pneumatic vs servo and ac heads

[Shanarchy]

What are the big differences, pros and cons, of a pneumatic indexer vs servo indexer, and pneumatic heads vs ac heads. I had an Anatol Horizon, all pneumatic, but I have no experience with the latter. I'm starting my quest for another automatic.

[ebscreen]

I've only ever had servo/ac, but I can say that if it came down to it I'd take ac heads and air index over the opposite.
Air heads can be jumpy, which typically doesn't matter, but with AC you can plow through the thickest inks with ease.

An indexer is just that. Servo will be faster and smoother, but pneumatic will get the job done as well.
Pneumatic will require more air and more maintenance, but if anything on a servo goes you're in for some $$$.

So in short, aim for servo/ac. If not, pneumatic/ac, if anyone actually makes that.


Quality work is done on everything from Challenger 3's to Jiffy Clamps and wood frames. I even remember Mr. Hood
exalting a printer in India using handstretched screens and homemade emulsion, yet chastising those of us in the US
that would think of anything other than Newmans.

[ZooCity]

I've only used air, unless you count the electric head on the old flat stock presses. Done right, as in the chopper and stroke cyls have sufficient bore and other characteristics beyond my knowledge of pneumatics, I don't think they could be a whole lot worse than an electric head.  If under spec'd they will stall out at too fast a stroke speed, chatter and slam into their stops flangin' ink all over the place.  Spec'd correctly I bet you could overcome all that.  A brand new press with air heads might be just fine. 

My question is why bother with the air?  You'll save $ on the initial purchase (pneumatics being cheaper than AC motors, etc.) but will need a serious dryer/chiller combo and who knows if that savings really means much after you add up the electricity used to compress the air to operate the press.  I would imagine it's even stevens on long term costs between the two. Or maybe in favor of air machines if your shop has copious compressed air already available. If that's true, there's no reason not to get AC heads.  It's much easier to control something electric on drive system, no brainer there in terms of ease of use and consistency in real life operating conditions.  Going new or given any option I'd take the electric up front.

Man, I totally agree, presses should have pneumatic index and AC heads rather than the other way around.  I think you see it the other way around b/c you can streamline mfg of a machine if all the units have the same servo driven base.  Pneumatic index can be annoying but it does work fine and, if you take the time to really dial it in for the exact platens you are using can be very fast.  Downside of air index is that if you don't keep it dialed you'll prematurely wear the bearings and forks and need a re-registration sooner than you should.

[alan802]

Funny that both of you mentioned you'd rather have a press with air index and AC heads rather than the other way around that you see most typically because I have felt that way for a long time but haven't heard anyone else mention it.  I have brought it up in the past and I think someone in the know responded as to why you see so many servo driven/air print head machines.  I can't say much of anything more than EB and Zoo said, those too are my thoughts on the matter.  I know air print heads are used by thousands of shops every day with great success, but I'd always pay extra for AC heads if I have the chance.  The few presses that I've been around that were air heads, it seems like the likelyhood of double stroking is far higher due to the inconsistent speeds.  When the speed changes the edge of the squeegee likely changes very slightly but enough to prevent some ink from shearing from the stencil therefore needing the second print stroke.  We all know air gets the job done, but AC gets it done faster.  Not necessarily better but definitely faster, and a good bit more quiet.

[dirkdiggler]

AC heads are FAR superior!  Many reasons.  If you can afford AC heads....do it!

[DannyGruninger]

So my first auto press was a v-squeegee all air tuff freedom press. Since that press I've had nothing but m&r machines which have ranged from all air to servo index/air heads, to our latest ch3 press which is all a/c. I agree with what has been said for the most part and that's the fact that almost any machine in the right hands can achieve the same print regardless of air vs a/c. I've done some incredible looking prints on all air presses that imo would not have improved on an electric machine. Now if your a shop doing lots of 4cp and sim process I would strongly suggest a/c heads for the pure reason of consistency as well as the digital readouts so you can measure the speed of the stroke. With air head machines this is one downer imo but as far as quality of prints don't let anyone trick you into believing an a/c head/servo machine can bang out much better prints....From my experience with the 5 autos I've personally had this has never been the case. Now would I ever go back to a machine that was air? Heck no, our all a/c machine runs super smooth, not near as noisey and we never have issues with air supply which we did with our air machines. Like Alan said, a/c is faster which in some shops like ours is a big deal. When we get busy we are slammed with little to no down time and when we can print faster it really helps us out. More then anything I think having an index system like a ch3 or the new press m&r is releasing that dirk is getting imo is a better benefit then anything. The fact we can leave screens on the press after a job is completed, setup the next job and not worry about getting ink from the previous job on shirts is a huge time savings for us. The fact we can double stroke jobs @ 65 doz/hr and run single stroke jobs @ 90+ doz/hr has made me a firm believer in the ch3 indexing system. I will say our next auto will be another ch3 or this new sporty for the pure fact of the indexing system. We like the system that much! If you can swing a/c heads and servo index I would strongly suggest it. Will it be a make or break deal, no but it sure is "nice"

[ZooCity]

we can double stroke jobs @ 65 doz/hr

This right here is probably the most impressive thing about an M&R press I've ever heard.  That would be an insane benefit to waterbased and discharge printers like us.  Also one area where air will work but, not as well- the up/down tabling is just plain slow. 

