My first printing attempt

[Chris Broster]

1 hour ago, Paul Aspden The 2nd said:

Sorted

Amazing! Thanks Paul

[Andy - a15cro]

3 hours ago, TableLeg said:

For Fusion 360 tutorials I'd recommend going through these.

https://www.youtube.com/user/cadcamstuff/videos

 

That’s my homework for tonight sorted then. many thanks.

[Andy - a15cro]

1 hour ago, EBD Engineering said:

print them in abs. and youll forget you ever used PLA😁

is ABS the preferred filament then? I’ve been trying to establish what’s best between PLA, PET-G and ABS before buying any more stock.

 

 

[nice_guy]

7 minutes ago, a15cro said:

is ABS the preferred filament then? I’ve been trying to establish what’s best between PLA, PET-G and ABS before buying any more stock.

 

 

 

Each has its advantages : PLA is easy to print, fast, detailed prints, but becomes soft at low temperature and is brittle when cold, ABS is hard to print, needs an enclosure to keep heat around the print, is troublesome to get sticked to bed, but is very tough, copes with heat and sands amazing, PETG is a bit in between, very tough, heat tolerant, but is prone to stringing (cobwebbing) and doesn't lead to as nice a surface, is a bit soft for nice sanding.

I use all 3 of them, PETG and ABS for engine bay, PLA for desktop toys, one off jigs or indoor use. PETG gets nicer for big hollow prints than ABS (airbox or indicator pods were printed in ABS). I also use more specialized filaments (soft filaflex, or bronze loaded PLA...)

[Paul Aspden (MoFast)]

1 hour ago, Chris Broster - Bristol & Bath AO said:

Amazing! Thanks Paul

no problem

[BenD]

I've found abs the most rewarding. It's a nightmare to get right but when it is its amazing 

[Chris Broster]

1 hour ago, EBD Engineering said:

I've found abs the most rewarding. It's a nightmare to get right but when it is its amazing 

Any top tips for ABS? Hoe does it differ from PLA or PETG?

[nice_guy]

8 minutes ago, Chris Broster - Bristol & Bath AO said:

Any top tips for ABS? Hoe does it differ from PLA or PETG?

 

It reeks when printing, needs 100°c + bed temp and an enclosed printer. It's tougher once printed, but also hard to print, because it has a bit thermal expansion, so as the part is printed it cools down, and warps ('lifting corners').

It was the first material to be printed, and fell into disgrace because of its younger sister, PETG. She's more supple, doesn't smell bad, prints WAYYYY easier.

PETG has also the same kind of comfort zone as abs regarding temperature, and is less brittle. And ABS is not foodsafe, petg can be.

PETG is also available in a lot more colours, including transluscent.

 

I still print some stuff in ABS because I have a lot left, but failures happen to me with abs (layer splitting). Failures do not happen to me with PLA or PETG.

 

Sanding ABS is easy, sanding petg is hard.

 

Both my airbox and indicators pod were printed in PETG, after finding no way to achieve a satisfying part (layer splitting on both)

ABS is notoriously hard to print for big hollow parts.

[Chris Broster]

@nice_guy many thanks, really helpful.  I have a roll of translucent red PETG that I am learning with before aiming to print my Vel Stacks.

[nice_guy]

1 minute ago, Chris Broster - Bristol & Bath AO said:

@nice_guy many thanks, really helpful.  I have a roll of translucent red PETG that I am learning with before aiming to print my Vel Stacks.

 

PETG is hygroscopic. If it bubbles and farts during print, it's due to spend a boit of time in the oven (60-70°)

 

Stacks are likely to turn out OK in abs (i.e : you may get a chance to have them right at some point), no sharp angle, and revolution thingy, retraction doesn't have a weak sport to strike, but PETG will work as well.

 

Transluscent PETG : 

 

 

ABS :  

 

ABS Sands easier, but surface finish was the same, if showing more because translucent petg.

 

PETG :  (a bit of hairy scrap where the print head travels in the air)

 

ABS : 

 

These are not easy parts by any mean, they are big (130 to 190mm tall), thin, hollow, that's a recipe for disaster, but despite my efforts no way with ABS, and internal constraints where it did not split did stay, so... And the pod will be primed and painted, the airbox has been assembled and wrapped in CF, so 0.2 layer and dimensions / toughness way more important than shiny surface finish, though you get nice matte finish with ABS. But there is more than meets the eye.

[Chris Broster]

15 hours ago, nice_guy said:

But there is more than meets the eye.

How many times do we see beautiful things that don't perform and ugly that does! The art is reach the happy balance of both....

 

Loving that shocking green PETG!

[nice_guy]

4 minutes ago, Chris Broster - Bristol & Bath AO said:

How many times do we see beautiful things that don't perform and ugly that does! The art is reach the happy balance of both....

 

 

I meant that the lines show way more on shiny transluscent petg, one may see the infill pattern through too, than on matte ABS. It's like machining : shiny doesn't mean flat. Surface aspect is paramount in some parts (pokemons, desktop ornaments, or the silly multigauge), but if you prime and paint you'll sand anyway, and I painted the face of the gauge with a couple of faint licks of black paint, lines disappeared at no effort. 

 

For the airbox, I needed a bit of speed (60-80 meters of filament per part) AND a rough finish for the cf wrap to cling on, so I sanded with 60 grit perpendicular to the layer lines to get good epoxy resin bond. It's incredibly soft inside, damn tough and 300 ish grams for the whole airbox. I could have done it fully printed, at filament expense, would have been heavier and less solid.

 

Printing is an incredible tool, but sometimes it's better to use several methods. Like you can build a workbench only with wood, dowel, mortises, or use screws.

Same story for airbox or pod, I could have printed pods in color matching petg or abs, with .08 layers to get the finished part out of the printer, but it would have UV aged differently from the paint, and a color match would have been impossible. Sand, prime and paint faster and easier.

 

The good thing is that I'll print 'n' paint several pods, so that I have spares !

 

But ABS is the plastic we all know, sands well, petg is more pliable foodsafe container type, and sands less well (gunks a bit more the paper).

 

 

 

 

4 minutes ago, Chris Broster - Bristol & Bath AO said:

Loving that shocking green PETG!

 

I swear it looked black on amazon... (I tend to print rather monochrome, or cheap regardless of for jigs. Pigments change the properties, transluscent natural petg has a funny aspect, but is the nicest I've used). I used the green petg also for Air duct elbows and conical filter mount, it's concealed under nose cone, and way thicker than the airbox, no carbon fiber.

 

Something you can do (but I didn't because of internal stress within the part that led to layer split, is friction welding. 30mm bit of filament in a dremel chuck, max speed, and use the rotating filament a bit like a welding stick, the friction when touching the part melts the filament and you can repair, but the part split because of internal stress. You can relax the stress in oven but you lose dimensional accuracy, so ABS in this case (large thin big parts) didn't work for me.