Trying to improve cutter accuracy

[CrossHairSB]

I lOVE my silver bullet, BUT!! the ONE thing I am plagued with is it's NOT repeating the accuracy of cuts from one job to the next. My product is a print-n-cut SKIN for a musical device. I added an attachment to show all the cutouts around each button or knob.
You see how I must make cut outs that are accurately positioned over each of the buttons, knobs etc.... Sometimes it works out good, sometimes its a little off. I consider myself an excellent registration point "picker-upper". Also the media I use is an inkjet printable MAGNET paper .026 thick.

Hope you can help me,
Sincerely,
Ken Pasque

[Gigi]

First things that come to mind - have you double checked your calibration to be sure it is as accurate as possible? What blade are you using to cut the magnet material? And are you sure it's not slipping at all on the mat - it is securely brayered or taped? What force are you using to cut and what velocity? Thanks.

[CrossHairSB]

Hi & thanks for the response,
Calibration: I recently did the blade to laser point calibration. THEN, rather than printing a rectangle and checking to see how off it is, I used one of my templates. I made changes to the calibration numbers until it was approved.

Blade: right now I am using the 60 (it's not cutting as good as the 45). So I am going back to the 45.

Slippage: I am using the mat supplied by Silver Bullet. It doesn't have any stickiness to it. I tape the magnet paper. But today I ordered "Craft companion" tack spray. I also use two outside rollers with a center roller clamped as well. This very well may be the issue, it makes sense the paper is slipping rather than the SB pro being inaccurate.

Force & Velocity: I normally would use Force 100, speed & upspeed 400. This is for the .015 thick magnet paper. I also was using the "software speed & pressure". Learned today I should use the Silver Bullet speed & pressure & turned up to something like Velocity 700 and force around 100.

[Gigi]

Ok on the calibration.

I don't have that particular magnet material, but I would have guessed that you would get better results with the 60 degree plus blade. That is what we suggest for magnetic material. You might get better results and less "pulling" and perhaps better cuts.

If the mat does not have stickiness, I highly recommend using the ReNu sheets as they provide phenomenal adhesion. Your slippage could well be happening there with the tape and the center pinch wheel. I don't think you need it and it might be creating more problems.

There is nothing wrong with using software speed and pressure - I use it all of the time. Occasionally there were issues of those settings not holding when selected in the software, but they have been working well for me - always. And yes, you can increase the speed to 700-800. Some times it seems counter intuitive, but these machines perform better at a higher speed even with detail. If you are cutting a thin material then you often need to slow it down a little - trial and error. But I think you should easily be able to increase the speed.

Keep us posted.

[CrossHairSB]

Thank you Gigi,
Okay, so you are saying I may have better luck using an adhesive over taping the paper to the mat? If so, I have that tacky spray on order so I will try that.
And I have the 60 blade but I don't believe I had the blade offset correct. I really don't know what the "blade offset" does to be honest.
Thank you,
Ken Pasque

[Bikeracer]

Hello Ken,

Without actually cutting anything just set your mat in the pinch rollers and if you're using a support table tape a sheet of paper with a line drawn at 90 degrees to the macine.

With the machine set to offline and the edge of the mat lined up with the line, run the mat backwards and forwards a few times to see if it stays parallel to the line.

I was having cuts veering off today and eventually put it down to using a small A4 mat that came into my possession with a used machine I bought recently. Even using three pinch rollers the mat would not run straight for some reason, but kept skewing anti clockwise, tried cleaning the rollers, that made no difference.

Put my old 12" x 16" mat in and everything was good again apart from the time lost finding an answer to the problem.

The blade offset is the distance the actual point is from the centre line of the blade and seems to usually be around 0.25.
I think it's explained in the manual.

Allan

[Gigi]

Ken -

Have you cleaned your mat recently? You would be amazed at how the adhesive comes back after you wash it with dish soap and a light scrubbie (non abrasive). I am always amazed at how sticky it is when it dries. I can usually wash them several times to get adhesion again before I have to reapply the renu sheets. And I realize you have ordered the tacky spray, but the renu sheets are easier to maintain and provide excellent adhesion - for the future.

