Off Contact Measurement/ Set up

[Maxie]

Are there rules for setting up off contact?
I'm sure the screen tension etc effect the off contact but where do you start?
Is there a distance from the top of the garment to the screen one should start printing at?
Height of a quarter or something like that?

[mimosatexas]

I set mine at 2 nickles height for shirts, a little higher for some other things.

[Screen Dan]

I always did nickels in the back and dimes up front to compensate for pallet deflection. 

...thinking back on it I should have done two dimes high in the back and one up front. 

[Dottonedan]

I've always heard you should be at or under 1/8th"  what ever number of nickels or dimes that might come out to.

The idea is to use a tight enough tension on your mesh that you don't need to have your screen frame and mesh so far off the pallet that you are stretching the mesh, causing miss registration and distortion. Consistent tension is also required for good registration. The closer the better. The higher tension, the better (up to a point obviously). You don't need to shoot for some kind of tension that is going to cause more pops than good prints. I've seen it as low as 1/16th and as high as 3/16ths"  with that shop. they mostly printed 1 color solid prints so registration or distortion was not visible thus, making off contact less of an issue.  Father way, makes it harder to clear the screen and get a good snap off.  When you see your mesh sticking to your print well after your squeegee has passed, that's a good sign of mesh tension being too low and the process of stretching the mesh out and image distortion is called bagging. This bagging happens less on nylon mesh, but on other types of screen printing, can become very apparent. You will see a drooping or sagging bag where the squeegee has stretched the loose mesh too far beyond it's memory strength.

All in all, tight screens promote close off contact,  close off contact promotes good registration and faster production.

[Iamavol]

Great information.  When I set the off contact, I use washers, is it best to have them on the frame or the mesh

[Underbase37]

Great information.  When I set the off contact, I use washers, is it best to have them on the frame or the mesh

Between the mesh and the pallet/platen.

Murphy37

[Iamavol]

Thanks

[ZooCity]

One caveat to add to Dan's post- high tension allows for minimal off contact but most machines have a limited ability to stay in parallel. As you decrease off contact you increase the need for the press to stay in parallel.  If your off contact is 1/8 th of an inch let's say then a 1/16 inch of variance will throw you off by 50 percent. Drop that off contact to 1/16 th and now 1/32 will throw it off by 50 percent and so on.  Determine your machine's ability to hold parallel before you strive to lower off contact via higher tension.

Sent from my SM-G900V using Tapatalk

[Maxie]

Do you mean parallel or height, I can see different pallet heights causing a problem.
I asked the question about off contact after I serviced the machine and saw that the printers have the off contact set to maximum.
This is crazy.
Don Newman once told me that it's not advised to work with his high tension screens and regular screens because his need a much lower off contact.

[ZooCity]

Parallel meaning the machines ability to hold even distance, or height, of the screen to the platen across all print heads.

Sent from my SM-G900V using Tapatalk

[tonypep]

One of the most overlooked factors that play in determining the tension/ substrate/off contact equation is ink rheology and viscosity. Which is why so many newer press have off individual off contact adjustments. The whole point of which is to allow for proper shear/ peel before the table lowers (or screens lift) Then again some people like to use pocket change. Its all about how serious you want to get.