3D printers - fun with FDM printers (Klipper-based)

[Martin Wynne]

.
This topic will be about using the latest high-speed FDM printers based on the Klipper G-code interpreter and driver, for printing timbering bases (and filing jigs). Initially about the Elegoo Neptune 4 series of printers.

For discussions about Marlin-based FDM printers, see instead this topic:

https://85a.uk/templot/club/index.php?threads/3d-printers-fun-with-fdm-printers-marlin-based.277/

and:

https://85a.uk/templot/club/index.php?threads/3d-printer-kingroon-kp3s-pro-s1.850/

and other previous topics about FDM printing.

 

[Martin Wynne]

@gavin @James Walters

Having assembled and adjusted the Neptune 4, I thought I should first try a test piece of timbering base using the printer straight out of the box. From previous experience of FDM printers I wasn't expecting doing that to be very successful.

In the event the result was excellent and amazingly fast. A 6-timber base which was taking about 66 minutes to print on the Kingroon was printed in just 15 minutes, i.e. a speed increase of more than 4-fold. Or a reduction from 11 minutes per timber to only 2.5 minutes per timber. That was using the recommended speed, and there is scope to go even faster.

Needless to say the out-of-the-box settings had some issues which will need dealing with:

1. it printed an unnecessary brim around the part. I changed the setting to omit it.

2. the top of the timbers had the usual mottled 3D-printed surface. I switched on the ironing function to produce a smooth surface.

3. the standard setting is for a 10% fill density. I increased it to 40% to match previous timbering bases.

That was using the "Normal" profile with 0.16mm layers.

After making these changes the next print time increased slightly to 16 minutes. This is mainly caused by the ironing function.

4. the soleplate detail was missing. This will likely need some changes to the default thickness dimensions in Templot to better match the layer height.

5. the usual scrub with a stiff nail brush caused the dropper-wire ridges to detach from the base. This will similarly require some changes to the dimensions to better match the layer height.

But there was no stringing at all, the sockets were perfectly clear even at the 220degC nozzle temperature. The sockets were spot-on for size, and the chairs clipped into place very positively.

---

The Neptune 4 printer is supplied with a customized version 4.8 of Cura. It was necessary to use that rather than the 5.6 version which I have been using, because only that has the required printer settings for the Klipper interpreter. I'm intending to get everything copied and set up in Cura 5.6 so that I can use the same version for all. I will post the files when I have them working.

I went with the automatic levelling on the tin PEI bed. It worked ok, but I haven't yet found how to switch off the fade-out in Klipper for constant thickness timbers. On the Neptune 3 I have managed to use a glass bed with perimeter priming run, so I will see if I want to do that with the Neptune 4 -- it does add some faff to the start-up of every print.

The printing starts off quite sedately for the first layer. It then sets off at startling speed for the remainder of the print, and the cooling fans come on full blast. They are very noisy, and this is one downside of the fast printing. It would be worth constructing a soundproof enclosure if the printer is installed in living areas.

Direct computer control of the Neptune 4 uses an Ethernet LAN cable instead of a USB cable on the Neptune 3. This means it can't be controlled directly from within Cura. Instead it is all done from the web browser (Firefox for me). This adds so much additional information and controls that it's probably worth the extra trouble of having to drag and drop a saved G-code file from Cura:

Printer start-up from switch-on is surprisingly slow, and the browser won't connect until the printer screen says it is ready.

Alternatively you can put the G-code file from Cura on a USB memory stick, and run the printer remotely without needing a computer anywhere near.

I will write more when I've done some more tests and adjustments.

cheers,

Martin.

 

[James Walters]

Hi Martin,
This is very interesting indeed. I've all but given up with my FDM machine so am looking for another. I was going to opt for the Kingroon having seen the quality of the prints you have been getting from it, but the Neptune 4 certainly looks like a useful contender.
I shall be following your progress with great interest.

 

[Martin Wynne]

Hi Martin,
This is very interesting indeed. I've all but given up with my FDM machine so am looking for another. I was going to opt for the Kingroon having seen the quality of the prints you have been getting from it, but the Neptune 4 certainly looks like a useful contender.
I shall be following your progress with great interest.

@James Walters @Steve_Cornford @Hayfield @gavin

Hi James,

I'm still very fond of my two Kingroon printers. If you are not in too great a hurry for your prints the clean accurate results from the Kingroon extruder are very appealing. Of the two, the smaller one is actually easier to set up and get going. But 180mm x180mm is undeniably a bit limiting for 4mm scale:

https://altwaylab.co.uk/collections...ingroon-kp3s-3-0-3d-printer-with-meanwell-psu

https://altwaylab.co.uk/collections...ucts/official-kingroon-kp3s-pro-s1-3d-printer

But I became aware that the suggestions and files I've been posting might not be applicable to the newer Klipper-based fast printers, and the only way to find out was to get one and see. I don't want to be saying things on here which are misleading for anyone.

