Printing Tips

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Redemptioner
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Printing Tips

Post by Redemptioner » Sun Dec 24, 2017 9:03 am

Hey All,

Wanted to share some printing tips and to get the community sharing theirs.

1). DO NOT use the scraper that came with the printer, this will tear up you print bead, it is rubbish just throw it in the bin so you are not tempted to use it.

2). This is a delta printer and does not play silly-buggers with the print bed shaking it around, this means we don't need such a firm adhesion to the surface like all the other printer jobbies out there. The surface that comes with the printer works great, for PLA run it at 50*C for first few layers then change over to 40*C for the rest. Give the bed 10mins or so to cool down after a print and the print will come off much easier. ABS you will have to play with but I find 100*C to begin with then 85*C after that works great but without an enclosure you won't be able to print anything too large without defects (write up on enclosures coming soon).

3). Print a couple of painters razor holders (get them from your hardware supplier, they are the best kind to use even if you don't have a holder), these are the ones I like to use but I am sure there are others.
This one for removing things from the bed - https://www.thingiverse.com/thing:1072713
This one with some alcohol to cleanup the bed - https://www.thingiverse.com/thing:245702

4). Use alcohol in a can, makes life easy, and some decent paper towel. You don't want to use paper towel that leaves fluff everywhere after you have wiped something. Avoid using something you plan (or have) washed as the product used to clean it can leave unwanted residues (that clean smell is left over washing liquid).

5). Make sure you add a fan shroud that points the fans where it needs to be as the stock setup will no do bridges well without help from a external fan. The basic fan shrouds over in the hardware section will suffice if you keep the fan on full before and after the bridging, I find the auto change over for bridging is not fast enough so I turn the min fan speed up to half speed and force it on for the whole print to ensure perfect bridges when I know there is a lot of it. The catch here is you need bridging to print the fan shrouds so force fans on 100% for the first fan shroud you print (maybe even an assist from a desk fan) then you should be fine once you attach it to print the second one. The positive & negative should is easily the best design but requires you to have a better shroud in order to print the bridging require for the print, so print a couple of basic ones first then attach and proceed to print the ones you want.
Basic - https://www.thingiverse.com/thing:2640056
Good ones - https://www.thingiverse.com/thing:2654436

6). Be careful on your first print when starting the printer for the day, it will often sometimes stop and drop the head into the print, fortunately the heater will die shortly after this and not melt everything. If this happens pull the plug on the printer, lift the head up and use a scraper you made above (the second one) to fix any height issues from the head hitting the print. When you are ready plug the printer back in and hit recover, it will take a second to get going and heat up again, just watch for stray filament when it starts and turn the fans off for the first 3 layers manually, it should go on fine from there without hassles for the rest of the day if you don't turn it off again. This seems to be reduced if you tell the printer to home manually before setting off a print.

7). Control the temperature around your build, even PLA gains and advantage if you can stop the temp changing over the lifecycle of the print. It also means you don't have to adjust your settings from winter to summer or control the room temp. Make yourself an enclosure for this printer and add a cheap digital temp sensor (ideally one with 2 temp probes (one at top of case and one at bottom). I will do a write up in the hardware upgrades section for a "pro enclosure" build, but for now head over to Elzariant Thingverse page and follow my comments and print off the panel brackets needed to mount some panels to use as an enclosure. This will make a night an day difference and the corflute panels are only worth a few dollars to buy and cut to size. Ideally you will control the ambient enclosure temp with a heater, fans and multiple temp probes hooked up to the main board to directly control the temp (cooling or heating the internal air). BUT not everyone is as anal as me about controlling the temp in the enclosure, if this is you then you can just use the bed temp to help control the enclosure temp as most filaments will tolerate a reasonable range in bed temps. Use the preheat feature to get the enclosure temp up where you need it then play around with bed temp after initial layers to keep it where you want. You can add a small fan off the roof of the enclosure with a cheap 12v manual fan controller to help stir the air and another one sucking air in from the outside of the enclosure to help cool it down.
You can find the stl's for the enclosure brackets over here - https://www.thingiverse.com/thing:2341308

8). Make the filament detector and guide by bLITzJoN, this will allow you to upgrade to a filament outage detector as well as ensure your filament does not come off the spool when the effector returns to home. https://www.thingiverse.com/thing:2629228

