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screen printing => Equipment => Topic started by: tonyt79 on December 27, 2014, 11:19:09 PM
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Big question here! If a/c heads and servo index is the way to go, then why not all electric?
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I guess the main reason would be the engineering of the chopper mechanism. Also the screen clamps. There is an Anatol Volt going in at a shop I service next week. I am going to check it out. I'll post my pluses and minuses.
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Controllable squeegee pressure was another thing that was brought up as a "minus" of a all electric press.
Brown and Graphica also have all electric machines.
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The cost and reliability of the lift and lower is also a factor. Whether you lift and lower the pallet carousel or the screens, the advantage is with pneumatic.
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What they said.
IMO I would rather repair/replace some air cylinders then an electric drive motor and or linkage for the chopper drive mechanism. There are other presses that use the all electric like mentioned above but if was that amazing I would think other major mfg would have jumped on the idea years ago or it would dominate the industry. If the chopper assm was changed it might be a viable option but costly one.
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Big question here! If a/c heads and servo index is the way to go, then why not all electric?
the right company has not built one yet, one never knows whats around the corner....
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Short answer is that it is too expensive.
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You know I often wonder if the screen industry is just void of solid engineers, with stepper motors acme shafts and actuators you could easily make a machine that could precisely move a squeegee with absolute accurate repeatable pressures and swipe speed. With the HUGE supply of open source micro controllers, motors and the like I think the cost excuse is just that an excuse to not re-engineering the old designs. It is so much easier to time, adjust and control electronics than pneumatics in my opinion. Has there really been any huge changes in the basic design of presses? In the last 30 years Not really.
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You know I often wonder if the screen industry is just void of solid engineers, with stepper motors acme shafts and actuators you could easily make a machine that could precisely move a squeegee with absolute accurate repeatable pressures and swipe speed. With the HUGE supply of open source micro controllers, motors and the like I think the cost excuse is just that an excuse to not re-engineering the old designs. It is so much easier to time, adjust and control electronics than pneumatics in my opinion. Has there really been any huge changes in the basic design of presses? In the last 30 years Not really.
Here at M&R we have 26 master degree engineers on staff and every one of them disagree with changing the chopper assembly to electric. It's not only cost. It's the right way to do it with pneumatics.
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No doubt it could be done but the added cost of doing it the RIGHT WAY would far outweigh the benefits.
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Why is it better? Your the expert I am just a telcom engineer who prints, help me better understand, because being more involved with electronics I tend to think that electric is always a better option and if a system only has one support system electric / air whatever it's a cleaner simpler, better system. Can you honestly say the press has undergone changes in design that have vastly improved the overall process? I say no we have only made tweaks to the existing machine. Minor improvements to the basic design. I know I have been critical of you at times but I really am not going down that road here. Just posting my thoughts on the industry. I interface with so many industries and see huge changes in most of them then I look at screen printing and scratch my head.
Food for thought, an entire industry full of experts agreed no one would choose to buy a data file over a cd or album... I don't think I purchased a cd in 15 years how about you?
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If you go back and look at some of the older machines and what they were capable of and some of the features they had it does look like on the surface that not much has progressed with automatics in the last 20 years. When I first started researching autos in 2006, I was floored by the lack of features on the new machines when comparing it to our 1990 American Centurian. In the last 5 years, I think more has changed with the average automatics' feature set than the 20 years prior combined. At least it looks like it from my perspective, which is just the average print shop manager.
BUT, look at these videos from 17 years ago and it looks like my statement doesn't really apply to the MHM machines.
https://www.youtube.com/watch?v=XUuZJCbTOt8 (https://www.youtube.com/watch?v=XUuZJCbTOt8)
https://www.youtube.com/watch?v=j-aVxhxN4N0 (https://www.youtube.com/watch?v=j-aVxhxN4N0)
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Great videos I forgot about them. Pretty sure this was around the same time of the Formulas. Yes the 3000 was definitely ahead of its time. Light years ahead of those old brown clunkers.