With the recent offers on the Neptune 4 you do get a lot of extra machine for the price difference, although the Amazon Prime price has jumped back up in the 3 days since I ordered one, and the difference for non Amazon Prime members almost pays for Prime for a year:

https://www.amazon.co.uk/dp/B0C9SZ7DCR

The extra features on the Neptune 4 Pro (segmented bed heater, metal rollers, metal top frame) hardly seemed enough to justify its increased cost over the plain Neptune 4.

Kingroon do have a Klipper-based variant, but it's not currently available in the UK via Altway, and the cost of it makes the Neptune 4 a better buy.

There are lots of other Klipper-based printers, but the Neptune 4 seems to be one of the least expensive.

No doubt I will be writing more about it in due course. But not today because I have a hospital appointment this morning.

cheers,

Martin.

 

[Phil G]

Hi Martin,
I too am following your klipper experiments with great interest.
I do get the idea of keeping up with developments for plug track input reasons, and the fact FDM printers are moving to faster prints, Something I can understand.

I have to say though I find the idea of a huge and noisy fan bank with the sole purpose of cooling the filament down quicker, so you can run faster. Somewhat counter intuitive especially when the total height of the job is only 3~4 mm above
the heated bed.
In reality just for plug track timber/sleepers, is it not a case of putting energy in to heat the bed, and then effectively putting more energy in to cool the filament and the bed with it? If so the extra speed gain must come at a higher operating cost.

I guess if you building up models that start to push the Z build volume, it starts to make a lot more sense.

It does strikes me the sweet spot for an FDM printer used mainly for making plug track bases has to be in the 200x200 to 235x 235 bed ranger, with a reliable and trouble free operation as possible.

I would be very keen after your investigation to know, if you think Klipper based faster machines, with all the (extra features you get) meet that requirement?
cheers
Phil

 

[Martin Wynne]

I have to say though I find the idea of a huge and noisy fan bank with the sole purpose of cooling the filament down quicker, so you can run faster. Somewhat counter intuitive especially when the total height of the job is only 3~4 mm above the heated bed.

@Phil G @gavin @James Walters

Hi Phil,

My thoughts too. There is an on-off switch on the top of the fan bank. I have tried printing 4mm/ft scale timbering bases with the extra fans switched off, with no apparent effect on the result. It certainly makes a significant difference to the noise level, although the printer is still quite noisy with the extruder fans and the power supply fan running.

The extra fan bank may be needed for the filing jigs, and for thicker timbering bases in 7mm/ft and larger scales. There is a lot of experimenting still to do.

Elegoo supply a customized version of outdated Cura 4.8 with their printers, but they do now have an updated customized Cura 5.6 version available for download:

https://www.elegoo.com/en-gb/pages/download

The bad news is that this refuses to run alongside the regular Cura 5.6 version, with each blaming the other for configuration errors.

I want to continue using my existing Cura 5.6 so that I can use my current settings for other printers, and get regular Cura updates. I think I shall end up transferring the Elegoo settings manually from one to the other, before I can post any suggested profiles.

I've restored the soleplate and the dropper-wire ridges, but I'm still tinkering with the settings to find the optimum results.

And I mustn't let all this distract me from getting 244a released. There is lots to do.

I would be very keen after your investigation to know, if you think Klipper-based faster machines, with all the (extra features you get) meet that requirement?

I can't say anything about machines I haven't got. But I hope to find out whether the extra cost of the Neptune 4 over other printers is worth it, at least for plug track purposes.

cheers,

Martin.

 

[gavin]

Hello Martin, James and others

Experiments with the Neptune 4plus continue over here with some success, but also a few challenges. However I have no doubt it will work out fine - just need to understand the limitations, which is taking a while as I am only doing it occasionally between work on News 237.

I am very much concentrating on being able to print longer lengths - my test is 300mm long. Seems sensible as the purpose of having the larger bed is to enable this.

I seem to have the tops of the sleepers at an acceptable finish now, but now started having problems with the ends of the lengths sometimes curling up part way through the print - I am assuming this is something to do with adhesion on the plate. Whether I have caused this issue by other settings I have not yet worked out.

So I have this time gone back to printing with the Brim (test 6) and will let you know.

The current settings I have changed from the standard profile are:

Global:
Layer Height = 0.12mm
Build Plate adhesion = Brim
Extruder:
Top Surface Skin Layers = 2
Enable Ironing = True
Iron Only Highest Layer = True
Monotonic Ironing Order = True
Ironing Flow = 15%
Infill Density = 80%

No doubt other people have used different settings.

If the picture uploads correctly, here is my curling template corner part way through a print! Off to the 'day job' now so may try post the result of test 6 later.

