‘What LatheXXXXX sorry 3D Printer should I buy’

[Ian ParkinParticipant @ianparkin39383]

Got my printer up and running and churning out widgets from thingiverse  by the bucket load very pleased so far however when i want to make 4 identical prints should i do them one at a time or all 4 at once?

Edited By Ian Parkin on 16/01/2018 13:35:09

[JourneymanParticipant @journeyman]

Ian, it is easier and quicker to do all four at once. Your slicer software will likely have a function to place multiple copies on the build plate. It will not have any effect on the accuracy of the parts.

John

[Ian ParkinParticipant @ianparkin39383]

I was just wondering whether the individual items would cool more between having new layers added making the layers not stick as well if done one at at time

[Neil WyattModerator @neilwyatt]

If four at once, you may need to play with your retraction settings if they seem to end up covered in 'strings'.

[JourneymanParticipant @journeyman]

Posted by Ian Parkin on 16/01/2018 14:00:54:

I was just wondering whether the individual items would cool more between having new layers added making the layers not stick as well if done one at at time

I can't say that I have noticed any problems but then again I havn't tested anything to destruction to determine the layer bond. If worried you could turn down the build plate fans (if fitted to your printer) or increase the hot-end temperature a few degrees to compensate.

Posted by Neil Wyatt on 16/01/2018 14:11:33:

If four at once, you may need to play with your retraction settings if they seem to end up covered in 'strings'.

Havn't noticed this effect yet, last thing I printed with lots of bits at the same time was NASA's Viking Lander probe which seemed to work OK

John

[Iain DownsParticipant @iaindowns78295]

This has ended up being a mixed experience, with issues with the printer. It looks like a combination of a controller board (which resulted in random leaps to the X or Y origin or mad reverse extruding) and a dodgy thermocouple / lead which resulted in break or something at heights from 2 to 8 mm which means it did not feed. The top and bottom of a small model, but no middle!

In the end it's all sorted out and, as I've said before, I can't praise Mike enough for support day and night with advice and replacements as needed.

If this had been a kit from China….

What it brings home to me is that this is similar in some ways to the metal side of our hobby. It won't work out of the box and needs tweaking. I've messed with my mill and lathe to get them working better – seems the same is needed here, but if anything it's even more sensitive!

On the positive side, I've managed to impress the wife more with a couple of prints on this (lizard soap dish and toothbrush holder) than all the swarf generation of the last two or 3 years!

Iain

[Colin LLoydParticipant @colinlloyd53450]

Posted by Iain Downs on 31/01/2018 21:35:14:

This has ended up being a mixed experience, with issues with the printer. It looks like a combination of a controller board (which resulted in random leaps to the X or Y origin or mad reverse extruding) and a dodgy thermocouple / lead which resulted in break or something at heights from 2 to 8 mm which means it did not feed. The top and bottom of a small model, but no middle!

In the end it's all sorted out and, as I've said before, I can't praise Mike enough for support day and night with advice and replacements as needed.

If this had been a kit from China….

Iain

Mine was a kit from China – and I had no problems with mis-functioning items. As most of the items in the Factory 3D printer were almost certainly made in China – the power supply, the interface board, the stepper motors, the extrusion unit, etc. with only the frame probably being made by Factory 3D, it's not really on to criticise Chinese kits,

From the Factory 3D site photographs of the Prusa i3 Printer – the thing I don't like about it is the lack of top support for the z-axis screw thread movement – but I may be wrong – difficult to see from the photos. And the support and screw travel rods are only M5 – the Geeetech's are 7mm in diameter. And just a single vertical aluminium plate to hang everything off ? The Geeetech Prusa i3 (and similar clones) have a 3-dimensional box-like frame that provides great rigidity to the x,y,z movements. I wouldn't swap my Geeetech for the Factory 3D Prusa printer based on what I can see from the Factory 3D website.

[Iain DownsParticipant @iaindowns78295]

Thanks, Colin.

My point wasn't that this was a better kit. It was that with any kit you can get good and bad parts. I had a UK one with some bad bits (as you say almost certainly made in China).

My point was twofold. Firstly, I'm happy that I chose a UK supplier in that had I had these issues with a chinese supplied kit the resolution would have been considerably more challenging for a beginner.

The second thing is that I don't think 3D printing in the hobby range is yet 'plug and play'. You need a certain amount of understanding and tweaking to get good results.