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If you go back and look at some of the older machines and what they were capable of and some of the features they had it does look like on the surface that not much has progressed with automatics in the last 20 years. When I first started researching autos in 2006, I was floored by the lack of features on the new machines when comparing it to our 1990 American Centurian. In the last 5 years, I think more has changed with the average automatics' feature set than the 20 years prior combined. At least it looks like it from my perspective, which is just the average print shop manager.
BUT, look at these videos from 17 years ago and it looks like my statement doesn't really apply to the MHM machines.
https://www.youtube.com/watch?v=XUuZJCbTOt8 (https://www.youtube.com/watch?v=XUuZJCbTOt8)
https://www.youtube.com/watch?v=j-aVxhxN4N0 (https://www.youtube.com/watch?v=j-aVxhxN4N0)
Yep. With the exception of the separate squeegee and flood bar all of the features shown date back to 1992
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You know I often wonder if the screen industry is just void of solid engineers, with stepper motors acme shafts and actuators you could easily make a machine that could precisely move a squeegee with absolute accurate repeatable pressures and swipe speed. With the HUGE supply of open source micro controllers, motors and the like I think the cost excuse is just that an excuse to not re-engineering the old designs. It is so much easier to time, adjust and control electronics than pneumatics in my opinion. Has there really been any huge changes in the basic design of presses? In the last 30 years Not really.
You mention the cost of engineering as an excuse but its not about the engineering costs but the ownership costs. Imagine a $100K machine re-engineered to have all actuators, stepper motors, acme shafts etc. etc. cost to the owner? Remember we print shirts very low margin stuff compared to other industries.
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You know I often wonder if the screen industry is just void of solid engineers, with stepper motors acme shafts and actuators you could easily make a machine that could precisely move a squeegee with absolute accurate repeatable pressures and swipe speed. With the HUGE supply of open source micro controllers, motors and the like I think the cost excuse is just that an excuse to not re-engineering the old designs. It is so much easier to time, adjust and control electronics than pneumatics in my opinion. Has there really been any huge changes in the basic design of presses? In the last 30 years Not really.
You mention the cost of engineering as an excuse but its not about the engineering costs but the ownership costs. Imagine a $100K machine re-engineered to have all actuators, stepper motors, acme shafts etc. etc. cost to the owner? Remember we print shirts very low margin stuff compared to other industries.
Cost to owner? If it's built right and maintained (electronics are easier to maintain over pneumatics) how would it be more expensive? Right off the top you can get rid of your compressor, oiler and air dryer what's that 5-6 grand?
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a few thoughts, as I've built a few 'open-source' controlled wood CNC routers (largest being a 4'x4')...
think of the size of a servo unit to lift a 800+ pound printing carousel straight up in a fast manner... you're looking at several grand right here alone.
servos/drives for each head.. (I suppose you could still use the current AC motor/VFD arrangement that's become 'standard' for AC head units tho).
servo indexer (again, same as we use today)
servo print head -- at least 2 servos to raise and lower the squeegee and floodbar, plus their various drive components... AND... while you'd have control of how 'far' they push, without some kind of force feedback controller you'd have much less control over the actual print stroke than you do by varying air pressure going to the print chopper... so your garment thicknesses had better be super consistent, and everything on your press had better be leveled PERFECTLY.
also consider the speeds we like to print at... in order to drive an acme screw at the speeds we run pneumatics at, the motors would have to be quite large... which equals more mass on the print head, which changes everything down the line.
once you have all this in place, you'll likely need a much faster plc than what's used today to communicate with all these drive components.
while I'll give it to you that electronics are easier to maintain over pneumatics, they're also MUCH more expensive to get the equivalent performance.
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Nothing is impossible but I just suspect you'd end up with less control than with air pressure.