Gavin
PS Must work out how to get notified for @gavin!

 

[Martin Wynne]

I seem to have the tops of the sleepers at an acceptable finish now, but now started having problems with the ends of the lengths sometimes curling up part way through the print - I am assuming this is something to do with adhesion on the plate. Whether I have caused this issue by other settings I have not yet worked out.

@gavin @Phil G

Hi Gavin,

A few points:

1. did you give the bed plate a good clean before first use?

2. I can't see much elephant's foot in that photo. To get good adhesion on the bed you need to drop the Z-offset about an extra 0.1mm to get a good squidge against the bed on the first layer. That leaves a slight elephant's foot which is no problem for the track bases -- the connector clips have a rebate around the underside to allow for it.

3. on the PEI beds, they need to be at least 60degC to stick. They lose grip below 60degC and the part falls free at about 40degC. For the track bases there is no need to have the extra-blast fans switched on, which may be reducing the bed temperature -- the thermal sensor is a couple of layers below the bed surface.

4. have you got the rollers on the vertical columns set too tight, preventing the gravity backlash-correction working on Z? You should be able to lift the X-bar a fraction by hand and it drops back easily under its own weight. As supplied the brass nuts should be slightly loose in the frames. This doesn't matter too much with manual levelling (because the Z-axis never sees a reversal), but with auto-levelling it does matter as the Z-axis bobs up and down as the head moves across the bed.

5. if still no joy, did you get a PVP glue-stick with the printer? Try turning the plate over to use the smooth side (cleaned). While it is cold, apply several dabs of glue-stick, and smear it out into a thin film using a slightly damp sponge. Using that side, you can set the bed temperature to reduce to 40degC after the first layer. This will much reduce the tendency of the finished part to shrink and curl as it cools to room temperature.


You are using 80% infill? Generally I have been using 40% for the track bases, and 50% for the filing jigs. The density is likely to affect shrinkage and curling, but by how much I don't know.

I intend to post some suggested Cura profiles for the Neptune 4. I just need a bit more time to experiment with it so that I'm sure I'm not talking rubbish. At present I'm tied up with coding because of an infuriating bug I created in the latest program update.

cheers,

Martin.

 

[James Walters]

@gavin

Great to see your progress.

Based upon my own FDM printing experience, I think Martin has hit the nail on the head re. temperature.

Martin's suggestion of upping the bed temperature and reducing the fans seems the best route forward to me.
It's looking good though. FWIW, on my machine, I found 85degC to be the optimum bed temp and I run with the fan off after the first couple of layers.

Once your settings are dialled-in you'll be well away.

 

[Michael Woods]

Hello Martin, James and others

Experiments with the Neptune 4plus continue over here with some success, but also a few challenges. However I have no doubt it will work out fine - just need to understand the limitations, which is taking a while as I am only doing it occasionally between work on News 237.

I am very much concentrating on being able to print longer lengths - my test is 300mm long. Seems sensible as the purpose of having the larger bed is to enable this.

I seem to have the tops of the sleepers at an acceptable finish now, but now started having problems with the ends of the lengths sometimes curling up part way through the print - I am assuming this is something to do with adhesion on the plate. Whether I have caused this issue by other settings I have not yet worked out.

So I have this time gone back to printing with the Brim (test 6) and will let you know.

The current settings I have changed from the standard profile are:

Global:
Layer Height = 0.12mm
Build Plate adhesion = Brim
Extruder:
Top Surface Skin Layers = 2
Enable Ironing = True
Iron Only Highest Layer = True
Monotonic Ironing Order = True
Ironing Flow = 15%
Infill Density = 80%

No doubt other people have used different settings.

If the picture uploads correctly, here is my curling template corner part way through a print! Off to the 'day job' now so may try post the result of test 6 later.

Gavin
PS Must work out how to get notified for @gavin!

I use an anycubic printer with one of these foil beds.....they work very well but try and position the print in the middle of the plate where you have the max temperature concentration. As you can see the lift is closest to the edge which will be the coolest part of the plate. Plus as Martin and James suggest increase the bed temperature a bit. But if you reposition you may not have to adjust the bed temperature.

 

[Martin Wynne]

@gavin

Hi Gavin,

Here is a test print just made on my Neptune 4. The profile I used is attached below.

There was no warping or curling. You can see at the blue arrow some elephant's foot where the first layer is squidged into the textured bed for adhesion.

Using the latest 244a version of Templot, the finished thickness is 3.3mm after a quick wet rub with the 400-grit sanding block. The design thickness is 3.36mm. Precise measurements are largely meaningless with a heavily-textured bottom surface.

If you are not seeing the elephant's foot, or your thickness is significantly more than 3.3mm, drop the Z-offset a bit, i.e. make it more negative.

