MH871 choppy / jagged diagonal lines

[sspvinyl 6]

It seems like this is starting to get worse and worse with my cutter. I put new blades in the blade holder and same results. I even purchased a new blade holder however I got the same results. Cutting on Oracal 651 vinyl.

My straight lines are perfectly fine however the diagonal lines are very choppy and jagged.

[Racer88 24]

My MH 871 does that sometimes as well, Don't know what causes it, I try different cutting speeds or slightly increase/decrease the image size and it usually goes away. It might be that I am using the usb connection (been thinking about getting a keyspan). I only use my cutter for personal stuff, but I would like to know what causes it as well.

[sspvinyl 6]

I use a USB connection. I use this for business use and it sucks b/c I dont like giving my customers this crap.

[lueman 19]

I had a similar problem, this week I even ordered a blade holder, but I think I solved it already! There is a small o-ring on the inside of the blade holder if the o-ring allows some wiggle (looks like even on new holders, this is a problem) then the vinyl comes out wobbly. I replaced my o-ring with a slightly bigger one, sorry I can';t give you size it's trial & error, but when I found one big enough to remove the wiggle but small enough to allow the holder to show blade the problem went away. Hope this helps.

[lueman 19]

By the way from you photos looks like your blade offfset is off .15 for 60deg and .25 for 45deg blades.

[Racer88 24]

I had a similar problem, this week I even ordered a blade holder, but I think I solved it already! There is a small o-ring on the inside of the blade holder if the o-ring allows some wiggle (looks like even on new holders, this is a problem) then the vinyl comes out wobbly. I replaced my o-ring with a slightly bigger one, sorry I can';t give you size it's trial & error, but when I found one big enough to remove the wiggle but small enough to allow the holder to show blade the problem went away. Hope this helps.

I'll take a look at the o-ring in my blade holder. Thanks for the suggestion!

[deth502 39]

im gonna say blade holder, only i cant see why replacing it wouldnt solve the problem.

i had the problem once in a while, usually a little graphite lube to get everything working smoothly cured it.

then i started tearing shit up and ruining everything. found it was because the holder was dragging the blade sideways. i completely dissassembled it, i packed the littlebearing in it with grease, as well as teh sector bearings in the top. turns out, it wasnt turning becasue, for some reason, (quite possibly too much lateral play in teh threasds, which could be corrected as per lueman's post) but because the blade was hitting the side of the hole in the holder and binding. i reamed the hole out a bit with a rat tail file, and between that and the greased bearings, i have never had this problem since.

[TomasB 23]

By the way from you photos looks like your blade offfset is off .15 for 60deg and .25 for 45deg blades.

How can you tell? I would like to understand this more so I can make my own tweaks. Been almost a year now still a newbie continuously learning and would appreciate it , thanks.

[lueman 19]

How can you tell? I would like to understand this more so I can make my own tweaks. Been almost a year now still a newbie continuously learning and would appreciate it , thanks.

Look at the corners on the "T" and the "W" they should be straight, with no rounded edges the font looks like a funky typewrite instead of timesroman. A true typewriter font would have a better defined round corner.and timesroman is always square edges.

[TomasB 23]

Thanks Lueman I just learned something new again. That's why I love this forum!

[lueman 19]

My final follow up: the Oring solution worked better than I thought. now my blades, even older blade i thought were bad, work like (better than) new.I had to reduce my blade pressure for oracal by 10 points, and my edges are razer (hint) sharp.

[sspvinyl 6]

I think I will go ahead an switch out the o-rings. Just seems weird that it would do it on diagonal cuts and not my straight line cuts.

[sspvinyl 6]

My final follow up: the Oring solution worked better than I thought. now my blades, even older blade i thought were bad, work like (better than) new.I had to reduce my blade pressure for oracal by 10 points, and my edges are razer (hint) sharp.

Do you know what O Rings you bought for them. I had a few here from left overs from car stuff and they were a lil to thick.

[sspvinyl 6]

Ok I changed out the O-Rings and I still had the same issues.

I just tonight tighten the belt that pulls the blade from left to right and I fixed the problem. There is a bolt underneath the end cap (end cap that has the power switch) that you can tighten or loosen to make the belt looser or tighter.

The belt was loose but not that loose. I tighten it up a few turns until it got somewhat tight. has a lil play it it but it is fixed and Im so happy again.

[sspvinyl 6]

well. choppy lines are back.

Running out of ideas.

[MZ SKEETER 4,709]

have you tried some light oil in your blade holder? 3-1... sewing machine oil..

[arty-rc 719]

I'm having the same problem with my MH-721. It was cutting fine until this week,(I am a hobbist user). Here is a list of my attempted repairs: tightned the belt, adjusted the blade pressure and length, cleaned and lubed blade assy, swapped complete blade holder assy from my MH-365, tightned the belt drive motor bolts on bracket and housing, cleaned carriage track and rollers, lubricated the track and rollers with silicon, cutting strip is not damaged Still cuts badly on test cut and graphics. I did notice that the cuts going from front to back and back to front are not jagged but the right to left and left to right cuts are bad. the diagonal lines are also bad. What else is there to check??

[sspvinyl 6]

I slowed down the cutting speed and its a lil bit better. I will have to deal with it til March when I attend the ISA show in Orlando. will be looking to upgrade then.