Friday, 25 November 2016

ScanNCut Basics 4c: Test Cuts are your friend!

I think we've all done it. Assumed we know what settings to use, set it to those, stuck our paper to the mat, told it to cut and 'WHAT???? WHAT HAVE YOU DONE YOU BEAST OF A MACHINE!!!!!' is more often than not the anguished cry that follows, especially when you're up against a deadline, and have limited amounts of the exact material that needs to be cut. Honestly, it would make a grown man cry! (and probably has!)

So this post is all about NOT assuming and instead doing Test Cuts to be absolutely sure that what we want to be cut will be done perfectly.  With the added attraction of the fun I had testing a cutting file for a designer Amy Purdie for her Embellish Cuts business - these gorgeous flamingos - as an example of what you can do if you persevere for long enough.
This stunning papercut design can be purchased as a PDF download for manual cutting from Amy's shop HERE

But before we get to my amusing adventures in the extreme sport of testing the machine's parameters with test cutting, let's talk about why we need to do it.

The machine is not an AI (artificial intelligence). It does what YOU tell it to do. Which means YOU need to know what you are doing to avoid broken blades and cut through mats. And to achieve that, YOU need to know how to work out a rough starting point for Test Cutting until you know you have the right blade depth, pressure and speed, and then you can tell the machine to cut out whatever it is you're doing CONFIDENT that it will not mess up.

Which frankly to a new user is a lil bit scary! How on earth are YOU supposed to know what a good cut looks like, never mind if the machine is going to 'like' the settings to do a good clean cut.

What does a GOOD CUT look like?
  • The Shape you are cutting: The blade cuts a neat clean line, meeting in the same place when it ends as it started (assuming it's a shape and you aren't just cutting lines in a sheet of paper from end to end), and the 'waste' material separates away from the 'shape' with only a little prod, possibly even just falling out by itself. There's no stray fibres uncut or bits clinging on that you need to tear or scalpel away, there's no mismatch in start and end points, any sharp angles are cleanly and precisely cut. The top layer of the shape isn't shredded or torn.
  • The Mat: You only see a very very faint scoring/marking on the mat if you wiggle it in the light.
Characteristics of a BAD CUT
  • Problem: You need to fiddle around to get the shape to separate, or cut or tear it away because it's cut through only part of the way to the back of the material
    Fix: blade isn't deep enough
  • Problem: There's a mismatch between start and finish point
    Fix: You need to Align the Blade see the post on Machine Maintenance
  • Problem: The material is rucking up underneath the blade and concertina-ing and ripping instead of cutting
    Fix: pressure is too high and you may need to increase blade depth to compensate for reduction in pressure.
  • Problem: There's a lot of 'bits' sticking up when you cut and it's getting in the way of the next area being cut
    Fix: pressure is too high and you may need to increase blade depth to compensate.
  • Problem: Only one side of the shape is cutting, the other side is a half cut - this can be an issue when you're doing something big.
    Fix:Increase your blade depth a little, this will cut a little too deep on the side that was cutting perfectly, but cut perfectly on the side that was giving you a half cut.
    ALSO try Aligning your Blade
    ALSO try moving the shape to somewhere else on the mat.
    ALSO learn to work around it.  It's a known issue that some machines don't cut well on one side due to manufacturing tolerances when they build the machines. It cuts, but needs fiddling with. If your machine does this then ALWAYS do your test cuts on the side of the machine that you know doesn't cut well. This will mean it'll cut perfectly on that side, and slightly deeper on the other. Because of that, make sure you rotate your mat and use both ends so that it doesn't end up severely scored on one side only.
  • Problem: You've cut through the material AND the mat
    Fix: Blade depth too much. Decrease and look at the post on Mats to find out how to fix your mat!
  • Problem: It's needing more blade depth than it did when I wrote down the settings to use for this exact sort of material from the same package only yesterday!
    Fix: Look at your blade under a magnifying glass. It may have the very tip broken off, it'll still cut, but not as well. If you think the tip is still there, very gently open the holder, make sure there's no debris, wind it on back up as far as it'll go and reset it, making sure the spring is properly attached to the holder.  If that doesn't work gently take the blade out and put it back in again (taking care not to break the tip). If all else fails, change blades!
  • Problem: The blade depth changes as it cuts
    Fix: Tell Brother they should send you a new one, means the Holder is dodgy. See the Blades Post for a temporary fix using plumber's tape.
  • Problem: It doesn't work at all, it just makes a hot mess no matter the settings.
    Fix: Probably a broken blade - check and replace.
    ALSO is there debris stuck in the Holder so the blade can't turn? Clean it out (see the Manual and my basic Maintenance post)
    ALSO some materials can be tempremental - do test cutting in smaller increments until it works. The finer and more intricate the cut, the less pressure required. And reduce that speed! Give the Blade time to get around those complicated tiny shapes!
Great, now you know what you are looking for, we can move onto the actual Test Cuts.

