I came up with this design a few years ago and I have been using it ever since. It's time to share with whoever wants it. I think it might be a contender for the smallest possible kovarex design. Feed both kinds of uranium in on the left and your extra 235 comes out on the right. A benefit of this design is it's very easy to elongate the transport belts and insert some beacons in there. Also, because input comes in on the left and output on the right, you can chain them together, you just have to add more 238 to each one.
03-16-2026, 19-41-02.png (441.84 KiB) Viewed 1765 times
Here's a low tech variant running in my current game:
03-16-2026, 19-44-27.png (1.04 MiB) Viewed 1765 times
Here's a version of the blueprint stretched out with beacons. I haven't figured out how to get the last beacon in there, but I'm not really motivated to try.
03-16-2026, 19-59-35.png (1009.36 KiB) Viewed 1765 times
Re: Smallest possible Kovarex?
Posted: Mon Mar 16, 2026 12:14 pm
by royce3
I stretched the beacon version a little too far. Easy fix. (I've never used this beaconed blueprint, I built it just now to prove if it really was that easy to modify it for beacons and it was.)
Might still not be the smallest setup using belts:
grafik.png (413.22 KiB) Viewed 1737 times
Re: Smallest possible Kovarex?
Posted: Mon Mar 16, 2026 2:19 pm
by quyxkh
Take the filter off the '235 loader, replace the '238 loader with an underground exit, the back '238 unloader fills, that saves the side lane.
Re: Smallest possible Kovarex?
Posted: Mon Mar 16, 2026 3:25 pm
by Loewchen
quyxkh wrote: Mon Mar 16, 2026 2:19 pm
Take the filter off the '235 loader, replace the '238 loader with an underground exit, the back '238 unloader fills, that saves the side lane.
I did not want to miss some 235 without the input filter, but practicality is not really the goal here anyway.
I think thats the smallest possible, got it from the forum I think, you dont need the beacons and can tear the units apart, this is just a small module that is balanced, ie it makes enough uranium to fuel the kovarex.
03-16-2026, 20-39-10.png (671.09 KiB) Viewed 1621 times
Edit: Updated the BP, should work without stalling now. I messed up some of the logic.
Re: Smallest possible Kovarex?
Posted: Mon Mar 16, 2026 10:45 pm
by quyxkh
Really, though, I think you can start with the one on the left here and extend to the row as desired:
pic
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Re: Smallest possible Kovarex?
Posted: Tue Mar 17, 2026 6:36 am
by royce3
Loewchen wrote: Mon Mar 16, 2026 12:55 pm
Might still not be the smallest setup using belts:
grafik.png
I like this, but it isn't perfect. It will backlog on 238 and stop producing 235.
Re: Smallest possible Kovarex?
Posted: Tue Mar 17, 2026 6:37 am
by royce3
quyxkh wrote: Mon Mar 16, 2026 2:19 pm
Take the filter off the '235 loader, replace the '238 loader with an underground exit, the back '238 unloader fills, that saves the side lane.
I don't like using unconnected undergrounds because I have a habit of accidentally connecting to them when building something else nearby and causing a huge mess.
Re: Smallest possible Kovarex?
Posted: Tue Mar 17, 2026 6:40 am
by royce3
inefficient wrote: Mon Mar 16, 2026 8:38 pm
I have this one:
I think thats the smallest possible, got it from the forum I think, you dont need the beacons and can tear the units apart, this is just a small module that is balanced, ie it makes enough uranium to fuel the kovarex.
03-16-2026, 20-39-10.png
I haven't seen something like this before and it makes me think, but there's a couple problems with this design. Most importantly it loses 235 on top that it doesn't recapture. You only want excess 235 to leave or it will shutdown prematurely. I think there's probably issues with 238 too, but I stopped analyzing once I saw the problem with 235.
Re: Smallest possible Kovarex?
Posted: Tue Mar 17, 2026 6:46 am
by royce3
quyxkh wrote: Mon Mar 16, 2026 10:45 pm
Really, though, I think you can start with the one on the left here and extend to the row as desired:
pic
screenshot-tick-910986.jpg
My first thought in seeing your design is that I do the same thing with recipes on Gleba that consume their own outputs like nutrients and bacteria. If there's one flaw with my design, it's that you wait a long time for the 235 to loop around which is agonizing when first starting to run. I could use this to redesign mine to go faster, even if it takes up a little more space it will be a win. I also think that incoporating this into my design will allow me to fit the max # of beacons which is a huge win.
All that said, your design is incomplete. It will backlog on an excess of 238 and it mixes 238 into the output. Those problems are easy to fix but it will make your design bigger. It will also let some 235 slip past that aren't excess and could shut down the process until another comes in naturally.
Re: Smallest possible Kovarex?
