3D Printers

**cvtem** · 20-10-13, 10:02 AM

I have managed to collect some 3D printers.
It all started on a proof of concept job, where I needed a large build platform

Felix 2 - The printer which kept melting.
I needed ABS, and this printer was made of PLA, disaster after redesign after disaster I have entirely redesigned it using makergear hot ends, it now has dual bowden extruders, all aluminium and ABS.
This printer is still my favorite, I have it set up with 0.5mm nozzles, and 60W heaters. I had to change up from the 40W standard due to the speed I was trying to print at, new FET's, and this thing now flies! The speed limitation is now due to uneven heating of the plastic, causing lower quality parts, the only solution is a longer tube in order to head the filament over a longer period of time to ensure that it all melts.... cold end -> Pre-head -> Hot-end. It might work? Going faster might not make a noticable different in most parts due to accel/deccel. I'll find out though.
It has printed at least 40kg of plastic. Unfortunately, being the temperamental beast it is, somewhere between 5 to 10kg of that 40kg is in the bin, and I do not exaggerate.
A lot of printing I still use 0.35mm nozzles, and run at 0.25mm layers. For show I use 0.1mm or 0.05mm, but it's for show, too slow for practical use.

Next, I had another job come up, an opportunity I could not let slide, and I needed a lot printed very quick.
I got this verified on Monday, that night, I had paid for, and was waiting for delivery on 2 new printers.

UP! Plus 2 - The printer which has no options.
Before I could even print I had to intercept the thermistor with 11 Ohms of resistance to get it to print at the right temperature, no temp settings, gah.
But the extruder design of this printer is excellent, infact, this whole printer is. For a first printer, using genuine UP! Filament, I couldn't reccomend anything else!
This printer I have had for 4 days, and has printed 3kg so far... and only 2 failed prints. The PCB platform, this is brilliant. It has not had a moments rest!

UP! Plus Mini - The printer which I never should have got
The same software as the UP! Plus 2, but smaller platform, a print bed of only 50C.........
As with the Plus 2, this printer has not stopped, but is still on its second roll of plastic (so still under 2kg). Small platform, bigger peices are warping due to lower bed temperature, tiny tiny bed.
I can't reccomend this fellah. Well, I suppose, genuine filaments, it would be as good as the Plus 2, but really, just get a Plus 2.

Deadline Tuesday Morning, 4kg more of printing to go. Never done so much in such a short time... never had so little failures.

Just thought I'd share a short history of printing.

I have printed all up about 50kg of ABS, about 250g of PLA, and 500g of Nylon

**Downunder35m** · 20-10-13, 11:46 AM

I started a 3D thread as well

Currently designing a full aluminium hotend.
Size does matter, so I'm still trying to make it smaller.
Still waiting on the tiny drill bits as the ones from Jaycar are only good to drill through wood or plastic.
Current design is just 2cm long and less than 15mm in diameter.
If I can solve the insulation problem properly I should be able to get down to about 12mm in diameter.
No heating from the side through a block either and temp sensor directly inside the tip of the nozzle.
Highest temp I checked so far was 320°, did not dare to go higher as the thermal paste around the heat resistor started to smoke.
Will redesign the front bit so I don't need to use any paste, this sould allow for print temps of over 400° if the sensor does not fail.
Was in the same boat with you (or still am) with very slow printing speeds and failed prints.
But to makes things harder I refuse to use a heated printbed which means low temp layers in ABS to prevent warping at the the start and after about 20 layers with 270° at full speed.
Lucky me has all printer parts machined from Acatat plastic but the original extruder and hotends are just crap...

**jok11n** · 20-10-13, 01:39 PM

Originally Posted by cvtem

UP! Plus 2 - The printer which has no options.

I have this one and it has been working great for what we use it for, money well spent for us

**bazzle01** · 21-10-13, 10:23 AM

Some pix added to the above posts would be welcome

Baz

**Downunder35m** · 21-10-13, 10:50 AM

Could upload some pics of my early prototypes, but I guess it would be much more interesting to actually seem them in action.

**cvtem** · 22-10-13, 08:58 AM

I'm not much of a picture taking person....
I actually have taken some of the early felix 2 days, the second day I had it I had melted it (PLA is such rubbish!), so machined a aluminium support..

As for other photo's, yeah, I might get around to it.