One way to judge the quality of the result is to check that the soleplate detail is evident on the toe timber.

The filament is Sunlu PLA+. Generally I prefer the eSun PLA+, but I tried this Sunlu because the colour was supposed to be "wood-like". It isn't.

Here's the Cura profile below if you would like to try it. It's for the Elegoo Cura custom version 5.6. It probably won't import into other versions -- Cura is very picky about accepting custom profiles.

I may change it later of course after more dabbling. There are several changes from the standard 0.12mm profile.

It's for 0.12mm layers, with 0.24mm first layer. Print time for the above 12 timbers was 38 minutes (3.2 minutes per timber).

It's possible to go faster using 0.16mm layers, but I found problems with the soleplate and the dropper retaining ridges. They would need some changes to the Templot default dims.

p.s. after importing it, you must select it in the profile dropdown in order to use it.

cheers,

Martin.

 

[gavin]

Hello all. Thank you very much for the advice above.

Success has been mixed, although progress has been rather delayed by other activities getting in the way. So sorry if it seems intermittent.

I do somehow seem to have gone backwards a bit.

So I took your configuration file, Martin, and James I increased the bed temperature. I also ensured I updated to the latest Templot version.

I then set the printer going and once it was on its way left it running for 20 mins or so then came back to check - by then I had a loose 'golf ball' of plastic wrapped around the print head. It would seem things did not stick properly and all got chewed up. Needless to say, I put it to one side for a week whilst other pressures were dealt with.

So back to it today. Head all cleaned (as far as I can see) but I now seem to not get even the quality I had before. I rolled back all the settings to pre-Martin, pre-James changes, but I am still getting very stringy results which are thus all going wrong.

The picture attached shows the beginnings of the problem. Yes I know it has a brim on - back to my original settings - but you can see that the strings are really messing things up.

I just wondered if anyone else had seen this. At the start of the print it seems to do a neat 'purge' line at the edge of the plate each time but then goes awry! Any advice welcome!

Thanks again
Gavin

 

[Martin Wynne]

@gavin

Hi Gavin,

Try dropping the Z-offset by about 0.1mm to squidge the first layer more firmly into the bed. i.e. after doing the auto levelling according to the book, change the Z-offset (make it more negative), and don't forget to tap the Save button afterwards.

My Neptune 4 is working fine using the profile I posted. Remember after importing it you must actually select it in the dropdown.

Also make sure you have the Neptune 4 printer selected as the active printer -- the Elegoo version of Cura is common across all their printers.

If you now have several gcode files listed in the fluidd jobs list, make sure you right-click on the correct one to start the print. They are not listed with the most recent one at the top. I have now made that mistake 3 times!

cheers,

Martin.

 

[Phil G]

Hi Gavin,

4. have you got the rollers on the vertical columns set too tight, preventing the gravity backlash-correction working on Z? You should be able to lift the X-bar a fraction by hand and it drops back easily under its own weight. As supplied the brass nuts should be slightly loose in the frames. This doesn't matter too much with manual levelling (because the Z-axis never sees a reversal), but with auto-levelling it does matter as the Z-axis bobs up and down as the head moves across the bed.

This quote from Martin is very important, I too had huge problems with jobs curling up, or as you have said coming totally unstuck from the bed. The issue in the end was all about the Z axis binding. My Z wheel positioning as supplied from the Elegoo factory were no good, and I did not pay enough attention to that.
After hours of readjusting I now have all 6 wheels with just a bit of resistance, I also found I had to adjust one of my Z lead screws because as supplied the X frame was racked.
I did this by loosing off one of the timing belt toothed wheels and then manually turning one side until there was no diagonal binding of the Z wheels, IE in my case top left and bottom right on the outside wheels were always very tight. once happy retighten the toothed wheel and re zero and everything was far better. I also found I had to pull the Z vertical columns out a bit at the bottom to ensure they were parallel top to bottom, (this can be done quite easily, because there is a quite a bit of play in the 4 x M5 cap head screws) used to tighten the vertical columns down.
Once all this was done I ran the attached bed leveling STL test. perfect result, when I tried the same test before starting to re-adjust my machine the first square came loose from the bed and was traveling around with the nozzle !!!

You should also check your X axis wheels for excess play, because the Direct drive head is heavy and tends to pull the head down if not set right. You can't see this and it does not matter that much until you try to set your initial Z height with that bit of paper, because that can easily push the head up a bit, if the X wheels are not set right. Again factory setting on my machine were no good at all.
I am not saying yours will be as bad but its worth checking everything is alighted and square because it really does matter.
I hope this helps.
Cheers
Phil,

 

[gavin]

Hello Phil

Thank you very much for all that - it does give me somewhere to look. I think I was quite lucky to start with as I did not seem to need to fiddle with Z-axis adjustment (although that might just have been my naivety!) - however having had the problem with the 'ball' of extruded plastic all around the head I would not be surprised if it has affected the Z-axis adjustment now.

