Cutting lines on a traction fed plotter

[bbankston]

Un-spools everything it needs before it starts to cut anything,
or as needed, every so often, during the cut job?

Just trying to trouble shoot with you.

I've tried that too, Stanton. Didn't work.

 

[bbankston]

As far as I know the pinch roller's grip is not adjustable. I have no idea what you're talking about here:

Quite often cut security strips for Windows lots of 5mm strips on a Roland or graphtec and would expect a summa to as well

 

[MikeD]

yours doesn't have a adjustable pinch rollers? there should be an up and down position for gripping tight or loose. You lift a lever behind each wheel and click it into position. Watch the springs move.

 

[bbankston]

MikeD,

Definitely non-adjustable. I just checked.

 

[letterman7]

I've had my T750 for years and have never had an issue with cutting parallel lines on it like you need to do. I cut police and fire striping regularly on it with reflective and it's been dead accurate every time. One thing I do is slow the cut way down - as slow as 1cm/s or even half that if I'm doing real long runs. Unspool what you need to cut the job so the plotter isn't pulling off the spool and slow the cut and see what happens.

 

[Stanton]

I've tried that too, Stanton. Didn't work.

Platen and pinch rollers squeaky clean?

Is the problem exactly the same each time or variable?

 

[bbankston]

On long runs you can see that it's going to mess up because the vinyl will eventually ride up on one side of the vinyl flanges and then it'll eventually ride up on the other side.

Things I've done:
Thoroughly cleaned
Replaced outside pinch rollers
Slowed the cutting speed
Rolled the vinyl out and let it sit overnight
Pre-rolled the vinyl and then cut

I've even made sure that my artwork is drawn so that the plotter cuts as efficiently as possible. (e.g. 1st line cuts up - 2nd line cuts down, etc.).

If I cut the whole 48 or even 36 inches it'll eventually bunch up or crease on me. I have to hover around the plotter and knock those creases out so it doesn't bunch up.

 

[Stanton]

I've even made sure that my artwork is drawn so that the plotter cuts as efficiently as possible. (e.g. 1st line cuts up - 2nd line cuts down, etc.).

If I cut the whole 48 or even 36 inches it'll eventually bunch up or crease on me. I have to hover around the plotter and knock those creases out so it doesn't bunch up.

That was going to be my next question.


OK, don't laugh too hard at this one...

If the mask in on a paper liner, could the knife be cutting into the liner
causing the liner to "accordion fold" and fail?

 

[MikeD]

you replaced the pinch wheels, but you may also want to check the grit rollers for any debris buildup.
I think there are multiple variables when it comes to overall speed. Up and Down acceleration controls the media feed speed on my S-75 if I remember right.
Sounds like it's just not tracking right and maybe needs to go slow.

 

[bbankston]

...could the knife be cutting into the liner
causing the liner to "accordion fold" and fail?

Negative, ghost rider. I make sure that the backing is not touched with the blade.

 

[Stanton]

Negative, ghost rider. I make sure that the backing is not touched with the blade.

You are not making this EZ.

 

[Kottwitz-Graphics]

The only other thing I can think of is cleaning the roller wheel under the pinch roller, which you said has been cleaned... The next step sounds like calling Summa and sending it back to get checked out. The only other thing that I can think is something is bent somewhere.

 

[paul luszcz]

Can you post a drawing or photo of what you're trying to do? It doesn't sound that difficult so I may be picturing something entirely wrong.

We have a Gerber sprocket feed and a Roland friction feed and I think either one would cut this successfully if I slowed the speed down enough. At high speed, either would eventually fail.

 

[bbankston]

Again, I'm only coming to you guys because you all have far more experience combined than I. I've actually had a Summa rep. come out and he says that I can't do what I want. I thought that maybe you guys might have a work around.

Here's a picture of one side of the 12 x 12:

 

[Stanton]

What happens when you rotate it 90º ?

 

[Bly]

Maybe it's the film.
You might have to go to the T series to cut thick mask.

 

[Matt-Tastic]

What happens when you rotate it 90º ?

This ^

If you are only moving the media to advance to the next box (3/8" max)

That may be the best avenue, as scan axis movement should be spot-on, while media-feed movement will vary.

 

[Stanton]

I've actually had a Summa rep. come out and he says that I can't do what I want.

Any one else think this is unacceptable?

 

[toucan_graphics]

I employ a low-tech solution for this (I have a friction feed plotter as well)

When I load the vinyl, I will line up the vinyl with itself before locking the pinch rollers. As long as you don't need to cut anything longer than 5 or 6 foot long lines you should be fine. Anything longer than this will require something to keep the media roll from drifting left or right as it feeds. I have used dumb-bell clamps on the feed rollers with some success. I'll try to post pictures later to illustrate what I am talking about.

If this still doesn't solve the problem, you may want to replace the rubber wheels. If there is a flat spot on one of them it will throw your alignment off every time the flat spot rolls over the friction roller.

 

[woolly]

Any one else think this is unacceptable?

Yes

would want a dam good exclamation to go with it.
Op you say the media bunches towards one roller. Possibly indicating un equal roller pressure. Acceleration too high. Poor blade and or holder
guess this material is quite tough or thick so may need a flat feed path not bending over the bed.
May even need 2times lighter cuts but needs to cut correctly first.
Try put a pen in and plot on to the material so you know its the cutting mucking it up