ok - i'm up and running with retraction enabled again and it clearly improved

ok - i’m up and running with retraction enabled again and it clearly improved my results:

I’m still printing at 200C and I’ve been told this is likely too hot for my PLA and that being too hot is likely causing some stringing (and clearly i still have some stringing to contend with).

I’m curious: would most folks next step be to reduce the temp or to tweak the retraction settings?

Tonight I plan to print this:

I’ll be printing the board/tardis first and for that I’ll be using a different PLA entirely: eSun PLA+ in blue. I’ve seen reports from folks suggesting that they love PLA+ and simultaneously that they needed to print a bit hotter for it to adhere well…

Anyone care to offer some advice here? I’d like to take my best stab at getting a great first print with this new PLA, but I won’t hold negative results against anyone :wink:

I’m using esun PLA but not the plus version. Running at 200c for my machine would have me concerned that I’m running too cool. The problem with temperatures and filament and machines is that one machine isn’t the same as the next. My numbers run on the high side, I’ve found, compared to others.

Too low temps will/may give you clogging or feed problems. I can tell when I’m running too cold on the bowden system by the stepper motor clunks and the skippy layers that appear. I kicked the temps up by five and all was happy again.

I have had to slow the overall travel speed down, which makes me think I should go hotter and faster, but the quality improvement from the slower speed negates that immensely.

As a protector, I can see the J1772 cap working well. As a wall mount, I can see it shearing off in short order. A trickier project would be to use a casting wax filament and sand cast the part you print in aluminum. I’ve read of people creating lost-pla casting projects, but the output usually appears a bit ragged. It would be difficult to get the necessary smooth insides for your J1772 using that method, but lost wax in a good quality sand mold should come out well.

Nissan Leaf? Tesla Model S? i-Miev? Kia eSoul? I can’t remember them all. Oh, yeah, Toyota Rav4EV?

I have had PLA’s range from 190 to 220 in order to get it to print well. When I start to see stringing and the required retraction settings vary for each one. 200 is typically a good value but there is room to drop it down if you are still getting excessive stringing. What are your current retraction settings and for what kind of setup?

Drop it to 195 and see if it pigtails when you extrude out a constant strand several inches above the bed. This will mean you are too cold and then need to raise the temperature back up and tweak your retraction settings. You also need to watch for separation of the shell layers which also requires a bump back up by 5C if you get too cold. This may lead to retraction settings being tweaked again. I have found that it works best to increase the speed first (not so fast that you chip the filament) and then increase the distance if needed. There is typically a +/-5C range where you can get a filament to print well as it’s behavior is interactive with the other parameters.

Always calibrate your filament for its dimensional and thermal properties to get consistent good prints.

thanks for the response :slight_smile:

ok, so 200C is maybe not too hot after all. Cura suggests it’s a bit cool in fact, so I guess there’s a couple points of reference there.

it will be interesting to see how the PLA print holds up over time. I’ve heard that baking the print at ~100C for some time (half hour or so) helps to harden it up too. i might try that - i do have two wall mounts to play with after all.

making a cast aluminum wall mount would be a fun project, but a lot more involved than i’m ready for right now. i wonder if i could get the PLA mount to be more robust by printing it at a different angle? make the direction of sheer orthogonal to the extrusion lines…? for now i’ll just use it as is and hope for the best. i’ve lived with nothing for a year and a half, i can survive if this doesn’t hold up well.

oh, and the car? it’s a nissan leaf. a rather disappointing car, but not so disappointing to be “bad”. it’s a commuter and ONLY a commuter. i have a 21.5mi round trip daily commute and that is absolutely all it is good for. with that trip i can happily use cabin heat, radio, headlights… wipers… you know, basic stuff - all without running out of power.

i tried a 214mi round trip once and spent 14 hours on the road ping ponging between chargers. not worth it. a couple weeks after that horrible experience i plunked a deposit reservation fee down for a tesla model 3. i think i’ll be much happier with tesla :slight_smile:

If you want to improve the design of the cap/mount, consider to add radial gussets and increase the size of the base to accommodate them. The forces applied to a wall mount would be better managed either with a tilt or a horizontal orientation, but much tougher to print. You might get away with a horizontal or tilted build if you had wash-away support filament.

