I’ve seen hydraulic cylinders up to a mere 150 tons, but they both used vee threads. But those cylinders can had far,far bigger than that. That would be a very good application of buttress threads. Much like the balls screws on a punch press. Lots of force in one direction.

Surgery is not required. You only need to 5% smater than the tool you are using.

A properly fitted straight bladed screw driver will fit snugly in the slot along it’s entire length. This offers more than the ‘two points of contact’ that your poorly chosen screw driver does. Add a hollow ground blade, they get an amazingly powerful grip. Learn to fit a screw driver properly and you will seldom have a problem with a slotted screw. As toolmakers and high end gunsmiths know and you don’t.

Of course, if you have neither the skill or enough ambition to be bothered to ensure the tool fits the fasteners correctly, you probably should choose a more foolproof tool and fastener.

At that diameter, I would probably recommend a bottle cap thread. It’s a rounded profile that is easy to print.

Never, ever, ever do more effort than is required.

Under Quality – Layer Height – First Layer Height. Adjust the layer height as needed. Generally speaking, your first layer should be no less than half the nozzle diameter. So, a .40mm nozzle first layer height should be .20mm. Thought for larger beds, you may wish to increase the first layer height a bit to help with bed adhesion over a wide area.

My first inclination is to got to Quality – Walls and surfaces – Avoid Crossing walls and check that box. See what happens when you print your Benchy.

If you still have issues, go to you filament settings for the filament you are printing with, (the little pencil to the right of the filament box), make sure you have the Advanced slider on, click on the Settings Overrides tab and check the Length, Z-hop height, On surfaces, (select All Surfaces in the drop down box to the right), Retraction speed, (the default is fine), the De-retraction speed, (set to zero), Travel Distance threshold, Retract on layer change, Wipe while retracting, and wipe distance.

This is a start.

Having single pointed 3"-4 Buttress threads on a manual lathe for punch presses more than once and hand grinding the tool bit from 1/2" x 1" HSS, I still have some PTSD over that thread form. But hey, if you are looking to make breaching for a 16" Navel Rifle, it’s really the only game in town…

As a toolmaker, I have seen Buttress threads used in only 3 places. Large artillery breaching, punch press ball screws, and VERY high end, (read expensive), machinist clamps. I own a pair I picked up at an auction 30 years ago in a bucket of “junk”. I think they were made by another machinist for personal use.

Edit to add: Buttress threads are directional. They can be either left or right. The choice being totally dependent the direction of the force applied to the threads. The perpendicular edge is the strong part. And the direction must always be called out.

Meh, slotted screws get used a lot. What most people don’t get is the reason they have problems with slotted screw heads is because they don’t use a proper fitted driver that fits the slot correctly. You always try to use an undersized driver and are then shocked to discover you have problems.

Don’t blame the tool for your poor choices. Use the properly fitted tool for the job.

Number series machine screws get their designations from wire gage sizes that they were made from. Which traces back to several different British thread systems waaayyy back in the day. While there is no hard and fast rule, the number series screws are sometimes referred to as ‘Machine screws’ while fractional series fasteners are referred to as ‘Bolts’. No one knows why, and Whitworth is dead. (Toolmaker humor).

All actual diameters of screws are a bit under nominal for external and a bit over size nominal for internal. This is the clearance needed to make a screw and nut fit together. This all applies to metric thread fasteners also. Thread fit classes are a story for another day.

I have used rpms, AppImages, Flatpaks, and source. I have even used a snap or two when I had no other choice.

If you can’t work with them all, can you even say you Linux Bro?

Kinky

A custom vee thread screw and nut, as you have done, is easily done in the Thread Profile workbench. As a workbench, I don’t think it’s all that popular, at least it’s not going to be as popular as the Fasteners workbench.

Other than creating the head of the screw and the shape of your nut as a separate sketch and pad, you can simply fill a couple of boxes with your own numbers, click the helix button, then click the Additive Loft button, both provided in the workbench toolbar, wait for the threads to generate, and it’s done. And it’s parametric.

