3DPrinting

(Continued from https://lemmy.world/post/43278229 a few days ago...) So, I tried fully removable for the index, but that is impractical as far as the size, space, and complexity. I can't see a way of maintaining concentricity.

Next I tried making various hollow spaces where the main pawl slaps the index with every shift. I wondered if it would sound or feel any different, but no dice. Printed pawls (don't last long) sound very different. The index tooth shapes sound a little different, but messing with the spring preload makes more of a difference.

I spent way too long trying to get a side screw mount to clear the shift lever arm. It is super challenging to mess with two angled vectors pointed across a Cartesian coordinate system and then adding two rotational components of a round object while locating a screw head and square nut around a central shaft... and thinking about print orientation. I broke my rigid sketch based linear workflow to make that one happen. I had to model separate bodies, then use assemblies to layer the coordinate systems.

Then I decided to stop screwing around and simping for big hardware. Obviously the curved shape of the removable index is a printed spring. I guess I was passively thinking I needed to avoid that flexibility or loading. It took me rotating the side bolt from center-ish, to as high as possible before I saw a good way to limit deflection while keeping a snap fit. The fit is actually too good now. I need to make an easier way to remove the thing and alter a bit of geometry to make more removal clearance.

One of the problems with removal of the index from the body is that the pawls need to be in the highest gears to access the location where there is space to slide it out. This makes the screw retained version want to fly apart once the screw is removed. Then omg it is a pain in the ass to get the thing back together with the index back under the pawls. So to solve this, I made an extra index address at the very end where the pawls can park outside of the removable section. This works fantastic, but creates a new problem. That location will be blocked by the RD high side limit screw on the bike. I have a few ideas of how to remedy the issue, but I think the best one is to make a little barrel limit device that sits on the exposed section of the RD shift cable at the RD, between the clamp bolt and housing termination. That could be removed to give access without altering the RD/cable. Another way, but much more involved design, is to create a release mechanism into the barrel.

I've been wondering if I could somehow add a small amount of adjustment to the whole index by changing the distance between the barrel and central axle by a millimeter or so. I had been thinking of simple ways to create such a variance, but adding a bunch more complexity, it might be possible to add the ~3mm of extra shift cable travel needed to get the pawls past the RD limits without releasing the RD cable.

For the rear cassette, I have plenty of room between an 11 speed 11-28 that I typically ride and my spokes. I wish I could find HG 10t cogs or a 9t built into a lock ring. Alas it is easier to extend the big cog side. While I cannot make a regular cassette cog fit, I can easily create a dished carrier for mounting a small chainring at the spoke side. Pretty silly to me as I never even use the 28t, but it would be funny to joke about the marketing of ""12 speeds"" and how my chainring on the back is smaller than many mountain cassettes now. I have a bunch of 38-42t inner chainrings I could use.

On another tangent... all of the 3d printed brake hoods I have seen are hideous. Still, I wonder about TPE as a replacement for bar tape and maybe even hoods. What if it was more modular. What if it was made so that the print creates ribbon like strands and these are braided on the bars. What if nice bar tape equivalent could be removed without damage. What if it was washable. What if the whole road bike system is made to be serviceable piece meal instead of all or nothing.

Then it occurred to me today, with my index measurement tool I made, all anyone needs to do is measure and print their own tuned spacers between the cogs of the rear cassette and every combination is possible. That is the Occam's Razor of solutions. All the fuss and marketing boils down to the size of those little rings of plastic between the cogs.

Not an affiliate. No tracking links. Just a pretty video of my new printer I thought you guys might like. Leave me a comment if you want to say hi. Hosted on my own Peertube instance.

https://watch.makearmy.io/w/6grfSx3huFoJmGZABh1z9a

Had to make the cable pull measuring jig and get it repeatable. Then had to model the interior of the shifter to know where cable contacts the pulley in order to fully understand why the pulley is eccentric and not round. The only valid reference surface is the main pivot shaft and the cable housing stop location is blind.

Then it was a matter of understanding the pawls and their mechanics. This is the oddball 2012 SRAM Red 10 speed stuff that was unique from all the rest. It turns out that the pawls mechanism is designed for the 10 speed 0.120" index standard. On this system, that is around 15 degrees of rotation per index position.

My present 11spd Ultregra 6k8 stuff is very worn out but it pulls around 0.100" of cable and is more consistent than this SRAM Red in factory form, as measured.

I was thinking about burying an adaptor in my bottom bracket shell on my frame. I have space for it internally. However, actually fixing it in the index or barrel sounded more satisfying.

