"He who marches out of step hears another drum." ~ Ken Kesey
Thanks for the responses. I talked with Sonny on the phone. With the responses here and talking to him I think I am using too low of mesh, too high squeegee pressure, too high flood pressure too high screen tension (40N) . I think my off contact maybe not enough. I thought I was at 1/4 with shirts but I just went out and checked and with a shirt and its 1/8" and 0 with a hoodie. I am going to lower the off contact a real pain on this old press and just run it around as its only 50 hoodie job and I would normally do these on the manual but just trying to get some automatic experience
Yes you are correct but since my old machine doesn't have central off contact adjustment its done by the either the screen holders or the platens I was speaking of lowering the platens to increase the off contact. I have been told by 2 people that that high of tension wasn't designed to be used on the machine I have. Its a 1995 Lawson Vector. I'm going to play around some more. The plastisol transfers I have made off this machine are great. Better then any ones I've purchased or made off the manual. I'm going to play around with some adjustments, off contact, squeegee pressure ,and up the mesh count on the next job. My main printing is spring and fall. The jobs I'm doing now I would usually of have passed on as they are simple spot jobs and 50-60 piece jobs. I'd rather do simulated process higher paying jobs.
Quote from: sben763 on March 09, 2014, 04:59:59 PMYes you are correct but since my old machine doesn't have central off contact adjustment its done by the either the screen holders or the platens I was speaking of lowering the platens to increase the off contact. I have been told by 2 people that that high of tension wasn't designed to be used on the machine I have. Its a 1995 Lawson Vector. I'm going to play around some more. The plastisol transfers I have made off this machine are great. Better then any ones I've purchased or made off the manual. I'm going to play around with some adjustments, off contact, squeegee pressure ,and up the mesh count on the next job. My main printing is spring and fall. The jobs I'm doing now I would usually of have passed on as they are simple spot jobs and 50-60 piece jobs. I'd rather do simulated process higher paying jobs.I was pretty certain that that's what you meant by "lowering", but then, of course, you aren't lowering the off contact, and I wanted to eliminate any confusion to anyone else who may read this thread.I am very interested in why high tension screens won't work properly on this old Lawson.
I have been told by 2 people that that high of tension wasn't designed to be used on the machine I have. Its a 1995 Lawson Vector.
Quote from: sben763 on March 09, 2014, 04:59:59 PM I have been told by 2 people that that high of tension wasn't designed to be used on the machine I have. Its a 1995 Lawson Vector.I'm trying to figure out why higher tensions will have a negative affect on the press.Let's say you want to print a 3 color, 65lpi image.. The first thing we consider is resolution so we pick a mesh with a thread count to hold those dots-that's in the stencil..The second thing is to make sure we can hold the required registration tolerance of 65lpi, so now we consider a screen's tension because the screen's static tension (before squeegee pressure) together with your inkwell distance, will inform you of what off contact distance the print head needs to be set at to be within the 65lpi tolerance.Now the higher the tension the screen is, the lower the off contact can be and still achive the 65lpi.. This high tension/low off contact is ideal for image tolerance/registration but comes at the expense of latitude for error.. (It's best that the press is dialed in and your squeegee's length does not push the limits of your screen's)For more midrange tensions, you will still be able to achieve the desired 65lpi but with larger inkwells (shorter squeegees and therefore smaller images, be prepared to sacrifice 5"-6" of screen width to the inkwell) and higher offcontact distances.Both scenarios should enable you to print with less pressure and faster stroke speeds-if you're using thin thread, high percentage open mesh areas and decent enough inks-with sufficient dynamic tension for ink transfer to occur without much issues.So static tension is used to set image tolerances and dynamic tension feeds ink to the mesh openings.Sent using Tapatalk
Quote from: starchild on March 09, 2014, 07:18:13 PMQuote from: sben763 on March 09, 2014, 04:59:59 PM I have been told by 2 people that that high of tension wasn't designed to be used on the machine I have. Its a 1995 Lawson Vector.I'm trying to figure out why higher tensions will have a negative affect on the press.Let's say you want to print a 3 color, 65lpi image.. The first thing we consider is resolution so we pick a mesh with a thread count to hold those dots-that's in the stencil..The second thing is to make sure we can hold the required registration tolerance of 65lpi, so now we consider a screen's tension because the screen's static tension (before squeegee pressure) together with your inkwell distance, will inform you of what off contact distance the print head needs to be set at to be within the 65lpi tolerance.Now the higher the tension the screen is, the lower the off contact can be and still achive the 65lpi.. This high tension/low off contact is ideal for image tolerance/registration but comes at the expense of latitude for error.. (It's best that the press is dialed in and your squeegee's length does not push the limits of your screen's)For more midrange tensions, you will still be able to achieve the desired 65lpi but with larger inkwells (shorter squeegees and therefore smaller images, be prepared to sacrifice 5"-6" of screen width to the inkwell) and higher offcontact distances.Both scenarios should enable you to print with less pressure and faster stroke speeds-if you're using thin thread, high percentage open mesh areas and decent enough inks-with sufficient dynamic tension for ink transfer to occur without much issues.So static tension is used to set image tolerances and dynamic tension feeds ink to the mesh openings.Sent using TapatalkOk here is my question. At what tension do you lose registration on a 65 lpi screen 25 ncm, 30ncm, 35ncm, 40ncm? I have held 65lpi halftone 4cp screens at perfect registration (ie. holding a rosette patern) viewed under a 45 power loupe on wood screens at 15 ncm.