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screen printing => Equipment => Topic started by: inkman996 on October 05, 2011, 12:48:41 PM
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Going from yesterdays topic about physics and chopper set up, air versus mechanical I thought I would start this as a new topic and share how i do it on my press, I am not new to auto printing but I am new to chopper system so i had to trial error myself to find what works best.
Just like Alan I use both to get the best results.
First I find my lowest palette in the bunch, it is not far off but it is best to use the lowest one.
I set my squeegee mechanically to stop just above the palette by using a magnet business card as a feeler gauge. I then give the choppers another rotation for good measure. Now my squeegee is mechanically stopping about level with the shirt maybe a hair more. From their it it simple to adjust just the air pressure to clear the ink better. By using the lowest palette I can find i am positive the print will clear on all heads.
This has been working perfectly for me once figured out and if I change angles I can count the clicks on each cylinder to get accurate adjustments. Yes all this can be avoided by simply using air only but I find screwy results doing it that way and a lot less consistency.
Here is my biggest problem tho. Since we are north east we print tons of fleece, many times with in the same run as t shirts, so I have to constantly adjust off contact. Being that I did not get the lift cylinder as advertised on my press ( one that has a click system for accurately adjusting) mine only free spins, I have been trying to document an accurate amount of spins on the OC to the amount of spins on the choppers to match the OC. Alas it is simply to sloppy to get it accurately and i have to test and adjust each and every time I change OC.
If my OC was accurate for example lets say I lower it by five clicks then it will take 10 clicks on the choppers, life would be good and change overs would be fast.
My advice for future auto buyers is to examine the type of OC the press has, if it is an accurate kind you will love it, if not then you will be doing what I do.
Alan question i know you have already mentioned it in the past but I will ask anyways because I forgot, what is the typical air pressure you are running? I find I am between 30 and 35 psi on 90% of stuff, but on thin inks on top of bases I can lower right down to 25.
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Wait.....what? You didn't get the option on the press as advertised? Sounds like bait and switch but what do I know?
Seriously though I'll bet theres a creative way to gauge that.
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No I did not get as advertised, in fact they even drilled the holes for the correct OC on y press but they must have ran out of the proper OC and substituted a smaller crappier one by drilling new holes, go figure!
Tony I can get really close by turning the OC carefully a certain amount but still it is sloppy and still takes a couple tests prints to verify first, if it was accurate man it would be sweet!
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Couldn't you machine up some shims for gauges? Might be way off here without a picture.
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I use the same pressures on my Printex chopper/squeegees as you. 30-35 for white and about 25 for top colors. In my Trident manual it says each revolution of the off contact knob yields .005 change either up or down.
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Shim what Tony?
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If you send a pic (or will you be sued?)I might be able to say but it sounds like when you turn the OC it does not raise or lower; even slightly. Thats sort of what I was referring to. Anyway your pretty smart; I'll bet you'll figure out something. If not try M&R!
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Post a pic up. Maybe some of us gear heads can figure out a solution for you.
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I use the same pressures on my asdfx chopper/squeegees as you. 30-35 for white and about 25 for top colors. In my Trident manual it says each revolution of the off contact knob yields .005 change either up or down.
asdfx = Print-Ex
lol word-ban
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:o
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If you send a pic (or will you be sued?)I might be able to say but it sounds like when you turn the OC it does not raise or lower; even slightly. Thats sort of what I was referring to. Anyway your pretty smart; I'll bet you'll figure out something. If not try M&R!
I understand now.
On my machine you raise or lower the lift rod on the lift cylinder to change OC. It is in constant contact with the underneath of the carriage so no way to shim like i could have on the Javelin. I am really just being picky because I hate constantly tweaking everytime I go from fleece to tee. Some of us around here are spoiled like Alan with digital OC adjustments!