The printing results are pretty good, Though I've made no attempts, as Neil appears to have, to head for thou level resolution!

Iain

[Neil WyattModerator @neilwyatt]

People do worry about lack of top support for the z-axis screws, including me – I fitted a pair of bearings.

To put it in perspective, if the 300mm long z-axis screw can waggle from side to side by 10mm (it can't the hole it goes in is much smaller) then that nice Mr Pythagorus tells us the maximum vertical error at the top of the leadscrew is 0.04mm, or an error in vertical size of 0.013%

Nuff said?

Neil

[Iain DownsParticipant @iaindowns78295]

Neil.

To put it in perspective, if the 300mm long z-axis screw can waggle from side to side by 10mm (it can't the hole it goes in is much smaller) then that nice Mr Pythagorus tells us the maximum vertical error at the top of the leadscrew is 0.04mm, or an error in vertical size of 0.013%

Or about 1.5 thou. If you can machine something 8 inches high that's 1.5 thou out you are a MUCH better man than me.

Iain

[Roderick JenkinsParticipant @roderickjenkins93242]

I suspect we are looking at these printers from the wrong perspective. These printers are very lightweight systems that achieve precision and acceleration by having low mass. Lack of upper support for the Z axis may, at first glance, look wrong but what advantage is actually achieved by constraining the vertical screw? As designed it is free to float so that it can make itself parallel to the Z guide bar at any given height, thereby avoiding any strain that might cause distortion – or so it seems to me. In a similar vein, tidying up the wiring into looms can provide a force that restricts the movement of the print head (that's my excuse ). To our engineering orientated eyes there are things that appear to look wrong but the proof of the pudding is surely in the results. My results are similar to Neil's – my various sized test cubes are consistently oversize by 0.15mm on all 3 axes. That suggests to me that there is no systematic problem with the X, Y or Z axes and I think that is pretty good.

Cheers,

Rod

[Colin LLoydParticipant @colinlloyd53450]

Iain – there are, of course, 3D printers "Ready-2-Go" but at a price. I found that building mine I learnt a lot that served me when things went wrong. With an assembled unit – this learning phase is missing – but the assembled unit will still go wrong – and you generally have no idea why.

Neil and Rod – I just don't like things waggling around. I appreciate that there might not be a performance "hit" from not constraining the vertical screw and actually mine is able to waggle by about 1mm in its top location hole.

With regard to wiring – I've put all the "flying" leads from the extruder unit (Fan, Heater,Thermistor) onto inline miniature plugs and sockets with drone-type LiPo battery XT60 plugs/sockets to take the extra amperage for the Heater. The stepper motor already has a plug/socket attachment. This is so I can easily remove the entire unit for servicing, clearing blocked nozzles, etc. – so much easier to do away from the printer.

[Neil WyattModerator @neilwyatt]

Posted by Colin LLoyd on 01/02/2018 16:29:48:

Neil and Rod – I just don't like things waggling around. I appreciate that there might not be a performance "hit" from not constraining the vertical screw and actually mine is able to waggle by about 1mm in its top location hole.

Ditto, that's why I went with fitting ball bearings!

I also fitted spiral wrap but I find the actual placement of the wires is important to avoid excessive movement near the hot end and spread it along the bundle.

As for 0.001" layers, I've recently got some 0.2mm nozzles and look forward to trying some really small objects!

[Colin LLoydParticipant @colinlloyd53450]

Posted by Neil Wyatt on 01/02/2018 16:55:54:

Posted by Colin LLoyd on 01/02/2018 16:29:48:

As for 0.001" layers, I've recently got some 0.2mm nozzles and look forward to trying some really small objects!

Neil – I look forward to your experience with 0.2mm nozzles. I went up from the supplied 0.3mm brass nozzles to 0.4mm stainless steel – mainly for speed of printing (and steel for longevity). Most of my 3D printing is for robust functional items – so I don't need a delicate touch – just quickly created items.

Will the stepper motor/filament feed mechanism be strong enough to supply melted filament through such a narrow orifice? Also – can you get 0.2mm drills to clear out blocked nozzles?

Colin

[Iain DownsParticipant @iaindowns78295]

Mike advised a plug for the hot end bits. As usual I have every bit I might need apart from the one I actually need and ended up with a PC PSU male and female connector. Does the job and can certainly carry the current, but it feels so ungainly!