Someone else already made a replacement barrel model and shared it on printables/thingiverse. I printed it and measured it, but the metal index gears protrude into the cable path and disrupt the index at 5th gear. Plus, if you look up ~1.1mm stranded steel cables, they all have minimum pulley sizes that are even larger than the factory original. I've snapped cables inside the shifter with SRAM Red, so this is not my favorite method either.

While reverse engineering the pulley and mechanism, I noticed how it will all work by gravity without the springs holding tension. This counters the intuitive notion that the loads are too high or this is some kind of "tough" thing. It really is not. Almost all of the actual load comes from inside the pawls and how they slide around each other. The index gear is not loaded very much.

I went on a quest to see how much variance the pawls could handle. Like are all the shifters the same and only the barrel changes diameter. That does not appear to be the case. Each unit seems uniquely made. So I started messing with height differences and small off sets to see if I could alter the index pitch with the original pawls and find a combo that still worked with 11+ speeds.

I do not really care about the extra gear. Heck, I am more interested in running dirt cheap 8 speed cassettes and chains that last longer.

Yesterday I discovered the index trick that works. I ditched the gear tooth profile in favor of a more complex tapered and angled triangular ramp. This "tooth" profile works reliably.

Another challenge was print orientation for index tooth details. Printing on supports at a steep angle was the only way the definition was sharp enough. Today I managed to fix that using internal micro structures around each index position and added an assembled part for the spring retainer to get the print orientation optimised. This got me to actual measurable parts in the iterative regime, and it exceeded the accuracy of my mechanism replication jig.

I still want to make the thing removable in whole or part to replace the index without rebuilding the bike. In so doing, I will likely remove the requirement for the road shifting specific cable head, or any head at all. Judging by the wear on cheap prototyping PLA, this will likely last at least as long as a chain(×2)/cassette in printed form. If it can be removed in situ, that is a compromise I am willing to make in order to run any shift system combo or alternative gearing I choose. There is enough travel present to run 12 cogs at 10-speed pitch index, or 14 with 11-speed pitch. It is only a matter of rear clearance spacing... and a mor gearz iz betar disorder I guess. I have several ideas swirling at the moment for how to design an entirely new shifter made for 3d printing. A waffler stack, a bearing detent, or a star ratchet are all possible for a barrel assembly type design from scratch. The cooler option would be a cascading stage compliant mechanism that prints in place and pulls the cable forward instead of requiring rotation. Each index position is only 2.54mm for 11-speed.

I cannot eliminate or make claims about actual accuracy with my little excuse for metrology. I could certainly improve this one with a third iteration. Based on my measurements and comparisons, shifting is only around 5%-10% the same value each time even on factory stuff. I can shift a dozen times and get the same zeroed measured result when shifting back down. But every upshift, the result varies more. Some are clearly bad shifts but most are within a similar margin of precision. I am using ways inserts in the index measurement tool, with mechanisms to control backlash, and three point contact on an internal sled. I also made housing clamps to remove their flex from the equation. Chasing that one... gluing a housing into the ferrule caps would likely make a large difference in shifting performance, especially over time. Motion here has a very substantial effect.

Anyways, that is just my musing on my project so far. I have a 10 speed SRAM Red shifter with 12 speeds of index at an 11 speed pitch. All to avoid the $500+ "proper" (exploding) rear derailleur... again.

Not trying to flood printables and co with more AI but honestly curious.

I am a person that has no sense for aesthetics whatsoever. In a creative process even less so. This would help me out im some situations. All functional parts j do in freecad.

A thread about myminifactory I asked about some ai site examples to evaluate the model quality. For example, do they know how to avoid overhangs if possible etc.

It got downvoted.

For real: what are some tested ai generators for stl?

EDIT: people are dming me links because (I assume) they don't want to admit they are not completely against ai. That is a healthy atmosphere right there. I agree that ai is taking a bad path right now but the tool itself shouldn't be discarded as a whole. You people are acting like calculators are bad because they let your mind rot. My grandfather was one of those. Simple answers are almost always wrong or incomplete. Think!

With the recent adquisition what do you think will happen?

Hi all,

I'm doing an experiment with a cabinet for filament with a small dehumidifier in it. I can get it to sit at 35%, but not much lower. I've sealed the cabinet with foam tape, and dried most of the filament first.

Are there any tricks to help improve performance of the mini dehumidifier? Maybe adding more heat to the cabinet?

The goal would be to use Home Assistant and the humidity sensor to turn things on and off as needed.

Thanks!