And also that description of how the head moves with the bit of paper - I have started seeing that as well all of a sudden which suggests your analysis is correct.

I will let you know how I get on - will be the middle of the week before I do any more careful testing.

Thanks again
Gavin

PS will try your test print as well

 

[gavin]

@gavin

Hi Gavin,

Try dropping the Z-offset by about 0.1mm to squidge the first layer more firmly into the bed. i.e. after doing the auto levelling according to the book, change the Z-offset (make it more negative), and don't forget to tap the Save button afterwards.

My Neptune 4 is working fine using the profile I posted. Remember after importing it you must actually select it in the dropdown.

Also make sure you have the Neptune 4 printer selected as the active printer -- the Elegoo version of Cura is common across all their printers.

If you now have several gcode files listed in the fluidd jobs list, make sure you right-click on the correct one to start the print. They are not listed with the most recent one at the top. I have now made that mistake 3 times!

cheers,

Martin.

Thank you Martin. I will also work through all of these.

Just to eliminate any possible thing wrong with my software here - I doubt there is but just being certain - could you at some stage send me the file for the simple 12-sleeper sample you printed and I will see if I can get that to print as good here.

No rush
Gavin

 

[Martin Wynne]

@James Walters

We haven't said much about FDM printers recently. I have noticed that the Neptune 4 is now down to £175 (post free to UK from Austria) which puts it in the same price bracket as the Kingroon:

https://www.3djake.uk/elegoo/neptune-4

My Neptune 4 is still working fine, and the Klipper speed increase over the Marlin-based printers is very noticeable if I just want to try a quick test of something. I would still prefer a glass bed, but I can live with the bendy tin PEI. There isn't normally any reason to remove it from the machine. (The inductive levelling sensor on the Neptune 4 doesn't work with a glass bed.)

The price reduction usually means that there's another one on the way -- Neptune 5 presumably.

Martin.

 

[KHC1]

My Ender 3pro is going just fine. I invested in a CR touch for levelling and Pei bed. These have revolutionised the printing. I can now safely set a print going and walk away. Once the print is done let the bed cool below 30 and items come off with no sticking.

Keith

 

[James Walters]

For anyone still looking for an FDM printer, the Neptune 4 at £175 (post free to UK) which I posted about recently was an obvious choice. But the price has now jumped back up a bit.

Hi Martin,
I think I'm going to bite the bullet and order a Neptune 4 today. I've been putting off replacing my Sunlu S9 for some time as I had lots of other stuff to do, but I do really need to have something up and running reliably.
May I ask, have you changed your Cura profile at all since you uploaded it here for Gavin's benefit a while back?
I'm keen to avoid the hassle of experimenting myself.

Cheers,
James

 

[Martin Wynne]

@James Walters @gavin

Hi James,

Naturally I can't remember what I uploaded for Gavin. Also, he grabbed a profile off my USB stick while I wasn't looking when I visited him recently.

Also, he has the Neptune 4 Plus, v. my Neptune 4 Ordinary. (I have a Neptune 3 Plus, Marlin-based, much slower).

I hadn't changed anything until today, but as we speak it's running at a slightly lower temp and extra retraction. I will compare results with yesterday.

Whatever, no problems. I will post an updated profile here if needed. I need to test switching off the auto-level fade-out.

Are you getting it from Austria? https://www.3djake.uk/elegoo/neptune-4

Faster delivery from Amazon UK, but a lot more expensive.

cheers,

Martin.

 

[James Walters]

Thank you Martin,

I was going to get it from here:
https://www.123-3d.co.uk/Elegoo-Nep...NQX76LYYu5rLBVksS-V5o6USCHHcOhncaAocqEALw_wcB

It seems like a good price.

Cheers,
James

 

[Martin Wynne]

@James Walters

That's a great price, with only £4 for postage.

I suspect the recent reduced prices mean there is a Neptune 5 waiting in the wings.

cheers,

Martin.

 

[James Walters]

I've just placed the order.

I'll try the profile you posted for Gavin here : https://85a.uk/templot/club/index.p...th-fdm-printers-klipper-based.873/#post-10798 unless you suggest something better.

 

[Phil G]

I've just placed the order.

I'll try the profile you posted for Gavin here : https://85a.uk/templot/club/index.p...th-fdm-printers-klipper-based.873/#post-10798 unless you suggest something better.

I would be interested to here your views on the course textured PEI bed. I have a Neptune 3 Pro. Which overall I like, but I hate the way the job tends to curl on this type of bed.
cheers
Phil

 

[Martin Wynne]

Which overall I like, but I hate the way the job tends to curl on this type of bed.

