Bluewing

I did say it was a lazy design choice. And change gears a mostly made as solid gears. You very seldom see spoke designs. It has to do with casting/machine time costs. So, solid gears are what I think about with change gears. The gears are still cheap to print and they only took a good afternoon to print all 4 gears and the job is done. And the post is about the weird crappy finish I got with GeeeTech PETG. And the simple nozzle swap solving the problem. And at this point, I just want to burn up this spool to just get rid of it. I won’t buy this brand again.

Turned out the real design sticker was that I needed a 16mm keyed center hole to fit the banjo shafts. And while 16mm hole just barely fits on a mod 1 20T gear, the 4mm key needed does not. I ended up modeling the 20T and 80T gears as one piece and the single 20T gear needed to be designed with a solid 30mm round attached to it to have some place for the drive key to go.

The upside to doing it how I did things meant that yesterday I used those 3D printed gears as made to do the lathe job I needed to do, burnishing a section of shaft in my lathe. Sometimes you just gotta go for it and hope it works out. I might even reprint them with a better PETG brand like DeepLee or better yet, MatterHackers and make them with 4 or 5 perimeters and 6 top and bottom layers with 80% gyroid infill. I have both on hand. For the few times I might need a .0025" per rev feed, they might well last for years. If I find a #2 and #6 pair of used gear cutters for cheap, I might buy them and machine a set from steel. But even decent gear cutters are stupid expensive. And if I don’t have a customer to bill the expense out to, it’s probably not worth thinking about.

I seldom use a .40mm nozzle much anymore since I mostly do functional prints like these gears. I have found the .60mm nozzle is a good compromise for speed in printing, better strength, and good accuracy.

Interestingly enough, a .40mm will print nearly or as fast as a .60mm nozzle on Bambu printer in general. This because Bambu optimizes their slicer setting for the .40mm nozzle. What it does give up a bit is between layer strength. This is due to to the smaller contact area difference between layers. I can get the same strength with 2 perimeters using a .60mm that would take 3 perimeters with a .40mm nozzle.

Part lazy design choice and part running these gears for a few minutes at speed to observe real world function. Spoked FDM plastic gears probably would not run long enough at 500rpms and there is no soft start on a lathe. And since most of the strength with FDM printed items lies in the skin of the part, removing half the skin would reduce the rigidity.

Been there done that. Didn’t work. It did print the calibration print just fine. It just sucks when I try and print these gears.

I need to know if the gear train will fit on the banjo of the lathe first. I might run the plastic just to see how long PETG might last. If I want metal change gears, I will either spring for the 100+ dollars needed to buy the proper gears. Or I will spend $60 for the proper cutter and cut my own gears. But I need to be sure they will fit first.

Dryer didn’t do squat to make a difference. The filament was at a steady 14Rh for several days for both nozzles. The only change that made a difference that made a difference was the nozzle swap.

Purple “School Glue” is all you need. It’s cheap and if you work in an elementary school, free for the bending over and picking it up. I’ve got a life time supply from teaching for a mere 4 years.

Lubrication is kind of an issue. You want to oils over grease. And only a thin coating. You will find that lubricated rods and rails attract dust. A lot of dust with kids and pets. And that dust is VERY abrasive and will chew up the seals on you bearings unless you are constantly wiping and relubing. So, this is a time when less is more.

I use a SuperLube silicone grease to fill the bearings before assembling them onto the rods for my Mk3S. They have wiper seals that are meant to wipe the linear rods as they move and hold the grease in. I never oil those rods. The dust they attract will destroy those wiper seals in short order. I do, however wipe the rods with a dry paper towel before I print. In the 8 years I have owned the machine, I have replaced the bearings just once after about 4 years.

The little Bambu A1 Mini I have has open bearings on their linear rails and rods. Those require wiping clean and relubing with a special high tack oil on a scheduled basis. And yes, they are filthy when I clean them.

Excuse me? LOL!

Seriously, as someone using an old laptop as my home server, I’m VERY impressed by your skills and determination. You are amazing.

Which reminds me, I have a spare 250gig SSD I should install in my 500gig server…

A quick and dirty workaround is to print a thicker first layer. It can get you through until you figure out the real cause.

Qidi printers are known to have issues with warped beds on occasions. So that’s a possibility. Their mesh leveling is not always the best either. That’s been a firmware issue in the past with the xmax-3. Though that should be fixed by now. are you running the latest firmware?

In northern Minnesota the humidity can vary greatly. Last weekend it was 90+% outside. While indoors the air conditioning had the house around 50%. And by winter time, the outdoor humidity can be as low 20% and indoors depending on heat source, around 30% to 40%.

I finally broke down and bought a dedicated filament dryer, Sunlu S2, because my trusty old food dehydrator died the week before. I do dry PETG when it tells me to, and I always dry TPU. But never PLA.

Just for fun, after I was done drying and printing some PETG, I dropped a mostly used spool of Sunlu white PLA into the dryer, (first time ever for PLA). That spool has been laying around in the open for at least 6 months now. The humidistat on the dryer showed 30%. I let it dry down to 20% and ran a test cube. No difference in print quality that I can see.