Iain

[Cabinet EnforcerParticipant @cabinetenforcer]

Posted by Neil Wyatt on 01/02/2018 16:55:54:

As for 0.001" layers, I've recently got some 0.2mm nozzles and look forward to trying some really small objects!

I found that the 0.2mm nozzles were really good for lithophane printing. Basic guide here: **LINK**

Print them vertically up from the long edge however, doing it flat as per the video leaves them rather rough looking.

[Dick HParticipant @dickh]

I like this thread on 3D printing and am inclined to buy the hardware. Sorry to be pedantic, but at some stage I ask myself as to when the effects of viscoelescticity/melt expansion and crystallinity/annealing will manifest themselves in 3D printing (i.e. in the dimensions, stress and strength of the part. In injection moulding there is a lot in the meltflow and how it freezes off. Stuff a melt through a nozzle, it expands afterwards. Anneal a casting and mess with the crystallinity and it will distort. How do you take these effects into consideration? In particular the crystalline morphology should affect the strength of the part unless it is just used as a form in a lost wax moulding process or as an ornament.

I had a bit of a crash course in these considerations in thermoplastic composites.

Dick.

[Neil WyattModerator @neilwyatt]

3D prints are weaker than injection moulded ones, but not by as much as you may expect.

They are marginally weaker 'along the grain' but this is dependent on the print temperature, the difference with well-printed parts is surprisingly small.

Distortion is a problem, caused by differential cooling, and dealt with using cooling fans and ensuring good bed adhesion.

Any expansion of the bead after extrusion is dealt with by calibration.

I haven't notices any signs of crystalline structure in printed parts. Printed PLA breaks with a brittle fracture (if you have a reasonable cross section) and negligible signs of yield i.e. broken parts will fit together well. In contrast, printed nylon is tough and flexible (virtually unbreakable).

Neil

[Dick HParticipant @dickh]

Thanks for that. Still drooling over Prusa offers.. Can you clean the nozzles by torching them the way you would clean an injection moulding screw? (as long as the polymer concerned isn´t PES)

[Barnaby WildeParticipant @barnabywilde70941]

Posted by Dick H on 01/02/2018 20:03:57:

I like this thread on 3D printing and am inclined to buy the hardware. Sorry to be pedantic, but at some stage I ask myself as to when the effects of viscoelescticity/melt expansion and crystallinity/annealing will manifest themselves in 3D printing (i.e. in the dimensions, stress and strength of the part. In injection moulding there is a lot in the meltflow and how it freezes off. Stuff a melt through a nozzle, it expands afterwards. Anneal a casting and mess with the crystallinity and it will distort. How do you take these effects into consideration? In particular the crystalline morphology should affect the strength of the part unless it is just used as a form in a lost wax moulding process or as an ornament.

I had a bit of a crash course in these considerations in thermoplastic composites.

Dick.

Every kid I'd normally give a card stuffed with £cash this xmas I gave them one of these instead :

https://www.thingiverse.com/thing:201097

It was amazing. You could predict quite accurately which ones would just smash it open & the ones who would touch it, feel it, squeeze it, poke & prod it. The questions were endless & a few have now put a 3d printer at the top of their lists.

Until you actually jump in & get on the bandwagon you'll never understand. This is the beginning, the very early days of something which HAS to get better & WILL become a major part of everyday life.

[I.M. OUTAHEREParticipant @i-m-outahere]

Mine is just about ready to go , i haven't worried about the z axis supports yet as i want to play with it for a while to weed out any other problems if there are any .

The only issues i had with the build was the Y axis belt tensioner was too big for the hole it is meant to live in , the x axis rods were too tight in the end brackets – both fixed easily with the little file they gave me and the threads in the Z axis top bearing plates were a litle tight and seemed to have some blast or tumbling media in them but i ran an old tap in there until it bottomed out and problem solved . There is a misprint in the build manual – only with some of the screw lengths but a quick cross reference with the parts list solved that .

With the remote controller box it meant i could make up some little harnesses and cut up a jiffy / project box to cover the plug interface so to remove the printer head it is just a matter of take the cover off , unplug the stepper , thermocouple and fan then undo two terminals for the heater and the whole printer head with harness comes away cleanly – same goes for the bed .