@Phil G

Hi Phil,

Drop the Z offset by 0.05mm or 0.1mm. i.e. make it more negative. And don't forget to press the Save icon afterwards. It's top-right on the screen, and the instructions don't make it very clear that it's essential.

Also PEI doesn't grip below 60degC, so that's the minimum bed temperature with PEI.

cheers,

Martin.

 

[Martin Wynne]

I've just placed the order.

I'll try the profile you posted for Gavin here : https://85a.uk/templot/club/index.p...th-fdm-printers-klipper-based.873/#post-10798 unless you suggest something better.

@James Walters

Hi James,

How are you intending to control the Neptune 4? You can do it all on the handset using a USB stick to transfer the file. But touch-screens and me don't get along -- I prefer to use the Fluidd control system over an ethernet cable from my computer:

https://docs.fluidd.xyz

This gives an amazing array of controls, and you can watch each layer being laid down:

(screenshots from Firefox)

• The Elegoo-customized version of Cura supplied with the printer is likely to be out of date. Don't download the latest version of Cura from the Cura web site because print profiles created with the Elegoo version won't be compatible with it.

Instead, download the updated Elegoo version from the Elegoo site. I'm currently using Elegoo Cura 5.6 and any profiles I post will be from that version.

It seems that auto-level fade-out is off by default in Klipper, so no problems there. It needs to be off so that the auto-levelling corrections are applied to every layer. This means the timbering brick will be the same thickness all over, even if not dead flat -- it will be flat when laid on a flat baseboard.

The Z backlash-correction is supplied free of charge by gravity. As supplied the fixings for the brass nuts on the Z screws will be loose and floppy. That's by design -- don't be tempted to tighten them. The Z rollers need to be adjusted loose enough for gravity to work -- you should be able to lift the carriage by hand a fraction, and it will immediately drop back. Check this with the nozzle down close to the bed where you will be printing timbering bricks, in case the columns are not truly parallel. Do these checks before your first test print -- it will be a disappointing failure if the Z rollers are too tight.

On machines without auto-levelling this isn't so important because the Z drive never reverses* in the normal course of a print, so effective backlash correction isn't needed.

*assuming Z-hopping is switched off.

A useful hi-tech attachment for the Neptune 4 is:

Small button magnet on top of the Z screw + blue-tack + cocktail stick pointer. You can watch this turning slightly as the head moves to and fro across the bed to check the auto-levelling is working. In the de-luxe version the cocktail stick is painted red.

If you make a lot of plug track timbering bricks, the Z-screw will be working over the same short 3mm section every time. Make sure it is well-greased to avoid localised wear.

The bank of cooling fans behind the head is not needed for plug track and can be switched off to reduce the noise. There is an on-off switch on top of them. Not much point in having a heated bed and then a cooling blast only a few mm above it.

So much stuff to write for plug track to be a success -- which hardly anyone will read.

cheers,

Martin.

 

[James Walters]

Thank you Martin,
This is all really helpful.
I shall take a look at fluidd this evening, but will start using the built-in controls and make a how-to video with the machine straight out of the box in the hope that it might assist a would-be plug-tracker to realise that the whole process needn't be at all daunting.
Currently, FDM printing of timbering bases (and the resin printing of chairs) is missing from my YouTube channel. Hopefully I can have them both covered-off before Scaleforum.

Thanks again,
James

 

[Martin Wynne]

how-to video with the machine straight out of the box

@James Walters

Hi James,

"Straight out of the box" might be a bit optimistic. First of all it has to be got out of the box, and then assembled. That's all quite easy for anyone with 3 hands. Then it may need some adjustments. The eccentrics on the Y-axis rollers are tricky to get at with the little spanner provided - they are both on the right-hand side. The ones on the head and Z-axis are easier to do if necessary. The initial paper manual levelling is fairly straightforward if you follow the instructions. It is easier to move the head around manually with the power off for the first levelling.

Nothing that someone capable of building a model railway won't take in their stride. But don't make it look too easy -- it's not fair to folks who have to ask which way to turn screwdriver.

cheers,

Martin.

 

[Martin Wynne]

@James Walters @Hayfield @gavin

More about the Elegoo Neptune 4

After using the Neptune 4 for a few months I have been starting to see some issues.

Adhesion problems :

The PEI bed worked well at first, but recently I have been getting adhesion problems. Prints not sticking all over, curling at the corners, etc.

It seems that the properties of the PEI coating wear off after a time. At first I assumed it just needed a clean, but a good wash with hot water and detergent made no difference.

To solve the problem I have done two things:

1. use a glue stick, as on a glass bed. I was surprised to find a PVP glue-stick included in the box with the Neptune, with no mention of what it was for. It seems that Elegoo were well aware that the PEI might need some help after several uses.

