3D Printers?

[DaveS]

Recommendations for a beginner?

Not too expensive (<£300 for preference), relatively easy to assemble for a cack-handed nerk, and capable of good accuracy as I want to print things like extension adaptors with metric threads.

Please keep your replies simple, as this is unfamiliar territory for me.

[Sylvester111]

I doubt any printer would be able to do small screw threads at the moment, they are just not precise enough.  Large threads (M20 or so I guess?) I think you could get away with, but they may not be of as much use to you.  Do not despair, however!  There are solutions.  You could get inserts to go in the 3D items you print, or do what I have done in the past and print holders large enough to go over the mounts and friction fit (for example, I printed an adapter to go from a webcam to a microscope top, it fitted over the camera shroud and microscope shaft).  More info on threads here:  https://shop3dchimera.com/blogs/connecting-the-dots/to-print-or-not-to-print-threads-and-3d-printing

As for printers, I have a UPPlus at home and have used an UPPlus2 (https://www.3dprinting.co.nz/products/3d-printers/up-plus-2-3d-printer/).  Both great small scale printers but older models now.  One thing to think about is the size of the parts you want to print.  They need to be able to fit on the print bed so a 20cm x 20cm x 20cm part won't print on a 10cm print bed unless you print it in sections.  Nicer to print it in one piece though!  I would also suggest that parts will reliably print on only about 80% of the print bed size without warping.  So, an 8cm part will print on a 10cm bed quite happily, a 9.5cm part is getting close to the edges and may warp.

I have also used a Lulzbot (https://www.lulzbot.com/) which has been great and has a much bigger bed.

 

Something else to consider is software.  The usual process is: Get or make a 3d model on your computer (usually called an STL file) > put it into the 3D printer software (sometimes called 'slicing') > send it to printer.

With the UPPlus I do my design, send it to the printer software and press print (the printer is attached to the PC).  With the Lulzbot I do my design, send it to the slicer software, this produces a file that I then have to walk over to the workshop and stick in the printer.

The slicer / printer software is usually not too hard to understand, but generating the 3D model can be a task.  4 ways:

1) Learn a 3d modelling package like Blender (free) or Solidworks ($$$).  Design your model and it'll be perfect.

2) Get someone else to do the design for you.  I think there are sites out there where you can send someone dimensions and get a model back.

3) Find the perfect model on a site like Thingiverse (https://www.thingiverse.com/).  Great for common shapes and objects that others may have printed before.  Generally no good for anything bespoke.

4) 3D scanner.  Unless these have much improved, my experience has always been that I need to do a lot of work on the results and generally am better off doing it all myself instead.

 

Feel free to ask any more questions.

 

[DaveS]

As an example of one of the adaptors I want to print is a M69 (NOT M68) to M54 with 32mm length. I could put together a series of adaptors / extensions but at the moment I can only find what I need on the TS site and they aren't delivering to the UK for the time being.

Has anyone used a photocuring resin printer? looks like greater precision but not sure about the resin.

[vlaiv]

Creality Ender 3 V2

(simple enough, right? )

 

[DaveS]

Right .

Added to basket, but not hit "buy" yet.

May also get a LCD photocuring printer for fine work.

[pete_l]

As vlaiv says, the Ender 3 series. It seems to be the "EQ6" or Ford Transit of 3D printers When mine arrives (bought from a spanish supplier, been "in delivery" for a month now) I will be able to speak with first-hand knowledge.

However I would be wary of trusting equipment to the plastic thread of a 3D printed adapter. Maybe if its payload was light weight and low value and the adapter was not used at low temperatures, it might be OK.
A better solution could be to send your design to a professional outfit that would do  a metal printed part for you. Though I can't say what engineering tolerances they would guarantee. With luck it would cost less than buying a printer!

Edited December 31, 2020 by pete_l

[Brutha]

8 hours ago, vlaiv said:

Creality Ender 3 V2

(simple enough, right? )

 

Yep, I would second that as a general beginner 3D printer too! Easier build than the ender 2 I had before.

[Dr_Ju_ju]

Personally, I'd recommend a Prusa i3 Mk3 (Original Prusa i3 MK3S kit (prusa3d.com)), or even a Prusa Mini (Original Prusa MINI+ kit - Prusa Research (prusa3d.com))...

Yes, you'll pay more, especially for the Mk3, but you'll be up & printing much faster, especially with the in place support & excellent free slicing software (https://www.prusa3d.com/prusaslicer/) and even guides produced by peeps like Tomas Sanladerer (https://www.youtube.com/user/ThomasSanladerer)

And I don't want to decry others perceptions, but its perfectly possible to print 'fine' threads, I can print down to M3 with no issues, or even larger threads 30mm x 0.5mm for adaptors.  

