@donkjr Am I looking at it wrong, or does it look like the ebay mount is one size fits all?
@Bob_Buechler did some searching in the community
https://plus.google.com/101614147726304724026/posts/ga4rFbaf6mQ
@Steven_Kalmar it suggests it fits up to 80CM and that makes me wonder how wide those mounts are and if they will fit in the tube bay. Is there a possibly it will take the beam off center enough to make the mirror #1 alignment difficult.
I sent the seller a question @Bob_Buechler perhaps you should as well to get their attention:).
@donkjr they would have to be at least 100 to 110mm wide. Even if they fit, there wouldn’t be enough lateral adjustment to make up for the frame twist of these machines. The mounts on these things need to be as small possible to allow for as much adjustment as possible, while still being strong enough to hold the tube securely.
@donkjr good call. Asked them too. We’ll see what they say. Worst case someone with some design skills can probably use this as a reference.
@donkjr @Steven_Kalmar I considered those mounts when I originally was going to change mine out but did not see how they would fit without a lot of shoehorning. I was then going to see about redesigning one and printing one that would fit the K40 but then saw the other designs and decided to go with them instead.
All the other designs just look more complicated then they need to be. One vertical dial and a simple horizontal slide is all it should need…
@Bob_Buechler I had some of the same idea about complexity + I wanted to make one that was laser cut.
I started that design but did not yet complete it because of other priorities.
Below is a link to the start of that design missing the horizontal mounts and the clamping schema.
I imagined it as 5 pieces:
- 2 halves of a lower clamp with vertical adjusting slots
- 2 halves of an upper clamp
- Mounting base vertical with slots
- Mounting base (lays horizontal) with slots
The clamps were to be made from 2 pieces of .22 acrylic glued together.
The base was planned to be .22 acrylic with a vertical piece glued to a horizontal flange
There would be rubber around the tube like the stock mounting
Fasteners for the clamps were to be brass inserts in the bottom clamp.
Up down is adjusted by sliding the clamps in the base
Left-right is adjusted sliding the base in its slots
I was going to add nut inserts into the frame to mount the base .
Your welcome to finish the design if you want :). I won’t get to it until I need a new tube.
@Bob_Buechler , @Steven_Kalmar I was wondering if you guys have to adjust your laser frequently. Mine came setup ok and I have never touched it.
I figured once it was locked in it wouldn’t need more tweaking but it sounds like you have to?
Any thoughts on what is moving?
@donkjr it depends on how often you are changing the arrangement of the laser. Anytime you remove a part or replace a part you have to go through the mirror alignment procedure. If the laser tube is parallel then it is quicker and easier to get your alignment back
@donkjr I’m having trouble getting it aligned as it arrived. Mine isn’t drifting, it’s just not well aligned, and I think messing with mirror thumbscrews is a good way to drive yourself crazy and waste a lot of time.
In my case, the beam lands too high on the first mirror, and I want to try correcting that with a tube adjustment first, instead of packing all the mirror mounts as well as the laser head. I would rather square up my mirrors and mounts to 45° and 90°, adjust the tube position and only then get creative if I have to. Overcomplicating alignment is probably why it’s such a problem for people.
But rather than manually packing and unpacking the stock mounts and risk damaging the tube in the process, I’d rather get a simple but effective replacement set of mounts to start with.
Looks like those eBay mounts are made by Chinese manufacturer Tecnr: http://www.tecnr.com/sale-9475809-50mm-to-80mm-diameter-flexible-co2-laser-tube-support-mount-brackets-ajusted-for-laser-engraver.html
Their product page says the height is adjustable from 85mm to 105mm. Based on that, and looking at the product photos, it looks like the mount should be around 85mm wide. Still, I’ve emailed their hotmail.com contact address and asked for dimensions there as well. I’ll update if I get good answers.
So far I have 20 mm lateral movement and 14mm vertical. There’s room to increase the vertical span by another 10mm at least . The whole assembly is quite rigid, more so than the frame it’s bolted it. I’ll move on to the adjusters and see if I need to increase the vertical span later. Quite happy with the initial print.
@Steven_Kalmar That looks much better than the other clamps I am using, Next time my tube goes I think I will be going over to your’s 
Tecnr got back to me on the dimensions of their adjustable tube mounts. Unfortunately, they are too wide for the stock blue and white K40 chassis:
@Bob_Buechler hey thanks,and darn. They got back to me and told me the tube size it supports lol.
Update: just got the same answer
I bought them for my 50w China and they where to wide. Can’t use them. I need to get someone to 3D print me some