LED Bulbs Already Failing

[244]

Pierre -- with all your testing goodies, do you know of a (low cost) device that will give a spectral output of a light from say 300nm up to 450nm

heck, what's even the name of a device like that?

https://learn.sparkfun.com/tutorials/ml8511-uv-sensor-hookup-guide

Been meaning to get around to it.

that's pretty cool.  while it only measures intensity, you could likely use this to build a light integrator.

I'm more looking for something that maps the output/intensity in NM

kinda like:

380nm = 0%
381nm = 2%
..
.
.
390nm = 100%
.
.
.
400nm = 0%

etc...

that way you could actually figure out if the spectral output is changing over time as the LEDs or light source ages.

would also be helpful for reverse-engineering why some of these units are providing such different (poor) results.

the intensity should remain constant for the life of the LED if its of good quality and the power source is constant. We have done extensive testing on our units and have seen virtually no drop in output or variance in wavelength. There are a couple other things that would shorten the life and/or output but that's another story.

[Rockers]

Depending on the transformer or power supply the output voltage can vary. Just a basic transformer that's wound for let's say 120vac in/ 4vac out may only be putting out 3.5vac when connected to 110vac. There may be another set of taps to connect the primary for different voltage ranges. Or use a "smart" power supply that can produce a constant output voltage by monitoring it self.
As far as Rockers, may have a two fold issue. The higher voltage and lower frequency of the power being supplied in Japan. This may not have been figured in the design.
Small flucations in voltage may cause the UV wave length to out of the ideal range of your emulsion.

Actually we are on  lower Voltage here, which we took care of by buying a transformer as recommended by Vastex.

[Rockers]

Today`s observations.
Room temperature around 50F. Vacuum time around 20 sec, exposure time set to 25 sec. First exposure of the day and the LEDs kick in 15 sec. late. Which leaves the screen with a real exposure of 10 sec.
Little break of 10 minutes, same test again. Same result. Next only a break of max 2-3 minutes between exposures and the LEDs kick in faster.
Then raising room temperature to almost 68F and the LEDs come on instantly .
Clearly this can`t be right.

[jvanick]

I would recommend shooting a quick video (even with your iphone camera) demonstrating this, and posting it both here and to youtube. followed by forwarding it to vastex.

Include in the picture a thermometer so you can see all the steps... don't edit... it, and make sure if possible the digits on the timer are somewhat visible...

[blue moon]

I would recommend shooting a quick video (even with your iphone camera) demonstrating this, and posting it both here and to youtube. followed by forwarding it to vastex.

Include in the picture a thermometer so you can see all the steps... don't edit... it, and make sure if possible the digits on the timer are somewhat visible...

I would reach out to Vastex before doing any posting. No point in stirring the pot before trying to sort it out. . .

pierre

[Wildcard]

I heard that Vastex have a policy on not engaging in any online banter/complaints/etc. I can't decide if it's smart to stay off that slippery slope, or if it's stupid to ignore this part of modern business and networking.

[TCT]

I heard that Vastex have a policy on not engaging in any online banter/complaints/etc. I can't decide if it's smart to stay off that slippery slope, or if it's stupid to ignore this part of modern business and networking.

I know this is policy for other companies as well, dumbest possible move if you ask me. If there is a problem with your service/product why not show the public that you stand behind what you do or put out?

[GraphicDisorder]

Vastex guys where always great people and we have nothing but good things to say about the company. I would be shocked if they told you to pound sand if you were having provable bad results with the LED unit. 

[markvas]

Hello Alan,
This is Mark Vasilantone, sorry for the slow response we honestly don't monitor the forums enough. I actually had to re-register my self to login. Please give us a call and we will ship a replacement light bar to you, today. The install is easy, two screws and a quick disconnect is all that is needed. The biggest pain will be sliding out the glass. My tech guy, Steve, can offer any advice if needed.

Also, I may be wrong but I don't think you ever took my offer for an upgraded vacuum pump. That offer still stands, we changed out the pumps a while ago and will upgrade you, just mention that when you call.

regards Mark

[Frog]

I heard that Vastex have a policy on not engaging in any online banter/complaints/etc. I can't decide if it's smart to stay off that slippery slope, or if it's stupid to ignore this part of modern business and networking.

I know this is policy for other companies as well, dumbest possible move if you ask me. If there is a problem with your service/product why not show the public that you stand behind what you do or put out?

In all fairness, even if a company is active on a forum or FB group, what about about the other half dozen forums and two dozen FB groups that crop up as well? While we like to think of ourselves as the place to be, and be seen, a discussion like this one could have sprung up anywhere.
That said, we always do encourage our sponsors and potential sponsors to be active and double down on their visibility.

[Vastex]

There have been arguments made as to why we should discuss the wavelength of the bulbs and they are all valid. The highest intensity is in the low 400s however they do output throughout the spectrum at varying intensities. The emulsions that expose in that range would give you the best results but we have tried dozens of emulsions with great results for what is need for screen printing on garments. We did hold 75 and 85LPI even though a 305 mesh screen is not meant to hold much higher than a 55LPI halftone. LDTronix supplies us with the bulbs, and we did quite a bit of testing with the Baby Joe 2000 before making the E-2000. There have been quite a few improvements that were made to the bulbs before we began putting them in our exposure units.

As a side note, I just wanted to give you all a little info about myself. I have been printing for over 10 years and was a Vastex customer long before I was an employee so I use the this equipment regularly in my own shop. I will make it a point to try to spend more time sharing my knowledge on the forum, not as a salesman, but a screen printer.

-Paul

[Gabe]

There have been arguments made as to why we should discuss the wavelength of the bulbs and they are all valid. The highest intensity is in the low 400s however they do output throughout the spectrum at varying intensities. The emulsions that expose in that range would give you the best results but we have tried dozens of emulsions with great results for what is need for screen printing on garments. We did hold 75 and 85LPI even though a 305 mesh screen is not meant to hold much higher than a 55LPI halftone. LDTronix supplies us with the bulbs, and we did quite a bit of testing with the Baby Joe 2000 before making the E-2000. There have been quite a few improvements that were made to the bulbs before we began putting them in our exposure units.

As a side note, I just wanted to give you all a little info about myself. I have been printing for over 10 years and was a Vastex customer long before I was an employee so I use the this equipment regularly in my own shop. I will make it a point to try to spend more time sharing my knowledge on the forum, not as a salesman, but a screen printer.

-Paul

Please! Grab a chair make yourself at home, we like to hear from you often.
 

[Wildcard]

Guess I my sources of gossip aren't that legit then
Hi Paul...

[Rockers]

Update,
we are currently working on all the issues right now with Vastex. The guys at Vastex have been exceptional in dealing with this problem/s. just wish it would not have happened in the first place.

[Vastex]

Update,
we are currently working on all the issues right now with Vastex. The guys at Vastex have been exceptional in dealing with this problem/s. just wish it would not have happened in the first place.

Thank you for the kind words. We wish this didn't happen in the first place as well, especially seeing as you are halfway around the world. It's a law of nature to run into issues with customers that are as far away as possible.