Old Gauntlet Squeegee pressure regulation

[Atownsend]

We run one of the old Gauntlets here. A 1989 6/8 non revolver model to be exact. We fight with it on almost every setup, but once each head is dialed in and its registered, it actually prints fairly well. One problem that I have run into lately, is on images where its near max size (15"). The image will blur slightly at the very top of the image. It was only happening on certain pallets, which is why I am thinking that some of our pallets have come out of level We have some good size sim process runs coming up, so I am going to relevel all of the pallets and check off contact on all of the heads tomorrow to eliminate that variable. We usually level to nickels in the back, and dimes in the front to combat the pallet deflection (a tip I found here).

I am also thinking this might be a squeegee pressure issue. We use S-Mesh, and I think that the pressure is just too much and when the pallet deflects back we get the blurring at the top of the image. To control the squeegee pressure, we currently use the kip levers to raise / lower the cylinder. There is no regulator for the cylinder itself. I am not familiar with other autos, but from what I read here, modern presses with air heads are able to regulate the pressure to the cylinders much more precisely. Has anyone rigged up a inline pressure regulator to control the air inside the choppers? I am thinking I can pickup a few inline regulators from harbor freight, splice it into the plumbing, and rig up a mount for the head so I can dial in the PSI for the chopper cylinders more precisely. What i'm wondering is, has anyone done this before on an older gauntlet? Or is this just an unnecessary waste of time when I should just focus on the basics (pallet leveling / off contact / sq angle / pressure regulation via the kips).

thanks in advance!

[jsheridan]

Great idea!

on those older machines.. with some regulators, some new fittings and a helping of creative thinking, of course. get on it!

take some pictures along the way.

of course keep the platens level, that's always just a given.

[Printficient]

You could try Double Bevel squeegees.  They require very little pressure and no angle adjustments.

[Doug B]

  Don't discount your flood pressure either. I have had that problem with our
older Gauntlet of blurring at the top of a large print.

[Sbrem]

our number 2 press is a '94 6/8; yes it need some upkeep, but it has paid for itself many times over...

Steve

[Atownsend]

Thanks for all of the feedback! I will mind the flood pressure. I might also try some double bevel squeegee blades. I am running a mix of single angle 70/90/70's at the moment, along with some 60/90/60's. Any particular duro recommended for double bevels?

While I am messing with the head, I think I'm going to try to rig up a air dump valve so that we don't have to turn off air to the whole press to remove / insert squeegees. I picked up some air fittings / valves / regulators online. The most difficult part will likely be the mounting of the bracket for for all of this. But it really doesn't look that difficult. Will post pics once I get this rigged up & tested.

[Atownsend]

Success!

I removed the 5/32" hose coming from the press though the guide for the proximity flags, then a longer hose was spliced in and routed to the 1/4" harbor freight regulator. This required a 5/32 > 1/8"NPT quick connect to a 1/8" > 1/4"NPT coupler, > 1/4" close nipple > the regulator. From the regulator, if reduces back down to a 5/32 quick disconnect, and goes to a 1/8" npt switch that I picked up from mettle air. The outfeed from the switch, goes to where the original air line fed to on the head. I have a ton of 1/8" acrylic sheeting here, so I cut it down with a jig saw, drilled a few holes in it and mounted everything up so that there is no interference. If I had a bit more time / patience, I would totally make this out of metal, but I just don't have the patience for that right now. It isn't heavy, so I don't anticipate any problems using the acrylic. sheet.

It's not pretty, but it is a functional prototype. I am going to test this on a print run tomorrow, and if it goes well I will replicate this for the remaining heads. I can now control the squeegee pressure in the cylinders via the regulator, and I can dump the air with the switch so I can insert / remove squeegees without having to turn the air off to the whole press. I am pretty blown away. Hopefully test prints will go well tomorrow and we can get some shirts moving through here & break our backlog.

[spotcolorsupply]

So cool.... I love this kind of stuff!!! 

[ZooCity]

Looks great!  Let us know how it works. 

[jsheridan]

Great start!

I'd find the smaller regs and dials.. easier to work with the smaller air fittings and less reducers and threads. The more thread you have, the more chances of air leaks.

The huge benefit I see to this.. anyone who has ever worked on these older chopper styles.. adjusting those clip knobs is a pia and they strip out all the time.. it's this tiny thread with a long bolt.. ugh..

this way you can hard bolt them in and control pressure with a reg like the newer style choppers. Using S-mesh you don't need much pressure or squeegee angle anyway so using the machines air deficiency to your advantage, waaalaaa! squeegee air control.

modify and repeat.. again and again.

keep it up! 

[jvanick]

I feel that good squeegee pressure regulation via air is the only way to go.. presses that don't, or can't offer that are pretty much worthless to me.

same deal with presses that let the squeegee rock back and forth by a single pivot point.  (like some certain green machines)

being able to have a consistent amount of force left to right and down lets you print and shear with much less effort, and in my opinion gives much better results for high-speed printing of plastisol.

when the squeegee is allowed to pivot or not conform to the surface of the garment you end up with differing ink deposits side to side of the shirt, and even hydroplaning of the squeegee when printing with minimal pressure and high speeds.

[ZooCity]

I feel that good squeegee pressure regulation via air is the only way to go.. presses that don't, or can't offer that are pretty much worthless to me.

same deal with presses that let the squeegee rock back and forth by a single pivot point.  (like some certain green machines)

being able to have a consistent amount of force left to right and down lets you print and shear with much less effort, and in my opinion gives much better results for high-speed printing of plastisol.

when the squeegee is allowed to pivot or not conform to the surface of the garment you end up with differing ink deposits side to side of the shirt, and even hydroplaning of the squeegee when printing with minimal pressure and high speeds.

Interesting on the "self leveling" squeegees.  We're moving one of our machines to those certain green ones.  They do offer a dual chopper option fyi but it only appears to be needed for the larger jumbo or aop type prints.  Self leveling makes far more sense to me for a number of reasons and MHM has always used it with excellent results but I admit I'm a bit nervous about having our main rig setup this way and doing some of our specialty, all over the front of a zip hood type of prints.  Curious as to why you see this as negative.  Sorry for thread derail!  If one of our hosts would like to split this that might be best.

[jvanick]

the issue is that you not only have a cantilever system where the pressure to the squeegee is coming down from one side, but also that the squeegee can 'float' side to side.  when printing in a high shear, high speed method, you really want pressure on both SIDES of the squeegee, so that the platen and shirt can't cause the squeegee to lift up on either side.  remember, you're just trying to kiss the top of the shirt.

I think that 'self' leveling print head designs like that are nearly as bad as a tuned up old Javelin... you have to print with so much pressure to overcome the rocking potential that now the squeegee is bent over.

[ebscreen]

If your only experience with floating squeegees is a Javelin then I can see where you are coming from.

But other than that, no. We've only had floating squeegees of two flavors for the last 8 years or so
and have never had a problem like you describe.

I can see where you would want double choppers if your screens or platens are out of parallel though.

[jsheridan]

I've used mhm for quite a bit of time and what you are describing does not happen. They're printhead technology is far superior to that of others and given the option would prefer to use their heads over choppers.