Several good dabs from the glue-stick, and then smear it out into a thin film all over with a damp sponge (when the bed is cold). One application will last for several jobs, it's not needed fresh every time. It doesn't affect the auto-levelling. It cleans off with hot water.

It must be PVP adhesive, not ordinary children's school glue sticks. If ordering from Amazon make sure that it says PVP adhesive on the label:

https://www.amazon.co.uk/dp/B08D6PJTWN/

2. PEI needs to be at 60degC to become sticky. The thermal sensor for the bed is on the underside, several mm below the print surface. It seems obvious that when starting the printer from cold, although the sensor may have reached 60degC it's likely that the print surface will be lagging several degrees behind. I increased the profile temperature to 70degC for the first layer, reducing to 60degC for subsequent layers after the bed should have warmed through.

Profile attached below. It's for the Elegoo Cura 5.6 version and probably won't work with other versions. The download details are above:

https://85a.uk/templot/club/index.php?posts/10648

---

Very noisy second layer:

The Elegoo factory profiles supplied with the printer cause significant over-extrusion of the first layer. This is presumably to help avoid the known sticking problem. This is ok for the outline walls of the first layer, but when continued across the infill areas it causes ripples in the layer surface. When attempting to lay down the second layer at high speed, the nozzle bumps into these ripples causing much rough noise and vibration. This must be bad news for the printer, causing wear to the nozzle and vibration likely to cause parts to come loose. It may also cause the stepper motors to lose sync and spoil the dimensional accuracy.

To prevent this I have reduced the infill flow rate for the first layer. This helps to remove the ripples a lot, although it is tricky to get it just right without making the adhesion problems worse. It's in the profile below. I also switched off the travel wipe and surface combing, and switched on coasting, all to get a clean smooth first layer.

---

Blind sockets:

Despite the above changes, the laying down of the first layer is still very messy around the sockets. The small rings of socket outline do not stick very well, and are easily knocked out of position by subsequent moves of the nozzle. This problem seems to be caused by the textured PEI surface -- the socket outlines are very cleanly laid down on a glass bed (on the Kingroon printer, for example).

After much experimenting I'm minded to revert to blind sockets, as on the original plug track experiments. This means the first layer has no socket holes in it and is able to grip the bed much more cleanly. For the next version 555a I have made this the default option, but it is easily unticked if not wanted (on a glass bed, for example):

This applies only to the first layer. The base of the sockets is very thin as the first layer (0.24mm, approx 10 thou). To ensure adequate bottom clearance for the chair plugs if roughly cut from the support pyramids, I increased the default timber thickness by the same amount, to 3.60mm in 4mm/ft scale, with the socket depth at 3.36mm. These settings can of course be changed if not wanted.

---

With all these changes I am now very pleased with the results from the Neptune 4, getting clean accurate prints every time. It's important adjust the Z-offset correctly to get a smooth first layer. Profile attached below.

cheers,

Martin.

 

[Phil G]

@James Walters @Hayfield @gavin

More about the Elegoo Neptune 4

After using the Neptune 4 for a few months I have been starting to see some issues.

Adhesion problems :

The PEI bed worked well at first, but recently I have been getting adhesion problems. Prints not sticking all over, curling at the corners, etc.

It seems that the properties of the PEI coating wear off after a time. At first I assumed it just needed a clean, but a good wash with hot water and detergent made no difference.

To solve the problem I have done two things:

1. use a glue stick, as on a glass bed. I was surprised to find a PVP glue-stick included in the box with the Neptune, with no mention of what it was for. It seems that Elegoo were well aware that the PEI might need some help after several uses.

Several good dabs from the glue-stick, and then smear it out into a thin film all over with a damp sponge. One application will last for several jobs, it's not needed fresh every time. It doesn't affect the auto-levelling. It cleans off with hot water.

It must be PVP adhesive, not ordinary children's school glue sticks. If ordering from Amazon make sure that it says PVP adhesive on the label:

https://www.amazon.co.uk/dp/B08D6PJTWN/

2. PEI needs to be at 60degC to become sticky. The thermal sensor for the bed is on the underside, several mm below the print surface. It seems obvious that when starting the printer from cold, although the sensor may have reached 60degC it's likely that the print surface will be lagging several degrees behind. I increased the profile temperature to 70degC for the first layer, reducing to 60degC for subsequent layers after the bed should have warmed through.

Profile attached below. It's for the Elegoo Cura 5.6 version and probably won't work with other versions. The download details are above:

https://85a.uk/templot/club/index.php?posts/10648

---

Very noisy second layer:

The Elegoo factory profiles supplied with the printer cause significant over-extrusion of the first layer. This is presumably to help avoid the known sticking problem. This is ok for the outline walls of the first layer, but when continued across the infill areas it causes ripples in the layer surface. When attempting to lay down the second layer at high speed, the nozzle bumps into these ripples causing much rough noise and vibration. This must be bad news for the printer, causing wear to the nozzle and vibration likely to cause parts to come loose. It may also cause the stepper motors to lose sync and spoil the dimensional accuracy.