You should be using the 60 degree plus blade - not the 60 degree blade. That is the recommendation in the cutting guide and it is what most users who are cutting magnetic material are using.

The offset was explained to you. Here is the recommended setting for the blades:

There are set figures for the blade offsets
0.25mm for the standard blades
0.6mm for the detail blades
0.7mm for the 60plus blade
If your shapes have rounded corners when you are using these offsets then it is for a different reason.

Overcut -

1.00 for regular blades
1.20 for 60 degree plus

0 for pen tool and other tools…

[CrossHairSB]

AH! you guys are so kind...thank you.
I am awaiting standard blades as well as a 60+ blade. The standard blade DID work before but thought I'd see how a deeper cutting blade (60) would do.
I'm also thinking that using all four pinch rollers is helping with the cut accuracy. I need these blades to work FIRST then I'll run a few templates to check repeatability.
Can we talk about how to set up the blade? MUST I use some kind of spacer to put between the medium? I mean...isn't just setting up the clearance between the medium and how high the blade retracts?
Again, thank you for your responses!
Ken Pasque

[Gigi]

No - using all of the pinch blades does not help with cutter accuracy. There is just no need for it unless you are cutting a heavy medium that could shift on the mat. It actually can cause more minor difficulty with pinch wheels getting sticky and skewing etc. No need for overkill.

Using the spacer to help set up the blade is recommended because you not only want the clearance but you need the added area for the force. You only have to use it once. I mean, once you change a blade and have it set up - you don't need to use it every time you cut the medium. I don't use the spacer, once my blade is set, unless I switch to a radically different medium - like card stock to chipboard. Otherwise I leave it alone.

[CrossHairSB]

I only have two thicknesses of magnet paper, .025 & .015. Prior to trying out the 60 blade I used the 45 and it cut great except the positions of the cuts weren't repeating accurately. As of right now I am awaiting a new 45 & 60+ blade. I feel the accuracy of the cuts improved by using all the pinched rollers. Maybe I have the 60 blade protruding out of the holder too much? Should it only protrude out as much as the thickness of the medium?
Much appreciative to you Gigi & thank you for another response you gave me on an older post. I ordered some of their vinyl this morning to see if it'll work.
Ken Pasque

[Gigi]

You are welcome. Yes you could have the blade protruding too far. It should not exceed the thickness of the medium. We used to say it should just barely show - about 1mm - for cutting regular card stock.

If there is not a big difference between the two magnet widths, you may not find it necessary to reset the blade height. Trial and error! We have another user on here who only cuts magnet material - alphabet letters for buses. I think her username is jumpontheschoolbus. You might want to search for her posts and see if there is anything that she shared that can help you - just a thought. She hasn't been on the forum in a while as she is happily cutting but we hear from her occasionally via email.

Every machine is a little different, but they are very accurate. Once you find the force and speed and blade(s) that give you the results that you want, it will be smooth sailing.

[Bikeracer]

I tried to find an article on blade stick out again, I could not find it.
Rather than post information that might be incorrect I have deleted this post.

[CrossHairSB]

It's smooth sailing as of late GiGi
I lowered the blade depth to exactly the thickness of the magnet material. It's now cutting very accurate with no rough cutting edges.
Here is a question for you: Does the blade HAVE TO protrude out the thickness of the material to cut through? I mean...if the thickness of magnet material is .025 thick and I have the blade protruding out .016...will it cut all the way through the .025 thick material?
Here's a picture of my latest skin.

83003590_2101776163258392_7983438910057349120_o.jpg

Thank you,
Ken
ps: I will search out her name and see her experiences

[Gigi]

Hi Ken -

Thanks for sharing. So glad to hear.

The rule of thumb is that the blade should extend approx. the width of the material but most of us are not measuring! The easiest way to judge if it is out too far, is to see if it is leaving marks in the mat when you cut. You will see light lines as the blade goes through the adhesive, but you should not feel the lines in the mat if you run a fingernail over the mat. If you can actually feel the lines in the mat, then it is extended too far and that will wear out the blade much faster, obviously, and cause cutting problems. The blade should just be skimming the surface of the mat.

Thanks for sharing the photo - your work is very nice and love the tribute to Kobe. *sigh*