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Great thread. I can give you some fairly exact psi for an opaque white ink, like Rutland Snap or QCM 158. Most spot colors will be close to the white with some of them actually needing more pressure because they don't shear well, especially on some of the higher mesh counts 230-305. The most pressure we use is printing black or white ink through 230 and 305's and we'll be at 45psi. I don't know if any other shops encounter any issues with their black inks, but most of the blacks we have used the last few months are not creamy, the viscosity sucks and getting it to clear a 230 with one stroke is almost impossible. I'd like to hear if any others are adding pressure to print simple black ink.
These numbers are for printing directly onto the garment with an opaque white. When printing on top of an underbase, you can back off the pressure by probably 10-20% across the entire range.
83/86=20-22psi
110=24-28
137=26-30
137=24-28
156=28-30
175=30
195=32 for most inks and 35-40 with black and white inks
230=35 " " 40-45 for black and white ink
305=30-45, this mesh count is very dependent on the ink we're trying to print. I can clear a 305 with union maxopaque golden yellow with 30 psi but black will be 45+. Process inks clear without much pressure as well.
This topic has me thinking about the use of specific mesh counts. I know most like to use higher mesh counts these days but we haven't followed the trend because I find it impossible to shear the ink on top of the shirt with higher mesh counts due to the amount of pressure needed to clear the screen. For example, to get a standard red on a light colored shirt, I think most would go with a 195 or 230 and that's ok for the really light garments but you'll be putting the ink into the shirt and certainly not on top, unless you're a freaking screen print ninja. If you're trying to maximize an ink's opacity on a medium colored shirt and don't want to use an underbase, I'd recommend going down to a 137 or 156 with a good thick stencil and printing with minimum pressure to get the opacity. Then comes in whether you need to print a bunch of colors wet on wet and then obviously you need to go with a higher mesh count, especially on the colors being printed first, as well as the larger colors of the design.
The last 6 months I've been really using the hell out of the murakami smartmesh s threads in a 110/71 and 150/48 and the psi needed to clear the 110/71 is pretty close to a sefar 83/120 and the 150/48 is the best mesh I've ever used. The 150 is very versatile, you can hold some pretty small halftones and then lay down a great layer of ink on top of the shirt with ease since the psi needed to clear a thick white through it is in the low 20's. And you can print super fast, maybe even max some autos out with print stroke. I've got about 20 newmans I need to remesh that I'm going to put only S thread on, probably 150/48, 200/48 and 280/34.
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Out of all the features on our press, the digital off contact is probably the most valuable. We switch garment types so often, and also we use newman rollers and shurloc ez's and they have different off contacts from one another so we change the OC all the time.
Product promotion done. Sorry, had to brag a little.
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Alan believe it or not I gave up a couple years ago trying to find a good black that cleared the screens well and started buying just Process black. As of yet it never gives me a problem prints extremely well and is plenty opaque!
I am in the same train of thought as you and leaning more towards lower mesh counts and higher EOM's All dark printing I do is on 160 bases and 200 top colors works perfect every time.
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Keeping the topic alive.
2 questions
1. Does any one here only print with air and forgo the mechanical stop? If so how does it work for you and what do you see as the benefits?
2. Am I right in assuming that if you print with the air pressure only doesn't that mean your chopper cylinder is at full extension and at that point always be placing the side load on the weakest part of the cylinder? If you used the mechanical stop and lets say that only allowed two thirds of the cylinder out wouldn't that have less stress on the cylinder than a fully extended one?
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Great post Alan! I was going to email you one of these days and ask you what pressures you are using. This is perfect. What squeegee & flood speeds are you using?
I've never had much luck printing with higher mesh counts, unless they are a top color. 110, 137, & 160 for underbase. 160 for most colors on light shirts. 200 or 160 for top colors.
The last few months, I've started taking more time to keep my screens nice & tight. Lowered my off-contact. Switched from 70's to 70/90/70. Higher EOM. My prints are really starting to pop.
I was using around 40-45 psi, but with the adjustments I'm now real close to your numbers.
