50w Tube replacement

[Mike Audleman]

I know I have been absent for quite a while. Well, because the laser has been too.

I am finally getting around to swapping out the laser tube that failed in 2015. Yea yea, it hasn't been a priority. Not really one now either but I finally got my round 'tuit.

So I ordered a tube off ebay and should be here next week, so I will give it a go.

Is there any docs on laser tube replacements? Never done one so its a new ball game for me. I was a UHF TV RF engineer so I got all the safety things down when messin with KV power. Its been powered off and unplugged for 2y but I will still verify no HV before touching anything. You usually only get to screw things up once before your widow gets all your stuff. Other than that, anything I should watch out for or be careful of? And general tips on bringing a new tube online for the first time?

[Bill George]

Hi Mike, nice to see you back. Its been off for 2 years, no issues but if you want to take a jumper and ground the HV lead for your own piece of mind. Take a picture or two of how the tube is installed now and just R&R, make sure the electrical and hose connections are the same as the old. Make sure you have water flow before powering up the unit. If you have a mA meter in the ground side of the tube you can make sure your not overdriving it. I purchased my new tube from LightObject and it had lots more power than the old one ever did.


I see you still have your 3D printer.

[Mike Audleman]

I am quite sure the HV is dead by now. But, as I said, you only get to be wrong once. Dumping it across an incandescent bulb is an easy peace of mind. And, yea, lots of photos, especially of position so I can get it back in the mounts in a similar position.

Looked there. They didn't have one labeled as 50w and nobody got back to me from their email link. So I got this one:
http://www.ebay.com/itm/282385158010
I contacted them to confirm it fit my machine and they said yes. Will see when it arrives I guess.

Still workin the Taz to death. Printed so much stuff its nuts. I have no idea how I would have put on my Halloween or Christmas light shows without all the 3D printed parts. From mounts for the flood lights to attachment clips on the 20' megatree.

I have videos up of some of the 3D prints as well as videos taken of the Halloween and Christmas shows. If ya wanna look:
https://www.youtube.com/user/MikeAudleman

I am wanting another printer and the one I want is the prusa original i3 Mk2. Been holding off on it as its 1.75mm filament only. And I have dozens of spools of 3mm for the Taz. Will likely hold off until I exhaust most of the on-hand stock before getting the new printer. Then I will make a 1.75 head for the Taz and convert it so both will take same size filament.

[Bill George]

As I recall there is really no such thing as a 50 Watt tube, there are good 40 watt ones that can be over driven, but not for long. Key is the length of the old tube and space for it to install or fit in. LightObject dot com I think they either have that info on the website or you can read what they have to sell. That is one reason you did not see a 50 watt listed! Your eBay vender lists your tube at 850 and 1000 mm or 39,,, inches.

A lot of new tubes get broken in shipping..... so be aware.

[Mike Audleman]

As I recall there is really no such thing as a 50 Watt tube, there are good 40 watt ones that can be over driven, but not for long. Key is the length of the old tube and space for it to install or fit in. LightObject dot com I think they either have that info on the website or you can read what they have to sell. That is one reason you did not see a 50 watt listed! Your eBay vender lists your tube at 850 and 1000 mm or 39,,, inches.

A lot of new tubes get broken in shipping..... so be aware.

What sorts of things should I look at? I assume obvious stuff like outer package damage and any obvious glass breakage. Anything else to look for?

[Bill George]

What sorts of things should I look at? I assume obvious stuff like outer package damage and any obvious glass breakage. Anything else to look for?

Mike the one I got, was in a huge cardboard box and surrounded by foam. The tube was perfect, Does your eBay vender say anything about shipping damage or who pays? I do not think you could tell by the box, unless it was really in bad shape.

[Mike Audleman]

Mike the one I got, was in a huge cardboard box and surrounded by foam. The tube was perfect, Does your eBay vender say anything about shipping damage or who pays? I do not think you could tell by the box, unless it was really in bad shape.

Just curious, what was your damage if it wasn't physically damaged?

[Bill George]

Just curious, what was your damage if it wasn't physically damaged?

Tube was perfect, no damage but it was shipped from US, west coast.

[Mike Audleman]

This one is coming from Tennessee. I purchased from a retailer that has US stock. Didn't want to risk the shipping from China.

[Mike Audleman]

Ok, the tube came today. Packaging seems ok. It was a fairly heavy cardboard box lined with styrofoam. The ends of the tube were wrapped with a type of bubble wrap so they seemed to package it well.

I have the tube mounted and wired. I had to tip the tube to get the bubbles out of the water chamber and re-secure it. Live and learn. The machine came with a tube of silicone caulk so I used that. Not sure how long it takes to cure so I will leave it sit until tomorrow to make sure its had enough time before I apply any power to the tube.

The label on the new tube says it was filled Feb '17. Don't know if thats accurate or not. Old tube had no such label.

I swear they mounted the original tube before assembling the cabinet. There is no freakin way you can get to the back screws on the rings. Not with any screwdriver I know of anyhow. I managed to get them loose enough and got the front two off so I was able to twist the upper ring off and over the old tube and back over the new one. Not a good scenario. I think I will look at designing up a different tube mount ring and 3D print it before I replace this tube again.

Guess its now a waiting game waiting on the silicone to cure.

So, is there any value to the old tube? Its outer shell is cracked at the cathode (output end) all the way around so it can't simply be refilled or recharged. What should I do with it? Garbage? Is there any consideration on it as hazardous waste? I don't think its anything but glass and a couple bits of metal and some CO2 gas.

[Doug Fisher]

>>What should I do with it?<<

I think a "roof test" where you drop it down on to the concrete below (making a video to post here of course) would be the best course of action.

[Bill George]

Well my old tube was not broken, just weak. I saved it for a long time, then one day I put in in a large garbage bag, used a hammer to make little pieces and that was it.

[Mike Audleman]

>>What should I do with it?<<

I think a "roof test" where you drop it down on to the concrete below (making a video to post here of course) would be the best course of action.

Haha! Nice. Unfortunately, then I have to clean up the glass so I, my dogs nor my granddaughters cut ourselves. I like the idea, but the cleanup makes it not so much fun. And our range doesn't permit us to shoot glass objects, obviously for the same reason so there goes that idea. I could easily make it go away big time at the range.

Shame the water jacket is cracked. Would make an interesting "tap" for the coffee maker at work

So I presume its basically safe to dispose of as you would any other glass item.

[Mark Taylor2]

Mike,

Call your local disposal company. Ours takes TV tubes (color) for a fee, BW at no fee, and laser tubes at no fee. It may be that your disposal company might charge to take it.

[Mike Audleman]

It lives!

Got the tube in last night. Checked this morning and the silicone seemed hard so I did a few tests and 10/20/30% power pulses. It all seemed ok and it didn't complain. The alignment is off a bit. The beam is well above center on the mirrors but there is not change in spot position as the gantry is moved so its all straight and parallel. I think the tube mounts are simply high. Not sure how to fix that. Yet. Had to go to work.

Ran the quick test with a file in memory at 10% power just to see if it would attempt to work. And it did. So, now I need to do a proper align and test higher power settings on something more challenging that posterboard.