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Servo lift is accomplishedd with the help of a spring floating the tables, the servo lift actually has more of a load pulling the table down. So the load is actually done with a small servo motor and dive pully system.
There are several machines that use the servo to drive the print carriage. IMO too much for a simple operation, the drive motor and prox sensors work fine. If you wanted to get fancy you could use a pinwheel type of pick up to count reveloutions to set the travel distance but again over kill for the operation.
The choppers could easily be reengineered to use one servo motor and controller per head if programmed properly. The unit would have to be able to sence load (amps) to replicate print pressure. This would allow you to fine tune the print pressure using a pressure relationship in stead of using stops like chopper knobs. The servo, sensors, controler and other components would be the high cost items. A mfg may have a few hundred dollars per head using air, a propperly configured electric system that would give the benefits of air and some would be several thousands of dollars per head. Greatly increasing the cost of a machine.
IMO a round/round press is a better machine then an up/down. The speed is faster while increasing dwell time between indexes giving more time to load and unload without sacrificing production numbers. The wear and tear on the press is much less also.
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Oh and squeegee/flood locks along with screen clamp issues can be over come with a little creative engineering.
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a few thoughts, as I've built a few 'open-source' controlled wood CNC routers (largest being a 4'x4')...
think of the size of a servo unit to lift a 800+ pound printing carousel straight up in a fast manner... you're looking at several grand right here alone.
servos/drives for each head.. (I suppose you could still use the current AC motor/VFD arrangement that's become 'standard' for AC head units tho).
servo indexer (again, same as we use today)
servo print head -- at least 2 servos to raise and lower the squeegee and floodbar, plus their various drive components... AND... while you'd have control of how 'far' they push, without some kind of force feedback controller you'd have much less control over the actual print stroke than you do by varying air pressure going to the print chopper... so your garment thicknesses had better be super consistent, and everything on your press had better be leveled PERFECTLY.
also consider the speeds we like to print at... in order to drive an acme screw at the speeds we run pneumatics at, the motors would have to be quite large... which equals more mass on the print head, which changes everything down the line.
once you have all this in place, you'll likely need a much faster plc than what's used today to communicate with all these drive components.
while I'll give it to you that electronics are easier to maintain over pneumatics, they're also MUCH more expensive to get the equivalent performance.
Pricing the big 240s you can get them for 340 retail
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I tend to agree with bink that a screen drop vs table raise is probably the better method tho I'd you were going to go all electric.
I still think the cost of all the electronics would really add up tho and make it not cost effective.
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To say pneumatics will be more accurate then electric drive, to me , is silly talk.
Cheaper sure, better? Who knows none built. I understand the economics and the increased costs but I really don't think, all things considered it would be much more over the life of the press. Obviously a home built cnc machine would not be the pricing model for building industrial equipment not even close but the open source market has lowered a lot of the electronics across the board including your larger drive equipment. Imagine if you might a press that you dial on your squeegee speed then change your inks out and it automatically adjusts, can't do that without electronics. What about a platen that senses when the thickness has changed on a print and alerts you? Gonna do that with air? The list goes on and on. Things that we all would drool over and want but no one is thinking about making, too hard too pricey, and the industry stays where it's at.
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Electric positioning is very accurate for getting to a repeatable place.
Force measurement on electric systems typically don't have very accurate measurement, at least ar the less expensive of the spectrum.
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To say pneumatics will be more accurate then electric drive, to me , is silly talk.
One could say the same for this thread
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To say pneumatics will be more accurate then electric drive, to me , is silly talk.
One could say the same for this thread
agreed!
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To say pneumatics will be more accurate then electric drive, to me , is silly talk.
Are we running milling machines producing $$$Valuable$$$ components, or are we printing t-shirts for pocket change?
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To say pneumatics will be more accurate then electric drive, to me , is silly talk.
One could say the same for this thread
It's just me being silly not the entire thread.
