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screen printing => Equipment => Topic started by: steve1coelho on January 28, 2015, 10:18:18 PM
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I have a 6 color Jennings press and was wondering if anyone had any tricks to set the off contact quicker
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It may not be the "right" way, but I have a Hopkins Pro-Line 6/4 and I just tape some spacers under the outer edge of the screen frames. You could use 1/8" Plexiglass or equivalent acrylic sheeting under BOTH ends of your screen frames to keep them nominally parallel to the platen. I don't usually use anything under the back ends. Paint stirring sticks are about right, and I've used them too.
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I've spoken to Roger Jennings himself (a few years ago) and he uses cardboard tapped to the frame.
BTW, I have all Jennings equipment.
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I have a 6 color as well. I purchased a piece of plexiglass for this. Get a perfectly square level frame, clamp it in and adjust based off the platen. You really need to level the base, then the arms so you can level and shim the platens. Once those are perfectly level then you can put the plexiglass on top of it and adjust the off contact. It seems like a lot but once it's all level you can use a bubble level to check everything.
So I adjusted the vertical bolts so the base of the frame clamp was 1/8 inch higher than platens, then I put in frame and adjusted the frame clamp up till I had the desired off contact on the out end, adjust the vertical bolts again and see where your at. It's a bit back and forth but set it once your done, when you do hoodies shim the bottom of the frame and put a piece of cardboard on the out end of the platen, ideal no practical yes sir.
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I've spoken to Roger Jennings himself (a few years ago) and he uses cardboard tapped to the frame.
BTW, I have all Jennings equipment.
That's what we did waaaayyyy back, until we got manuals with side clamps. It worked very well.
Steve
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Thanks for the info I have decided to put the Jennings press up for sale and i bought a 6/4 workhorse mach.
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How much did you get for it
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Thanks for the info I have decided to put the Jennings press up for sale and i bought a 6/4 workhorse mach.
Actually, the Mach has a similar problem with off contact adjustment as it also produces pitch (cocking the screen and losing paralellness with the platen).
Hence, Roger's suggestions of shims may apply as well.Coincidentally, he covers this in the recent issue of Printwear.
Here's a link to the online version.
Article starts on page 94 in the online version (90 in print) This subject is on page 96
http://read.uberflip.com/i/453044 (http://read.uberflip.com/i/453044)
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Yes but workhorse and M&R have introduced a convenient way to adjust that where Rodger refuses to. I'm not saying this machine is bad but who wants to wrench on their press constantly when tool free is available.
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I haven't sold it yet
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Well, no one has ever accused Roger of not being old school. :)
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Wouldnt you just set the off contact once? with the plexiglass? Only take prob 2 minutes.
The plexiglass does shirts and when you go to sweatshirts i taped a paint stick on the screen and viola, off contact for fleece.
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Wouldnt you just set the off contact once? with the plexiglass? Only take prob 2 minutes.
The plexiglass does shirts and when you go to sweatshirts i taped a paint stick on the screen and viola, off contact for fleece.
I'm with you on this. I have a Hopkins 6-4 (Pro Line) that is definitely "Old School" but it is simple, effective and reliable as the sunrise. The design for the lower center bushing for the carousel was arguably of poor design, but I replaced mine with a flanged bearing made for Agriculture "disc" cultivators.
Once you get your off contact set for your normal platens (which was FAR more than a 2 minute job, for me anyway) you can adjust simply with stirring sticks or whatever...front and rear. The Registration Gate "guides" are simple Hex Headed Cap Screws 3/8-16 X 1.5" made out of nylon. The nylon bolt ends are "sacrificial" in nature and simply slide against the lowering print head...a clinic on elegant simplicity. I grease them with a wax stick. It will outlast me. The upper carousel bushing is the only remaining area of concern. I oughta order a spare from BWM, but it's tapered and as such, adjustable for wear. Mine will hold registration virtually for EVER. Riley Hopkins actually owns a farm 25 minutes from my house. His wife happened into my shop one day a few years ago. I guess I'm a fan, sortof.
I've nothing whatever against the newer "hardware". But I've manually printed at shows and workshops with at least one new press I wouldn't take home for free.
I've never seen an R. Jennings press, but I've heard pallet deflection is nearly zero. That's a pretty big deal...if true.
