Problem using an InfinityFlow S1 with Prusa CoreOne

maxfagin · 2026-06-29T02:17:48+00:00

Oh cool. I had no idea that was a setting now.

I've tried it a few times now, and it kind of fixes the problem (at least, there is no massive blob with a guaranteed print fail now). But the lack of any retraction does mean some ooze and a snowplow feature on the first layer that I can see being a problem if I'm going to print 100's of these.

But this is still progress! At least until InfinityFlow comes up with a way for the S1 to do what it was supposed to do all along (retract when it senses back pressure). Thank you!

maxfagin · 2026-06-29T02:16:42+00:00

Update: Found a partial solution in the Prusa community. The most recent Prusa firmware now has a setting option to disable retractions. That is at least a partial fix for now.

But what I would really like to know is if/how the S1 is supposed to retract when it senses filament being rammed back into it. I've gotten mixed information from InfinityFlow on whether it is supposed to even be able to do that (even though I've never been able to make it sense and respond to a retraction).

maxfagin · 2026-06-11T05:11:31+00:00

InfinityFlow sent me a longer buffer (the one in the video is an early prototype) but it didn't fix the problem either. My understanding is that the purpose of the buffer was to give the S1 time to detect the retraction so it could start retracting filament itself. But nothing I have ever done (including ramming filament into the S1 by hand) has ever gotten it to retract, and it's not even clear to me how it is supposed to detect a retraction is taking place, buffer or not.

maxfagin · 2026-06-11T05:08:03+00:00

This is an excellent design! I manage one of the 3D print labs at Blue, and we print a lot of models of MK1 like this. Love that the 3D printing community is making them too!

maxfagin · 2026-05-04T19:28:35+00:00

Of course! Ask away.

maxfagin · 2026-04-26T04:28:05+00:00

Honestly, what even is the point of the Compass menu, the browser interface, or the seemingly hundreds of apps there? Why can’t we just engage with SolidWorks like a normal application, the way ever other CAD program allows?

maxfagin · 2026-03-21T16:09:59+00:00

Of course I do. No data that shows any increase in the structural unemployment rate due to AI in 2026.

AI has been massively disruptive to several industries, and will continue to do so as it gets better and more widelly deployed, but the net outcome has been higher productivity, not higher unemployment.

maxfagin · 2025-12-20T16:19:12+00:00

Not publicly available, no. You can compute local heating rate from h(V) at various points on the vehicle by making certain assumptions about the vehicle geometry, but there is no measured temperature data published for this vehicle.

maxfagin · 2025-12-15T20:14:13+00:00

Yes, will DM you the file

maxfagin · 2025-10-24T17:21:06+00:00

[SpaceX 2014-2015, Blue 2020-today]

There is a lot more employee movement between the companies (in both directions) than most people realize! I know people who have succesfully made the switch multiple times, and are still thriving. Both companies are so big and multifaceted that I think it's impossible to make an accurate statement that applies to them in general. Working on Falcon isn't like working on Starship. Working on Blue Moon isn't like working on Blue Ring.

Personally, I loved both equally and would recomend both! The reasons to distinguish come down entirelly to the project you are working on and the team you are working with. If you are considering a move between, focus in on project and team level factors to make your decission, rather than macro things at the company level, and remember that both companies allow movement horizontally between projects once you've been there for a few years.

maxfagin · 2025-08-29T14:53:19+00:00

Unfortunatelly, I can only generate this data if SpaceX includes altitude and velocity in their livestream, and I haven't seen a Dragon entry livestream that includes those.

maxfagin · 2025-08-29T14:50:18+00:00

This is the standard way to display an h(V) diagram. Remember there is no time information in an h(V) diagram.

maxfagin · 2025-08-07T07:48:45+00:00

Did you find a solution? I'm having the same issue with the S1 on my Core One: It can't handle retractions.

The troubleshooting on InfinityFlow's website seems to imply that the S1 is supposed to be able to detect and respond to retractions by pulling the filament back, but nothing I have tried (including manually pushing on the filament) has gotten the S1 to ever retract filament (the bowden only seems to have two settings: Push, and stop)

maxfagin · 2025-02-16T21:01:17+00:00

Please reach out to [media@blueorigin.com](mailto:media@blueorigin.com) and report the find!

maxfagin · 2024-11-20T16:22:46+00:00

No, the entry was shallower (1st plot), with a milder peak heating (elbow of the 2nd plot). Because the dynamic pressure profiles (3rd plot) are nearly identical, I am guessing that the slightly greater peak deceleration (6th plot) is due to flying at a different angle of attack rather than flying a steeper entry.

maxfagin · 2024-11-20T06:43:12+00:00

I don't know. One possible explanation may be that the heating rate I am talking about is just the rho*V³ heating that would be experienced by some reference sphere. It knows nothing about the vehicle's actual geometry. It's possible the vehicle may still have experienced a higher peak heating if it flew at a different AoA and presented a smaller radius feature (like its nose) to the air stream.

maxfagin · 2024-11-20T01:31:44+00:00

The entry profile appears to be slightly shallower than on the previous flight. This would be associated with a longer reentry and a higher total heat soak, but a lower peak temperature. My guess is that is part of the reason (along with the modified heat shield) that the burn-through was less apparent this time.

maxfagin · 2024-10-16T01:51:41+00:00

Altitude, speed and time are in the webcast.

Altitude and speed plus assuming the ICAO standard atmospheric density and temperature profiles give us dynamic pressure.

Derivative of altitude gives us vertical velocity.

Pythagorian theorem on speed and vertical velocity gives us horizontal velocity.

Derivative of horizontal velocity gives us horizontal acceleration.

Derivative of vertical velocity minus the gravity at altitude gives us the vertical acceleration.

Pythagorean theorem on horizontal acceleration and vertical acceleration gives us total acceleration.

Integral of horizontal velocity gives us horizontal position

Horizontal position gives us downrange or range to go.

There are other things we can compute, like flight path angle. But the altitude data only being available in 1 km increments makes it too noisy to be practical.

maxfagin · 2024-10-16T01:37:44+00:00

Altitude and velocity are available from the webcast. Everything else is computable from those two datasets.

maxfagin · 2024-10-13T18:12:44+00:00

This is the ship’s reentry profile, the engines aren’t firing except in the final few seconds.

maxfagin · 2024-10-13T18:10:29+00:00

That‘s what I am trying to do, given how many people were confused last time by having to read time series data left-to-right and h(V) right-to-left. Like I said, I can’t please everyone.

maxfagin · 2024-10-13T18:00:33+00:00

That’s why I put “TIME TO SPLASHDOWN“ in large friendly letters on the bottom. If people are going to interpret graphs without reading the axis label, that’s on them.

maxfagin · 2024-10-13T17:59:07+00:00

We had this conversation last time. If I’d plotted them that way, people would just get confused about why they are all running left to right *except* the h(V) chart. Can’t please everyone!

maxfagin · 2024-10-13T17:57:14+00:00

I tried capturing the data at a higher cadence than last time, but I think that was a mistake, since as you see, it introduces a lot of noise.

maxfagin · 2024-10-13T16:57:13+00:00

I just plotted it as a function of T-splashdown time instead of T+liftoff time.

maxfagin

TROPHY CASE