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Hey Kevin, glad you found this place. Nice to have another RPM guy here as well. Over the last 6 months or so I have really started to experiment with print speed and have been very impressed with how most of the time, printing faster will yeild a more opaque print. For the first few years I just printed everything fairly slow, white inks were almost always set to 4 (4"/sec for us RPM guys) and I never messed with it. Now we are frequently printing thick white inks at 10-15, depending on the artwork. You do have to add some pressure, if you are at 22 then you might bump it up to 24-25 if you are printing at 15 instead of 10 but it's more dependent on if you have thin lines or fine detail the ink has to pass through. Union ultrasoft brite red through a 156 can pretty much be printed at 30, which is top speed for our press, it's really dependent on the viscosity and shearing ability of the ink and the mesh openings. For dark ink on light shirts, we used to be consistently in the 6-8 range but now we've bumped everything up to 12-20, and occasionally I'll put it on 25 as long as the ink doesn't start flinging around.
Our flood speeds are always dependent on print length. On a longer print, maybe 16-18", I'll flood at 14, which puts the flood stroke at the top of the image just before the index is through and the table is ready to come up. A left chest only needs to be around 6-8. The rule of thumb I use is to have the flood stroke finish just before the carousel is stopped and ready to lift. You never want to be waiting around for a flood to finish before the table will lift and start the print stroke, and flooding really fast and way before the index is through can get messy and fling ink around and is no more beneficial really than a slower flood. Oh yeah, we use a hard flood and it's allowed us to decrease our print pressure by a significant margin, I'd guess around 20% less since using a hard flood.
For anyone who wants to try and get more opacity out of an ink, especially your underbases, try speeding your print stroke up, it really does make a difference.
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Thanks Alan. Glad to finally have something to contribute!! Ha ha.
Up until a few weeks ago, I was printing almost everything with 4-6. And I was double stroking everything. Bill told me a while ago to use a slow flood and fast squeegee. The hard flood helped, but everytime I tried to speed up the squeegee, I could't get it to clear. The faster the stroke, the worse it was.
I lowered my off-contact to almost nothing, and bingo!! Now I am getting much better opacity. I'm guessing since my off-contact was too high, I had to use more pressure to get it to clear. But even though I would hit it twice to get it to clear, it was driving it into the fabric, leaving me a dull print.
The reason I stumbled upon it, was that I was printing black t-shirts. I switched to hoodies, but forgot to raise the off-contact. The hoodies were a lot brighter than the t-shirts I just printed. The only change was the off-contact.
Since lowering the off-contact, I am using much faster squeegee speeds. I'll speed em up even more and see what happens.
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For anyone who wants to try and get more opacity out of an ink, especially your underbases, try speeding your print stroke up, it really does make a difference.
Alan,
It’s funny you said print faster this week. I just did that this week. I could not figure out why I could print a really nice print on my manual and then when I go to do it on the Auto it’s a ton of problems. I was printing manually and figured out that I print really fast on my manual. My flood and print stroke was 10 times faster then I have been setting on my auto. I WAS Printing at a 2 or 3 speed (MHM is 1-12 for speed on the flood and squeegee, Even thou I can only adjust it 1-11). This week I set it to 6 flood and 6 squeegee. Works great and I am sure I could set it even faster.
Thanks
Jon
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All this talk of pressure and angle with the chopper style press leaves me out, as my 2001 M&R Gauntlet does not have a pressure gauge on the squeegee pressure. Wonder if I can add this. It looks like a very valuable option when buying a press.
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Didn't read the first post just jumping in right here so If I,m out of line let me know, but anyway I was checking my choppers and what made me check this out is the new winged floodbars I got from Rich at M&R. The winged floodbars on my press have to be at 0 angle straight up and down...I have the click type adjustments for my choppers and I notice that one side was higher or lower than the other with both at 0. I checked both choppers and I found out one choppers push rod is about 1/4 longer than the other, have any of you notice this on your presses with your choppers. They can be adjusted, but there not even in clicks one might be at 3 clicks and the other at 3 1/2 clicks to match so i get the same pressure. I guess the more you use your press the more things you find as you try to get better at your game.
Darryl
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We print with pressure, my numbers are higher than Alan's for sure, we basically just adjust until the ink clears the screen.