I wish my recently acquired auto was as reliable as my old manual, but I'm gradually getting things all sorted.
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I think every pretty much covered your original question. But, I"ll also add that the off contact on this press was designed to be set and left alone. I feel this is how all presses are. Some have presses have tool-less off contact adjustments, but ideally you want all your heads to have the same exact off contact and be level. I think the quickest way to adjust off contact is to shim the screen as previously mentioned. It only takes an extra second when loading your screen.
I liked my Jennings a lot. I think the only 2 changes I would make to this press would be M&R style aluminum pallets (Roger is adamantly against aluminum pallets) and Vastex/Anatol/Antec style micros. I think you would then have the perfect manual press. The micros were the only thing I really didn't like when I had one.
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It may not be the "right" way, but I have a Hopkins Pro-Line 6/4 and I just tape some spacers under the outer edge of the screen frames. You could use 1/8" Plexiglass or equivalent acrylic sheeting under BOTH ends of your screen frames to keep them nominally parallel to the platen. I don't usually use anything under the back ends. Paint stirring sticks are about right, and I've used them too.
Amen. It's what I always do to maintain off-contact when any flexing occurs, and it will.
I use cut down pieces of plain old yardsticks, but think I'll check out the paint stirrers (tks). Lately nobody is 'giving' away yardsticks, but paint stirrers are always free, lol.
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Thanks for the info I have decided to put the Jennings press up for sale and i bought a 6/4 workhorse mach.
BTW Steve, I have a workhorse 6/4 and I STILL use spacers taped to the front edge of the screen so flexing won't nose it down. The back generally maintains it's off-contact.
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I think every pretty much covered your original question. But, I"ll also add that the off contact on this press was designed to be set and left alone. I feel this is how all presses are. Some have presses have tool-less off contact adjustments, but ideally you want all your heads to have the same exact off contact and be level. I think the quickest way to adjust off contact is to shim the screen as previously mentioned. It only takes an extra second when loading your screen.
I liked my Jennings a lot. I think the only 2 changes I would make to this press would be M&R style aluminum pallets (Roger is adamantly against aluminum pallets) and Vastex/Anatol/Antec style micros. I think you would then have the perfect manual press. The micros were the only thing I really didn't like when I had one.
The diagonal micros are a pain until you get the hang of it, and by the hang of it I mean get spot on registration on each screen before it touches the press so you don't have to use the micros lol
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Valid points from everyone I'm not bashing this press I do own it and also drove 7 hours to buy it. I do believe that the work horse will be a much faster set up. I also tried the paint stick or shim but seems to not work for me.
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I think every pretty much covered your original question. But, I"ll also add that the off contact on this press was designed to be set and left alone. I feel this is how all presses are. Some have presses have tool-less off contact adjustments, but ideally you want all your heads to have the same exact off contact and be level. I think the quickest way to adjust off contact is to shim the screen as previously mentioned. It only takes an extra second when loading your screen.
I liked my Jennings a lot. I think the only 2 changes I would make to this press would be M&R style aluminum pallets (Roger is adamantly against aluminum pallets) and Vastex/Anatol/Antec style micros. I think you would then have the perfect manual press. The micros were the only thing I really didn't like when I had one.
The diagonal micros are a pain until you get the hang of it, and by the hang of it I mean get spot on registration on each screen before it touches the press so you don't have to use the micros lol
I have been printing on Jennings manuals for almost 15 years, although the micros are not the best once you get practice and realize they are "micro" adjustments and not for big movements (especially left and right) you can get dialed in very quickly. Not so easy for a beginner but once you get the hang of it they work.
As someone else said the lack of pallet deflection is awesome, there are a lot of reasons I haven't moved to another press. Roger built his press in a vacuum, he did not take compatibility into account which is great when you continue to print manually, once I added an auto they do not work hand in hand. I have toyed with switching to a more auto-compatible manual but I like it so much that I don't want to get rid of it for compatibility sake and end up with a host of problems I never had to account for. (We still run a lot of small/non-traditional jobs on the manual)
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Ok so why when I put the paint stick in the chanel does it introduce pitch into the screen again
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Ok so why when I put the paint stick in the chanel does it introduce pitch into the screen again
Sounds like something is not paralell
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So this machine should be level at all points from back to front of the head right
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Edited
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I do not put the stick in the channel, i just tape it under the screen.
