Replacement Tube from LightObject

I have a couple of the 5th Gen Hobby 20x12 lasers at my maker space. It’s time for a new tube and I don’t feel like paying FS prices, so I’m on Light Object’s site.

We’re using “40w” tubes now, so I looked at their 40w tube first, but it saying it won’t fit in the K40 and being suspiciously long…

I’m assuming I probably want the 35w tube they recommend for the K40 instead.

Has anyone else ordered a LightObject replacement tube that can confirm? Or give me another recommendation?

@NedMan got the SPT tube sold by Lightobject for his K40 — I think it was the nominal 35w tube, but he can confirm.

Their 35W SPT tube is the first listed as a likely suggestion here:


I am assuming they have good tubes, I am wondering if this particular one fits in a Full Spectrum 5th Gen and works similarly to 40w tubes from other sources. I’ve installed plenty of tubes, but this is the first time I’ve had to buy one.

As Michael quoted me above, I’ve been very happy with my SPT replacement tube I got for my K40 from LO and I’ve heard of other people being happy with their tubes as well.

The tube I got was indeed the 35W tube the recommended for the K40 as the K40 was never a true 40W machine. You can go by the length of your current tube to determine the appropriate tube for your FS laser.

Looks like the FS 5th Gen Hobby 20x12 might be able to handle a 45W tube as FS sells a standard 40W and an enhanced 45W tube for the 5th Gen hobby.

You can also contact LO to see what they say, they’ve been helpful with my questions in the past.


Gotcha. Yeah, I’ll have to haul my butt back down to the space this weekend and get a measuring tape.

The 45W tubes are too long for the case, but they provide a port so you can still install one. We’ve talked about that, and decided that until someone can fab a cover so there’s not a glass tube sticking out right in the way of everything with no protection, we’re going to make sure everything fits.

Thank you!


LO actually sells a case extension for the K40 to use with longer tubes. It would probably work for you if you wanted to put in a longer tube.


Just to be clear: the protection that matters here is against the 20,000V or so going to the end of that tube. :relaxed: