View Full Version : Tube sizes and tube mounts - going from 32W to 45W tube. on K40

Mark Taylor2
12-01-2015, 6:29 PM
A question.. I have the Micromark equivalent of the K40. I'm looking at a tube upgrade and all I do is cut. Lightobject sells a 45W tube that requires an extension on the housing (not a problem) but the tube diameter is 5mm bigger than what is in the unit (32W called a 40W).

I've not got any answers anywhere I've looked except "modify the existing mounts". Has anyone done this? I'm not sure what "modifying" would entail to ensure that I don't change the mounting alignment.

Thanks. This forum is a life and mind saver.

Dave Sheldrake
12-01-2015, 7:47 PM
what mounts do you have Mark? some have rubber sleeves , some are metal, some are plastic

to be honest the benefit of going to 45watt just isn't there...it will be a 40 watt with a peak of 45 so given the cost of bigger tubes not really worth it

Mark Taylor2
12-01-2015, 11:48 PM
Well.. for what I want to do, it's the best way, I think, for me to get there. I'm retired, I use it for my hobby. I'm going to be starting a new model sometime after new year and want to cut the frames.. I just don't quite have enough power to cut through 1/4" boxwood. It barely handles 3/16" boxwood. I shipped some to a friend who has had the upgrade done (yeah, he paid someone to do it.) and the 45W tube cut it just fine. I asked about his mounts and he thought he had a plastic block type.

Here's a pic of the current project (taken quite sometime ago.) 326199

Ok.. back to topic... here's a pic of the tube area. 326200

They're metal bands with what I think is rubber approximately 5mm thick. Should I remove the rubber and replace with something? Or try cutting rubber down? That last just doesn't seem doable to me. If I'm replacing it, what should I use?

Bert Kemp
12-02-2015, 12:14 AM
Thinking on this and I've never done anything like it , sounds like you will need the tube to sit lower then the one in there. They have adjustable mounts that can be raised or lowered to get the tube to line up with the first mirror. you should be able to buy mounts for the tube dia that you are gertting.so if you have mounts that will fit the tube and you can adjust the height you should be able to line things up. correct.

Mark Taylor2
12-02-2015, 2:46 AM
They do make a mount for the 60mm tube but... it won't fit into the tube space for the k40 type. I'm currently thinking about how I can remove 2.5mm of the rubber part all the way around. Then the centerpoint should stay the same. Still doing some head scratching on this. If there's no answer, maybe I'll have to make some out of wood and with a bit of foam padding. I wish my friend had more info but he's not a tech type only a user type.

Bill George
12-02-2015, 7:48 AM
There is no adjustment at the bottom of the mount for height? Or is it just hunk of plastic with holes bored or cast for the tube. I bet someone with a 3D printer could make you new mounts. Another thing is the power supply, did Marco at LO suggest replacing? When I replaced my 35 watt (peak) with a true 40 watt not only was I surprised at the power gain, but the tube dimensions were not exactly as advertised and it was a piece of cake to R&R and I used the same PS.

Matt McCoy
12-02-2015, 8:43 AM
Can your friend send a quick pic of the modifications?

Mark Taylor2
12-02-2015, 10:29 AM
Marco's posts indicate the PS will work, but to limit the current draw. I'm not making any mods unless I have parts in hand which is an old habit I learned the hard way.

I'm trying to get some.

Bert Kemp
12-02-2015, 11:26 AM
could you just remove all the rubber from the mounts then buy a sheet of the thickness you need and cut the strips from it?

Bill George
12-02-2015, 1:44 PM
I think Bert is on track, and I think just a turn or so of either vinyl or rubber electrical tape would do the trick. But my replacement tube, turned out to be the exact diameter as the one I removed. It was longer but it did fit in the case ok.

Matt McCoy
12-02-2015, 3:05 PM
Looking at that pic, the mounting straps don't seem to tighten all the way. They appear to be adjustable and may not need a retrofit.

Dave Sheldrake
12-02-2015, 4:23 PM
could you just remove all the rubber from the mounts then buy a sheet of the thickness you need and cut the strips from it?


Bert is bang on, my mounts that still use the old system just have the rubber removed, thin sheet of foam (sticky backed stuff) and you are good to go

Mark Taylor2
12-02-2015, 6:03 PM
Thanks everyone. I appreciate the help.