We also print about 4-5-6 (1-12 setting) on most jobs. Keep in mind we are often printing 17 inches on a 23x31 which is near the max you can get out of that on our press with that size screen. Shorter prints I try to run harder when Shelly will let me.
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Hey Darryl, we have one chopper out of 40 on our press that is just like you say yours is. I don't know how common it is but I'll bet you money we aren't the only ones that have a slightly different chopper on our press. Ours is the left chopper on printhead 3 which is rarely used and it is 1/8" higher than the right side chopper. If I have the right side set at 1.5, I have to set the left to 1.6 which is probably different than other manufacturer's markings. If that chopper was on a different printhead and we used it everyday, I still don't think it would make one bit of difference but for the sake of being anal about everything, I have thought about putting a shim somewhere to balance that out.
I'd like to add that when printing faster, we have to increase squeegee angle accordingly to get the ink to shear. Sharp edges to your blades are very important to printing faster too. I haven't come up with any concrete info to share about which duro works best for faster printing, but the smiling jack blades do allow you to print faster than a regular or triple duro. If I had to put numbers on the SJ blades, I'm pretty sure the blade itself is an 85 duro, but I think because of the design, it prints more like a 70, but that is purely a guess on my part. Not that I have any credibility or 1/100th of the experience needed to tell Joe Clarke how to build a squeegee blade, it is of my opinion that the blade duro needs to be less, and because of that the smile of the blade should be flatter with less curvature. I'd like to experiment with an SJ that was a 75 duro with half of the curve that's on the blade that's made now. I know all of this was thought through and tested but I've always thought the blade would work even better than it does now with some slight changes. It's entirely possible that my ideas for the blade could turn it into a worthless tool, highly likely.
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Alan, thats so funny, mine the one I check so far was the #3 print head and its on the left side as well looking in from the front. I have not checked any of the others, but like you said I really don't think it will make a difference on the print.
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Hey Darryl, we have one chopper out of 40 on our press that is just like you say yours is. I don't know how common it is but I'll bet you money we aren't the only ones that have a slightly different chopper on our press. Ours is the left chopper on printhead 3 which is rarely used and it is 1/8" higher than the right side chopper. If I have the right side set at 1.5, I have to set the left to 1.6 which is probably different than other manufacturer's markings. If that chopper was on a different printhead and we used it everyday, I still don't think it would make one bit of difference but for the sake of being anal about everything, I have thought about putting a shim somewhere to balance that out.
I'd like to add that when printing faster, we have to increase squeegee angle accordingly to get the ink to shear. Sharp edges to your blades are very important to printing faster too. I haven't come up with any concrete info to share about which duro works best for faster printing, but the smiling jack blades do allow you to print faster than a regular or triple duro. If I had to put numbers on the SJ blades, I'm pretty sure the blade itself is an 85 duro, but I think because of the design, it prints more like a 70, but that is purely a guess on my part. Not that I have any credibility or 1/100th of the experience needed to tell Joe Clarke how to build a squeegee blade, it is of my opinion that the blade duro needs to be less, and because of that the smile of the blade should be flatter with less curvature. I'd like to experiment with an SJ that was a 75 duro with half of the curve that's on the blade that's made now. I know all of this was thought through and tested but I've always thought the blade would work even better than it does now with some slight changes. It's entirely possible that my ideas for the blade could turn it into a worthless tool, highly likely.
Wouldn't be an expensive experiment with gradual arched bumper jig and a router with the right bit. You should get on that! ;D
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Daryll you bring up a great point.
On our press they did not level the heads when set up, they said it is not necessary as long as the platens and hangers are paralleled. Well not one head on my press is parallel to my platens which means every single chopper cylinder is uneven by quite a few clicks. That is probably why i do not print with air it does not make sense to me to have so much pressure on one side because it needs to compensate for the lower side.
I have always believed and heard that an auto is supposed to be paralleled in three parts, Platens/hangers/print head. According to !@#$ thats not so and they did not parallel my heads only the hangers and platens. I guess it would be to much work for them to have to shim every single head side to side huh?