Posted: Tue Mar 17, 2026 8:20 pm
by quyxkh
I hadn't bothered going for a do-it-all 'cause as you say the fixes are easy, but giving it a shot led me to this, which surprised and pleased me with how well it works, so, thanks for the prodding!
pic
screenshot-tick-4609705.jpg (130.73 KiB) Viewed 1417 times
Re: Smallest possible Kovarex?
Posted: Tue Mar 17, 2026 11:44 pm
by coffee-factorio
Note that the red belt demonstrates a shorter pathway that can be used when the machine is less motivated.
Screenshot 2026-03-17 173351.png (537.25 KiB) Viewed 1370 times
Ah, the belt gave out . This is somewhat close to optimal, it uses quyxkh's trick of using a low speed belt to force ejection. I did not know that one before. Is it cheating if I use a filtering stacker? It takes a wire and configuration, so it might count as unacceptable.
coffee-factorio wrote: Tue Mar 17, 2026 11:44 pm
Note that the red belt demonstrates a shorter pathway that can be used when the machine is less motivated.
Screenshot 2026-03-17 173351.png
Ah, the belt gave out . This is somewhat close to optimal, it uses quyxkh's trick of using a low speed belt to force ejection. I did not know that one before. Is it cheating if I use a filtering stacker? It takes a wire and configuration, so it might count as unacceptable.
Dude, finish that, you can get it into 5m high + any beacons and everything but the initial input prep fits in the beacon box.
Re: Smallest possible Kovarex?
Posted: Wed Mar 18, 2026 11:11 am
by coffee-factorio
quyxkh wrote: Wed Mar 18, 2026 10:37 am
Dude, finish that, you can get it into 5m high + any beacons and everything but the initial input prep fits in the beacon box.
Okay, you'll have some versions after my shift. Sometimes I leave things so that others can pick it up and improvise off it. I can just, see a line of kovarex when you don't have beacons. But when you do, you actually have to have the extra arms to get the full potential out of the machine.
Re: Smallest possible Kovarex?
Posted: Wed Mar 18, 2026 11:56 am
by royce3
quyxkh wrote: Tue Mar 17, 2026 8:20 pm
I hadn't bothered going for a do-it-all 'cause as you say the fixes are easy, but giving it a shot led me to this, which surprised and pleased me with how well it works, so, thanks for the prodding!
pic
screenshot-tick-4609705.jpg
That's definitely way more elegant than mine! awesome!
Re: Smallest possible Kovarex?
Posted: Wed Mar 18, 2026 12:25 pm
by royce3
quyxkh wrote: Tue Mar 17, 2026 8:20 pm
I hadn't bothered going for a do-it-all 'cause as you say the fixes are easy, but giving it a shot led me to this, which surprised and pleased me with how well it works, so, thanks for the prodding!
pic
screenshot-tick-4609705.jpg
I decided to try it out and see if I could get it fully beaconed. It jammed on the output bulk inserter on my first test.
03-18-2026, 20-24-24.png (947.43 KiB) Viewed 1230 times
Re: Smallest possible Kovarex?
Posted: Wed Mar 18, 2026 1:03 pm
by atomizer
Look closer at the design - the slow belt after the splitter is important. Also the right column of beacons doesn't reach the centrifuge.
quyxkh wrote: Tue Mar 17, 2026 8:20 pm
I hadn't bothered going for a do-it-all 'cause as you say the fixes are easy, but giving it a shot led me to this, which surprised and pleased me with how well it works, so, thanks for the prodding!
pic
screenshot-tick-4609705.jpg
I decided to try it out and see if I could get it fully beaconed. It jammed on the output bulk inserter on my first test.
03-18-2026, 20-24-24.png
I fixed it, this is going in my blueprint book for sure. I couldn't figure out how to get it to come out on the opposite side, but it's no big deal to use transport belts to bring it around and chain it's output into the next one.
I also don't like that I needed an extra inserter to take out the excess, but I couldn't make that work and keep all beacons. This beast could create 42.9 U235 per second if I could keep it fed, but it spends a lot of time in ingredient shortage or output full even with 2 legendary bulk inserters each on output and input.
03-18-2026, 21-56-34.png (1.02 MiB) Viewed 1197 times
Re: Smallest possible Kovarex?
Posted: Wed Mar 18, 2026 8:36 pm
by quyxkh
Stop feeding in external '235 once you've got started, it's why your output's clogged. The centrifuge will eventually buffer several full loads ahead of the one in the oven.
And, now you're not going for smallest, you're going for fastest. Here:
pic
screenshot-tick-245909.jpg (216.39 KiB) Viewed 1107 times
drop 40 '235 in manually it reaches 100% uptime soon enough. Sounds gratifyingly like a steam locomotive getting up to speed.
edit: turns out you can still squish this some, you only need 5 inserters. Replaced the image.
. This is somewhat close to optimal, it uses quyxkh's trick of using a low speed belt to force ejection. I did not know that one before. Is it cheating if I use a filtering stacker? It takes a wire and configuration, so it might count as unacceptable.