[sweetts]

Its so crazy this was posted I was just talking about this. Good question

[TCT]

The difference is well worth it. I think A LOT of people end up with all air presses because that is the cheapest way to go. Which if it is your first press is fair enough. I remember buying our first auto, all the sales guys were trying to push the ac heads, I just didn't understand how different things were until I got a press with ac heads.
Sometimes for us(up north where it gets cold) in the winter white ink with pneumatic heads would suck to print in the morning. Our shop would get as low as 40 at times over night, and that ink was like concrete. The ac heads just kinda power through it either way. There is more even and exact control with the ac heads. On your anatol you probably just adjusted the dial at the end to a speed you liked right? Problem is sometimes that "value" if you will wouldn't always be the same speed, say you were printing all heads and the press was really sucking air. The ac heads print at what you set them at, period. They are also much faster. If you are doing 1 or two color basic spot color stuff and are not going to try to run your press at top speed all the time, the ac heads are probably not necessary, nice, but not necessary. If you want more exact control(alan's RPM is still my favorite press for complete exact control)  the ac heads are the way to go.

I think you guys have a valid point with priority on a press being ac heads over ac index, but I think Zoo probably hit one of the maid reasons on the head-

I think you see it the other way around b/c you can streamline mfg of a machine if all the units have the same servo driven base.  Pneumatic index can be annoying but it does work fine and, if you take the time to really dial it in for the exact platens you are using can be very fast.  Downside of air index is that if you don't keep it dialed you'll prematurely wear the bearings and forks and need a re-registration sooner than you should.

If you are going to break out the money for reliable and exact ac heads, chances are you are going to want a indexer just as reliable and exact. When those print heads start flying, why would you want the indexing function be the thing that slows you down. Think of it as the weakest link in a chain analogy. I am pretty sure if you order a press new, you can specify a pneumatic indexer. But how much exactly do you save? $1000 maybe(I could be way off)? If you are going to buy a $40K or more press, the $1K or whatever to me seems like small potatoes especially for such a intricate part of the press as a whole. 


I'll probably catch heat for it but, if you are looking at a intermediate level press(just assuming you were if you want ac heads) you really owe it to yourself to check out a S.Roque YOU or ECO. Both are all ac machines.

[Prosperi-Tees]

I am also a fan of the rpm head controls. That seems so nice to be able to adjust on the fly and record what that job printed at. Is there a patent that, that is preventing other manufacturers from adopting that control?

[Shanarchy]

Thanks for the replies, and keep them coming if you have more to add.

I am searching both the used and new market. If I go new, I'm pretty sure I want to go AC and servo. The ones that stand out to check out are The Horizon XL, Stratus, RPM, S Roque, and of course Diamondback XL and Sporstman. The only presses I have not actual seen on that list is the Stratus and RPM. I didn't include MHM on the list because I'm pretty sure that is going to be out of my price range. I still have a lot of calls and research to do. I'm not looking to buy tomorrow, just trying to get my ducks in a row.

It seems a lot of good deals come up on the used market for the all pneumatic presses.

[Prosperi-Tees]

I wouldn't exclude MHM, it is probably very close to the RPM and Sroque machines pricewise although that Diamondback XL is an excellent value for what you get.

[TCT]

Not sure when they are doing it, but MHM was supposed to drop the E-Type. Then their S-Type was supposed to be their entry level press.... That is an expensive entry level press....

Out of the three(MHM, S.Roque, RPM) The RPM and the S.Roque YOU  are roughly half(maybe closer to 45ish %) the price of the S-Type. You get the digital controls and readouts(which I absolutely LOVE) with the RPM, but you get more press and capabilities with the S.Roque.

When we got our last press(about a year ago) S.Roque, RPM and MHM were our finalists as well.

[inkman996]

Another benefit of servo not mentioned is you have full control at a touch of how it acts. You can reverse direction if needed, you can half index for easier screen access. and you can control its index speed any way you need.

[3Deep]

Only thing I know about servo is they run smooth and quiet, and I really can dig having AC print heads, an all air machine gets the job done but it sounds like your working in a machine shop LOL.

Darryl