Another option with the cap/mount you have would be to add additional support to the cable immediately below the mount, to reduce the load on the mount weak spots.

I’ve wrestled with a few J1772 rigs and find that alignment is pretty important. I’d expect that the first three or four times you insert/remove the handle would go well, but in short order you’ll hear a crack sound and have to remove a ring of PLA from the J1772 fitting on the handle.

Yeah, your Leaf is indeed a good commuter car. ICEs don’t get up to temperature in such a short trip, well, maybe close on 10.75 miles one way, but with electrons, you are warmed up for those to do the work immediately on turning the key.

Now that the Bolt is a compliance vehicle instead of a full-tilt distribution, there’s no competition for the model three again.

Alloy 910 is a great solution for something like this, I find it’s cheaper than ‘cheap’ filament because it is so reliable, less failures and less infill needed for a very strong part. My first roll is going a long way since it has not failed a print after tuning a profile for its temps and speeds and retraction.

It does not grind easily, motor may skip but the filament chunks between drive gear teeth stay attached instead of coming off and gumming up the drive gear. So it extrudes at pretty low temps and one needs to watch out for layer attachment when tuning. It won’t warn you if it’s too cold the way other filaments will, by not extruding from pressure and grinding instead, at least if the extruder and drive gear are strong.

A stronger extruder stepper (in my case 84oz. 1.8a) will shove the strong filament through soft but not bonding. Allow a few strings and heat gun them off and the parts are perfect and very strong printing at a slightly higher rather than lower temp. Great layer adhesion, hurt yourself trying to break an A910 part so be careful if you’re not used to it, I totally hurt my wrists trying to break a test part I could easily rip apart in PLA.

I tweak temperature to match print speed. PLA does not like being cooked, so at 0.05 layer heights or less the filament stays in the melt zone for too long, and then I drop the temperature to as low as 185 to compensate. 0.1 at 200 and 0.2 at 210.

@Jeff_Parish i’m running my eSun PLA+ at 215C-220C with better results than the el’cheapo PLA from the video.

I’m using 80mm/s retraction rate; 4.5mm retraction length; and otherwise the cura defaults (there was something about lifting the z axis a small amount when retracting and how much lateral motion is required before retraction would be used, but i don’t recall the numbers)

I’m not sure what you mean by the “setup”? this is an XMachines Lorei Duo printer, though i’m only using one extruder so far. i don’t have a heated bed or an enclosure for the printer yet, and i’m printing in a cold basement (15C-20C most of the time i’m printing).

i tried dropping the temp and i did see at 195C that the filament ‘pigtailed’ a bit (curled up towards the hotend). so i went back to 200C and increased the retraction speed from 60mm/s to 80mm/s (and then promptly switched to a better filament before trying another print)

calibration for dimensional properties: you mean measure the diameter with a caliper and adjust the flow rate accordingly? i’m curious why folks don’t seem to just modify the stated filament diameter in the slicer (in cura it seems i could enter any diameter i want)

i’m now printing with the eSun PLA+ and still have some stringing to work out, but it’s far better than the other stuff was. i’m thinking i’ll likely ignore that old roll of cheap stuff and just focus on calibrating for the better quality filaments. i’m curious which filaments others (you) prefer?

@Fred_U i’m not likely to venture into designing radial gussets into the design anytime soon… but printing at an odd angle seems easy enough to me. especially since i don’t care what the outside of this thing looks like. i could simply tilt it @ 45 degrees and drop in a tall, solid raft of sorts. that could be done without encumbering the function (or mounting) of the final object. i’d have an odd block of plastic underneath the mount, but who cares?

so far it is holding up well enough. that j1772 connector slides in and out more easily every day and i figure it will hold up well as long as i don’t torque it too much. i setup a bungee cord to hold up the weight of the cable itself a bit (much like chargepoint stations use) but that was more for aesthetics (to get the cord off the ground).

my big fear: i have a 3 year old son who LOVES to plug in and unplug my car. so far he wasn’t noticed the mount on the wall (i sneak up after he unplugs my car and move it to the mount), but when he finally starts pulling the adapter out of the mount… yeah, it will likely break soon after that. we’ll see. if it survives the winter (when plastic seems most brittle) i’ll be impressed.

