Roll to Roll Becoming Loose

[Cranniga1]

I have been having some trouble running full rolls of 150'x60" Oracal 3951 Ra on our Mimaki JV300-160. The Take-Up Reel starts out great, and winds it up tight and consistent until about halfway through the roll. We re aligned the position of the reels and got the same results. Then we got a replacement motor/reel and its the same deal. Any ideas or thoughts would be appreciated.

 

[T_K]

Are there any stated limitations to what the takeup roll will handle? I know, for example, I can only run about 10-12 feet for a print-laminate-cut job and it be accurate on the cut lines. Could this simply be part of the normal operation of the machine?

This doesn't specifically address your issue, but I try not to run more than 30-40 feet at a time on my printer. I've never managed to get it to run through the laminator perfectly straight, and by 30 ft I tend to get up to a 1/2 inch lateral movement. Running less before cutting it off obviously makes it more manageable.

I'll add the caveat that we're not a high production facility right now, so there's not commonly a need to run a full roll in one go.

 

[Solventinkjet]

Although you should be able to print a whole roll in one shot, there are a lot of factors that go into doing it successfully and I rarely see anyone accomplish it 100% in the field. The 3 main factors are:

1. The vinyl manufacturer needs to roll the vinyl on perfectly without any telescoping and then avoid telescoping during shipping and storage. If those conditions are not done correctly, the vinyl will feed crooked no matter what you do.

2. The media holder in the back and take-up system need to be perfectly aligned. If the media holder is slightly offset from the take up reel, the media will run crooked. You can use a long piece of banner material to feed through the platen and wrap it around the cores of the material and the take-up to align them. You want to make sure that they are aligned left and right but also you want to make sure that one side is not higher than the other on the take-up side.

3. The pinch rollers should be clean and not worn out. If there is adhesive built up on the rollers or the grit roller underneath, this can cause the media to skew. The platen should also be as clean as possible. Adhesive builds up on the platen over time and should be cleaned with alcohol.

There are other reasons (static, malfunctioning parts, user error etc.) it may not run completely straight but these are the main concerns.

 

[Kentucky Wraps]

Another thing it may be is ...whatever you have holding the rolls on could wobble a tiny bit loose and no longer be flush against the end of the roll which would make it do that.
If you have clamps that go against the rollers, make sure they're all the way up against the end of each roll and tightened.

 

[Cranniga1]

The Specs on Mimaki's website say 88 lbs or less. I cant find the weight listed for 150x60 oracal 3951, but the point at which it starts skewing and becoming loose on the take-up reel wouldn't have that much weight at that point. Checked the rollers and they are clean. I don't understand why it starts perfectly and runs for about 75 feet before it gets off track. If it was out of alignment wouldn't it skew from the get go?

 

[player]

The Specs on Mimaki's website say 88 lbs or less. I cant find the weight listed for 150x60 oracal 3951, but the point at which it starts skewing and becoming loose on the take-up reel wouldn't have that much weight at that point. Checked the rollers and they are clean. I don't understand why it starts perfectly and runs for about 75 feet before it gets off track. If it was out of alignment wouldn't it skew from the get go?

Perhaps 74' is the real weight limit of your take-up system. Try less, or stop and cut and re-core the remainder.

 

[Commando]

You need to make sure you have it strait when you attach it to the roll.
If not, it will look like that

 

[Cranniga1]

It is straight when it goes on. I feed it out and pull the center of the media taught, release the lever and back the pegs on the feed reel, lower the lever, print a justification print. cut the corners of the media and tape it to the take up reel before printing.

 

[MuhammadOsta]

i have the same machine (JV300-160), it has bad engineering regarding the reel that holds the media. the black plastic is easily affected by the media regardless of it's weight. try press it with your hand, hold it and check it back and forth and see what i'm talking about.

but there is a way to make it right. after loading the media, tap the right holder from bottom and then press it a little from above before you tight the screw. also, you see the empty space left between the (holder-cone that goes inside the roll tube) and (the plastic holding the holder-cone) if you press hard from both sides till there is no space left, this will make the wrapping more accurate. usually, we have to leave a Little space between the two parts i mentioned so the roll can balance itself if there is a slight slanting, but doing so will make the paper goes a little right and left while printing thus causing the media roll to be as in the photo.

important points to take into consideration:
- some times, the white plastic on the take-up device tend to go back (out) which make the tension softer, this happened a lot with my prints, you need to push it back in.

- it helps a lot when you load the media and put the paper in till it goes out of the printer to run the vacuum (at high) before you release down the lever. to run the vacuum: menu> #test> action test> vacuum

- loading the media while the heater is on (especially above 40C), this will cause a little crumpling to the media.

- slowing down the feed ratio (media feeding speed) make the roll tighter, i usually print with no more than 50%.