 

[DaveS]

Had a look at the Prusa, but it's out of my price range.

[wormix]

I got an Ender 3 this year and love it - really easy to use and set up, plus I have been able to print some very fine threads. As other have said, I wouldn’t trust them with anything too heavy though. 
 

 

 

[DaveS]

OK. clicked BUY on an Ender 3 V2, and a starter reel of PLA. I expect to be using other filaments as I get more experience.

I am still looking at LCD resin printers.

[Mognet]

Good choice. They are easy to assemble and maintain, even for someone as hamfisted as me, and replacement parts are easy to get hold of if something goes wrong

 

[MaJiC79]

For a cheap starter package, I don't think you'll beat the Ender 3 V2. I'm not sure if they come with a heat bed or of the box, and only a few materials will let you print on a cold bed (PLA will). There are many upgrades as you become more familiar with it

[MaJiC79]

Resin printers tend to require more post processing and chemicals, but also are usually much higher resolution and somewhat faster to print (it depends on a few factors). The resins are usual more expensive as well.

[PeterW]

I’d still avoid fine threads in polymer, some  SLA resins are pretty hard and stiff. They can be higher res than FDM and lack the visible layers and reduced anisotropy.

ender 5 is one a colleague has. Personally i use OpenSCAD and often mod files from thingiverse. I mostly work with PLA, prints well and is nice and stuff. Plenty of options depending on the properties you are looking for.. stiffness, temperature, environmental performance.

Welcome to the community!

 

Peter

[DaveS]

I'll probably get and LCD printer as well. Can't afford real SLA but I think the latest LCD models are pretty good, with mono screens, and some running 4k. Good enough for my needs at any rate.

[tooth_dr]

Can ask what is the main concern over threads? I’m a newbie to 3D printing (few weeks with printer) but so far have printed some (what appear to be to me) decent treads - 0.75mm pitch in varying diameters M28 M42 M48 M54 M60 M72 both male and female.  Is it structural failure?  I’ve tried to break/strip the threads by over tightening but to no avail.

Thanks in advance

Adam  

 

[DaveS]

I've also seen engineering grade photopolymer resins that look to have very high rigidity and strength. Not cheap mind, but for special projects.....

[saac]

On 31/12/2020 at 21:56, tooth_dr said:

Can ask what is the main concern over threads? I’m a newbie to 3D printing (few weeks with printer) but so far have printed some (what appear to be to me) decent treads - 0.75mm pitch in varying diameters M28 M42 M48 M54 M60 M72 both male and female.  Is it structural failure?  I’ve tried to break/strip the threads by over tightening but to no avail.

Thanks in advance

Adam  

 

 

I agree Adam, I think it tends to be one of those urban legends that just gains traction. I have the Ender 5 and have had little problem printing fine metric threads for extension tubes and adaptors - particularly using Paul Gerlach's Fusion 360 add on for M42 T adaptor threads (see low Spec Spectroscope thread) .  I have a number of very successful adaptors together with some other non astronomy related threaded components using PLA and yet to experience any problems.  Just give it a go and experiment. 

Jim 

[Steve Clay]

I print some high detail parts with an Ender 3 for model rockets. No problem at all.

[vlaiv]

Out of interest, since I don't still own 3D printer (it is on my future list ...)

Can I print something like M90 to 96 ID flange adapter on it that will be of satisfactory quality / rigidity?

Also question - how does one overcome "fear of plastic parts"? I mean, when it comes to telescopes - I guess we have heard, read and experienced many times that plastic parts are low quality parts. This has become somewhat of a norm in the way we think about things - you know "Plastic focuser? Pass that one ..."

and here I am, thinking of attaching focuser (and consequently - all that goes on it) to OTA with a piece of plastic. I don't really need to further describe uneasy feeling, right?

[DaveS]

I think there are plastics that may be strong enough, eg carbon fibre loaded PLA, but need special hardened nozzles.

[vlaiv]

Just now, DaveS said:

I think there are plastics that may be strong enough, eg carbon fibre loaded PLA, but need special hardened nozzles.

From my research, most of plastic used in 3D printing is actually strong enough as is.

Much more important is print/slice orientation and parameters and infill. But even with basic settings - things are very strong.

Check this video out for comparison:

https://www.youtube.com/watch?v=ycGDR752fT0

 

[DaveS]

Thanks for that link Vlaiv, very interesting and informative.

[Steve Clay]

If strength and rigidity is required then use a reasonable quality PLA. As said above infill density will add to strength.