@AlohaMilton never heard of alloy 910 before. looks like great stuff, but wowzers $80/kg? it might be a little while before i venture towards consumables quote that fancy :slight_smile:

@Quentin_Harley interesting point regarding cooking the PLA. i’ll take the numbers you posted as a rough guide, but i wonder what your print rate is at those numbers? i’m currently printing at 100mm/s (30mm/s for top/bottom layers and 150mm/s for infill). i suspect your values for those rates would play a role here too?

@Jared_Eldredge Your comment allowed me to recognize another benefit to an electric vehicle, especially today’s designs. Your youngster isn’t as likely to help Dad fill up the fuel tank from the water hose! Good to hear your design is holding up well.

One of the 3d YouTube channelers did a test recently. Even ordinary PLA benefits from tempering, making the plastic slightly stronger and slightly more heat resistant.

If you’re the creator of that test sequence, I apologize for my lack of brain cell capacity. I suffer from “new stuff in, lots of old stuff gone!” syndrome.

@Fred_U i’ve seen the video in question (and no, that’s not me!)
as i recall the ‘regular’ PLA improved more than some stuff that was specifically meant to be tempered… i’ll try to find that video again. i think they baked the prints @ 100C for @ 1 hour? does that sound about right to you?

I think those numbers are in the ball park.

@Jared_Eldredge By setup I was referring to your machine and extruder type. Retraction settings are different for different setups. For a Bowden extruder your numbers seem a little high to me but I’m not am expert with that type of filament feed. I use 2.5 mm at 30 mm/s on my direct drives and get very little stringing. I have read that others with your type of set up use 0.8mm of retraction distance and speeds of around 40 mm/sec. Someone else will have to chime in here.

Calibrating for dimensional and thermal properties is more than a measurement of the filament. And yes, changing the nominal diameter in Cura is just one factor to adjust for it. When a filament is heated up and cooled again it does not return to the same size as the nozzle diameter it was extruded from. Not all filaments will expand and shrink in the same way. temperature and extrusion speed (ie. pressure) affect the end results.

To account for this I use these calibration clips found here: http://www.thingiverse.com/thing:1037301 I calibrate each roll of filament I use. I find a good extrusion temperature where it does not pigtail or stretch as a starting point. Then I print a set of clips (rotate one of them 90 degrees) using the measured diameter of the filament with calipers. If the clips are loose when I flip one over and fit them together then I lower the nominal filament size in Cura. If they are too tight then I increase it. If I get separation between shells and the clips are close to fitting nice I will increase the temperature by 5 which will tighten them up a little and close the gap. Once I get it calibrated at the right temperature and nominal diameter then I print an accuracy block found here: http://www.thingiverse.com/thing:1616694 These tell me if the filament is stable dimensionaly.

While you can change the flow to get the same results most people (especially kids at schools) seem to find it easier to just change the filament diameter in the slicer. Works great for me.

I print mostly in PLA and a few exotic blends like bamboo fill and flexible. As for good filament I have had good success with Matterhackers but find that Hatchbox seems to be more consistent. Bad filament is a plague that makes it really hard to diagnose issues. My favorite PLA filament was from a local manufacturer I was working with to dial in highly calibrated and consistent filament recipes. Sadly they closed their doors. I’m going to be working with the new owner in the coming weeks to start it back up again. I’ll let the community know the results.

@Jeff_Parish ​ thanks for that calibration process! I’ll definitely give it a go here :slight_smile:

Yeah, bad filament is a bigger problem than i expected. Searching on eSun i see reports from a few years back where they had ~0.75mm ball bearings in a bunch of their filament. Clogged up nozzles and pissed off users. I read that AFTER ordering my esun pla+ … I’m hopeful the old reports were either fiction, rare, or that esun has matured greatly.