HewlettHackard @ HewlettHackard @lemmy.ca

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Joined

2 yr. ago

Well, that’s the key… “still being worth getting”. The $100 special Ender 3 at monoprice probably isn’t worth getting for many people because of the frustration involved.

And so in reality the best answer for the question depends on each individual’s time-money tradeoffs.

Thanks for this. I was worried about how some of my filament was wet in a very dry winter, but this explains why it broke in the spots it broke.

Does this apply to printed parts that are under load as well, then, or are they safer because they don’t get bent/unbent the way filament does (assuming you aren’t trying to do a living hinge or other flexing design)?

On the other hand, an experienced driver might forget it’s there since they never use it. Add in a high-stress situation, and you get a problem.

Now imagine you’ve been driving the Tesla for a long time and don’t ever use the manual release because you’re not supposed to so you don’t mess up the window. And then imagine you’re in a high-stress situation. That’s how having an unmarked backup can fail.

Plus, that handle doesn’t even look like a normal handle - I have never see a car where you pull up to exit instead of sideways away from the door.

On the other hand, if you never use the mechanical release and have spent a long time only driving your Tesla, wouldn’t it be possible to forget it’s there while in a high-stress situation?

Lower cost products sometimes have more variability and maybe you got a good one from the factory.

This is an interesting suggestion. The unsupported overhangs at the transitions are part of why I don’t like using gyroid infill; I don’t need my infill to introduce new potential problems in a print. That said, reducing layer height would be disappointing in most cases because I also don’t need my infill to slow the print down (and with some filaments, it’s also pretty visible), so the other suggestions might be more difficult-but better-ideas. It’d be cool to try a patch someone submits.

Did they describe the types of user error that could cause this?

Or too thin (much less than one layer height)?

It’s not necessarily fluff; features do matter, but which ones matter and how much they matter is complicated. Do you want to tinker with a printer, or do you just want a tool that works?

If you want a tool, I recommend a Prusa or maybe a Bambu. My Prusa just does what I ask it to; I’ve done zero calibration, optimization, tweaking, etc. Cheaper printers often require understanding bed leveling, figuring out how to adjust them best, etc. or vary more copy-to-copy (so one Ender 3 might work great, while another might be a source of frustration) or require upgrades to really become enjoyable.

Do you have a budget? Or is it just about making sure you’re getting your money’s worth (so $2000 is fine if it’s 10x better than a $200 printer)?

Yup. My kid found the idea hilarious when I explained why I’d swiped a washable glue stick from the arts and crafts box.

It hangs on well, but also makes removal easier.

You could always try it…

I use PEI instead of glass and find that a thin layer of glue stick works great for helping sticky materials release.

Could you share some examples of what you’ve been able to create, and approximately how long they took?

Wow, thanks for the incredibly broad write up! That’s a crazy number of tools to try.

FreeCAD:

giving up as soon as any two edges’ fillets touch

I haven’t quite had that issue with FreeCAD; an ordinary corner works fine. Where I’ve had that issue is when the fillet is large relative to the edge sizes though, so there are definitely failure cases.

not working well if you don’t learn its definition of good design

This is so incredibly true. I’ve had to restart projects because I didn’t realize how I’d need to approach them to get FreeCAD to allow me to do what I wanted to do. That’s probably the biggest issue I have with it: you really have to know how it wants things done, and often you won’t learn that til you’ve tried, failed, and watched a couple YouTube videos from more experienced users. Fortunately, after a few projects I’ve gotten to the point where I can usually get relatively simple designs right the first time…but I have no doubt I’ll still sometimes have to start over or take big steps backward to change my approach to a problem.

Others have mentioned OpenSCAD and that’s what I started with years ago; it’s fine for simple things (or fractals/programmatically specified forms) but when designing something with more complexity I find it very difficult to manage, compared to just directly drawing what I want and then constraining it appropriately.

You’re right, 50%@70f (let’s say Texas indoor conditions) is 19%@100f, so you’re right that just heating is probably perfectly good.

You’d need a very sensitive filament to bother doing more. That said, if you did have a peltier with the cold side at 32f, you’d get 25%@70f or 9%@100f…which actually isn’t amazing since you still need to warm it up to 100f to get that 9%! Peltiers are inexpensive and I might still experiment with it one day, but…it doesn’t seem like a huge win.

I see. You have a huge delta-T there, which is unnecessary for keeping a filament box dry.

A couple sources say PA6 (a random moisture-sensitive filament) should be stored below 20% , or at 15% relative humidity. In a 66f/19c room temperature, that 15% RH would be a dew point of 17f/-8c according to dpcalc.org. In a 74f/23c room, 15% is a dew point of 23f/-5c; as you warm up the temperature further the dew point to achieve a particular RH increases (which is why we heat air to dry things).

Huh? Running it backward as a thermoelectric generator is low efficiency (Carnot limit) but the efficiency pumping heat from e.g. freezing to room temperature isn’t that awful. Picking some completely random model from DigiKey, if the hot side was at 27c/80f, and you wanted the cold side at 0c, 2.4 amps at about 7V (16.8W input power) would let you remove about 15W from the cold side with a deltaT of 30c (i.e. the cold side at -3c/27f) per the graphs on page 5. That’s a COP of about 0.9 for cooling. You’d need to remove about 30W from the hot side.

In practice, cooling the hot side is difficult so you might instead use the Th=50c graph, at which point 2.4A @ 8v (19.2W input power) would give 3-4W cooling power with the cold side at 0c, for a COP of about 0.18. But nowhere near your numbers.

If you put some decent thermal mass on the hot side and operated intermittently, as long as you drained the condensation, you could get closer to the Th=27c performance.

I don’t think the efficiency is a big deal; you’d only have to run the peltier intermittently (e.g. each time you open the box) as long as you can drain the condensation somehow and it’s otherwise well-sealed. I’ve idly pondered OPs idea myself and I think it’s not a terrible way to dry a box. You avoid the consumables or need to recharge your dessicant materials.

I’ve been really happy with the MK4 kit I built months ago. While I haven’t seen a Bambu in person, I’m pretty satisfied with the print speed and picked up an 0.6 nozzle in case I really want to print something bigger, faster.

I had seriously considered building a Voron Trident, but have no regrets about my decision to go with Prusa. It’s nice having a machine that didn’t require a bunch of tweaking; it was fun to build the kit but now it’s an appliance I don’t have to mess with; it’s almost like my Brother laser. I hit print, it prints*. (Asterisk because I have to clean the bed sometimes, occasionally I make a poor choice slicing and don’t add a support I needed, etc, but these aren’t printer-specific issues).

As far as bed-slinger vs coreXY, even Bambu recently released a new bed slinger, so I suspect the tradeoff is more complex than just “coreXY is better”. The whole “model flings around” just isn’t a problem I’ve seen in practice; maaaaaybe if you’re building exceptionally tall, thin structures that can’t be oriented properly it could matter but realistically most people are going to mostly print relatively small things. Even fast printers are slow; as soon as you use a printer you’ll realize that huge build volumes are absurd because big prints just take soooooooo loooooong even on fast machines. And there’s either upcoming support or existing support for bed-axis input shaping, since the slicer does know the amount of filament it’s extruding and can tell the firmware how much more the bed weighs as the print proceeds.

I don’t think Bambu printers are an unreasonable choice for people, but I think if Prusa is affordable to someone, their products are still a good choice.