MH 871-MK2 - Straight Lines - Help!

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Hi all. We are new to vinyl cutters and having what seems to be a simple issue but can't fix it. We've searched this forum and other sites, have tried several things including adjusting speed and pressure. The problem is nothing cuts "clean". We can't get straight or curved lines or letters. Sometimes we will get a straight letter within a word or a single line in an image but have never been able to cut an image/wording where the entire thing is perfect (or close enough). As "newbies" I hope some of you more experienced people will have some advice. Thank you in advance!

I have posted an image below which pretty much combines some of our issues into a single image.


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  Is the cutter new or used? What cutting software? on which computer.?.  Where did you get this file?  Is it traced?  Or created by you from scratch?   How did you set your blade depth.? What is your blade offset set at?  Are the screws in your grit rollers tight?  Is the carriage head wheels firmly down into the track?  Is your cutter grounded to the stand if you have one?  If on USB, put it on a serial or a Tripp-Lite Keyspan adapter, that is the brand name, you will wish you had. Those cutters have a flaky cheap Chinese chipset. It is not TRUE USB like higher end cutters. 

That cutter has very limited memory,  so you will have trouble with large files even completing. just so you know. 

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I agree with Skeeter. You most likely have new user set up issues. Like she mentioned it will help some to know what you bought and what software you are running it with. 

Machine set up is critical with the budget cutters. (Well, any cutter but the high end ones will still do passable work even when poorly set-up) Typical set up would proceed in an order something like this:

1. Blade depth, 2. Pressure, 3. Speed, 4. Offset, 5. Over cut (if needed) 

The only one that really matters in the stack is that you set the blade depth first. MZ SKEETER gives about the most concise instruction to set your blade so maybe do a search on posts by her. Here is a quick rundown: Pull the blade holder off the machine and set the blade so you basically can't see it. Take a scrap piece and with your hand drag it across the scrap vinyl with some pressure, not like scary hard but SOME pressure. If the blade cuts all the way through the vinyl and the carrier you are too long. If the blade does not make it through the vinyl to the carrier you are too short. If you can cut the vinyl and scratch the carrier but not cut all the way through the sheet you are about right.  Replace the blade holder in the machine. You should not have to adjust this again if you got it right. All further adjustments will be made with the blade pressure. 

To set the Pressure you will start out light and cut a small square (half inch will do). Some machines or software will have a test cut feature for the pressure some do not. Start light and work into the material until you cut through the vinyl completely and lightly scratch the carrier sheet. You should see the scratch clearly but not be able to feel it from the back side. There is a decent amount of forgiveness with this but if you go too far it will cause vinyl bunching, can cut clear though and damage your tip or the cutting strip or if you cut too deep but not clear through you will find the waxy part of the carrier sheet coming up with your vinyl when you go to install. 

Speed should be set 1/4 to 1/3 of the highest setting your machine will go. If it goes to 400g start about 100. Speed kills accuracy especially on a budget machine. 

Blade offset will be something like 0.35mm and should have come in your instructions if you can read them. The number is just a close guess and you will likely have to "tune" it. The same square you used for the pressure will do. If your corners are nice and clean you are good to go. If they are rounded you need a higher number, if they have little tails you need a smaller number. 

If you find your end of cut does not make it all the may to the start and leaves a little bit you can add some Overcut (may not be available on your machine or may only be within your cutting software) Most machines don't need it but some do. Rule of thumb is it shouldn't need to be much more than your blade offset or you have something else going on there. 

I am attaching a little blade tech knowledge from Roland that is good tech and applies to any machine. Good luck. (I don't usually get this prolific with the writing but was sitting here waiting for a return email from someone and had a spare moment.)


ra_cutter blade knowledge.pdf

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