Pre-reg!

[ZooCity]

Alan, I'm suggesting either pre-punch sheets or print from roll and then punch the sheets, either stacked or one at a time, whichever works best.  The goal here is no reg marks, no aligning of positives using reg marks.  None of that.  Just print - punch - align to tabs and go. 

These hole punches are designed to let other types of printers perfectly align their substrates on the table.  We should be able to put the film in the punch and square it up accurately.  Assuming the sheet sizes are consistently cut or, if roll, the printer cut the roll at the same place it should be very close as far as the punching part goes.  An easy check would be to always print a little 0.5 pt dash at the top to make sure the roll film is starting at the same place each time and use a cutter to trim the top off if needed. 

Homer, this is all speculation, I haven't tried it out yet but will soon. 

Now regarding the printer itself, I think roll feed would be fairly accurate seeing as the roll on the 4800 isn't like a toilet paper holder, it actually indexes the film forward at a certain rate.  There is variance on longer prints on inkjets but here's my take:  you have to deal with that whether aligning the positives by eye or with punch holes.  The real challenge is getting the media to feed very accurately. 

All that said, even if it's a little off by the time it all gets on press, I'd be a happy camper with all that time saved.  Think about it- even if it's not perfect, you run your base print or a key color, check each screen visually before printing, maybe tweak a micro or two, test print, maybe tweak again, maybe not and run.  The only movement happening on press would be from the micros and if you think that takes too long, think of all the time saved in pre-press with this method.  It's literally film output to on-press with no visual alignment whatsoever up to that point.

Perhaps one of our resident inkjet gurus could chime in on the concept?

[alan802]

Ok, I got some pics here.  I'll start with what we are doing now, then what I want to do in the future. 
















One of the main things I want to change with the next version is where the "bump stops/post" come into contact with the frames.  I don't like my posts and I don't like that they bump up against the rollers and want to move them to the newman and shurloc frame corners.  I think I'll get better results by doing that.  I also will move to square bump stops as seen on the next set of pics. 

This is one option I have for an FPU.  Notice I have the square tube aluminum bump stops located in a place where the frame corners will touch them.






Now I have the MHM style option that I am seriously considering.  Disregard the almost nonexistent grid I have on the next set of pics.  I just drew them for the sake of taking these pics but I'll make something much more professional looking with a nice grid on a white mdf board or something similar.  I'm going to build it up so when I lay the screen down it will come into contact with FPU while the corners will bump up against the square stops.








Those are just a few pics with some random ideas.  I think I might run into a problem when using the MHM style FPU and trying to fabricate a pallet jig since the frame will be one side up on the FPU and then flipped upside down when putting the screen on the press.  I will make the bump stops tall enough but I'm still uncertain whether they will touch the frame corners in the exact same place because these frames aren't perfect.  I can see there being some angle on the corners and there being a difference in location where the corners touch the stops from pallet jig to FPU.  I could be wrong and there is only one way to really find out, trial and error.

[ZooCity]

Nice pics Alan.  The MHM style thing you have is what I'm leaning toward.  I feel like anyone good with fabrication skill could whip this up for not too much cash.  If you were to use punched sheets all you would do is line 'em up at the top to a set of pins, smooth down the film, tape the film on and gently remove the screen/film to go to exposure.  You could take second to inspect both the screen and the film at once.  You could also stack all the films up, going one at a time for visual inspection to check for art or reg errors before putting each one on their separate screens at a station like this.  If one film is a little out you manually align, forgoing the pins or mark that screen so you'll know it will need tweaked on press. 

You said:

I will make the bump stops tall enough but I'm still uncertain whether they will touch the frame corners in the exact same place because these frames aren't perfect

And I came to the conclusion after looking hard at the newman pin-loc system that both screens and presses have more variance than the film alignment system does.  Just embrace the variance and don't worry about having absolutely perfect pre-reg is my take on this.  Why fight to have supremely accurate film alignment when the screens will throw it off and so will the press variables?   Just keep it quick and clean and then adjusting micros now and then won't be such a huge deal. 

[jsheridan]

It's literally film output to on-press with no visual alignment whatsoever up to that point.

Perhaps one of our resident inkjet gurus could chime in on the concept?

This was and still is the best part about imagesetters, they came with a cutter and punch option.

It'll be a glorious day when this technology is realized by Epson or some other Joe who makes and "add-on" so when the film feeds out of the printer, it feeds through the punch and does the magic.. all from your 17" ink jet.. there's a pre-reg system waiting to be exploited.

[Dottonedan]

It's very much awesome to see people really discussing such beneficial and educational subjects. The pictures are an addded bonus. Thanks for the extra effort you guys. I think I'm gonna cry.  Sniff. Sniff.

Good stuff.
Ok,  carry on.

[ZooCity]

Well epson has the cutter already.   

Thing is, the cutter should be as accurate as the part that indexes the film forward.  At least that's what my theory is banking on. 

