What's your opinion on filament size?

What’s your opinion on filament size? Is there trend towards either one and if so what could be driving it? Machines? Manufacturers? I’m interested as had assumed it was personal preference until recently. We use 1.75, or will do once the machine works! Are there performance or application differences?

After using both, I prefer 1.75mm but there difference is really minor. NEVER buy it unspooled though.

I’m not convinced that the future of reprap is filament. I see so many posts of failed prints that I seriously doubt the economics for commercial applications. Reprocessing of flash and scraped parts is common in injection moulding, why not apply the same principals to additive manufacturing. There is a huge variety of materials already available in granular form, you can top up a hopper on the fly and it should be possible to deposit more material faster.

Well, that’s a hard one to answer definitely, in part it depends on your printer and in particular your extruder/hot end combo. I’ve used both 1.75 and 3mm and I can’t speak for any noticeable difference in print quality. However, if you are using a direct drive cold end, there’s a compelling argument to go for 1.75 as your volume of extrudiate for a given # steps will be lower thus you’ll have a lower minimum extrusion rate. Conversely, if you’re using a geared cold end, 3mm may be a better option as versions like the wades extruder have a 1:5 ratio so top end extrusion rate will be limited if you use 1.75mm.

@Tim_Rastall , have you noticed either working better in a Bowden setup?

The only real argument I’ve seen in favour of 1.75mm is retraction.

I think we’ll be using filament fit under foreseeable future unless sla hobby printers really take off. I like the idea of pellets purely on cost