I've been struggling with my K1 since Christmas. I bought it on sale for Black Friday and no matter who I contact at Creality, no one can tell me what replacement parts to order. K1 parts don't fit my printer. They want pictures to see what 'buckle' I have, because my serial number isn't enough information, but who wants to tear down a printer just to take pictures? Now my thermistor is broken (a leg weld just fell right off while I was fixing a clog), and I can't order a new one because what do I order? This printer doesn't take K1 parts. Every time I order something, it has to get shipped back. I'm annoyed and venting, but also trying to help anyone else considering a Creality printer. Don't do it. Their support is a joke and they take zero accountability.

I've added an image for help explaining the problem. These two JST connections are completely different, but both are supposed to be for the K1. And both of these listings are Creality Official:

Here's one and here's the other.

So I did some testing with greentec (high temp bio filament) and before i tried anything I did all the usual calibrations: 21 m3/s max flow; 1,005 flow factor; 99,73% xy and 100,27% z shrinkage; low to medium-high cooling; ...

due to the recommendation from the manufacturer i started with lowish bed temps of 47C, Nozzle temp of 217C, 1 slow layer, nocooling on first layer and a flow of 17 m3/s - prints without brims failed. ramped up the bedtemps to 65C - the same prints stuck well without brim. tried a larger, more infill multipart print: everything warped as if it was abs...

parts that printed well and behaved as intended:

• snap in place plugs / adjustable flow restrictors for ventilation holes in finnish sauna
• bakelite bed spacer holder (printerforants/micon+ formbot kit specific)
• fanshroud for my Ender3V3 (reprinted my upgraded one as petg was obviously starting to deform after 60h of use)

will try 75C bed, +5C nozzle temp, 16 m3/s, lower cooling 17% -> 7% turning it off if layertime is > 50s, force overhang cooling 100% -> 85% fan speed, 3 slow layers, and no cooling for the first two layers... maybe i'll add a brim as well, as failures are quite pricy when needing 350g and price/kg is 51,3EUR

do you think it is a good plan or are these too many changes at once? i'm not sure if lowering or hightening the nozzle temp, will be better, any idea?

do you have any experience with greentec on unenclosed bedslingers or otherwise?

Today, we are releasing the full CAD files for the CORE One and CORE One L frames.

There seems to be a custom licence.

The Restriction: You cannot commercially exploit the design files (selling the product or remixes) without a separate agreement.

The Protection: It includes an explicit patent license grant, protection against AI data mining, and a codified Right-to-Repair.

Most of the linked article is about the licence.

There's been a lot of talk about Prusa turning evil. Maybe it's a good step back.

Continuation from this Post: https://lemmy.blahaj.zone/post/36954883

After many of you Suggested that Heat could be a Potential Solution to Regaining Sanded PETG Colour, I got myself a Heatgun Capable of 600c°.

While it did Improve the Colouring, Especially for Darker parts it wasn't Enough. To be a bit more Specific, Both Green and Yellow Parts Fully did regain the Colour Red Improved a Lot, but not quite Satisfactory And Black did make a Difference, but its not Nearly Close enough, being a Matte Dark Gray instead of... Black

I've noticed that the Black only did regain its true Colour once actively Melting and Warping which doesn't help... Otherwise its a Light/Dark Gray Matte Black.

So I think the Heatgun Method doesn't quite hold for Dark Parts. What other Methods of Regaining Colour are there?

I do still have MEK that I could Try. I also Heard that Clearcoat could Work and that there are 3D Printing Specific Brands, should I give that a Shot?

I've got a roll of Blue Geeetech ABS+ that starts to smoke when it's still so cold that its layer adhesion is terrible, and just burns in the nozzle whenever it's not actively extruding if the temperature is high enough that it sticks to itself. Obviously, this is bad, and it sooted up a nozzle so badly that it needed to be replaced before I gave up on it.

So far, the only ideas I've had are just to leave it on a shelf indefinitely or to landfill it, neither of which are a great use of nearly a kilo of plastic.

I'm looking into getting a new printer, and I'm interested in building my own. I know Voron 2.4 and Trident are the obvious ones to look at. But I can't help but notice they are both 3+ year old printers. Considering how much the industry has grown in the last few years, it got second guessing if Voron is still the way to go.

How do Voron printers compare to the current state of the art (Prusa CoreOne+, Bambu P2 series, Qidi Plus 4, etc.)? Are there mods that are essential to improving them? Are there other DIY printers I should look at?

Thanks!

Well, almost. I didn't give myself enough tolerance in the cutout for the speaker and it doesn't fit well. On to v1.01!

I'm reorganising my hobby space and I could really use some inspiration for cool and effective ways to do this. I have a rectangular room of about 15sqrm (6m x 2.5m) for this, I also have a treadmill in there so I don't have tons of space.

