Holding registration -- what is a reasonable expectation?

[redwoodtees]

I have a manual back-clamp press (Workhorse Mach). I'm starting to do jobs that require tighter registration, and I'm getting frustrated. I'm trying to get a feel for what kind of variance is normal or acceptable for my situation. Here is what I am experiencing: I register a screen, tighten everything, raise the screen, gently rotate the carousel back and forth to simulate normal operation, drop the screen back down, and I am out of registration by as much as 1/16". So I re-register and repeat, and again the registration is off. Is this to be expected on a back-clamp press, or does my press need adjustment? Or perhaps I am just doing something stupid (I am still relatively new at this). I'm also reaching out to Workhorse, but wanted to get some general feedback on manual presses holding registration.

Chris

[244]

I have a manual back-clamp press (Workhorse Mach). I'm starting to do jobs that require tighter registration, and I'm getting frustrated. I'm trying to get a feel for what kind of variance is normal or acceptable for my situation. Here is what I am experiencing: I register a screen, tighten everything, raise the screen, gently rotate the carousel back and forth to simulate normal operation, drop the screen back down, and I am out of registration by as much as 1/16". So I re-register and repeat, and again the registration is off. Is this to be expected on a back-clamp press, or does my press need adjustment? Or perhaps I am just doing something stupid (I am still relatively new at this). I'm also reaching out to Workhorse, but wanted to get some general feedback on manual presses holding registration.

Chris

Something is out of adjustment. You should be able to print dot on dot with no gain.

[Frog]

Are your registration gates allowing movement and slop? Those are the white nylon bolts.
Adjust and grease.

[3Deep]

I have a back clamp press and it stays dead on, I would check the head that is off, and Frog is right check your gate bolts.  Also it sounds like your screens aren't tight enough in the clamps, you might want to check that also, there so many things that could be wrong it's very hard to say because every brand of press is built a little different and have there own set of problems.  What every brand of press you have I would ask if any has that press and compare notes.

[Prince Art]

Gate bolts were my first thought, too. But if that isn't it, go through every part that's adjustable, and make sure there's no play in anything.

Question: I assume you're having the problem after using micros, right? In which case, see above. But if by chance you're talking about it going out after registering manually , then it's not unusual (in my experience) to have screens shift when clamping. There are a few ways to compensate for that. One thing I've done is put some cut pieces of pellon between the clamps & screen, which allows the clamp surface to turn freely as it tightens, rather than biting in & moving the screen.

Another less-likely thing to look at is whether you are putting pressure on the screen in a certain direction when registering, and then not doing so when you pull the screen down for a check or test print. This might happen if you stand to one side during reg (I've done this, to reach micros) and push down one side of the screen; then when you're checking later, you stand straight on & pull down from the middle.

[BrazosDesigns]

I have a Mach 6/6 and I had the same problem.  Single colors jobs were fine, then got into multiple and 5-6 color gigs and had to figure out what was going on.

1.  Make sure you register all screens to one station.  Designate station one as your registration/setup.  Each screen gets setup to that.
2.  Check your registration nylon bolts.  The screen should slide down in the gate with just a nudge of tightness.  If too tight and you hear a squeak as it goes down, some screens may make it push out to the left, some to the right, ESPECIALLY if you have a unit that is not all-heads-down.  These are the only bolts that don't have to be cinched down too tight.
3.  Make sure your nuts and bolts are tightened.  Micro registration x/y nylon bolts: the bolt/nut on each side must be very tight or there will be a bit of play regarding maintaining your off contact the entire squeegee length.  Trust me, tighten them.
4.  Once you get your off contact/tilt adjusted, tighten those bolts two bolts on the head that go left/right.  If not tightened you will have some play.  The play will go left to right putting you out of registration just enough to make you pull out your hair.

Doing these will help you gain registration success.  I had COMPLETELY disassembled my mach 6/6 when I got it (very used) and didn't quite tighten things.  Once I did, it was easy. 

