mgunlogson

6 ms·

1.
by mgunlogson 3mo ago
It does work. Just not very well. Not enough to be widely usable. If it was an idea it wouldn't have thousands of lines of code and working binaries. 100% infill doesn't remotely solve the problem I'm referring to. I'd a
2.
by mgunlogson 3mo ago
Yes. It's a modified triangle infill pattern. A solver pairs the triangle with one of its neighbors. Then cuts a window at the bottom during the slice. So plastic gets injected into the top of a triangle tube and flows through the wind
3.
by mgunlogson 3mo ago
Because that's not accessible. IMO the reason other efforts to achieve similar Z reinforcement have gone nowhere is because it was one guy fiddling with G-Code. All the big innovations in 3DP have been community projects. Now anyone ca
4.
by mgunlogson 3mo ago
Thank you! A lot of people here took issue with the crappy docs. My mistake, I barely spent any time on them. The reason this "came out of nowhere" is because I was working on it in secret for a long time. So that patent trolls co
5.
by mgunlogson 3mo ago
because the plastic has to displace air. This method seals the nozzle against the tube and injects under pressure (theoretically). And leaves a path for air to escape. Pretty much a micro version of injection molding
6.
by mgunlogson 3mo ago
Z layer weakness is the main reason that 3d printed parts are brittle and much weaker than injected molded ones. This is meant to knit together the part in the Z axis
7.
by mgunlogson 3mo ago
You can set the tube height to like 4mm and that's pretty much what you'll get. The tubes only need to be tall enough for a "window" at the bottom and a splitter in the middle so that plastic will flow up one side and do
8.
by mgunlogson 3mo ago
> Will this pressure could cause the walls to delaminate from each other or deform? Nobody knows :) . Give it a try! > You're also parking the nozzle at the injection points, which will cause a lot of uneven cooling at the surfac
9.
by mgunlogson 3mo ago
Resin would be very interesting. The tube design seals them everywhere below the top layer. And the two ends of the tube tops are always at the same Z. You could technically inject anything liquid enough into the tubes. Grout, resin, glue,
10.
by mgunlogson 3mo ago
I did some basic calculations on isotropic heat loss in a circular tube. I don't have the knowledge to model it in detail but I don't think this is correct. You can set tube height to something tiny like 5mm. It takes a fraction o
11.
by mgunlogson 3mo ago
It's more than that. I added a SAT solver to refine the tube endpoints so that nearby tubes don't start or end on the same layers. Even the default greedy solver (CP-SAT is SLOW) does a pretty good job at "staggering" th
12.
by mgunlogson 3mo ago
The post was from a week ago. Must have been refreshed by the algo (or admins) for more visibility. Originally never got any comments. Have you looked at the code or tried the binaries? I can assure you it very much exists as described. May
13.
by mgunlogson 3mo ago
The injection probably happens faster than you think. With a high flow hot-end and 5mm deep channels its reasonable for the injection to complete in less than a second. > How are you expecting this filament to stay as hot as the inside o
14.
by mgunlogson 3mo ago
> The problem that the author is describing is that the plastic is actually far too hot when injected and causes wall collapse. This is because the author isn't taking into account that FDM walls don't handle the required press
15.
by mgunlogson 3mo ago
The filament is injected into tiny triangular U shaped channels, about twice as wide as the filament diameter. The depth of the channels is configurable and you can go as shallow as ~4mm. If you inject at a high rate that's not nearly
16.
by mgunlogson 3mo ago
No, unfortunately. I've printed a ton of objects but nothing clean enough to be interesting. The top of cells always melt as I'm using the same material for injection and the rest of the print. Someone with a dual nozzle printer c
17.
by mgunlogson 3mo ago
Here for any questions about how it all works :).
18.
Show HN: 3D print Z reinforcement via injected loops(mgunlogson.github.io)
66 points by mgunlogson 3mo ago|58 comments
19.
by mgunlogson 10y ago
Google's Guava Bloom implementation is very well tested. I suggest looking at their guava test GitHub repo. They even use pre-seeded and manually verified filters as controls as some responses suggested. Or you could just use Guava&#x2
20.
by mgunlogson 10y ago
Depends on the language I guess. The most efficient way to represent buckets is to pack the buckets right next to eachother in a giant memory block made of bits. The other part of your question about using a flag, your method definitely wor
21.
by mgunlogson 10y ago
No problem, The paper authors left a lot of the specifics off... I got burned by the victim cache too. I saw one in their reference code and thought it was pointless until weeks later when I got around to writing tests and had one of those
22.
by mgunlogson 10y ago
The code should use bits, the point of the filter is to increase space efficiency so you need to pack everything together as close as possible. Having fingerprint sizes of only multiples of 8 bits doesn't make sense. Also, from the quo
23.
by mgunlogson 10y ago
Hi there, I've wrestled with Cuckoo filters myself, so I took a look at your lib and there's a some things that stood out. Fingerprint size- It allows fingerprints that are too short, basically less than 4 bits doesn't allow
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by mgunlogson 10y ago
The thing with Cuckoo filters is that the item's alternate position is determined solely from it's current position and fingerprint. Mathematically this is done by XOR'ing with a magic mixing constant borrowed from Murmur2 :)
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by mgunlogson 10y ago
Hmmm.... this might be an artifact of the python implementation? The insert speed should be roughly constant until the filter begins moving items into their alternate buckets(when one of the two buckets for that item is full). In my impleme
26.
by mgunlogson 10y ago
Just so nobody is confused, HyperLogLog etc. are used for a different operation than Bloom/Cuckoo filters. HLL is used to determine how many unique items you have, the cardinality of a set. Bloom/Cuckoo is used to determine set me
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by mgunlogson 10y ago
I try to think of these filters as the opposite of a cache. Bloom/Cuckoo has no false negatives and a cache has no false positives. Besides this they are very similar conceptually and used in the similar contexts.
28.
by mgunlogson 10y ago
I built a cuckoo filter library in Java that nobody uses :) https://github.com/MGunlogson/CuckooFilter4J
29.
by mgunlogson 10y ago
So this bot also creates fake hackernews upvotes? because it's fairly obvious that it does...Nothing in the last 20 hours has more than 10 upvotes in Show HN
30.
Show HN: CuckooFilter4J – A concurrent Cuckoo filter library for Java(github.com)
1 points by mgunlogson 10y ago|0 comments

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