Recently, the performance of my 100w Chinese unbranded machine dropped off significantly. I hadn’t been messing with any machine settings and rarely change power/speed settings as I primarily cut 3mm MDF.
The first port of call was to clean all the mirrors and lens followed by an alignment test and adjustment. With no improvement I fitted new mirrors and lens and then realigned the beam to the best I think it’s ever been, but still the machine was needing more power to cut the same material. 3mm MDF 15mm/s @ 25% power up to 45-50% power. I’ve double checked the max power settings set on the controller (95%).
The RECI tube is approx 6mths old so I hoping this hasn’t given up n me, when it’s firing the beam is a nice pink/purple colour and I’ve clean the lens at the end of the tube.
This issue is a real head scratcher for me… I’m wondering if the power supply could on it’s way out or is there something else that I need to check out?
TIA
You can’t see the beam, but the color sounds correct.
I’ll assume you’ve got it aligned.
Did you test the tube for TEM00 mode or resonance. Usually when the tube goes out of resonance, it will be difficult to align and won’t be consistent.
I’d suggest a test of the tubes output beam to check it’s mode. It only takes a second to check this at m1, doing it simultaneously with alignment.
Don’t burn a hole through it a light touch is needed. You want to see the power distribution (Gaussian distribution) across the beam. Dark in the center getting lighter going out… again a hole doesn’t tell anyone anything… You can post a photo here…
- properly working tube
- clean and aligned optics
- proper focus
If you have these three, they work
Good luck
Hi Jack,
Thanks for the reply.
Using the pulse button I got these results on masking (paper painters tape).
It was difficult not to get ‘burn through’ so I tried using 3mm MDF
I can’t see what I want to see, you blew a hole through it 
Although from m2 with burns near and far, I still have a good visual of where both pulses left a visible mark.
You can tell if it’s out of resonance by the power displayed across the beam. This is a Gaussian power distribution. You can only see it from the top (right) with a paper target. If you burn out the center, that’s where the information we want is.
This is a target that was taken at m1 and shows the tube moving out of TEM00 mode. It’s a tad dark, but it was clearly a failing tube. I had to replace it.
Make sense?
Hi Jack,
Thanks for your help with this problem.
I presume this testing is to see if the tube is failing?
Here’s another set of pulses where I’ve tried to lighter handed.
The numbers are just shooting order at M1
I hope that RECI don’t make idle promises
It’s difficult to actually see the results. I expect a circular mark and these are not…
Can you lower the power and try again?
What is the wattage rating on the tube… I can see 4W on the tube that’s exposed… what’s the leading part of it?
A good tube should last 10k hours, I’d expect your machine to outlast 10k hours.
Hi Jack,
Thanks for the reply, I did reduce the power and I agree that the pulses are a bit non descript. I’ll try using paper or a thin card to see if the burn mark is clearer.
I’ll check the label, it is a 100w tube, so I presume the mark is 104 or 114w.
Cheers
I’m hoping it’s not 94W 
Maybe it’s a fake reci tube
Probably not a fake, more like a grade B version.
If it doesn’t make it’s specified power, RECI doesn’t sell them to clients, only to other vendors who put them machines and/or sell them as a low cost replacement…
Doesn’t seem round to me… I think you have a tube issue…
There are others here that can comment.
Thanks for you help on this Jack.
It’s not the answer I was looking for… so much for buying a reputable brand of tube.
Most people don’t like these types of answers, sorry… wish I could fix it for you…
The output from the tube should be round… and the hot part should be in the middle.
Reci usually warrants these tubes for at least a year, sometimes two, but states the mtbf to be 10k hours.
Sometimes things just fail…
If it’s relatively new, I’d check with the vendor.
Where did you get the tube… was it a replacement?
The new RECI tube was to replace an old tube, it was bought in the UK last September. I’ll be contacting the company on Monday… we’ll see what they have to say?
Cheers
Jack
Hi Jack,
The tube is out or warranty (6 months), however, they suggested that the poor performance might be due to a failing PSU.
Have you come across this or is the tube ‘bad’ not matter if the PSU isn’t delivering the correct voltage? TIA
You’re in the tough spot where it could actually be either.
If you’re getting the correct current, I’d suspect the tube… It’s the ORU (Optimum Replaceable Unit). Some will claim lps, but I think the light bulb usually goes before the power supply… Then add the Chinese dependability issue…
Since the tube is working, just in the wrong mode, I’d put my money on a tube. Most supplies don’t partially fail, they usually really go bad.
I’ve never seen a tube that’s gone out of it’s resonance, end up to an lps failure.
Too bad it’s only a 6 month warranty.
You’re going to have to make a choice…
- good luck 
Thanks again for the reply Jack.
There no harm in a little straw grasping at this stage. 