I have done a small dry print to test motion and heating and it seemed to go ok and i don't seem to have any wobble on the Z axis , from some of the videos i have seen i am now starting to think that they haven't backed out the locating grub screw before clamping the flex drie to the feed screw or they have bent something .

I have purchased some boron silicate glass and stainless 0.4 nozzles so now all i have to do is fit the glass instead of the aluminium , level the bed and run a test print .

I have some more mods in mind but more on that later !

Ian.

 

Edited By XD 351 on 02/02/2018 04:45:23

[Neil WyattModerator @neilwyatt]

Posted by Dick H on 01/02/2018 20:21:37:

Thanks for that. Still drooling over Prusa offers.. Can you clean the nozzles by torching them the way you would clean an injection moulding screw? (as long as the polymer concerned isn´t PES)

Nozzles are so cheap, I buy them in packs of ten.

Bear in mind that they wear (OK you can buy ceramic ones at $30 each…) so you may as well treat them as consumables. They don't block often if you send the filament through a sponge wiper before it goes into the hot end.

Neil

[I.M. OUTAHEREParticipant @i-m-outahere]

  Here's a tale of 3 test cube prints, the mangled one was first up and broke away from the table and ended up doing a waltz around the table with the print head. The horrible first few layers was me trying to get the extruder to feed enough to keep up with the rest of the machine which comes factory set to break the land speed record !
The other two are second ( left cube) and third print . The lighter shade line on the second print was me tweaking the print and extruder speed ( sped up the table and slowed down the extruder a touch too much . Its hard to see but the last print has a better finish  what sort of print nozzle to print bed clearance are you guys running ? Geeetech recommended .5 – 1mm which seems excessive as the nozzle is 0.4 mm – i tried it and it won't stick to tue table , 0.2 and it won't extrude so i settled on 0.4  but this is difficult to achieve as the alloy tablebows considerably when heated . I have some boron- silicate here and will be setting that up along with some knurled nuts under the table on the adjustment screws to make leveling more convenient . Material is ABS .

The factory  settings were 100 on table speed  and 100 on the extruder  but after tweaking i ended up with the table speed  at 35 and the extruder at 290 – 300 . I may have set something up incorrectly in cura  – not really sure .

I watched a video about using repetier to set the machine up and it looks  like the program has some very useful  attributes and is fiarly simple to use .

The cube is meant to measure 20 mm and when i measured the second print which was still quite warm it measured spot on , i then measured print 3 when it was cold and it 0.1 under soi checked the other one which was now cold and it measured 0.1 under as well  so i guess it was shrinkage ? 

Ian.

  

Edited By XD 351 on 21/02/2018 05:51:11

Edited By XD 351 on 21/02/2018 06:16:59

[Neil WyattModerator @neilwyatt]

Posted by XD 351 on 21/02/2018 05:41:50:

Its hard to see but the last print has a better finish what sort of print nozzle to print bed clearance are you guys running ? Geeetech recommended .5 – 1mm which seems excessive as the nozzle is 0.4 mm – I tried it and it won't stick to tue table , 0.2 and it won't extrude so i settled on 0.4

Factory 3D recommend the thickness of a sheet of A4. so nearer to 0.05mm, for levelling.

I now set it by eye, using its reflection in glass looking for a small but definite gap.

For the first layer I use 0.3mm.

If I get any issues I rely on tweaking the bed levelling rather than changing settings.

—-

I had an interesting failure last week, I did a 5-hour print then when Ni came to release it it was very fragile and the sides of the box (it was a battery storage box) were effectively a fine mesh.

Turned out that I had somehow typed 2.8 in the filament diameter box instead of ~1.75. result – massive under-extrusion!

I have discovered ways of printing OO scale plastic mesh.

Neil

[John HaineParticipant @johnhaine32865]

Posted by Mick Charity on 01/02/2018 20:31:47:

Every kid I'd normally give a card stuffed with £cash this xmas I gave them one of these instead :

https://www.thingiverse.com/thing:201097

It was amazing. You could predict quite accurately which ones would just smash it open & the ones who would touch it, feel it, squeeze it, poke & prod it. The questions were endless & a few have now put a 3d printer at the top of their lists.

That is cool! Now I wonder if one could machine the cap using CNC? Or is something that could only be either 3D printed or moulded?

[Author]

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