Downunder..
I am not sure if that is the solution, as long as the heat is constant is all that really matters, and aluminium could be the failing point...
By moving it closer you will be able to get more efficient heating, but you will also be causing a greater delta over the area.
Look at it this way.
Aluminium is about, what, 250 W/m.k whereas copper is 400 W/m.k
Heat capacity per volume is the other factor, and that is about 2.4 vs 3.5 as well.

I will be looking at my own heating block, I probably will use aluminium simple because its so damn easy to work with and cheap.
Will use the makergear setup, but as mentioned, looking at a preaheat, so 2 resistors to heat the block, one on the left upper, and right lower (if you know what I mean).
That way I can keep the temp down, but acheive the heat needed...

Heated bed is a godsend on large prints, as is a heat retention chamber.
On large prints the printer lives in a 35C room with heated bed (Felix)
Dropping the room to 25C, turning on the fan, or turning off the heatbed = banana.
And you can't always design it with expansion/contraction in mind (circles, splits, etc...) so you need to have it cool as slowly and consitantly as possible.

**Downunder35m** · 22-10-13, 12:27 PM

You are right in terms of the heat conductivity, but after checking numerous designs on the net I realised
a) either brass is used
b) Aluminium is used anyway
All desgins that previously used a normal heater block with single resistor are now converting to a double heater block - to prevent uneven heating and to get more constant temps.
Of course I could your brass or even copper instead, after the rods are not that expensive for a few nozzles.
But the biggest problem with a design based on those two materials is insulation.
You have to use a ceramic heater capsule, a resistor or at least a heating element with an electrical insulation to the actual print head.
By using Aluminium I can overcome all these problems and use a design with far less weight and mass than standard designs.
The current design stage (not print ready yet) is under 10 grams for the hotend without cables and the heat barrier.
With less than 12mm in diameter I can design a multi-print-head with basically the same footprint than currently available single hotends

There is less than 1.5mm between the heating wires and the filament, resulting in reaching print ready temps in under 3minutes.
If I get it working the way I hope it works the hotend will be able to print up to 500° withupt problems, so printing the impossible materials will be possible if you get the filament.
If you want you can even print with solder on copper plates LOL

**tristen** · 22-10-13, 03:54 PM

Originally Posted by cvtem

I'm not much of a picture taking person....
I actually have taken some of the early felix 2 days, the second day I had it I had melted it (PLA is such rubbish!), so machined a aluminium support..

Thanks for posting the pictures - I am unable to view these graphics. I have tried on two different computers, one using both Firefox and I.E. running under XP Corporate Pro. and on a Mac. I have a similar problem with viewing pictures posted in another thread.

Can other members view the graphics in post #6? Please advise.

**Bibliophile** · 22-10-13, 04:58 PM

I cannot open then using Win 8.1 & IE11.

**tristen** · 22-10-13, 05:45 PM

Thanks for your confirmation, Bibliophile.

This is not an isolated problem for me, as I have a similar experience with links to graphics in a post in the IPTV section.

It's not something I have encountered before in this forum, so it must be due to some recent change.

I seem to remember that the recent forum mail out (multiple e-mail messages - Austech Needs Your Support - 19 October) referred to a recent change of some sort.

**allover** · 22-10-13, 08:01 PM

Me too! thought i had done some thing wrong

**cvtem** · 23-10-13, 08:25 AM

Images .... I can't see them either.. Must be a forum issue.

Printing metals, the biggest issue is that it is extremely sudden solid to liquid, and low viscosity when liquid, it doesn't have the huge forgiving window that plastics do, you would need to print just above melting point, and yet have enough residual heat to ensure the layers bind, while cooling it quick enough it doesn't run away.
I got some tin rods, I could have a play and see but my confidence in it working is somewhat minimal. at least, without a much better cooling system. I am pretty sure I could get my head to 330C so could even try lead, which I doubt would be any easier...

Now on 500C Plus, you should take a page from smelters and look at using induction for heating, and IR for temp reading. No issues of burning out, and can keep material just as minimal.

I won't be trying anything like this at this stage, but I see where you can go with this, and it is very interesting... but at this stage, I have a 4D Router which does all the other pieces I need satisfactorily.

**allover** · 22-12-13, 12:42 PM

**allover** · 29-01-14, 04:09 PM

Try again

**lsemmens** · 29-01-14, 08:32 PM

Envy is a sin! I'll repent....one day. Want, desire, lust after, all the others. Bloody good price too, pity I haven't got a spare 5k kicking around or I might mortgage the wife and buy one!