Advice on failing squeegee clamps

[inkman996]

Kind of hard to put a proper title for this. We all know what press I have so please ignore that and keep the criticism away its not the point of this post.

As you can see in the video the squeegee is easily over coming the pressure of the clamp. this is actually one of the better heads at the moment. It has been an issue since install but not as bad as it is now.

On most heads if I lower the pressure enough to avoid the squeegee from opening the clamp the flood bar does not have enough pressure to even drop itself to flood (I would think gravity could help atleast)

On several heads I have to use the mechanical stops on the pistons to control pressure which sucks I prefer printing with pressure control. It is also causing the need for double stroking where it should not be a need.

I am a lot like Alan I like to print with as little pressure as is possible but to go that way i suffer with non working flood bars.

I know it is probably not possible but is there any way to increase pressure to specific lines? Will replacing with larger pistons help or is the pressure what it is no matter the piston. Is there mechanical clamps made to lock the FB/S in place for a short term solution? Also is it possible the choppers could be mounted not plumb and causing a little binding hence why the flood bars need so much pressure to drop?

Anyways have a look and advice is welcome (other than buy a new machine)

https://youtu.be/sbMN3E8RTWM

<iframe width="560" height="315" src="https://www.youtube.com/embed/sbMN3E8RTWM" frameborder="0" allowfullscreen></iframe>

[jvanick]

why wouldn't you just plumb the air lines for all the clamps into something that's before the air regulator (or immediately after the main regulator of the press)?

seems weird that adjusting the print pressure would adjust the pressure for the clamps. 

in any event, it would be a pretty easy (i give it a 1/2 a 6-pack rating) job to replumb them.

[blue moon]

I got 5 of these, would that work? Make me an offer!

pierre

[IntegrityShirts]

I really doubt the squeegee/flood  clamps are run through the head regulator. But if it is, fix that asap and it will be fine.

I run mine at 30psi or lower to avoid the sqeegee from pulling on the clamp. The clamps have issues holding, plain and simple. Bink suggested lowering print pressure a while back for me and I did and never had another issue.

Sometimes when I print poly white I'll throw manual clamps on the sqeegee to keep it from moving, but that's rare.

[inkman996]

why wouldn't you just plumb the air lines for all the clamps into something that's before the air regulator (or immediately after the main regulator of the press)?

seems weird that adjusting the print pressure would adjust the pressure for the clamps. 

in any event, it would be a pretty easy (i give it a 1/2 a 6-pack rating) job to replumb them.

The clamps are not plumbed to the same lines as the choppers, the pressure to the clampas are static but the problem is they are to weak to handle the drag the chopper causes.

[inkman996]

I really doubt the squeegee/flood  clamps are run through the head regulator. But if it is, fix that asap and it will be fine.

I run mine at 30psi or lower to avoid the sqeegee from pulling on the clamp. The clamps have issues holding, plain and simple. Bink suggested lowering print pressure a while back for me and I did and never had another issue.

Sometimes when I print poly white I'll throw manual clamps on the sqeegee to keep it from moving, but that's rare.

The original machine worked about the way you described, this machine it is much worse and getting worse. On one head I can pull the squeegee out by hand no problem and that head I am using c clamps to hold the squeegee in place. On most heads if i lower the pressure as low as I wish for a really low pressure print the flood bar does not have enough pressure tochop, really annoying.

[inkman996]

I got 5 of these, would that work? Make me an offer!

pierre

Now that is exaclty what i envisioned in my head some home made fabbed clamps would look. Only 5 do I get a discount for an odd number? As long as the profile filts I will buy them off you, name your price.

[blue moon]

I got 5 of these, would that work? Make me an offer!

pierre

Now that is exaclty what i envisioned in my head some home made fabbed clamps would look. Only 5 do I get a discount for an odd number? As long as the profile filts I will buy them off you, name your price.

$25 and your UPS number? I have no idea what I paid for them, but $5 ea seems more than fair. . .

pierre

[inkman996]

I did some tube tracing to get an idea of what is feeding the air to the clamps.

Attached picture shows a manifold with a line that comes up from the main air line just after the regulator. Once at the manifold it sens a line to several heads, their is a few of these manifolds one each for four heads I think. From the manifold it runs down the head and then splits off to several other lines, screen clamps and choppers and the sq/fb clamps. My thinking is it is just not enough to hold screen clamps, sq,fb clamps and choppers all at once so when pressure is put on the squeegee the clamps do not have enough pressure to hold it tight.

Question is, is there any practical way to up the pressure, being right after the regulator I could up the entire pressure but it is already set high and I don,t think I want it any higher. Maybe add new manifolds and keep the clamps separate from the other lines? Or increase tube sizing etc would that even do anything?

I told my printer about the clamps and he is understandably not happy about the idea of having to manually clamp squeegees in. So hopefully there is a solution I can come up with.

[jvanick]

air pressure is air pressure... the size of the hose or connection controls the amount of flow.  for example... (not real #'s)... a 1/8" hose at 100psi provides the same amount of pressure as a 3/8" hose... however, the 3/8" hose will 'fill up' a cylinder that much faster than a 1/8" hose would.

One solution would be to find a cylinder with a bigger bore and replace them.

[inkman996]

Bout what I figured on the hose size. replacing all the cylinders sounds pretty expensive to replacing some tubes etc.

[screenprintguy]

I'm sure you already checked this a million times, but are you sure the squeegee is seating correctly when it clamps down. We had a squeegee holder pop out on Tuesday in the middle of a run on our new press. I have no idea how it could have happened, I was told it was probably not seated in properly when the clamps clamped down, which I didn't understand because the clamps will piss air if you don't get them in right when you throw the switches. I do have it happen quite often on our new machine, gets on my nerves to have to stop and go flip the squeegee holder around until it catches properly, but sometimes I think it's how the grip the metal when they activate.

[inkman996]

If we don't seat it correctly it pops out on the first print stroke. But either way that wouldn't account for all heads having the issue, and some being much worse than others. Printing poly ink or some flouro's is the worse because we have to switch over to using the mechanical stops on the cylinders which takes time to get them perfectly level. There is now way in any hell that the press can print any thick ink and relying on those clamps to hold the squeegee in place.

[screenprintguy]

dam that sucks. like you've stated, too bad there wasn't a way to beef up the pressure on those clamps