HOW TO DO TEST CUTS

Firstly, look in your Manual - Chapter 1 Getting Started - Test Cuts. It explains in there that on the first screen in the Machine (where it says Pattern and Saved etc) there's a button that says TEST. If you click that it gives you 4 shapes - a square, a triangle, a circle, and a sideways V cut. Always follow the Manual! I'm not telling you here how to do a test cut - the Manual does that already! But what the Manual doesn't do, is explain how to tell if your Test Cut is working or not. So that's what the rest of this post explains.

Brother have specifically included these differently shaped Test Cuts for different requirements of the type of material and the type of cut being done. If you are using paper, then a Square is probably the most useful. If you are doing an intricate cut with lots of curves, use the circle as well, and if the cut has a lot of sharp angles, use the triangle. The reason the Manual concentrates so much on fabric is because the machine was originally designed to cut fabric and only later did Brother realise that people wanted to use it for paper, card and thicker materials etc.

I've found the most consistent results come when I use the Square Test repeatedly until I get the result I want.  When you choose the Square from the Test screen, a tiny square appears on the Mat in the Machine Screen, I then load my Mat with the material on it, and do the Background Scan - then I move the Square Test Cut shape to the bottom in one corner of the material (away from the top and the blade), so that it will cut it, and I can easily examine whether it's worked or not without dislodging the blade or mat.

I do a test cut, look to see if it worked, if it didn't I go back to the screen where I can move the Test Cut square, move it along a little bit, change the settings and try again. I keep doing that until the Square cuts perfectly. Then I try it with the triangle and circle if I need to.

I end up with a neat line of test cuts, starting with them barely scoring the surface cutting deeper and deeper until I get one where the Test Shape pops out neatly leaving barely a mark on the Mat.

It may be obvious, but I'll say it anyway you TEST CUT using the ACTUAL MATERIAL you are going to be cutting with your actual image!  There's no point doing a test cut on 80gsm copier paper then expecting the machine to cut 400gsm super heavy card. It won't! they need different blade depths and pressures - it takes more force and a deeper blade to go through a thicker card than it does for a thinner piece of paper. And I repeat the machine CAN'T TELL what sort of material you are putting through it. You have to tell it by making the Pressure and Blade Depth settings right.

TEST CUTTING WHEN YOUR MAIN CUTTING IMAGE IS ALREADY ON THE SCREEN

It's worth being aware if you ALREADY have your final cutting image on the screen, you can use the ADD button to add a TEST shape for TEST CUTTING. 

If you use the Test Shape function, the machine KNOWS that's what it is, you can tell it to start to cut, it will do the Test Shape ONLY. Then it will stop and ask you if you want to quit cutting on the screen. The Green go button will be lit up. Therefore, if you're happy with your Test Shape, you can press the Green go button and it will cut your image. If you aren't happy you can click the Quit Cutting and go back and move the Test Shape and have another go.

How cool is that!!!! I love that it knows that I'm fiddling on and don't want the main thing until I'm ready to cut the perfect cut! I often forget to test cut first, so it's a very useful function!

There's also a Test Cut button when you Scan in an image to cut, very useful to use because if you've got prestamped images for example, you want to know they'll cut cleanly, using the Test Cut function means you can be confident they will. 