9). Don't print lots of small and tall parts (relative to their width/diameter/base area) at the same time without a decent Brim connecting the parts together (keep them to the inner 100mm radius of the print bed if you do). The printer's heat bed is not good at heating evenly nor is the bed real level (especially when you consider how thick the build-tac is). I think this is why many people modify the bed and run a decent glass plate on top of the actual bed. Until you take a whole bunch of time calibrating and fixing the small variances in the endstops length and hundreds of calibration test for the various temps you will use, then this is just going to end in parts falling over at the end of the print. There are things you can do to help but generally you are going to only add around 20-40mins total to overall print times on a long print (say 16 hours or more) by cuttings the number of parts you print each time down and running more print cycles. If you plan to do this, try and avoid doing when you are not around to keep an eye on the print. You can always pause a print and take corrective actions and then resume once you have taken action, saving many hours of print time and wasted filament and more importantly saving your mental health :roll:

10). If you notice prints starting to move/wobble, just grab your hot glue gun and put a small bead of glue around the bottom to secure it again back to the bed. This won't work on filaments that require a really hot bed as most hot glues will start to melt around the 80*C mark. Sometimes you can get away with the hot glue on hotter beds if you pause your print, let the bed cool a bit, hit it with the hot glue, let it cool a little more, then resume print. This is especially helpful when you are printing multiple tall objects which will cause all sorts of problems if one falls over. It is worth noting that the bed on the Tevo Little Monster is horrible at keeping an even temp, the bed does not heat well out to the edge which means small tall objects out at the edge are prone to falling over due to the bed not being hot enough for the first layers. If you are doing wide prints turn the bed temp up an extra 15-25*C for the first 4 layers and turn the fans off for the first 8 layers. If you are printing super slim and tall items then just hit them with the hot glue once you get enough layers up to get the hot glue down easily without getting it in the print itself (like 30-50 layers up). Also be careful with the hot glue, it shrinks a little as it cools (so stay away from the top of slim parts) and can string/spiderweb everywhere and you don't want this stuff in between your layers on the print. If something does fall over and you notice it within a a few layers, then pick it up, add some hot glue to the base and press it back down where it belongs really well (you want to squash the glue out from under the part), you will never get it exactly back where it was and it won't print perfectly but it should be close enough to allow it to keep dropping the parts layers down on it so it does not ruin the rest of your parts. Another great place to put the hot glue is between parts as well, especially if it is nice and close to another larger part that can help support smaller/taller parts (also might be a better option if you have a hot bed). When it comes time to remove the glue, just use some spray on alcohol and peel it off, the alcohol makes the glue loose it's adherence without melting it (hot glue relies on surface tension to stick) and it will come come straight off without leaving a mark or requiring any effort (great for fine brittle parts, don't be scared of using plenty of spray, it won't hurt anything).

11). Ensure the printer is dead level, I won't get into all the maths around this but it makes a difference on accuracy and finish. Also make sure the place you have it located is solid, this is a tall printer that can move really fast, this makes most tables/desks not suitable as they move under the tremendous speed this thing can move at, sure you can slow it right down but then you might as well but a non-delta printer. As much as I don't like it being on the floor, this is generally the best place for it in most places. I have my LM's sitting on a 1/2" steel plate that are shimmed level and sitting on the concrete floor. I have considered getting a concrete shelf made as part of the concrete walls in the corner, which will make it super stiff and perfectly level, to mount them up at a more reasonable height to work on them but I have been too lazy to organise and pay for this (floor works well).

12). Keep the moving parts and electronics cool. Keeping the main board, stepper controllers, motors and power unit cool makes more of a difference than you would think. Heatsinks are super cheap, if you are up to it, replacing the heatsink on the stepper controllers and power packs is a great way to spend a weekend, while you are there upgrade the fans (also cheap) and adding passive heatsinks to the motors will improve the finish of prints and keep the motors running significantly longer before they wear. Also adding and maintaining silicon grease on the rails, bearings and heim joints makes a difference as well to quality of prints and a big difference to their lifespan. All these things add a very small amount to your overall print quality and accuracy but they all significantly increase the lifespan of these parts.
If it ain't broke then modify it

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Xerxes
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Re: Printing Tips

Post by Xerxes » Tue Dec 26, 2017 9:34 pm

Hey nice post. I have been updating my original post over time on getting the TLM printing with ABS. It's pretty much a tutorial at this point. I seemed to have a lot of trouble at first getting any kind of quality but I am slowly starting to get results.

viewtopic.php?f=26&t=341

Redemptioner
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Re: Printing Tips

Post by Redemptioner » Wed Dec 27, 2017 3:54 pm

Thanks bud.

