3D Printers

[Stub Mandrel]

1 hour ago, tonyowens_uk said:

deprecation of threaded fasteners

I've found threaded fasteners work very well with 3D prints.

M4 and a above a printed thread finished well with a tap.

Below M4 thread direct into a plain hole.

Fluteless taps might be the way to go with printed threads.

I did some experiments for my book, figures are approximate:

Table 5.3 – Thread Strength

Thread	Material	Engagement	Force	Result
M6	PLA	10 threads	35kgf	No effect
M6	PLA	5 threads	35kgf	No effect
M5	PLA	10 threads	35kgf	No effect
M5	PLA	5 threads	35kgf	No effect
M4	PLA	10 threads	35kgf	No effect
M4	PLA	5 threads	30 kgf	Surrounding bulk of print failed
M3	ABS	6 threads	25kgf	Plug of material broke out around thread
M6	PLA	8 threads	240kgf	Gradual failure of surrounding material

 

 

T-mount adaptor, PLA:

M3 - fracture in bulk of material (ABS) rather than failure of thread at 25kgf.

M4  in PLA, again failure of bulk of material, not stripping of thread at 30kgf.

M6 in PLA, used a 10:1 lever to apply approx 240kgf, about 1/10 of what you could expect in steel (from memory). An M6 thread into PLA should easily take the weight of an adult as a static load.

 

 

[tonyowens_uk]

That's very interesting material!

I did not mean to diss the use of screws just to draw attention to the ease of using clip fits and one-piece alternatives to the usual multi-part assemblies. Bonding-in threaded brass inserts works well where thread wear is an issue. But I note that on one of my unfinished printed designs, for a tip-tilt guidescope mount designed to go onto a Losmandy D rail, I've used a 1mm pitch M8 polished precision threaded stainless screw straight into a slightly undersize 3D printed and reamed hole to do one of the adjustments. Creep and a little heat does the rest. The print will be CF-reinforced PC or similar.

13 minutes ago, Stub Mandrel said:

I've found threaded fasteners work very well with 3D prints.

M4 and a above a printed thread finished well with a tap.

Below M4 thread direct into a plain hole.

Fluteless taps might be the way to go with printed threads.

I did some experiments for my book, figures are approximate:

Table 5.3 – Thread Strength

 

Thread	Material	Engagement	Force	Result
M6	PLA	10 threads	35kgf	No effect
M6	PLA	5 threads	35kgf	No effect
M5	PLA	10 threads	35kgf	No effect
M5	PLA	5 threads	35kgf	No effect
M4	PLA	10 threads	35kgf	No effect
M4	PLA	5 threads	30 kgf	Surrounding bulk of print failed
M3	ABS	6 threads	25kgf	Plug of material broke out around thread
M6	PLA	8 threads	240kgf	Gradual failure of surrounding material

 

 

T-mount adaptor, PLA:

M3 - fracture in bulk of material (ABS) rather than failure of thread at 25kgf.

M4  in PLA, again failure of bulk of material, not stripping of thread at 30kgf.

M6 in PLA, used a 10:1 lever to apply approx 240kgf, about 1/10 of what you could expect in steel (from memory). An M6 thread into PLA should easily take the weight of an adult as a static load.

 

 

 

[Gina]

I tap direct into plastic. 

[Dr_Ju_ju]

Like Gina, I always properly tap the holes before fitting any bolts, as I usually find the act of trying to insert the screw\bolt, even with correctly printed\drilled holes, compresses and distorts the material, making the area around the hole weaker... 

So yes, you have what appears to be a secure screw\bolt, but the structural integrity in the surrounding material is compromised, possibly leading to failure of the part.

[Stub Mandrel]

Yes, that's why I usually tap. If you have serial taps the two-ring one is a good choice, giving a tight thread without removing too much material.

[Gina]

I bought the Ig2 Universal Tap and Tapping Drill Bit Set from Axminster Tools.   Been exceptionally useful for tapping metals as well as 3D printed items.  I use them with my battery electric drill (adequate for plastic) or bench drill press.

[TheMan]

On 16/09/2018 at 11:27, Atreta said:

Hi, Louise. I just bought a creality ender 3 and I'm waiting for it to arrive. It's a good printer under 200 usd. There are a few videos on YouTube reviewing it. 

+1 for the ender 3. I couldn't be happier with mine.

[Chriske]

I hardly tap in my printed parts. Only when there's little or no force involved I use tapped holes.
Where there's a force involved I always use nuts to fasten the parts against each other.
In this part the upper-right hole I put a M3 bolt. About 15mm lower there's a 'square' hole. That's the hole were I insert a M3 nut. I use this system all the time. Makes mechanical connections even stronger. And what's more, when inserting a nut it never wears out if the bolt has to be removed from time to time. And second I don't worry at all destroying the thread when I firmly turn the bolt.
That square hole is a press-fit, so the nut will not revolve in it's hole.