WHERE TO START WITH BLADE DEPTH, PRESSURE AND SPEED

Go back to the Test Cutting: Blades post, there about half way through I talk about starting points. There's a link to a PDF created by a blogger called the Gentleman Crafter who gives rough starting points for a wide variety of materials.

Alternatively, if you are in Jen Blausey's of Jam Sessions on YouTube's Facebook group, she and Nicola have created a PDF that shows starting points for a wide variety of materials INCLUDING different kinds of vinyl. (It's for group memebers only, so I'm not linking to it here).

Personally my Speed is ALWAYS set at 1. Then it's something I don't have to worry about.

My pressure - I have a starting point of minus 2 or less for things like construction paper because it tears easily, it's minus 1 for 80gsm copier paper, at 0 for 130gsm type cartridge/art paper and plus 1 or 2 for HunkyDory Adorable Scorable 350gsm paper.

My blade - I expect about 2.8 to 3 for 80gsm copier paper, about 3.75 for 130gsm cartridge paper and just over 5 for the Adorable Scorable 350gsm paper. So I start them HALF a point under that as my test cutting starting point.

Why do I know these off by heart? Because these are the types of paper I use most frequently. Also I have them written down!

This means that if my blade won't cut at or around those settings, it means the blade is broken or jammed with debris, and I know roughly where to start looking to sort it out. 

GETTING THE RIGHT PRESSURE & DEPTH

Assuming you are making life simple for yourself and your speed is permanently set at 1, you do a Test Cut at your starting point settings, then see how it worked, then keep repeating them in a slightly different place on the Mat changing only ONE setting at a time so you can keep track of how the cut is going. Personally I start with a lowish blade setting, and increase it either a full number, or a half or a quarter (depending on how I feel it's going) until the square cuts out pretty cleanly.

Sometimes the Square cuts well on the straight sides, but not the corners, so I increase the pressure by 1 to see what difference that makes to the next Test Cut, if it doesn't make a difference, then I put the pressure back down to where it was before, and instead increase the depth a teeny weeny bit. This usually gives me a good clean cut, if it doesn't I keep alternating the change in pressure with a change in the blade depth until it does.

Once you have the Test Cut going well, then in theory the machine should cut anything out of that material on those settings perfectly.

But what if it doesn't?

WHEN THE TEST CUT LOOKS PERFECT BUT THE IMAGE WON'T CUT?

I've found this happens when the image I'm cutting is very intricate, OR the material I'm using is tricky.

Intricate image problems: 

As to an intricate image, don't forget you have a PAUSE button. You can use it to see what's going on and whether you need to try increasing or decreasing pressure or the blade depth depending on what you think is happening. You can then make the adjustments and if it's cutting fine, let it carry on, or you can pause and adjust again until it's cutting right.

Also don't forget you can CUT MORE THAN ONCE. If it looks like it's cutting perfectly but actually some of it is only half cuts and not all the way through the material. Just press Go green button again, and the machine will redo it. Often this is enough to go through the half cuts because it's already half way there and with the same blade pressure and depth, it'll cut. If it doesn't, increase the blade depth a max of half a number and make it go a third time. So long as your Blade Alignment is good, it'll cut in exactly the same place. Your mat may be a little scored in places, but not so that it shows on the back!

One important thing to remember is - DON'T EJECT THE MAT until you are absolutely sure it's cutting right! Once you've ejected the mat, it's highly unlikely if you loaded it again it'll cut in the same place. But if you keep the mat loaded, you can recut and/or adjust the settings using the pause button multiple times and it WILL cut in the right place every time.

Tricky Material:

Paper and Card have some characteristics that are worth knowing about because it makes them behave in certain ways when cut or creased

When made by machine, the fibres are all laid in ONE direction.  This means that paper and card bend more easily in one direction than another.  You can google this and there's info online about it.

If you aren't convinced, get a piece of say 100gsm ish cartridge paper, cut a piece a couple of inches square and bend it one way then the other. One way bends far more easily than the other. So. If you are using your machine to cut out card into actual card blanks, bear this in mind, it will score and bend more easily in one direction but be more stiff in the other. Orient your card or paper on the mat and the shape you're cutting from it when this matters (say with a pop up card perhaps).