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Ok so why when I put the paint stick in the chanel does it introduce pitch into the screen again
This is a back clamp machine yes? I believe you set the off contact for the back, and the paintstick (or whatever you use for shims) goes on the front end, and has to land on the plate; hence, you get the same off contact front to back, and it won't dip...
Steve
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Ok so why when I put the paint stick in the chanel does it introduce pitch into the screen again
This is a back clamp machine yes? I believe you set the off contact for the back, and the paintstick (or whatever you use for shims) goes on the front end, and has to land on the plate; hence, you get the same off contact front to back, and it won't dip...
Steve
What he said.
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His video sows the shim goes into the clamp under the screen. Yes it is a back clamp
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Once the clamp is set up paralell, a shim underneath the screen should not add pitch.
A shim of the same thickness added to the front of the screen merely adds support
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Silly question, but what type of screens are you using? I'm assuming you're not clamping the roller end of a Newman, but if so that could present an issue.
I've never personally used a paint stick. Is it warped or thicker on one edge?
Can you post a picture of what is going on ?
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My thinking -
An auto raises the platform and the squeegee drags across maintaining equal distance between the screen and the platform maintains even off-contact as the swipe occurs.
I believe with any manual 'back clamp' press, there will be flexing in the arm when you pull (or push) a squeegee across the screen due to the only thing holding the screen up is the arm and pressure exerted down will be more than the arm can withstand without flexing.
So if you taped any object (paint stick, cut yard stick, etc.) laterally under the front edge of the screen so it contacts the platen when pulled down, the mesh will maintain the off-contact and roll like an upside down tsunami when printing. Without a shim, flexing will lay a larger than desired part of the mesh down on the substrate and could compromise the print by picking up an undesirable amount of ink back to the underside of the screen.
IMO
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I'm using Newman's and clamping the square end. Also I am using a oversized screen so I cannot put a shim at the end for off contact.
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If putting the shim in the screen clamp to raise your off-contact you then do not need the shim above the print the be on the frame, just place it enough above the image as to not affect your squeegee pull but hit the top of the platen. Cardboard taped to the screen works great as it is very light. The main goal is to raise the screen equally at the screen holder and at the top of the print. As other posters have stated if you have pitch your press is not setup properly and needs adjusting.
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My thinking -
An auto raises the platform and the squeegee drags across maintaining equal distance between the screen and the platform maintains even off-contact as the swipe occurs.
I believe with any manual 'back clamp' press, there will be flexing in the arm when you pull (or push) a squeegee across the screen due to the only thing holding the screen up is the arm and pressure exerted down will be more than the arm can withstand without flexing.
So if you taped any object (paint stick, cut yard stick, etc.) laterally under the front edge of the screen so it contacts the platen when pulled down, the mesh will maintain the off-contact and roll like an upside down tsunami when printing. Without a shim, flexing will lay a larger than desired part of the mesh down on the substrate and could compromise the print by picking up an undesirable amount of ink back to the underside of the screen.
IMO
Um, what he said too...
Steve
ps. the main reason I like side clamps. Haven't shimmed anything since the seventies...
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My thinking -
An auto raises the platform and the squeegee drags across maintaining equal distance between the screen and the platform maintains even off-contact as the swipe occurs.
I believe with any manual 'back clamp' press, there will be flexing in the arm when you pull (or push) a squeegee across the screen due to the only thing holding the screen up is the arm and pressure exerted down will be more than the arm can withstand without flexing.
So if you taped any object (paint stick, cut yard stick, etc.) laterally under the front edge of the screen so it contacts the platen when pulled down, the mesh will maintain the off-contact and roll like an upside down tsunami when printing. Without a shim, flexing will lay a larger than desired part of the mesh down on the substrate and could compromise the print by picking up an undesirable amount of ink back to the underside of the screen.
IMO
Um, what he said too...
Steve
ps. the main reason I like side clamps. Haven't shimmed anything since the seventies...
And back in the '70's, those side clamps helped flatten those warped screens as well.
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Once the clamp is set up paralell, a shim underneath the screen should not add pitch.
A shim of the same thickness added to the front of the screen merely adds support<br/>
This