post-printing work are you expecting/willing to do? Do you want to just take it off the printer and put it into use? Do you expect to have to sand and/or paint it? Will the layer lines bother you, or is the 5 foot rule something you live by?
As a slot car racer, I must assume that you enjoy a bit of tinkering, and there's no such thing as a "hit print and go" consumer (or commercial) 3D printer, so you WILL be tinkering with the printer, both to set it up and to keep it going, and repairing it when it fails for some reason. Here's a copy of my "tips for those interested in 3D printing" to kind of start you off. This is based on FDM/FFF (e.g. the "hot glue gun" type of 3D printing, but some probably applies to other types, such as SLA (vat of liquid resin) type. I hope this is informative. To head off the inevitable question, I have two Prusa brand i3 Mk3 printers, as well as a Multi-Material Upgrade v2 on one of them. You can find out about these printers and accessories at shop.prusa3d.com. I do not have any other printers.
Greg's "Learn from my fail" for 3D printing...
- Build it yourself. Unless your 3D printing budget includes paid support/maintenance, you WILL be having to fix it. Building it yourself means you're already familiar with it. For the actual building, take your time and follow any provided guide TO THE LETTER. It does not matter how much or how little you pay, or how complete the kit is. Whether you buy a complete kit like I did, or build it with off the shelf parts and a bill of materials (BOM) for making your own printer, just BUILD IT YOURSELF! That said, there is still an element of "you get what you pay for" and often times the really cheap kits are more trouble than they are worth. However, spending more will not necessarily net you a perfectly reliable printer from the start. Buy the best kit you can find within your budget. Buying a kit versus an assembled printer often means you can get more printer for your money as well.
- Keep all filament in a ziplock bag with the silica gel, or an air tight container with dessicant... even PLA, from DAY ONE! If it's not printing, store it properly in a dry bag/box. Most filament will come with a packet of silica gel for a reason, but many don't come in a resealable bag/container. One gallon Ziplock bags are big enough for most 1kg filament reels. As soon as you open a new spool, get a bag and put the silica gel packet in there in order to store that reel when you're done with it. Some people even go so far as to set up a "dry box" container with the filament spooling out the side of it. Although it seems like plastic, it's not that simple, and keeping it perfectly dry is a must. You might think your house is dry, but this stuff can be sensitive, especially cheaper filament (and we all love saving money!).
- Your first layer, and the adhesion to the build plate is EVERYTHING. I mean it. Seriously. If you don't have a good tune of the first layer, then you don't have a good foundation. There can be problems if the first layer (e.g. how close the nozzle is to the build plate for the very first layer) is too high, or if it's too low. Those problems often translate into bigger problems as the print progresses. Finding the "sweet spot" can be a challenge, and some printers make that process easier or harder. What kind of surface your build plate has (glass, PEI, whatever) also makes a big difference in how well things will stick, but if the first layer isn't going down right, chances are you'll have a failed print soon. After you get the printer assembled and calibrated, you'll want to spend some time trying to find the sweet spot for the first layer. Since every printer has its own way of setting that, you'll need to refer to the support/community for your printer for help with that.
- When something goes wrong, look for help before trying to solve a problem or fix a failure on your own. Just because you built it, doesn't mean you know the BEST ways to fix it. There are usually guides that will save you more headaches. You could cause more problems if you fix something the way you think it should be fixed without knowing for sure. I could have avoided some of my major down times if I had reviewed the published resolution to my issue prior to "fixing" it. Crazy, right?
- Keep the extruder clean. Cheap filament (especially when it hasn't been properly stored) is often the cause of MANY printing problems. As soon as you even have a HINT of problems, make sure you clean it well. This doesn't always mean jamming something up in there or cranking up the heat. If there's residue from bad/old filament up in there, it won't always work itself clear. I've found that an "atomic pull" at 90 degrees with cleaner filament is working SUPER well for me and my printer, and I do this whenever I expect to leave the printer unused for any amount of time, or right before I use it if it has been unused, and/or when I'm changing to a different color and/or brand/type of filament. Since every printer is a little different, be sure to look up the tried and true maintenance methods for the one you build.
- Don't put (heavy) things high on your printer frame. This will depend a lot on the type of printer you have, of course, but for Prusa and its clones, where there is a rigid frame that the print head moves up and down on with a sliding heated build plate, you don't want heavy things up high. This is because the motion of the print head and bed moving quickly will cause the weight up high to move and depending on the pattern of motion it can start to resonate. Sometimes nothing is wrong with the print, but sometimes you get printing fails due to knocks or layer shift. In extreme cases, whatever is up there could come crashing down. Setting your filament spool up there is super convenient, but supporting the spool elsewhere is better. Similarly, don't hang tools and other things up there. It's nice when everything is compact and portable, which is why I did it at first, but inevitably, you want reliable printing more than you need a convenient location for things.
- Make sure your table is sturdy. If the table is not perfectly level, that's probably not a big deal, but you DO want it to be perfectly flat so that your printer doesn't tweak just by resting on it, and you want it to be sturdy so that the table can help absorb the motion and not resonate or wobble as a result. Some people use small tables and make them sturdy with a concrete paver of some kind. Weight will reduce motion, so a combination of weight and sturdiness is a good thing. The very affordable IKEA "Lack" table is quite popular. My current table was cobbled together with scrap and hardware, but the table top is a HEAVY chunk of something that's been sitting in the garage forever. I don't even remember what it ever was. Now it's a printer table.
- Don't change too many things at once. Preferably, only change ONE thing at a time. This applies to settings for printing, as well as changes to the printer, or filament, or whatever. If you change too many things, you won't know which change caused the desired result or the undesired fail. Sticking with PLA until you're comfortable is a good idea. Play with other filament types after the initial learning curve is well and truly over. I would almost say wait for a big fail or three, but if you're lucky enough to have problem free printing, you might as well jump into the tough stuff. Sooner or later, you'll be learning new things about your printer.