MSP 3140 advice

[SI]

Getting the Ink solid helped a lot, I now know what my correct exposure time is.  I checked the glass and it is the original or appears to be.  I have yet to check the voltage, that is the next step.  The exposure time on it is 81 LTU on white 180 mesh with SP-1400 emulsion.  Going to have to get a new lamp for it ASAP as 81 LTU is a burn time of 9:20.  So either the voltage taps are incorrect or it is in serious need of a lamp.

Pierre I wil try out the T-rip, but that means breaking out the windows machine, and Windows hasn't made a good OS since XP as far as i am concerned.  But if it lets me do custom film size it would be worth it.  I didn't see where I can do custom Film sizes with Accurip, unless the paid version adds that feature.

[blue moon]

Getting the Ink solid helped a lot, I now know what my correct exposure time is.  I checked the glass and it is the original or appears to be.  I have yet to check the voltage, that is the next step.  The exposure time on it is 81 LTU on white 180 mesh with SP-1400 emulsion.  Going to have to get a new lamp for it ASAP as 81 LTU is a burn time of 9:20.  So either the voltage taps are incorrect or it is in serious need of a lamp.

Pierre I wil try out the T-rip, but that means breaking out the windows machine, and Windows hasn't made a good OS since XP as far as i am concerned.  But if it lets me do custom film size it would be worth it.  I didn't see where I can do custom Film sizes with Accurip, unless the paid version adds that feature.

If the emulsion is dual cure, your 9 min exposure time is probably not that far off. They usually run several times longer than then pure photopolymer.

Pierre

[jsheridan]

something sure isn't right.. I've shot hundreds of thous of screens on a 3140 with diazo based and never exceeded 5 mins exposure.

[ebscreen]

1 LTU should ~= 1 second.

I can't remember if the integrator has an adjustment or not, but something is way off.

[Gilligan]

1 LTU should ~= 1 second.

I can't remember if the integrator has an adjustment or not, but something is way off.

Light Units are used in place of seconds (time) because time isn't important, LU's are.  As a bulb ages it will put out less LU's so it will take longer.

That said, on my 3140 with a "fresh" bulb I get about 1 LU = 1 second... but that's more of a coincidence than on purpose.

[ebscreen]

That's my point, something is waaayyyyyy off.

[blue moon]

50% EOM on a 110 with Diazo emulsion could be in 9 min range with an older bulb that still exposes correctly.

How are you coating the screens?

pierre

[ebscreen]

Right, the time might not be off for a correct exposure, but the LTU reading for it certainly is.

[SI]

I am using the Glisten method, shirt side first, rounded edge of coater, nice and slow, then one coat squeegee side the same, 2nd coat shirt side.  Dry in rack shirt side down.  Just got done ruining some shirts, going to check the voltage taps shortly.

    1 LTU is def not one second on this thing.  maybe .1 LTU = 1s, and I don't even know if that is correct.  I can expose two screens at a time, and when i pull them off i have enough time to wash both screens out, dry them, and take a break before the next set of screens are exposed.  I think its either a voltage issue or lamp issue at this point.  I appreciate all the advice, Thank you Pierre for pointing me towards a Rip,  that was definitely one major issue I had.  Films are printing like a champ now at least.

[Frog]

I am using the Glisten method, shirt side first, rounded edge of coater, nice and slow, then one coat squeegee side the same, 2nd coat shirt side.  Dry in rack shirt side down.  Just got done ruining some shirts, going to check the voltage taps shortly.

   

Using the glisten method to achieve the needed EOM involves finishing on the squeegee side. That's what pushes the emulsion through to the shirt side where it does its good.

[blue moon]

I am using the Glisten method, shirt side first, rounded edge of coater, nice and slow, then one coat squeegee side the same, 2nd coat shirt side.  Dry in rack shirt side down.  Just got done ruining some shirts, going to check the voltage taps shortly.

    1 LTU is def not one second on this thing.  maybe .1 LTU = 1s, and I don't even know if that is correct.  I can expose two screens at a time, and when i pull them off i have enough time to wash both screens out, dry them, and take a break before the next set of screens are exposed.  I think its either a voltage issue or lamp issue at this point.  I appreciate all the advice, Thank you Pierre for pointing me towards a Rip,  that was definitely one major issue I had.  Films are printing like a champ now at least.

Our older 3140 is at 90 sec for 2 LTU. This is the first gen, prior to M&R.

1+1+1 with Aquasolv, dull edge and 5 seconds per coat would produce at least 40% EOM.  3 sec per coat, Aquasol HV with glisten method is about 25%.

Pierre

[jvanick]

coating technique also depends on what screen mesh he's using, as well as the viscosity of the emulsion.

a 1+1 in our shop results in nearly 50% EOM on a 150S

in order to have EOM in the 20% range, we do 1 coat on the shirt side, nothing on the squeegee... having 45-50% EOM was causing us all kinds of issues for us in both exposure and printing.

[SI]

I have no idea what my EOM is, have yet to buy the tester for that.  I forgot that on the last batch of screens i just used a 1:1 coat of SP-1400, second coat on squeegee side.  as far as thickness though I couldn't tell you.  The tester is on my purchase list, along with 100 other things I still need to get.  The more posts I read on here the more stuff i seem to need to purchase   

  All I know at this point is it takes forever to expose the screen, but with the proper films now, I am getting good exposures, no more pinholes in the screen during printing, and sharp detail.  So long exposure times are a small price to pay at the moment for good screens.  I opened the Expo unit up and the wiring has been worked on some, lots of splices.  I will have to contact M&R to see if I can get a wiring diagram for it.

[jsheridan]

  I opened the Expo unit up and the wiring has been worked on some, lots of splices.  I will have to contact M&R to see if I can get a wiring diagram for it.

That's not good.. Lets hope it's not to bad of a rats nest in there.

Anyone got a 3140 manual around they can scan in the diagram for our friend here?

[SI]

Just opened the other side up.  Looked closer at the wiring, really only two wires with splices, not how i would have done them so i will redo them properly, but they are working.

So as for the testing.  Ran the unit for 1 minute and checked the line voltage, 120V even, wires were on the 125V tap.  moved to the 120V tap.  Noticed the LTU were moving much faster.  Did a full 81 LTU test.  Prior results on the 125V tap was 9:20.    New results moved to the 120V tap at 81 LTU is 6:54.  Good improvement.  At this point I will be getting a new lamp.  This is just times for the integrator to see 81 LTU, not actually exposing a screen.