Question: Still new to vinyl cutting. Sawtooth or jagged edges on Vinyl Cuts?

[gwizah]

Greetings,

I am still fairly new to vinyl cutting, and everyday I learn something new. Im using a Mutoh Kona 1400 and Oramask 813 film to make stencils. I recently noticed I am getting more "sawtooth" edges on curves where I was previously printing smooth, clean curves. How should I handle this issue?

I have read that changing the pressure of the blade or even removing the tool holder and making sure there is lubrication can fix this. I was wondering if this is common after several cuts. This machine was a "hand-me-down" from a generous vinyl shop I've worked with so it had a good long run.

Should I be replacing the blade-? Is it something more serious? Any help is appreciated!

Ive uploaded an image comparing the two. The one on the left (partially obscured by transfer tape) is the clean one that I cut about a month ago. The one on the right is the new cut from today.

 

[Texas_Signmaker]

I've never seen that before...that is odd.

 

[Notarealsignguy]

Maybe your blade holder is worn out? Pop the blade out and put in a drop of lube. Then replace it

 

[Jburns]

check your blade holder - looks like its really loose - also pinch rollers and make sure media is unrolled

 

[letterman7]

Yep, all of the above. I've even seen static do that on my own machine (buildup affecting the head - rare, but it happened). Could be the head is on it's way out as well.

 

[signheremd]

We had something similar happen on an old Graphtec - the rails needed to be cleaned as well as the wheels that ride in them (that allow the machine to move the blade left and right). Pull some covers off and look around for signs of dirt or graphite - unplug first... check the pinch rollers to be sure they are clean and their drivers are clean. May just need a good cleaning.

 

[bob]

All of the above is good advice but anytime a plotter starts flakey behavior such as you have shown, remove any dust cover from the tool carriage and blow all of the dust and crud out of the carriage. Pay particular attention to the blade up/down mechanism.

 

[gwizah]

Hey all,

Thank you for the responses. I just cleaned the heck out of the machine, making sure to remove any dirt from the platen and pinch rollers, and generally clean the cutter head. I did not find any buildup of residue on the knife holder end and added some thin oil to the blade holder tip to make sure it turns smoothly. I added a little white lithium grease to the "up and down" rail for the tool holder as well.

I checked the height of the blade, and it just barely leaves a mark on the backing on oramask 813. The force is set at 120 grams. Drop Speed is 60 (i dont know if these settings affect the cut quality)

Attached is a close up pic of my blade tip.

I feel like I am slowly weeding out the issue...but after another test cut, it seems to not be as bad as before, but still showing up towards the edges of the cuts.

Im kind of stumped...Could it be tension on the belt?

 

[XtremeXccessories]

Have you changed the blade recently or changed the knife offset setting? Cut strip in good shape?

 

[balstestrat]

Turn down the speed and take a slow motion video of this issue. Most new phones can do for example 720p 480fps.

 

[gwizah]

XtremeXccessories:
So I changed out the old blade today. Same issue.

Below is the test I ran. I also ran an offset test in VinylMaster Cut 4.0 which is what I am using. The test is below, but I believe the machine offset is currently set at 0.54.

Balstestrat:
I have linked a video here showing the machine in slo-mo for twenty seconds that I shot on my iphone: http://gwizone.com/mutoh/mutoh_slowmo.MOV

Jburton: The settings panel on the plotter reads "down velocity" at 60. I am guessing that's the speed that the knife drops? I dont know where the setting for the overall speed would be. Is that something that can be modified via the cutting software?

 

[TammieH]

I think its something to do with the handshake between your plotter and computer,
or you changed some of the settings on the plotter by mistake, "Offset" for example

 

[balstestrat]

I just had a quick look of the video, sadly it's a bit short and dark but to me it seems like it's doing a little jagged move. Like there is something wrong.
Not sure if it was the exact spot where you have the issue.

 

[unclebun]

In the video starting at about 10 seconds you can see the cutting carriage visibly wobbling front to back as it moves left to right. I would look at the nylon wheels that bear it along the track. I bet one or more is loose, broken, or worn.

 

[gwizah]

Wow, good suggestions. I am going to disassemble the cutting head tonight and take a close look at the wheels.

 

[gwizah]

Okay so after disassembly and re-assembly, there are no broken wheels, and the plotter is cutting much better. It seems there was some adjustments needed, but everything appears to be working well again.

I am wondering if there are just certain parts that are wearing down and reaching their end-of-life such as the wheels on the cutting head. This was a hand-me-down so I wouldn't be surprised if there is just general wear-n-tear on the machine. I can keep using it in it's current state since I am not delivering high-precision work, but I am hoping to upgrade to a new machine eventually.

 

[Texas_Signmaker]

Forget Summa and Graphtec... Cricut is where it's at.

 

[gwizah]

Thanks for the suggestions. I may...*MAY* being based on my income level at the time, may just get a print/plot solution. I currently own a dinosaur HP designjet that is built like a tank (and just as slow) and its younger sibling who is below a home-made shelf/mount.

I think tossing three machines that are old enough to vote, drink, and rent a car collectively may be worth it.

 

[Outlawsignz]

Hey Gwizah,

Just my two cents! I run an older 48 inch Mimaki CG II series plotter - I bumped into it carrying some substrates one time and bent the rollers away from the rail - I didn't see if anyone mentioned that (apologies if its in here somewhere) and I had to 'bend' it back into shape so that the wheels 'touch' the aluminum rail. I was getting similar results. In your video, the entire 'House' of the cutter is moving - it should not be. If it is all tight to the rails, something else must be loose - when you lightly move it by hand, it should NOT move much at all..
Good luck!

 

[Stacey K]

Huzzah!
When you do go looking for a new plotter, you'll find most folks here are married to either graphtec or summa. Feel free to make a post asking for recommendations, but I could do a pretty reasonable facsimile here for you if you like:
1 Summa!
2 Graphtec!!
3SUMMA!!
4GRAPHTEC!!!!
5 I still use a gerber 4b...

I've been married to my Graphtec for 14 years and I love him to pieces! We have a great relationship, he never cheats, doesn't talk back and has been the most reliable husband I've ever had, and I've had TWO! LMAO!