50W laser tube with 40W power supply? Is this right?

I bought 50W laser cutter / engraver. I believe it's either a Shenhui brand or similar. Looks a lot like this one.....

http://image.ec21.com/image/shenhuil...raving_and.jpg

It is no where near as powerful as I was led to believe. So I bought a Mahoney Power Meter and found the output is 35W.

After using it for a year now, I have only just noticed on the power supply unit a sticker it says it is for a 40W laser.

Should I have a 50W PSU? Maybe I bought a 40W laser which was claimed to be a 50W laser?

I am in discussions at the moment with Shenhui about buying a couple of 60W tubes and a 60W PSU but they never say the PSU is 60W they deflect all the time and just call it a PSU or compatible PSU..

I can't find any definitive answers on this forum about the size of the PSU c/w the wattage of the tube.

Can someone please clarify?

(PS they are quoting, $110 USD ea for the tubes, $90 USD for the PSU and $430 USD to deliver the 2 tubes + 1 PSU via DHL to Melbourne Australia in 3-5 days - is this a good price?)

Well nobody has replied and I've posted this question a couple of times so either everyone is in the dark as much as me or the people that do know are not reading these forums!

So I've bitten the bullet and forked out $1000 AUD for two 60W tubes and a (hopefully) 60W PSU. The tubes are 845mm long - my "50W" tube is 800mm - so hoping this means they should be more powerful.

Vickie at Shenhui said they tested the 60W tube they had in stock and it was down on power so they've ordered another couple. I asked them to check the output before sending because I have a meter and will also test when they arrive. Been a week now and no word they have sent them.

Fingers crossed I get a reasonably adequate laser cutter after all this.

Ouch. I'd buy from Cole tech and not shenhui. I bought 2 150 watts machines from them and the one I kept (two business locations so the one at my location) had an iffy tube. They advised me to destroy and wait for a replacement. And, while they were good at getting replacements out, the first few by DHL, they seemingly couldn't ever get the packing right unless shipping with a machine. They ALL came broken. Anyways, whats done is done but fully check the package upon arrival! No cracks, no broken glass! Good luck.

On the PSU, I think you'll be fine and you can use a larger one so long as you font exceed the amps to the tube, ie make sure you have a meter.

I gave up on shenhui after 6 or 7 tubes and bought an 80 watt Cole tech which was wrapped with foam on the outside and arrived safely. I also tracked the package and told Dhl to hold at the airport for pickup so no chance of local driver breaking it on the last leg of the trip.

Hi gfacer - thanks for the advice, sounds like a bit of a bugger you had, hope I have more luck.

Did you have to contact DHL directly to organise an airport pickup option?


I've forked out extra so that they transport each tube in foam in it's own plywood box, seemed like a good insurance policy - they are going to take pictures of them before they send. You've got me very worried now however.


If I have issues I might just go with coletech but looking at the tubes on their website the only one that fits my machine is a 40W (700m).

Their 50W is 1000mm. I can only fit about 850-900mm maximum unless I modify the machine housing.

Cole tech did foam on the outside, which I think was great, cushions and better than a fragile sticker. Shenhui on the other hand didn't always had padding at the ends of the box. Having said that, I now know mostly the damage shows up in the same place regardless. The back high voltage side is just more fragile. Not sold on the crate either...would go for just the cardboard (with foam on outside ideally).... Crates tubes seemed to arrive more broken, the crate makes the couriers more careless I think. Coletech should have the fatter shorter tubes too, last time I looked.

Thanks yes I emailed them same time I posted in this thread and they replied one hour later, saying they did have 85mm tubes, didn't say what power output though. $455 US for one tube and power supply delivered, more expensive parts but cheaper DHL costs.

I'll wait for my tubes from Shenhui and then if broken will buy from coletech.