To prevent this I have reduced the infill flow rate for the first layer. This helps to remove the ripples a lot, although it is tricky to get it just right without making the adhesion problems worse. It's in the profile below. I also switched off the travel wipe and surface combing, and switched on coasting, all to get a clean smooth first layer.

---

Blind sockets:

Despite the above changes, the laying down of the first layer is still very messy around the sockets. The small rings of socket outline do not stick very well, and are easily knocked out of position by subsequent moves of the nozzle. This problem seems to be caused by the textured PEI surface -- the socket outlines are very cleanly laid down on a glass bed (on the Kingroon printer, for example).

After much experimenting I'm minded to revert to blind sockets, as on the original plug track experiments. This means the first layer has no socket holes in it and is able to grip the bed much more cleanly. For the next version 555a I have made this the default option, but it is easily unticked if not wanted (on a glass bed, for example):


View attachment 11019


This applies only to the first layer. The base of the sockets is very thin as the first layer (0.24mm, approx 10 thou). To ensure adequate bottom clearance for the chair plugs if roughly cut from the support pyramids, I increased the default timber thickness by the same amount, to 3.60mm in 4mm/ft scale, with the socket depth at 3.36mm. These settings can of course be changed if not wanted.

---

With all these changes I am now very pleased with the results from the Neptune 4, getting clean accurate prints every time. It's important adjust the Z-offset correctly to get a smooth first layer. Profile attached below.

cheers,

Martin.

Hi Martin, very interesting observations
What I found especially interesting is just about everything you have written about your Neptune 4 also applies to my Neptune 3. The only major difference is the Neptune 3 is still using the Marlin software, however the basic machine design is very similar less the huge cooling fans supplied on the Neptune 4. So my only real question, is your supplied profile only for klipper machines?

My personal conclusion is the metal PEI build place is in fact not an improvement on previous designs of build plates.

In fact I have to wonder if the Elegoo series of FDM printer are up to the engineering level required to get the best out of plug track!
I think if you are an expert on FDM printer settings, you can just about keeping adjusting to hold them where they need to be. For the rest of us. I am less convinced.
I agree for some things, they are great for simple projects, such as the rail jigs and my knuckle bending jig. But good enough to hold gauge I am not at all sure about that. Only time will see.
cheers
Phil

 

[Martin Wynne]

So my only real question, is your supplied profile only for klipper machines?

@Phil G @James Walters @gavin @Hayfield

Hi Phil,

It's only for Elegoo Klipper-based printers. At present that means only the Neptune 4. Possibly future Neptune printers too, if any are introduced -- or possibly not.

It won't work on the Neptune 3 because of the much faster print speeds specified -- which the Neptune 3 probably isn't capable of, needing a higher-rated power-supply at least.

Even if it could work on other printers, I doubt Cura would agree to import it -- it's very fussy about its profile files because they contain a reference to an existing printer profile and the differences from it.

To create a fully independent profile requires that you first create a default custom printer, and then create profiles for that. We did that for the Kingroon printers. We could probably do the same with the Neptune 4 printer, but this profile is not it. I do intend to try that, because I would much prefer to be using the generic Cura 5.8 rather than the custom Elegoo Cura 5.6 version. At present I have to have both installed, and they are not friends with each other.

However, most Neptune 4 users will be using the custom version, and I am trying (but failing) to keep things simple.

cheers,

Martin.

 

[gavin]

Hi Martin, and others

All your experiences mirror mine with the Neptune 4, as you will no doubt be aware.

The curling up corners on the first few layers were I suspect one of the reasons why I was caught by the 'blob of death' (such an endearing term from Elegoo!) which resulted in me having to purchase a new 'hot end' - the nozzle bit under the hood of the print head.

First print after switching on is the most likely one not to stick fully - and I would concur that this is caused by the bed not being full heated. I have considered altering the code 'header' to introduce a delay (to give it more time to warm up across its full width) but so far not done so.

One of the things that came with the new 'hot end' from Elegoo was advice about the first layer not always sticking, and I now watch this religiously to be certain it is ok - if not I cancel the build at this stage and start again. Most likely though is that it is the first print of the day that could fail like this.

And - ahem - cleaning. Well you know me, always doing things a bit awry. I have found that NOT cleaning the bed regularly, but instead leaving the ultra thin layer/shadow of the material from previous prints, does seem to improve the adhesion as well. To my mind this sort of makes sense, but each to their own!

Not yet got back to the chair printing but will be in touch.

Gavin