Hello, who do you guys get your files from? Im trying to find some cool designs and someone who drops files pretty frequently to make it worth using printer space, let me know what you guys think! Thanks

It will be a 240x280x70ish speaker stand. The first go ground with it flat and support free resulted in warping despite a 60°C chamber, so I stood it on its end, cut print speed by a third, and added the breaks to reduce stress.

This will take a while...

Note that the bottom has a chmafer, so although there's a shadow it's not warping.

TL;DR: Very happy with my purchase, impressed so far. Will update when the print finishes.

I was using and Ender 3 v3 KE before and I see now the difference, and understand people saying if you just want plug n play - go Bambu.

I can’t speak to the print quality yet, (although the progress looks good) but the smarts built into this thing are really impressive. First setup it goes through a 15minute calibration mode - it checks and compensates for its location by performing speed travel changes and vibration testing to adjust its settings - the aim being to minimise the effects of its travel and bed direction changes based on what its sitting on.

It even has a little wiper blade thing (that’s actually very aggressive) which catches and removes extrusion waste during heating and filament changes etc. I suspect I’ll be buying an AMS for it when the sales come around. The filament changes seem like they might be a bit more time consuming than the ender, it took a lot of “retries” telling it to feed more filament in, for the filament to reach extrusion. The ender doesn’t have a PTFE feed tube so I am accustomed to just forcing more filament through the print head manually - which is the source of my impatience but that is trivial at most. Once the extrusion was working - it then did a flow calibration on its own. Checking temps and extrusion force I presume. One more thing built in that you don’t have to think about

I didn’t realise it came with a lil camera built in. I wasn’t too fussed but it’s a nice touch.

The machine beep sound is obnoxious so i turned that off straight away, but handy for getting attention over a noisy workshop I can imagine.

I was a bit dubious about moving away from Orca as I had become familiar with the settings etc, but this UI is almost the same and seems as intuitive as the rest. Haven’t tried any significant modifications to the model in Bambu but it looks like it’s going to be just about the same.

Overall I’m blown away by the polish and functionality it offers, and the ease I’ve had setting it up. Bambu Product Managers must be good at their jobs and if they’re not experienced enthusiasts, they must actually go out and speak to a lot of their customers as this is a great product.

Appreciate everyone who’s posted before me, and shared their thoughts on printers when others have asked for advice - reading through that content has led me to this purchase which I’m very pleased with already.

Happy printing team!

I'm curious why I don't hear more about mattercad here or elsewhere? It's free (not FOSS), and for me really fills the gap between tinkercad and most professional cad software. I often see questions about people wanting to move beyond tinkercad but being intimidated by the learning curve and the fairly large jump between it and higher powered software. Mattercad fits so nicely in this space. Yes it's a bit slow once shapes get more complex, and it has some frustrating bugs that I don't think will ever be fixed, but it's both powerful and simple. I'm curious if there are places people think it falls short or if you think I'm wrong and there is a better intermediate software package I should be considering?

This particular filament (Sunlu matte HS PETG) is one of the absolute worst I've ever used WRT being hygroscopic. It arrived so wet that I had literal steam from the extruder the first time I wanted to use it. It took almost 48h in my drier to dry it completely so I could use it. Its been sitting in an airtight box with dessicant for 5 weeks and I needed to dry it for >16h for it to be usable again. The wet part in this print was in the bowden tube between dryer and printer, I restarted the print after took this image.

Sure it prints well at 300mm/s, but it is by no means matte at the temperatures that allow printing it at high speeds, it is actually very glossy. A huge bummer.

smooth first layer...so nice

I'm trying to find the reason why my bigger printer suddenly decided to constantly create blockages as high as the PTFE tube in the cooling block (so a little bit above the heatbreak).

It's an older V6 head. The discolouring on the heating block comes from the single time the nozzle came lose and PETG was pressed through the threads upwards, that was a year ago though. I didn't change anything, from one day to another it just decided that (for both PLA and PETG) it'll now stop working properly.

Waiting on a stronger cooling fan (strongest Sunon I could find, the one with 9000rpm). Other than that I'm just confused why this suddenly happens.

I got one last week and it's good, real good. But like too good? So I'll never have to worry about bed adhesion, which is not a problem very often but is the most common problem on the stock textured PEI plate that the printer comes with. But with the cool plate I definitely don't have to worry about it. Conversely, I have to worry about getting my prints off the bed without damaging them.

I think what I'm learning is that some prints are more appropriate for one plate and others are better for the other.