Despite the fact that I dislike the evil turn Bambu has taken, my A1 mini is a good piece of kit. Running it in LAN mode and with Orca Slicer it’s dependable and produces very good results.

My trusty Prusa Mk3s is the printer your momma says we have at home. Rock solid, dependable, and easily and cheaply repairable. Its biggest sin these days is that it is slow. But I was fairly easily able to run klipper with an old RPi 4 that doubled my print speed with adding an accelerometer and calibrating the input shaping. And it can be done for under $100.

Hey, it’s cool. I got that tee shirt too.

How many is multiple? I want to know because this is important information to me. But I also want to be unbiased in my evaluation of risk.Your link is the first I have heard of the mini having issues. And they only list 1 mini, all the rest are A1 machines. I cannot find in my searching for any other mini that has melted or caught fire. It certainly does not show up in any other 3D printing forum I have been in except here this one time for one machine.

I’m in the US and on 120V power. Which only provides a quarter of the power vs the 240V mains used in Europe, to the heat bed making it far less likely to happen. Plus, I use a surge protector for it. Nor do I run overnight prints because I don’t trust ANY 3D printer. And that includes my Prusa. I’m no Bambu fanboi, but one reported case of a mini catching fire is statistically irrelevant.

That said, there is an inherently greater risk of fire with certain types of hobbies. And 3D printing is one of them.

I’m giving it a go too. I got some noticeable warping on my first try. Shows promise, though the implantation of Orca seems a bit unstable for me running in Kinnonite. I intend to follow and test versions now and then.

I got tired of waiting for that and was going to buy the Qidi X-Smart-3, but I waited just a couple of months too long and had to settle for a an A1 Mini combo instead, and no it’s not connected to the cloud.

I do have to admit, I do like the AMS lite because it allows me to use every last gram of filament off of a spool and then auto switch to a new spool. But I did have issues with their software/firmware in the beginning. It damaged both of the plates I had within the first month. I had to wait for the next firmware update for the fix.

For PLA, any brand that has the blue you seek. PLA is not that complicated.

Ahh yes, the “make it so only Bezos and Musk can afford firearms for their minions” approach to gun control.

They actually have all the gun laws they need. They just don’t really bother to enforce them, and they enjoy just adding more useless laws on top of the pile they already have. They need to look good “thinking of the children” and pander to their voting base.

This time though, it’s about surveillance and right to repair things you bought and paid for everyone disguised as “gun control”. A slippery slope many gun owners have warned the rest of you about for years now.

Brands mean a lot less than people think. Most brands are just relabeled filaments. A couple phone calls and you to can have your own brand of filament. Nor are there aren’t that many make lines in the world. And the base stock comes from an even smaller handful of manufacturers.

I have yet to meet a filament that I couldn’t get to print decently, and I have a very low taste in filaments. The cheapest of the cheap! Some of them took extra effort, but in the end I got what I wanted from them.

Try setting the scarf steps to 1 and the Bridge Flow ratio to 1.5, (as low a 0 and as high as 2). Then under Speed uncheck the Slow Down for Overhangs and set the speed to 20mm/sec. This is often a good place to start and works well on my Bambu mini. For testing, I print an upside down box with a 50x50 cavity and a height of 8mm.

Prusa is a good choice if you are willing to spend the money. My Mk3s has been and will always be a tank to print with. These days the Core 1 is what you want from them. But multicolor printing is going to cost a noticeable amount more. If you set on multicolor prints, this is a hang up for many.

If you decide you can’t/won’t spend Prusa money, then maybe look a Qidi. A bit rougher around the edges, but seems to have decent hardware. They really lean into being able to print high temperature engineering filaments. My next printer will be the Q2 as soon as management, (Grandma), OKs the funds. I probably won’t get their AMS because I already have a Bambu A1 mini with AMS lite. But Qidi has their own version of AMS that won’t set you back as much as Prusa will.

Not that it matters too much, but Prusa runs on Marlin firmware and Qidi runs on klipper. Marlin is more beginner-friendly, but klipper is a lot more adaptable and changeable in the hands of someone that knows what they want. While still being very approachable to beginners.

Isn’t amazing what slicers can do? There ain’t no guard rails where we’re going!

Ha! Years ago, I once spent nearly 2 whole days trying to unknowingly splice PLA and PETG together. All because I was an idiot and didn’t read the spool labels. I just assumed, with the obvious results and damage to my ego…

Always, always buy Gates belts. And belt tension is a real issue with CoreXY printers. And I consider the belts to be consumables that need to be replaced on a schedule. If you’ve been running those belts for 2 years, replacing them will make you happy again.

Chamber pressures for the 5.56 Nato is 58,000psi. And 9mm is 35,000psi. It takes a pretty good piece of pipe to contain those pressures. Your average seam welded pipe is around 4000 to maybe 10,000 psi.

Zip guns made from hardware store pipe are just barely good enough to contain a low pressure 12ga bird shot shell.

It’s more that stainless steel is cheaper than brass these days.