Various Items on 3D printing

[m.marino]

Hello Folks,

I have been running two MK2S Prusa's for over a year now and they are now upgraded to the MK2.5S. The expense is worth it in my view and will be buying some MK3S's shortly for business production. The items that I find interesting is that so many of the 3D printing world does NOT take into account the tolerances of the plastic that is being extruded, Now for organic and non engineering parts you can get away with that. The moment you step into anything that has tolerances you really have to pay attention to what your expansion/contraction ratios are for a given plastic.

Has anyone else run across this type of issue?

Michael

[cropwell]

I have, I use ABS and when I print a hole, it is always smaller than designed. Where it is critical, I run a drill or reamer through. There may be guidelines for the spreading of the extrusion, but I find it easier to design out criticality of dimensions.

[magicniner]

I measure filament.
My printer makes parts absolutely predictably 0.15 past the edge of the model, both internal and external, allowing me to compensate precisely and make on size parts.

[Doddy]

Just a curve-ball... the resin printers (and I'm thinking the Anycubic in particular) are becoming rather affordable and offer quality (and dimensional accuracy) far beyond what my fdm machines has achieved. Build platform size is the compromise, as well as buggeration in post processing but its impressed the hell out of me. There are some limitations particularly for "engineering" designs (rather than organic modelling) but they are at a price that makes them interesting.

Hint: I managed to print modelled internal separate M3 tapped holes in a printed enclosure (4 in each of 3 enclosures) that each worked flawlessly without any post-processing beyond UV curing. Presentation of the model is almost presentable (this is the area I'm concentrating on)

[cropwell]

I measure filament.
My printer makes parts absolutely predictably 0.15 past the edge of the model, both internal and external, allowing me to compensate precisely and make on size parts.

Measure ? Length? Nick, how does this work?

I presume you mean diameter to be within spec. I also presume that your spreading figure is 0.15mm and is independent of the model X and Y dimensions.

Cheers, Rob-T

[magicniner]

Measure ? Length? Nick, how does this work?

I presume you mean diameter to be within spec. I also presume that your spreading figure is 0.15mm and is independent of the model X and Y dimensions.

Cheers, Rob-T

Rob,
Yes, the filament is rarely bang on size but the slicer assumes you gave it a precise diameter for volume calculation so I correct for variation in filament OD.
Bang on with "Spread" too ;-)

[cropwell]

Nick,

It may be that the slicer I use is just too vanilla for the niceties of compensation for filament diameter. I use Makerbot slicer, an old version as the new one wants me to log on and asks me awkward questions about my Makerbot machine, which is a Wanhao 4DS. I think I may have a look at Cura, which I use for turning jpegs into lithophanes etc...

However, for what I do, accuracy is not so important.

Rob

[m.marino]

Yeah measuring the filament is something that gets done on all incoming spools as they vary. SLA/DLP is getting down in price point but I am waiting for SLA1 as they have been doing a lot of work to make it work with as many resins as possible and i have clients in different fields who have interest.