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Re: nGen ?

Posted: May 19th, 2016, 3:43 am
by Amedee
I haven't found the sweet spot yet.

I started with How to print with nGen, averaging the values. It gives a nice print but layer bonding is crap.

So I increased the temperature (235-240°C range) and dropped the fan. That gives me a strong print.
I also have enable coasting (Cura 2.1) and it ls looking quite good.

I need to see how far I can re-introduce the fan, but I don't want to spend time on that before I actually get my super-duper-neotko fan shroud mounted.

Re: nGen ?

Posted: May 19th, 2016, 9:30 am
by LePaul
Ha ha! I'm in the same situation! I am thinking it would be good to print the side pieces with...but wasn't sure it would like no fan!

p.s. Good link...50% fan is what they say...well, perhaps none works even better!

Re: nGen ?

Posted: May 20th, 2016, 9:47 am
by LePaul
Well my second try at the top pieces for the shroud mount came out lousy in CF. I cooked the printer to 150 and tried to gently slide it out of the print head. I heard a snap...the filament snapped in the teflon. Ah fun

I put the nGen in and heated to 230. Thankfully the CF started to ooze out and the pressure from the nGen made its way thru. Wow. This stuff has some really nice flow!

Since I have no fan I decided to print the two parts at the same time. My thinking was maybe the pause between layers would allow enough cooling.

I went with the Cura settings from ColorFabb. I also went with 235 since you mentioned that was a good range for your printer.

Layer wise (and with the ruby's help), it looks good. I wonder if my vertical structures are due to no fan or too hot?
image.jpeg
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Re: nGen ?

Posted: May 22nd, 2016, 9:10 pm
by LePaul
I did some searches on nGen and some guys reported best luck printing much cooler. I tried 220 and it wouldn't come out the nozzles.

225 seemed better. Fans on low (as best I can gauge them) 40 mm sec
image.jpeg
Then 230, again low fan. Decided to try printing at 45mm for this
image.jpeg
I know 235 worked ok but wow this stringing is frustrating

Re: nGen ?

Posted: May 22nd, 2016, 9:21 pm
by LePaul
Here's the simple test piece I've been using.

I'll be curious what works for you!

Re: nGen ?

Posted: June 20th, 2016, 4:13 pm
by Izzy
My nGen print settings.
Nozzle temperature 235, with the Ruby nozzle, 230 with a brass nozzle.
Bed temperature 80.
Speed 50mm/s * :!:
Although I printed off a couple of snap on guides for Roberts feeder, the 1st with 35% fill, the 2nd with 100% fill. It seems that nGen is a little brittle not liking to flex and both have broken, so I'm going to try with ABS.

*When is 50mm/s not 50mm/s? :geek:
I was doing some filament testing and a previous volumetric flow test appeared wrong when I timed and calculated the rate. So I redesigned a test piece calculated that for the outside diameter of 59.68mm with a 0.4 mm wall thickness and a 0.2mm layer would give a layer volume of 15mm3. This has a circumference of 187.49mm.
Wanting 4.0mm3/s then 15/4 =3.75 IE 1 revolution in 3.75 seconds.
187.5mm/3.75s= 49.99mm/s
So why when I had the file print speed set to 50mm/s, the printers print speed set to 100% did it take 5 seconds, giving me a measured print speed of 37.5mm/s :ugeek: :roll:

Re: nGen ?

Posted: June 20th, 2016, 4:40 pm
by Amedee
Maybe you printed a bit too cold...
At 230°C I don't get good layer adhesion.

Re. the speed, you need to take acceleration into consideration ;)
(But on 19cm it should not affect too much the average speed)

Re: nGen ?

Posted: June 20th, 2016, 4:55 pm
by Izzy
Re the nGen I had good layer adhersion but will do another test at higher temperature but they recommend 220-240. ;-)
Re the test piece, it's a cylinder with 10mm per test band so it has constant velocity for 50 layers, I time it for 10 revolutions to reduce error after it has completed 2 revolutions to stabilise the speed. :geek:

Re: nGen ?

Posted: June 20th, 2016, 5:08 pm
by Amedee
Strange, I really need to go to 235°C for good adhesion, tried with different colors...

Re speed, velocity is not constant when you have a z increase!
You should try with a very big circle to compare (you don't have to actually print something ;) )

Re: nGen ?

Posted: June 21st, 2016, 4:09 pm
by Izzy
Strange indeed, the speed setting just didn't seem right, the 0.2z increase each revolution doesn't slow the head down and it keeps a constant speed, just the wrong speed :roll:

Re: nGen ?

Posted: June 21st, 2016, 4:21 pm
by LePaul
What speed were you using at 235C, Amedee? I was doing 40 mm/sec

Re: nGen ?

Posted: June 22nd, 2016, 4:45 am
by Amedee
Typically 40mm/s. Depending on the object and the desired result sometimes faster inner parts (50mm/s) and/or slower outer wall (30mm/s)

Re: nGen ?

Posted: July 5th, 2016, 3:31 pm
by LePaul
Has anyone else done any tweaking with nGen?

Re: nGen ?

Posted: July 5th, 2016, 4:09 pm
by Izzy
Tweaking?
Although I'm testing some rigid.ink filaments at the moment and the PLA prefers slow print speeds 25-30mm/s at 215'C

Re: nGen ?

Posted: July 5th, 2016, 4:28 pm
by Neotko
I will never get ngen. It's a material for technical stuff rather than finished stuff. Also I hate not to be able to sand stuff. Pla & pla-tec atm are my materials.

Btw lepaul (offtopic) a guy used a e3d amplifier and inatalled the um2+ on his umo (not plus). Check the forum, it seems like a fast & way to do it