Also, I've had it for a year and didn't realize until 2 months ago that it was an all heads down until someone mentioned it.  I had overtightened those screws not realizing what they were.  All-heads-down is wonderful (if yours has it).

Oh, and finally.  Make sure your pallets are tight enough on the bracket and the bracket is tightened enough and does not move.  I spin my stations from the pallet (and sometimes with a bit of force when moving quickly) and I have nudged the pallet out of registration.

Let me know if I can help...

[screenxpress]

I have a workhorse 6/4.  I've had to tighten up all the bolts on the arms where attach to the center plate.  A slight shift in the platen arm will drive you nuts. 

As others have said, check the nylon gate bolts.

How is the mesh tension?  Loose screen mesh can affect registration. 

Also thin wall aluminum frames can give and flex causing reg problems. 

When out of registration, is it left to right, top to bottom, or a mix?

[mimosatexas]

Glad I have a Kruzer... Haven't had to tighten or level or generally f with anything for almost a year. Pixel perfect registration all day every day. I hate the nylon bolts on every press I've tried them on.

[Sbrem]

Personally, I've never liked back clamps, though I know plenty of folks are successful with them. We just trashed a really old Rototex 6c, and kept all of the side clamps from it to use on a Hopkins we picked up years ago, but almost never use...

Steve

[screenxpress]

I don't care for back clamps either.

Wish I had known the issues before I bought the workhorse over 10 years ago. 

Ya got what ya got until you get something better.

Maybe someday I'll be able to dump it and get me a Kruzer

[Frog]

With today's aluminum frames, I miss side clamps much less. Back when half of our wooden frames were warped, the side clamps really helped level things out.

[CBCB]

Tons of excellent advice in here.

All I can think to add is to really make sure you have even level off-contact between the screens. Tight/new screens definitely makes a difference.

Make sure your platens and brackets are tight! That has driven me crazy before. Same with the nylon bolts, as mentioned.

Good luck!


Sent from my iPhone using Tapatalk

[redwoodtees]

Thanks for all the great advice.. I plan to spend some quality time with the press this weekend and get everything dialed in. I'm happy to hear that perfect registration is an achievable goal!

[screenxpress]

Red,

I asked above if your out of reg was left to right, in to out, or something else.  I don't think you answered.

IF it's "in to out".........to insure your off-contact is uniform for all screens......what I do, is break up an old yardstick and tape a 10 in. strip across the top of the screen and another 10 in. strip across the clamp end as close to the screen frame as possible and where they will set on the platten when you pull the screen down.  What that will do, is maintain uniform off-contact and take any arm flexing out of the picture which can easily throw your registration off "in to out".

I use the "broken yardstick" method printing single or multi-color prints just to maintain a uniform off-contact to eliminate arm flex to leave part of a screen image to lay on the substrate and not allow it to "snap" to clear the ink from the screen.

I have found on my workhorse the nylon screws do the job for left to right, but arm flex raises issues for me and this seems to have solved my problems. 

In my mind, this action emulates what the auto's do since they don't have a single arm and raise the platen to maintain correct off-contact for the squeegee.

[mooseman]

It may not be your screens it may be your plattens that are moving when you rotate the press. We have a Vastex 2000 very heavy machine. When I first started out had the same issue and discovered the the energy I needed to rotate the press was more than the screws that held the plattens to the press arms could handle.
A tip from a board member suggested using non skid tape like the kind applied to stair steps to the arms and pallet brackets to gain some much needed friction to the assembly.
We also ditched the hand screws and replaced them with same size bolts that get tightened with a wrench....end of problem. As I said the Vastex is a very heavy press built like a tank and throwing the press around by the pallets initially was way more than it could hold with the OEM method of attachment.It has been years now and no movement there any more, in fact we almost always set our art for butt registrationand have no issues, tight roller frames, back clamps and some good luck I guess.
mooseman