So, if you're accurate enough in squaring up the top of the film to the punch it should be kool and the gang.  The bastards do tend to just feed film for no god damn reason on a regular basis so you'd have to watch out for that. Having that little indicator line print out on your films would notify you when that happens.

So imagesetters had all this jazz included?  Do they still?  Kind of makes that massive up-front costs look more justifiable and sounds like a good time to me. 

I was watching that newman pin-lock video again and there is so many steps on these systems.  I know the goal is to absolutely minimize change-over and downtime on autos.  It just seems like a lot of alignment and taping to me.  There's room for error in initial placement on the carrier as well.  With the system I'm describing, whomever placed the file onto the output template makes that decision and sets it in stone.

[Homer]

Zoo - I agree 100%. I watched every damn video over and over again too, it seems like way too much tape and room for error. I'm not saying my system is great, perfect or anything spectacular -but the one you are going at sounds pretty damn sweet.  not much room for human error -that I like. And I would pay a decent amount of coin for a system like that. Plus, the newman system requires me to use nothing but rollers and I have to alter my screens. There needs to be something that works on any type and size of screen, out of the box, no alterations needed, print films and go. . .and a reasonable price.

[Denis Kolar]

Alan, thanks for the pics, that gave me an idea. Will get back to you guys with the pics when it is done. It should be the simplest one to use (at least for manuals with the rear clamps).

[ZooCity]

Just picked up a pin-lock system as chance would have it.  I'm going to run the system the "traditional" way once we get it setup and then, once I know the parameters of the pin system, I'll use it as a control to test out the punched films theory.   I know the pin lock is likely as accurate as it gets, next to mhm's pin system so it should be a good starting point and eliminate any chance that a jerry-rigged 3 point reg is the issue.

Spoke w. George from Stretch about this and had a great talk.  I also invited him over to the boards.  Newman did sell their punch for awhile but not too many shops wanted it or were willing to pay for such a system. It looks like the film reg pins are fairly standard, oblong shape and/or I may be able to swap out for my choice of reg pins.  There's still plenty of industries and arts using this method so the gear is out there.  Theirs used a vac table (like a graphics or transfer press) to hold down each film sheet so it was not only square to the punch but perfectly flat- this should eliminate all but the printer itself and the squareness of the film as major variables.

I'm going to homebrew a vac table/punch setup sometime before the year is out hopefully and give this a whirl.  I have high hopes for this but if it doesn't work we can still use the system the regular way and it'll still work out just fine for single color prints either way! 

This thread has been a good kick in the pants.  Thank Homer for sparking up this topic with your glass-reg masterpiece.   

[ZooCity]

Plus, the newman system requires me to use nothing but rollers and I have to alter my screens. There needs to be something that works on any type and size of screen, out of the box, no alterations needed, print films and go. . .and a reasonable price.

Oh, and I agree, this is a weakness.   Then again, 3 point has it's weaknesses too seeing as all the frames are bit different.  The pin lock is easy going in that all you have to do is remove two end bolts on the short roller and put 'em on.  But, if there was a way to get universal pins on all screens it would be optimal.  I know you can do this easily if everything in your shop was mhm but I somehow don't see three new mhm presses in my future.  It can be done though- your own type of pins and a jig and there you go.  Bet you could even bolt the newman pins onto statics somehow.   I think Roger Jennings had something going like this at one point. 

[alan802]

Here is what I plan on doing with my aluminum slab then I'm going to affix the pallet extrusion that is on the current pallet jig.  I plan on putting the stop blocks on the pallet jig to duplicate the FPU.  But I think I'm going to make a change to the stop blocks and keep the one that is on the long side of the frame the same and turn the 2 blocks that are close to one another into one 90 degree L shape block.  I don't really have a reason for doing so other than I think it will be easier to do that rather than get the 2 blocks perfectly placed to form a 90 degree angle.  I think getting those 2 units to be exactly the same is the key and if one is just slightly different than 90 degrees, I will get bad results.

[Homer]

Al -you can't cut that aluminum yourself? might take a while but the right blade and a jig saw will do it.

[ZooCity]

Aluminum is easy to cut w. a carbide blade.  Just remember to reverse it on a table saw.  I almost impaled myself with a 2"x16" shard of aluminum trimming down a platen once. 

[jsheridan]

Al -you can't cut that aluminum yourself? might take a while but the right blade and a jig saw will do it.

Drop it at the local waterjet shop, give him some freebie shirts with his logo (if you have a DTG) for the business call then go back, print and make money. Pick it up a few days later and all the cuts are perfect, edges are smoothed and all the tap holes to mount the stop blocks are ready for tapping.

F that jigsaw and table saw.. I've cut enough 6061 to know it's gonna take me 2 hours to measure and make all those cuts, then sand the edges and drill and tap holes.. yeah no thanks. send it out.

[squeegee]

Hey Alan, good stuff dude, have you thought about backlighting the art board?