3D printer uses

[thin-woodsman]

does it cut on size with the router? you should be able to get better than .037", however it'll probably never be dead nuts. I generally accept that if I want positive clearance off the build plate, I should go +0.010" on diameters, or print more tightly and hand ream them out with a drill or scraper blade.

That's a good question - whether the accuracy is inherent in the mechanism (ball-screw linear rails, if I recall right) or specific to the print head (extrusion)/slicer. I haven't tried the other fuctions yet, but I did determine that the features of the printed part are being *located* correctly, they are just of inconsistent size. So I'm not worried about the accuracy of the machine. I'm working on a final mod to the print head, then have to permanently wire up the breadboarded ESP32-CAM/DHT11 sensor and I'll be good to go. Should know whether the problems are reduced or fixed in a few days. Kinda excited to see how the inline filament drier works out, actually.

[nickel-city-fab]

I have been pondering buying a 3d printer but I can't decide if I have enough need for one. Most people seem to print out figurines, toys etc. as their main use but that isn't anything I would do. Is there a valid shop use for one. I have a few ideas but not enough to warrant one.

One of the earliest users that I heard of, was using it to print out long-obsolete Harley motorcycle parts. The kind that cost a fortune if you can even find them. The 3D prints were then used as patterns to cast actual replacement parts in iron and alloy. They have a mark on them to show that they are not originals. His first product was a set of the raw casting for the "Knuckle head" heads. Castings were $750 ea (back in the 1990's) which is a good deal because an original will set you back a few thousand $$$. There are also repro carburetor castings, tractor parts, etc etc. So yes, it can be lucrative in connection with a foundry and the right customers.

Making otherwise unobtainable parts, at least somewhat obtainable for the restoration crowd.

[loose nut]

Actually one of the things I want to do is to make patterns for casting. One of my friends has a small home foundry and is very good at casting AL and brass/bronze. I know another guy doing cast iron in his garage. The ability to print out brackets, sprockets and gears for low load limited use projects is another plus.I just hope the learning curve isn't to bad.

[thin-woodsman]

just hope the learning curve isn't to bad.

It's about a month of real learning, most of which is learning the effects of various slicer settings (for Cura, see https://support.ultimaker.com/hc/en-...Print-settings for a list of what is configurable). After that is apparently a lifetime of mods and tweaking. If you're not worried about surface finish, then your big concern is mostly going to be the optimal speed settings for the filament you want to use.

If you already know CAD, then you just have to learn about what works on an extrusion machine (e.g. avoid overhangs and curved surfaces, design for supports or rafts, etc).

[epicfail48]

I just hope the learning curve isn't to bad.

It isnt horrible, but dont believe anybody who uses adjectives like "easy" to describe it, or tries to tell you youll have perfect prints in an hour or two. Those people are like the career machinists who tell the new hires theyll be taking perfectly finished and tight-tolerance parts off the mill by the end of their first shift. Liars, in other words.

Honestly, learning how to use a 3d printer is very similar to learning how to use a mill. Doesnt take long to make a finished part, but it takes a lot longer to learn how to make a finished part, what parameters you need to tweak for best results, how to identify specific problems and correct them, and this is all after you learn how to set up the machine. It wont take you a lifetime to master of course, but its going to be a few weeks worth of experimenting to try to figure things out. Again, its not horrible in the least, if you know how to weld youve already gone through a learning process thats several orders of magnitude more arduous, but if you go into it expecting an easy, "press a button and get perfect results with no effort required", youll end up rapidly disillusioned with the process

On a less doom and gloom note, meet Benchy, your new best friend: http://www.3dbenchy.com/
Be prepared to use your entire first roll of filament just printing plastic boats, trying to learn what parameters to mess with for best results. Also, check out this guys channel: https://www.youtube.com/channel/UCbg...ikmtoLqtpc59Bw
Personally, i dont know of anybody better at explaining the basics of 3d printing for a newcomer, his videos are well worth spending some time in

[loose nut]

Well I spent 30 years doing "manual additive manufacturing" AKA: welding so I get your point. I have been doing CAD for many years so that isn't a problem and I downloaded Cura and have been playing with it so I can at least get some familiarization with it's operation but that isn't the same as actually printing stuff.I've also been watching everything I can on YouTube including Teaching Tech. CHEP on YT is also really good especially about Cura.Still not the same as doing it. I'm taking a positive outlook with this, I've already ordered spares, tools and some upgrade parts that have been recommended on many videos.even though my printer won't show up for several weeks, Covid shipping mess.

[Stu]

The Ender3 default settings for Cura are pretty good and work well for most prints. The only ones I mess with are skirt, brim and raft for adhesion and Infill percentage and wall line count for strength. I've found changing too many things at once can take you down the rabbit hole.

[thin-woodsman]

changing too many things at once can take you down the rabbit hole.

boy does it ever

With an new model/filament combo, you really have to watch the first couple of layers as they print, to make sure bed adhesion is suitable and the filament is doing anything stupid. It's very tempting at those early stages to abort, tweak a setting, and start over without making a note of what you've gone.

I've taken go keeping my Cura projects in a git repo so that I can save them when I have a definite improvement, and roll back to that improvement when I have lost that breadcrumb trail back to a working print.

[loose nut]

I know what the brim and rafts are for but what is the skirt for???

Doesn't seem to have any purpose.

[Mike Amick]

Sometimes the hot end isn't totally primed so it takes a while (5-10 secs) for the filament to actually come out so the skirt just gets the printer printing properly
before it starts on the important part. You're right, it has little to do with helping your object to stick.

Also if your lucky enough your printer will support baby steps which allow you to adjust the head up or down in .1mm steps while it is printing the skirt.
So it lets you fine tune the distance from the bed .. to get the best first layer.

[loose nut]

I've been playing around with Cura and it is doing something weird. I exported the barrel model of my model as an STL file and then opened it in cura. Everything looks good but the rifling ins't there. I also made an STl of the same barrel but only a 1 1/2" long section. In cura this model has the rifling but the outside is a course polygon about 10 or 12 sides instead of being round????? Any ideas, they are the same model except for the length.

[epicfail48]

I've been playing around with Cura and it is doing something weird. I exported the barrel model of my model as an STL file and then opened it in cura. Everything looks good but the rifling ins't there. I also made an STl of the same barrel but only a 1 1/2" long section. In cura this model has the rifling but the outside is a course polygon about 10 or 12 sides instead of being round????? Any ideas, they are the same model except for the length.

Certain features might be too small for the printer to actually print, so the slicer omits them. Usually you see that happen with things like walls that are thinner than the nozzle size, but it crops up other times as well. Im guessing that the rifling in your model is just getting caught as an unprintable feature. If memory serves theres a setting in cura called "print thin walls", you might try ticking that box and seeing what happens.

About the polygonal outside, could be one of 2 things. Could be Cura displaying a low-poly render during the placement stage to ease up processing needs, could also be that when the STL file was exported by whatever software you used, it wasnt done at a high enough resolution. Fusion 360 i know will let you choose how much refinement an exported STL file has, set it too low and you get that polygonal look

[elf]

Switch to PrusaSlicer

[loose nut]

Prusa... Prusa ...we don't need no stinkin' Prusa

Well maybe???

I don't understand why the rifling Is there on the short section but not the full length version, it is the same model

[loose nut]

OK I went back into the CAD program and made some adjustments in the STL export settings and the polygonal problem is gone, the lack of rifling on the full length barrel is still missing but is on the short section of the same model.