Yeah, I found slic3r just wasn't cutting it for ABS, spent a lot of time with issues on corners and fine detail. Changed over to simplify3d and first print was near perfect. Fiddle a little since and now it prints ABS like a pro at 240mm/s, admittedly I have a fully enclose unit and control the air temp. Simplify3d is worth the cost just for the support material capability and ease of settings and profiles (hate silc3r's way of doing this, have to save every freakin time.....), but I add a crap load of support these days due to how easy it is to remove without a concern for it affecting the print of being difficult to remove, than and I can control and add/take the support where I like (tend to support all the bridging as well, lol).

Got a bunch of genuine parts in the mail atm for one of these machines, will be interesting to compare them once it is running full duet, a real E3D volcano & extruder, decent 0.9* motors all round and 16 tooth pulleys that don't have the belts rubbing against the carriages and rollers..... which reminds me, need to start a thread on physical & electrical upgrades :)
If it ain't broke then modify it

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Re: Printing Tips

Post by Xerxes » Wed Dec 27, 2017 5:25 pm

I've lost count of how many hours of tuning I've done on slic3r before swapping to slic3r PE.. At least I learned how to fix the ABS corners (fan)... Though it seems for every correction you do, you break something else that wont show up until you try a different calibration model. Slic3r PE default configurations for the Prusa i3 (modified for the TLM) seem as good as what I had arrived at after about 60 prints playing with Slic3r.

Seems like it may be worthwhile to try simplify 3d..

I'm starting to realise I need to build a temperature controlled enclosure for the TLM to print with engineering grade filaments.. Should be fairly easy with a temperature controller and ceramic heating element/fan from ebay. I am a little worried though how long the extruder stepper motor is going to work within a 60-80C environment as it gets quite warm when its well ventilated.

Do you think when swapping to PC or nylon it is enough to replace the nozzle with a hardened steel one, or is a complete hotend replacement needed?

Also what bed materials do you print with for ABS, nylon and PC? So far I've tried the original TLM bed sticker for ABS with seemed to work though it bubbled fairly quickly and became unusable. I then went to PEI, and found the stuff I got permanently adhered to ABS at any bed temperature (40C bed and it was welded permanently.) So after two PEI beds to about 5 prints I've given up on it. At this point I'm going to try using the glass and apply ABS slurry.

Cheers

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Xerxes
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Re: Printing Tips

Post by Xerxes » Wed Dec 27, 2017 6:34 pm

I agree that bed scraper is a piece of crap.. an artists palette knife seems to work well as a replacement.

I pretty much have refused to use PLA though it's caused me a lot of frustration starting fdm 3d printing using only ABS. Much grief and little joy :cry: But you have to learn somehow, so whatever I print at the moment is in ABS. That said I'm currently holding a glow in the dark ABS 3d benchy that shows almost zero surface imperfection and is as solid as a rock... Still all my prints currently fail if I try something larger than about 5 hrs though which is depressing :lol: On the list to do to correct this are hardware improvements like the fan covers, and a heated enclosure.

Improvements I've currently made to my TLM include a dry box spool with bowden fittings and long ptfe tube to the extruder which seems to work well to keep the filament dry. I have also fitted 8 diode tl-smoothers, and swapped to a 0.6mm nozzle. I currently use PTFE grease on the moving parts of the printer.

I've thought about moving the extruder to the side of the printer both to protect it from heat (in the future enclosure) and to reduce ringing.. The extruder floats on the carriages but the PTFE tube connecting it to the effector is rather rigid and it still shakes around a fair bit at high speeds (60+ mm/s). I've added more tension to the timing belts holding the floating extruder and added additional belt spring tensioners (3 on each now) which seemed to help. My research suggests a bowden setup would likely cause problems with oozing.. still its temping to try..

I figured though once I can get that working well enough I'll move onto nylon and PC and make some nice toys.

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Re: Printing Tips

Post by Redemptioner » Tue Jan 02, 2018 2:43 pm

Yeah enclose has a big effect, lifting the extruder up a bit (200mm PTE tube) and adding the additional holder with springs also helps a lot, remove the plastic tube covering the wires and replacing with mesh helps and so does a filament guide wth some PTFE tube to help guide it so you get even and resistance free spool feed is also good. Everything adds up :)
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Re: Printing Tips

Post by Redemptioner » Wed Jan 03, 2018 4:09 am

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Re: Printing Tips

Post by Redemptioner » Wed Jan 03, 2018 4:12 am

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Re: Printing Tips

Post by Redemptioner » Wed Jan 03, 2018 4:14 am

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Re: Printing Tips

Post by Redemptioner » Wed Jan 03, 2018 4:16 am

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