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Does anyone know what router bit they are using at 17:45 in this video?

They are shaping an angle after the brace is glued to the top/bottom. Also, what is the metal guide on the bottom of the router that is tracing the braces?

https://m.youtube.com/watch?v=gS78naDiB4k

Video not showing... wrap the URL in [ youtube ] tags and make sure it starts with http:// and not https://

Fixed link

It looks more like the braces are being rounded over rather than having an angle routed into them. So I'm guessing some kind of round over bit.

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Looks to me like he is using more than one bit, perhaps a v-groove and at 18:04 a round over, ovolo type.
Notice the straight edge guide on the underside of the router base.

I'm seeing a chamfer bit for the top braces (probably around 15°) and some sort of roundover for the back braces (either a specialty bit or let's say a 1/2" roundover not cutting to full depth)

the metal guide is at the very least acting as a stabilizer for the router base riding on something that is at most 1/2" wide...it may also reflect the bits don't have a bearing, and would also help in making the cuts in one pass as you have the knowledge you're pushing the guide against the brace for stability which also implies the bit is making the full desired cut

edit: the above is kind of completely wrong...I note the user is not flipping the parts around and is seen making passes on both sides of the braces with the same motion...this implies to me the metal bar is dead centered on the bit and really begs the question just what sort of bit is being used? by the time you account for the width of the bar one would have to have the bit set pretty deep to get a profile, and that would probably mean the bit going through the top/back, so what did they do? cut the tip off a bit or custom order one (very pricey from my experience)

also upon closer viewing of the video I appear to see that the top braces are getting different types of profiles, and since this is a production shop it's logical to assume that there are multiple routers set up for very specific tasks...I also note that for the back braces one can see a piece of wood attached that rides on the top of the other braces

and yes, I'm being too lazy to find that video on my TV and watch it in high resolution on a big screen which might shed some light on the subject...since I never plan on being a production builder I'm pretty sure I'll have no use for the discussed router set up

As Ken Lewis said, it's more about the edge guides than about the particular router bit. On the top braces where braces crisscross only a short fence (and a steady hand to balance things) is being used. Where the back braces are being routed a longer fence and a subbase that extends over several same height back braces can be used so less manual dexterity is required to do the routing.
For a small production shop it does provide a way to shape braces quickly and uniformly and have a pretty result on the inside of the box, with only a modicum of handwork to bring the braces to final form.

Hi Mike,
The bits are probably the typical bearing-less roundover (ovolo) and V groove, but they are centered on the edge guide rather than being off set to one side. Being wider the cutter extends past both sides of the edge guide to perform the cut.

Yep, basically they're like a router table / fence setup with the bit at least 50% buried in the fence. Just a way to quickly and easily put an attractive profile on the braces.

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"Music is what feelings sound like"

the guide appears to be 1/4" square stock...so proportionally to a router bit with a bearing of that diameter you're actually losing none of the profile...the bits in use appear to be blue, so that pretty much axes the idea of anything custom as those would be bare most likely. it would be real easy to simply remove a bearing and cut off the threaded stem leaving only the carbide cutters. The bevel I see on the top braces is way more (or less I guess according to your perspective) than 45° so the idea of a v-groove bit can be thrown out the window. I'm scratching my head on the whole bar guide attachment but I'm sure that would go away if we could see the set up from the bottom and fully understand (I see only one fastener on the base and you'd have to have 2 per section of bar to hold it in place...probably something drilled into the sub-base of the router and not seen in the video)

and yeah, since I have the day off I took the time to watch the video on my TV and get a better look

I was thinking the same thing about the bar stock guide. There has to be another attachment point.
I have a manufacturing background and my OCD means I like to do things in a repeatable manner. I love this solution for it's consistency. It'd be pretty easy to set up dedicated routers.

If I were making that set up I'd attach a piece of stock all the way across the router using the (I assume) factory holes first, then add fasteners to the sub base (bar having already been drilled and countersunk), proceed to remove the bar (making sure to label things) and cut away the material that would prevent a bit from being present, then reattach the now 2 pieces and proceed from there to first test then use it.

My style of OCD is over thinking about everything before I actually implement anything as I suffer from FOFU (Fear Of F****** Up)

I still don't understand why people install these large pieces of wood(braces)and then go through all sorts of contortions to shape them to the desired profile.
I almost completely shape both top and back braces before they are glued to the top/back.
At most I do a little touch up once they are installed.

I came to the same conclusion about the bits - removing the bearing and stem would leave about the same width as the fence.