In addition, paper is made using not just water and fibres, but also a binding medium. Generally some sort of 'glue'.  Depending on what the material was made for, it will be easier or harder to cut. For example chipboard is actually tiny little fibres going in all different directions (so is MDF) with the 'glue' holding it together, so it's very dense. And depending on how 'strong' the material is intended to be, the glue itself can also be dense.

Vinyl for example is made of plastic, so it rips, but not in the same way paper does, and also it stretches in a way that paper doesn't. You need far less pressure for vinyl, assuming it has a backing paper, you could go down to -9 for very intricate cuts with tiny lettering.

Construction paper is not made to have any 'tensile' strength, like newspaper it rips super easily, so you need lower pressure for it. Minus 2 or minus 3 is needed to stop it ripping even though it seems the same 'weight' or 'depth' as 80gsm copier paper.

Cartridge paper and art papers can be rough or smooth surfaced - can absorb a lot or liquid or not much at all - because they are intended to 'hold' dry media like charcoal or soak up the wet of watercolour etc. Those characteristics change the way the paper cuts. Some may be 'harder' for the blade to cut and put up more resistence than other papers.

Some papers are coated and those coatings may be designed to stretch for scoring and folding (like Hunky Dory's Adorable Scorable) so maybe you need less pressure so that the blade slices the coating rather than pulls to cut it so you don't see the core at sharp angles (where the blade's most likely to 'strip' a little bit of coating. If there's less pressure, you need slightly more blade depth to compensate.

So think about not just the thickness you are cutting but also the density when deciding the blade depth & pressure.

If in doubt you can go for a slightly higher blade depth and a slightly lower pressure than you think you need. If it's no more than 1/4 or 1/2 higher than the blade depth number that gives you a mere scratching on the mat and a decent cut in your Test Cuts, then it won't damage your mat and it should cut ok each time.

You could actually make it a habit of just going slightly higher (by a tiny amount) on the blade depth once you get a decent Test Cut to compensate for any density or thickness differences in the material you're using or in the Mat itself. That's up to you. I only do that if I know I've got problems I need to fix.

BE CONSISTENT IN THE TYPE OF PAPER OR CARD YOU USE



This is about making your life easier for yourself.

Basically, it really really helps if you use the SAME type of materials consistently because you can work out the Settings and be pretty sure it'll work time after time. If like me you have a few decades worth of random craft purchases you want to cut up - bear in mind the SnC can cut VIRTUALLY ANYTHING, but whether or not it will cut it WELL and CLEANLY depends on where YOU put the settings.

So having lots of different sorts of paper that need different settings EQUALS test cutting for each different sort because the best way to get a GOOD CUT, is through Test Cuts, repeated until you know they're right!

Whereas if you only have a few types of paper or card you use consistently, a particular brand or weight, then you ought in theory only have to make tiny adjustments to settings, and test cut with a new packet of it, rather than test cutting repeatedly every single time you want to cut something only because it's a different type or brand of paper.

That's not to say that you can't use lots of different sorts of paper - you can. I'm merely saying that if you find fiddling around with blade depth and pressure a faff and not much fun, make life easier for yourself by limiting the types and brands you use so you have a limited number of settings to work out! Me, I enjoy fiddling around getting the perfect cut on a 4" square of card that's probably long since out of production and that setting will never be used again lol. but that's just me!

Finally, be aware that as blades age, they'll need higher depth and pressure to cut the same paper or card, but it shouldn't be more than incremental at a time. If you suddenly need a much higher number, check if the blade is broken or debris is in the holder.

Some people have multiple standard & deep cut blades, one for vinyl, one for intricate paper cuts, one for chipboard etc. Some people even have multiple holders - it's all about your budget and how frequently and how much you use them. For the average domestic crafter that's probably not necessary - but it's entirely your choice!

Next post will be Adventures in Extreeme Test Cutting - Testing the Flamingos SVG for Amy HERE. (the picture at the top).

1 comment:

Slideshow of all cards/ projects posted so far....

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