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The most common thing I've ever had to fix on any press is air valves/lines. While maybe not feasible to completely remove air,
I will say the less of it the better. Squeegee choppers would be the most difficult as you need some amount of cushion.
What about big adjustable springs, which is essentially what a pneumatic cylinder is? Sure springs wear out, but so do cylinders.
(save for the Kuhnke brand apparently)
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I tend to agree with bink that a screen drop vs table raise is probably the better method tho I'd you were going to go all electric.
I still think the cost of all the electronics would really add up tho and make it not cost effective.
The boys in New Orleans have this on their 12? color... it's done pretty well. Thought time will tell, they are certainly putting it through it's paces!
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To say pneumatics will be more accurate then electric drive, to me , is silly talk.
Are we running milling machines producing $$$Valuable$$$ components, or are we printing t-shirts for pocket change?
Why measure screen tension, emulsion thickness, why level a press to the thousandth of an inch it's only a shirt. That might be why change is so slow sell what the people feel is good enough. Thanks, it's clearer to me now. Why change if there is no call for it? If it ain't broke and people buy it why change it. It's just good business, till some idiot comes along and changes things lol.
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We have debated this a lot in our shop. When we were deciding on or last press the RPM hung in there till final 3(actually pretty close to final 2) and it was simply because of how exact everything could be controlled digitally. I have had my hard head argument that there was no excuse to not have android phone type device on the end of every print head that would control EVERYTHING.
In our shop we have debated/questioned why other advanced options and features are not available on presses. What we keep coming down to(not that we are equipment manufacturers) is a assumption of what people/customers will ACTUALLY pay for. It seems like manufacturers are always trying to come out with a press that will be less expensive, not more expensive. The slogan "we added a few touch screens and 15% raise in list price" isn't exactly a great pitch! :)
I think M&R has a very good example of what I am saying. From my understanding(please correct me if I am inaccurate) the main difference between the CHIII and the CHIIID is more exact and digital control throughout the machine, but especially on the print heads. Here you can get a equally capable machine, but you have the option to add(pay) the extra bells and whistles. Essentially serving two different prospective customers.
I think when machines like the Sabre and the newer interface of MHMs start becoming more common place, the other brands will almost have to eventually follow suit at some point and ditch the switches, buttons, and dials. But who knows, we all may be printing on 4 head 12 station DTG presses by then! ;)
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I'm a bells and whistles kind of guy, but I know it's not for everyone. I would get bored with no toys or tools to play with out back. If it was just toggle switches and rheostat knobs I'd need something else to get the blood flowing and there is no telling what that would be. I like vintage land cruisers, fine watches, and automatic screen printing presses with bells and whistles :) but I don't expect everyone else to like the same things. But when it comes to the thread topic, AC heads can make a huge difference when used properly. I know I'd hate to be printing white ink through 156/64's, 195/55's or even a 110/81 in this weather with air operated print heads. I have nightmares about that...and being attacked by large women with no clothes on. Wonder what that means? Don't answer that...I don't want to know.
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Why not Jack up the price when adding $500 per head... that equates to 15% right? ;-)
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Why not Jack up the price when adding $500 per head... that equates to 15% right? ;-)
My guess is it would be much more than that, and that is kind of my point in this hi jacked thread- We want these ultra futuristic options and features but my guess is that the majority if presented with the dollar figure to upgrade to the digital SOB, most would pass.
$500 per head for all digital upgrade, I'd go for that.
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I was mostly meaning price of the tablet/device on there.
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Interesting Thread!!!!!
All of these issue have been answered.....Anatol makes a ALL Electric Press (the VOLT) which is tested in the field with over 35 press sold. Servo driven for speed, strength and reliability We have in the field, small and larger press in fact a 14 station 12 color.(so Far) Customers rave about the press.
No issues what so ever with the performance. Pneumatic screen clamp issue has been solved. Please come visit me in ISS Long Beach Show Booth#471 and I will personally show you the press.