Squeegee/flood chopper topic

[inkman996]

Going from yesterdays topic about physics and chopper set up, air versus mechanical I thought I would start this as a new topic and share how i do it on my press, I am not new to auto printing but I am new to chopper system so i had to trial error myself to find what works best.

Just like Alan I use both to get the best results.

First I find my lowest palette in the bunch, it is not far off but it is best to use the lowest one.

I set my squeegee mechanically to stop just above the palette by using a magnet business card as a feeler gauge. I then give the choppers another rotation for good measure. Now my squeegee is mechanically stopping about level with the shirt maybe a hair more. From their it it simple to adjust just the air pressure to clear the ink better. By using the lowest palette I can find i am positive the print will clear on all heads.

This has been working perfectly for me once figured out and if I change angles I can count the clicks on each cylinder to get accurate adjustments. Yes all this can be avoided by simply using air only but I find screwy results doing it that way and a lot less consistency.

Here is my biggest problem tho. Since we are north east we print tons of fleece, many times with in the same run as t shirts, so I have to constantly adjust off contact. Being that I did not get the lift cylinder as advertised on my press ( one that has a click system for accurately adjusting) mine only free spins, I have been trying to document an accurate amount of spins on the OC to the amount of spins on the choppers to match the OC. Alas it is simply to sloppy to get it accurately and i have to test and adjust each and every time I change OC.

If my OC  was accurate for example lets say I lower it by five clicks then it will take 10 clicks on the choppers, life would be good and change overs would be fast.

My advice for future auto buyers is to examine the type of OC the press has, if it is an accurate kind you will love it, if not then you will be doing what I do.

Alan question i know you have already mentioned it in the past but I will ask anyways because I forgot, what is the typical air pressure you are running? I find I am between 30 and 35 psi on 90% of stuff, but on thin inks on top of bases I can lower right down to 25.

[tonypep]

Wait.....what? You didn't get the option on the press as advertised?  Sounds like bait and switch but what do I know?
Seriously though I'll bet theres a creative way to gauge that.

[inkman996]

No I did not get as advertised, in fact they even drilled the holes for the correct OC on y press but they must have ran out of the proper OC and substituted a smaller crappier one by drilling new holes, go figure!

Tony I can get really close by turning the OC carefully a certain amount but still it is sloppy and still takes a couple tests prints to verify first, if it was accurate man it would be sweet!

[tonypep]

Couldn't you machine up some shims for gauges? Might be way off here without a picture.

[IntegrityShirts]

I use the same pressures on my Printex chopper/squeegees as you.  30-35 for white and about 25 for top colors.  In my Trident manual it says each revolution of the off contact knob yields .005 change either up or down.

[inkman996]

Shim what Tony?

[tonypep]

If you send a pic (or will you be sued?)I might be able to say but it sounds like when you turn the OC it does not raise or lower; even slightly. Thats sort of what I was referring to. Anyway your pretty smart; I'll bet you'll figure out something. If not try M&R!

[JBLUE]

Post a pic up. Maybe some of us gear heads can figure out a solution for you.

[IntegrityShirts]

I use the same pressures on my asdfx chopper/squeegees as you.  30-35 for white and about 25 for top colors.  In my Trident manual it says each revolution of the off contact knob yields .005 change either up or down.

asdfx = Print-Ex

lol word-ban

[GraphicDisorder]

 

[inkman996]

If you send a pic (or will you be sued?)I might be able to say but it sounds like when you turn the OC it does not raise or lower; even slightly. Thats sort of what I was referring to. Anyway your pretty smart; I'll bet you'll figure out something. If not try M&R!

I understand now.

On my machine you raise or lower the lift rod on the lift cylinder to change OC. It is in constant contact with the underneath of the carriage so no way to shim like i could have on the Javelin. I am really just being picky because I hate constantly tweaking everytime I go from fleece to tee. Some of us around here are spoiled like Alan with digital OC adjustments!

[alan802]

Great thread.  I can give you some fairly exact psi for an opaque white ink, like Rutland Snap or QCM 158.  Most spot colors will be close to the white with some of them actually needing more pressure because they don't shear well, especially on some of the higher mesh counts 230-305.  The most pressure we use is printing black or white ink through 230 and 305's and we'll be at 45psi.  I don't know if any other shops encounter any issues with their black inks, but most of the blacks we have used the last few months are not creamy, the viscosity sucks and getting it to clear a 230 with one stroke is almost impossible.  I'd like to hear if any others are adding pressure to print simple black ink.

These numbers are for printing directly onto the garment with an opaque white.  When printing on top of an underbase, you can back off the pressure by probably 10-20% across the entire range.

83/86=20-22psi
110=24-28
137=26-30
137=24-28
156=28-30
175=30
195=32 for most inks and 35-40 with black and white inks
230=35 " " 40-45 for black and white ink
305=30-45, this mesh count is very dependent on the ink we're trying to print.  I can clear a 305 with union maxopaque golden yellow with 30 psi but black will be 45+.  Process inks clear without much pressure as well.

This topic has me thinking about the use of specific mesh counts.  I know most like to use higher mesh counts these days but we haven't followed the trend because I find it impossible to shear the ink on top of the shirt with higher mesh counts due to the amount of pressure needed to clear the screen.  For example, to get a standard red on a light colored shirt, I think most would go with a 195 or 230 and that's ok for the really light garments but you'll be putting the ink into the shirt and certainly not on top, unless you're a freaking screen print ninja.  If you're trying to maximize an ink's opacity on a medium colored shirt and don't want to use an underbase, I'd recommend going down to a 137 or 156 with a good thick stencil and printing with minimum pressure to get the opacity.  Then comes in whether you need to print a bunch of colors wet on wet and then obviously you need to go with a higher mesh count, especially on the colors being printed first, as well as the larger colors of the design.

The last 6 months I've been really using the hell out of the murakami smartmesh s threads in a 110/71 and 150/48 and the psi needed to clear the 110/71 is pretty close to a sefar 83/120 and the 150/48 is the best mesh I've ever used.  The 150 is very versatile, you can hold some pretty small halftones and then lay down a great layer of ink on top of the shirt with ease since the psi needed to clear a thick white through it is in the low 20's.  And you can print super fast, maybe even max some autos out with print stroke.  I've got about 20 newmans I need to remesh that I'm going to put only S thread on, probably 150/48, 200/48 and 280/34.

[alan802]

Out of all the features on our press, the digital off contact is probably the most valuable.  We switch garment types so often, and also we use newman rollers and shurloc ez's and they have different off contacts from one another so we change the OC all the time.

Product promotion done.  Sorry, had to brag a little.

[inkman996]

Alan believe it or not I gave up a couple years ago trying to find a good black that cleared the screens well and started buying just Process black. As of yet it never gives me a problem prints extremely well and is plenty opaque!

I am in the same train of thought as you and leaning more towards lower mesh counts and higher EOM's All dark printing I do is on 160 bases and 200 top colors works perfect every time.

[inkman996]

Keeping the topic alive.

2 questions

1. Does any one here only print with air and forgo the mechanical stop? If so how does it work for you and what do you see as the benefits?

2. Am I right in assuming that if you print with the air pressure only doesn't that mean your chopper cylinder is at full extension and at that point always be placing the side load on the weakest part of the cylinder? If you used the mechanical stop and lets say that only allowed two thirds of the cylinder out wouldn't that have less stress on the cylinder than a fully extended one?