My head one is the worse it is atleast a 1/2" difference from one side to the next, I don't know much about any thing but I really think that must add some serious unnecessary stress on the clamps and what not.
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Leveling a press is pretty much the same; in principal; for most if not all presses. The actual process varies from both machine to machine and yes; even the technician or operator performing the task. I could walk you through it but this is something far better learned in person. Any independent tech can perform this. All you need to do is assist and learn and you are good to go. I would addess this very soon if not immediately.
Guess all those pictures of shims and levels did not help much.
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Tony the shims on my press are only to raise the over all height of the head not to level it. It is something I can do myself when quieter god knows I spent 15 years keeping our Javelin leveled.
Again i was told it was not necessary to level the head because the choppers will make up for the differences, in a perfect world I wish the numbers on our chopper cylinders were equal side to side.
Look at the pic below and you can see how unlevel my heads are. And yes that is set to have the squeegee parallel to the platen.
(http://i76.photobucket.com/albums/j35/inkman996/chops.jpg)
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Wow I don't think I've ever seen a press so out of level. I would contact the manufacturer immedi..........oh, sorry.
Anyway good to know you can straighten things out. Sometimes Saturdays are good for projects like these. Having someone help makes it go quicker.
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Wouldn't be an expensive experiment with gradual arched bumper jig and a router with the right bit. You should get on that! ;D
On second thought, I'll just let it ride as is!
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Tony the shims on my press are only to raise the over all height of the head not to level it. It is something I can do myself when quieter god knows I spent 15 years keeping our Javelin leveled.
Again i was told it was not necessary to level the head because the choppers will make up for the differences, in a perfect world I wish the numbers on our chopper cylinders were equal side to side.
Look at the pic below and you can see how unlevel my heads are. And yes that is set to have the squeegee parallel to the platen.
([url]http://i76.photobucket.com/albums/j35/inkman996/chops.jpg[/url])
No frickin way, something is seriously out of wack or bent! My choppers are all within a couple clicks of each other height-wise. Take a pic at the screen level looking straight down the head so we can see the twist in the printhead arm, because if there's 1/2" of difference from side to side we should be able to see the whole print carriage assembly off compared to the screen holders. eek!
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Heck, I bet they aren't that bad on my 1999 Gauntlet. You need to have a real tech go through it. I am sure there is somebody around you that could do it. It might take a half a day, but it will be money well spent.
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Machine Guru, Technicians Technician, and world traveler.............LMFAO.
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Brian AKA Binkspot installed my press and I see him on here sometimes, maybe he can explain to us why it is done that way. He is a great tech and obviously he learned from you know who, so i am not throwing Brian under the bus. I was never comfortable with the heads not being leveled but I accepted it as what it was. Maybe now I know better and come to think about it since head one is the worse and that is the head white is printed on I should get it leveled at least as a start.
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Damn Mike, when you first explained the printheads being out of parallel I didn't think of them being twisted or leaning one way or the other like that, I thought of them just being simply out of parallel linearly in the direction of the printarm and pallet. Is the actual printarm leaning one way or the other or is the print carriage assembly leaning or both? If the printarms are leaning it seems like a simple fix with some shims on the low side to bring it up a little. I would expect most presses to be off a click or two here and there but like others have already stated, that looks a bit extreme with your choppers. Is there any chance that the choppers are all different and maybe not the printheads? I know finding your highest chopper and shimming all of the others up to it would be a PITA but it might be worth it long term, plus your lucky it's not a 16 color, that would take forever.
Musterd, you use the same choppers right? Do your choppers seem to be in close tolerance from side to side?
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Ink from what I see there that is way off, I,m thinking mine problem is the chopper cylinders itself, my print arms and platens are dead on. One day maybe in December when things slow to a crawl I might go around the press and pull and match up choppers. I can see where having to much pressure on one side can cause problems (screens for one) and ink deposits etc.
