Triggering UV LED on & off

[Tstern83]

Hey all,

I'm just starting out with my first flatbed, based on an Epson R2880. At this point I'm putting together a BOM so I can order everything and start building once it is all here. One of the 1st things I've ordered (foolishly or not) is a 50W UV LED module, can't remember the wavelength at this moment but  suited to what the ink supplier said it required. I also ordered a dimmable power supply.

The basic concept for triggering which I thought about is using two optical switches at each end of the travel but then I came to realize that the printer does not always travel the full distance because I might print on a smaller area. An accelerator comes to mind, however this feels like an overkill. Perhaps there's some digital signal in the printer that I can tap into and using a simple MCU (or even with just logic components) trigger on & off?

Thanks!

[reptilesink]

You just need some form of switch to turn it off when over the capping station.

This could be a simple proximity switch.

[Tstern83]

That's where the printer's head "spits out" ink at the end of the travel on the right side?

BTW, also worth asking - how far from the printing surface does the LED mounts?

[reptilesink]

Yes on the right where the head starts from.

The light needs to turn off before it goes over there so that it doesn't cure the ink in the capping station.

They need to go just above the height of the head.

 

[Tstern83]

Thanks!

Can you please explain in a few words what am I seeing here?

[reptilesink]

Thats the led's fitted in a cooling housing mounted to the side of the print head.

[reptilesink]

[Tstern83]

2 hours ago, reptilesink said:

Thats the led's fitted in a cooling housing mounted to the side of the print head.

I figured that much :)

I've meant what is in the cooling box? is it a heatsink with fans? any electronics for temp. sensing?

[reptilesink]

In that one there is a heat sink and fan with an external dimmer control.

Other versions of it have liquid cooling.

Also a switching transistor can be used to connect to an arduino and use pwm dimming.

Edited February 6, 2019 by reptilesink

[Tstern83]

OK got it!

Thank you!

[Mister_X]

@ Tstern83: Really very nice UV printing system!!!!

Today i have received my Epson 1500W and i also plan to build UV light system because i want to print on objects, not on garment. Unfortunately there is not so much information available for UV light printing. Can you help me as a newbie with your experience to clarify some basic UV light questions???

1. Where to get the UV light to be used in the printer? Any shop in EU/Germany?

2. Is it necessary to place the UV light in the printer beside the printing head or would it be also possible to use normal UV light (e.g. as used for nail polish) for curing outside of the printer. Is this mandatory to cure immediately inside the printer or just to increase the productivity speed?

3. Which UV ink and UV light can you recommend for Epson 1500W printer?

4. Is there also other non UV light based ink available which could be used to print on objects? Or is UV ink the best and only solution for this task?

Many thanks in advance for your answers!!

Chris

[jcalp]

On 2/6/2019 at 9:08 AM, reptilesink said:

You just need some form of switch to turn it off when over the capping station.

This could be a simple proximity switch.

Is there any diagram or diy of how to do it ? i need one of those for my setup.

[reptilesink]

The light needs to be mounted to the print head so it cures as printing.

There are various types of inks such as eco solvent and latex.

For eco solvent you will need tk replace a lot of parts on the printer or it will melt the plastics.

Latex you need a heat source to cure it as it prints.

 

For the on/off of the led light when over the capping station you can just use a momentary lever switch like used for the backstop, a laser, proximity sensor etc. You just need it to be triggered by the print head as it goes over the capping station.

[Andy - Admin]

You can use a switch and / or modify the arduino programming and use a relay to turn it on and off only during the printing sequence.

[jcalp]

Hi there andy,

 

My setup doesn´t incluide any arduino since is not a flatbed yet,  but i would like to try. what else besiders de arduino board do i need ? 

[reptilesink]

Stepper motor, stepper controller, various switches, plus various materials to build the base and platen.

[jcalp]

 Yeah, that i know.. but for now just the auto switch on/off.

[vanrithy]

Hi,

How would I wire this system to work with proximity sensor?

As a noob at this I've searched around for a while but I seem no clue about this.

Thanks in advanced!

[Andy - Admin]

It's most likely the signal plug.

Wire it to a limit switch or a proximity switch that the head is going to trigger.

[vanrithy]

Hi Andy!

What proximity sensor should I use?

- AC-NC Proximity Sensor 2-wire

- DC-NC Proximity Sensor 2-wire

Do I need to use relay to connect the sensor to the system's signal wire (black & red)?

Thank you!

 

[reptilesink]

You would need to find out the spec of the unit for if it needs an no or nc sensor and what voltage it operates with.

I would expect it to be using dc.

[uhim]

22 hours ago, vanrithy said:

 

How would I wire this system to work with proximity sensor?

As a noob at this I've searched around for a while but I seem no clue about this.

Thanks in advanced!

 

[vanrithy]

16 hours ago, reptilesink said:

You would need to find out the spec of the unit for if it needs an no or nc sensor and what voltage it operates with.

I would expect it to be using dc.

Hi Reptilesink,

This is its spec.

• Power: 0-50W adjustable
• Voltage: DC22-24V
• Wavelength: 395-400NM, 365-370NM
• Use chip: South Korea LG imported South Korea LG imported chip
• Forward current  Forward current: 0-2000mA
• Optical power: (395-400NM wavelength) 0-12000mW/cm, (395-400NM wavelength) 0-2500mW/cm.
• Recommended irradiation distance: 5-10mm
• Lamp head dimensions: 35.8 * 14.6 * 22.4 mm
• Radiator size: 230 * 186 * 123mm
• Packing size: 29.5 * 24 * 20.5cm
• Suitable for small size printers, Epson R1390, L1300, L1400, L1800 and other printers modified UV flatbed printers
• Use Epson XP600, TX800, DX5 print head

It seem to use DC. I'll check whether it needs NO or NC sensor more. Thank you!

11 hours ago, uhim said:

 

Hi Uhim, Thanks for your input!

I just know that much! I wanna attach proximity sensor like this:

So, do I just need to connect like Blue + Black & Brown + Red as normal or I need additional stuff(s) to make it works?

Thank you!

[jcalp]

On 2/6/2019 at 11:18 AM, reptilesink said:

where i can find those fittings you are using for the ink tank lines?

[johnson4]

On 2/6/2019 at 10:18 AM, reptilesink said:

do you have a flatbed version and the paper fed version? Your LED/head Photo vs your video show both. If I find the time I'd like to try my hands at a paper fed version. Your ink system looks pretty serious, very good job on the build!! 

Have you previously shared what that system consists of for the ink system? That was my main caveat, the need to remove the oem ink system and not really knowing what to replace it with " properly". 

Anyway, not trying to bum your hard earned info, Just curious because that looks well thought out.