I recommend checking it out if you’re using FreeCAD.

Prusa Core One with MMU or Qidi Plus 4 and the Qidi Box. The Qidi Box is at the pre-sale point now. They have been taking things slow with their AMS unit. Either printer is affordable and in the size range you want. Both are corexy, Qidi run Klipper and Prusa runs Marlin firmware. Both brands have heated enclosures to make printing fussier filaments easier. And PETG definitely benefits from that.

If I was starting over and wanted a larger printer, it would be a coin flip choice between those 2 printers.

I got caught the same way with an impulse buy of an A1 Mini/AMS Lite last fall. I’m still running the 1.04 firmware and Orca Slicer on LAN mode for several months now with little issue, (sometimes it drops the LAN connection on start up and needs to be manually reconnected). If you do upgrade to the evil firmware and don’t like it, Bambu currently does let you downgrade to an older firmware and you can go back to a safer firmware.

Most of the Bambu users I have interacted with don’t care because they want to run their printer from the Bambu Handy app. And if you want to use the Handy app, you can’t use LAN mode because you need to be logged in. But I don’t like using my phone for such things anyway.

Meh, you can get used and working benchtop electric heat treat furnaces for around $500US that would be suitable for home use.

Honestly, my second choice from the Core One would be the Qidi Plus 4. I wanted the X-Smart 3 180³ sized printer as a second machine. But it was discontinued before I got off my butt to buy something. (I ended up with a Bambu mini combo as an impulse buy). But if I was starting over with my first printer, I would seriously consider a Qidi machine.

As a bit of Prusa fan boi myself, I too would recommend the Core One over the Mk4s at this moment. It’s a matter of “Buy once. Cry once.” Cheap often costs more in the long run.

When you are facing a 30 hour print or a long project, a bit extra speed is not only nice but helpful. Plus the heated enclosure can provide access to more engineering grade filaments. While you might not need to print nylon or ABS every day, you will probably find you are going to want to at some point a bit of those types for a project or two. And I believe the Core One also has filtered exhaust air to control nasty fumes that FDM printing can cause, (yes, even PLA has particulates that won’t kill you immediately, but they ain’t good for you either long term).

Personally, I find the MMU to be a god awful design mess. A rat’s nest of loose tubes and spools of filaments, but it does work. I might consider the Box Turtle over the MMU just for the neatness of the design. I find the multi-filament units, cool for very little color printing I do, but it’s the ability to use up spools that don’t have enough left one them to complete a print by switching to a different spool that can finish the print automatically to be far more valuable. It’s cut down my clutter of mostly used spools to near zero. I paid for all that kilo, I’m bloody gonna use it all dammit.

The problem with new PEI sheets everyone sells, is that they make the PEI so thin that it wears out so fast. It’s like when they go to cut a slice off the PEI tree, they damn near miss the whole tree. And the popularity of textured sheets doesn’t help either.

I have a smooth PEI sheet that came with my Prusa Mk3s 6 years ago. It has 1000’s of hours of print times on it. After about 4 years of heavy use, it just wasn’t much good anymore. And I didn’t feel like buying a new sheet, so I took the chance and very lightly hit with some 1000grit wet/dry sandpaper to renew the surface. It now holds better than when it was new. And I can probably sand it again if it ever needs it. But new PEI plates aren’t coated half as thick either. So my Bambu plates will have to be replaced at some point.

They stated 250C was for annealing to final product. That’s a temperature any bog standard toaster oven or kitchen oven can do. Sadly, they said nothing I saw about actual extrusion temps.

FDM printing ABS/ASA is far easier and safer than resin printing since most CoreXY printers are enclosed these days. A simple fan and ether venting to the outside world or through activated charcoal air filters is a relatively simple procedure. Printers with all of that filtration are easily purchased these days. Even vapor smoothing can be done outdoors if it’s warm enough.