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No mine are dang near dead on. Here's a pic of my "worst" which you can't really even tell from the pic it's only a few clicks more on one of the adjusters:
(https://lh6.googleusercontent.com/-OkElGkOO17A/To5jxJSn6TI/AAAAAAAAAOs/W3bVJqBfcVM/s800/2011-10-06%25252022.26.08.jpg)
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I clamped a straight edge across the top of the print arm perpendicular, I then measured from both sides of the palette up to the straight edge and it is exactly 3/8" off. Not a half inch but close.
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Tony the shims on my press are only to raise the over all height of the head not to level it. It is something I can do myself when quieter god knows I spent 15 years keeping our Javelin leveled.
Again i was told it was not necessary to level the head because the choppers will make up for the differences, in a perfect world I wish the numbers on our chopper cylinders were equal side to side.
Look at the pic below and you can see how unlevel my heads are. And yes that is set to have the squeegee parallel to the platen.
([url]http://i76.photobucket.com/albums/j35/inkman996/chops.jpg[/url])
Jesus that's awesome.
Brian please tell us how this is normal? Heck, I bet they aren't that bad on my 1999 Gauntlet.
Of course it's not, its built by a company that know's what they are doing.
Someone please explain to me what good all this "new" technology is if you can't build a press correctly.
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LOL Brandt I was dumb and drank the kool aid but now I now I been snake bit.
Thank good there is people in our industry like Rich Hoffman and the guys at Anatol, they both have helped me out on our press when I needed it, since Ptex is not honoring their warranty.
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Tony the shims on my press are only to raise the over all height of the head not to level it. It is something I can do myself when quieter god knows I spent 15 years keeping our Javelin leveled.
Again i was told it was not necessary to level the head because the choppers will make up for the differences, in a perfect world I wish the numbers on our chopper cylinders were equal side to side.
Look at the pic below and you can see how unlevel my heads are. And yes that is set to have the squeegee parallel to the platen.
([url]http://i76.photobucket.com/albums/j35/inkman996/chops.jpg[/url])
It's not "New Technology" it's "Better Technology". As the picture clearly shows.
Jesus that's awesome.
Brian please tell us how this is normal? Heck, I bet they aren't that bad on my 1999 Gauntlet.
Of course it's not, its built by a company that know's what they are doing.
Someone please explain to me what good all this "new" technology is if you can't build a press correctly.
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LOL Brandt I was dumb and drank the kool aid but now I now I been snake bit.
Thank good there is people in our industry like Rich Hoffman and the guys at Anatol, they both have helped me out on our press when I needed it, since Ptex is not honoring their warranty.
I thank the Printing gods every day I didn't give in and buy a Playtex. I LOVE my M&R. Think of all the time all this "new" technology has cost you. It is suppose to save you time you know that right?
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Either the linear rail that the chopper plate rides on is installed at an angle, or the print arm itself is pitched where it attaches to the main body. Which part is funky?
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Either the linear rail that the chopper plate rides on is installed at an angle, or the print arm itself is pitched where it attaches to the main body. Which part is funky?
Given a lot of other things we hear about these presses, how about BOTH?
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Either the linear rail that the chopper plate rides on is installed at an angle, or the print arm itself is pitched where it attaches to the main body. Which part is funky?
It is the print arm itself and I understand that steel tubing like that can be less than perfect unless machined, I just always thought every print arm is paralelled with the hangers and palettes as a standard operating procedure. I will do it my self some day this way all movable parts have the least amount of stress on them. Now that i think about it we already have a blown seal on the flood chopper on head one, I wonder if that happened because there is more pressure on that side? Or simply a bad seal. I have not needed to replace it yet because it is minor but eventually i have to replace that seal. I will check my parts package for one, oops I forgot I did not get a parts package lol.
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Either the linear rail that the chopper plate rides on is installed at an angle, or the print arm itself is pitched where it attaches to the main body. Which part is funky?
I will check my parts package for one, oops I forgot I did not get a parts package lol.
Bait and switch son.
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On that blown seal that uneven pressure can definitely cause a seal to blow prematurely.
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This is great case for sure if that tube is in fact twisted. This is something that they should have noticed if they had assembled the machine over there. Im not knocking the guy that put it in but they should have never left that machine that way. It should have also been noticed during the install. That sucks!!!!!!!!