If Table5.3 higher up in this thread will be redone using this technique, well,  it would look completely different.
I use this technique for many years now and it has never failed me once.
While drawing, It's a habit,  I even don't think about it anymore, it's  become standard to me to install that nut.

[JamesF]

So is it fair to say then, that when it comes to 3d printing, you're completely nuts?

James

[Gina]

I've used the same system where strength is required.

[Chriske]

34 minutes ago, JamesF said:

So is it fair to say then, that when it comes to 3d printing, you're completely nuts?

James

Please do...

???

[RolandKol]

Hi again,

thanks for the advice on the software, I have decided to stay with AutoCad and TinkerCad (for the fast/simple sketches). 

Blender was really interesting, maybe once I will come back to it.

As per Filaments: I will start testing PLA and probably PLA plus.

In ideal, I would like to print something strong as Polycarbonate, but I am sure my "Anycubic i3 Mega S" is not able to print it as it needs around 300C degrees in Nozzle and etc.

Mine is able to reach around 270C, and the hotbed around 110C, - whats the strongest material I will be able to use with these temps? (For small 5-10cm dovetail and/or 1kg camera holder).

Am I capped with ABS?

Edited January 5, 2019 by RolandKol

[Dr_Ju_ju]

You could probably try PetG, or E3D's Edge, a PetG variant (more expensive but gives superb results), and maybe even ASA.

Try Rigid Ink's offerings (https://rigid.ink/) as they produce multi types & have lots of guides on how to get the best out their products.

[Gina]

Arrived this morning...  I thought a Giant 3D printer deserved a giant reel of filament 8Kg  ? - I just couldn't resist it!

[Gina]

What's confusing Chris?  Don't you think that's a big enough reel of filament???  ?

[Chriske]

Well no Gina, but depending on the height of your renewed Giant, you'll need a crane to lift these things...
And not to forget, we're only getting older...aren’t we..?

And btw ordered some more PLA, couldn't resist myself.(at these prises..)...?
Bad news is : prices of that ColorFabb economic-filament is at it's regular price again. 42€ for one 2.2 kg reel.

[Gina]

I needed the sale to end - too much encouragement to spend money!!  I have enough filament I think ?

[Gina]

AAMOF my Giant printer project is on hold as I'm designing another 3D printer with a view to best achievable accuracy.  This is as a result of finding problems with my two smaller printers.  Also, I find I'm using different filament types now compared with what I started out with.  In the beginning it was mostly ABS but now I've gone right off ABS as it has been superseded by more user and environmentally friendly filaments.  I shall start a Blog on the new printer once I have the basic design features sorted out.

[Gina]

The industrial strength hardwood plywood for the box of the new printer has arrived and it's heavy.  Sheets of 18mm x 610mm x 610mm (2ft x 2ft).  I have yet to decide on a name, though one thought was "GinaRep Deluxe".  The size works out as between my present "Titan" and "Giant" printers with an estimated printing volume approaching 400mm cube.  (Titan 290mm x 290mm x 250mm - Giant 470mm x 490mm x 600mm).

[RolandKol]

9 minutes ago, Gina said:

The industrial strength hardwood plywood for the box of the new printer has arrived and it's heavy.  Sheets of 18mm x 610mm x 610mm (2ft x 2ft).  I have yet to decide on a name, though one thought was "GinaRep Deluxe".  The size works out as between my present "Titan" and "Giant" printers with an estimated printing volume approaching 400mm cube.  (Titan 290mm x 290mm x 250mm - Giant 470mm x 490mm x 600mm).

OMG Gina!
I can only imagine how much time it takes to print something in that size  week?

[Gina]

Not necessarily - depends on size of nozzle.  This printer will have interchangeable hotends and possibly nozzle sizes up to 2mm though smaller sizes will probably get more use.  But the main design principle is for accuracy more than speed.  Hotends will go from the standard Volcano with nozzle sizes ranging from 0.4mm up to 1.2mm to home made heaterblocks with greater filament melting abilities and larger nozzles.

[Gina]

Previously I have gone for a range of printers of varying sizes but it struck me that one size, well designed and solidly built printer should be capable of small, accurate prints as well as larger prints either talking longer to print or faster and less refined using a larger nozzle and thicker layers.

Edited January 8, 2019 by Gina

[Gina]

Re. name...  Thesaurus hasn't really come up with anything new.  The concept is very good and large - best results were "Deluxe" and "Grand".  My original thought of "Deluxe" seems to fit and sound best.  I think I want to give more an impression of "Posh" or excellence rather than large.  I'm open to suggestions though - as occurred when naming my Titan. 

[RolandKol]

GiDeluxe+ 
:)

[tekkydave]

The first thing that dropped into my head when I thought of large/powerful with beauty/finesse was "Concorde"