Blade depth changing during cutting.

[Goatshaver]

So this is new to me and not sure why it's even happening. I do die cut stickers on my D140. I do two passes for cuts to score them deep so they are easy to pop out. Well one sheet I tried yesterday, it started fine and a test cut was good, so I cut the whole sheet and when I pulled it I noticed the cuts got lighter further up the sheet it went. Just thought it was a random occurrence. I reprinted the sheet and tried again today and it did the same exact thing. I have marks on my blade holder so I can visually see the amount I turn it when setting depth. Well the blade got turned back, counter-clockwise, which recesses the blade, hence the cuts got lighter and now to reprint the sheet again.

Why would this happen? I just don't understand how this can happen.

 

[gabagoo]

Can't say that I have ever experienced the actual blade depth turning on it's own. I was going to say that possibly one side of the blade is worn heavier than the other or the tip is snapped off but the blade holder turning on its own is freaky

 

[Goatshaver]

Can't say that I have ever experienced the actual blade depth turning on it's own. I was going to say that possibly one side of the blade is worn heavier than the other or the tip is snapped off but the blade holder turning on its own is freaky

It's happened twice on the same job. I have a couple black marks on my blade holder so I can see how much I'm turning it when I adjust my depth. After I cut this sheet it had moved by almost a 1/4 turn. Very strange and not sure what to make of it. I reset the depth after and cut another sheet and had no issues. So I can't figure out why on this particular shape it's doing this. I've cut thousands of stickers this way and never has this happened before.

Since I had to reprint the job for a third time. I figured I'd try rotating the cuts and see if that makes any difference.

 

[S2S]

I have noticed...the blade in the holder is a compression hold...i have seen it just drop during cutting...I thought maybe a different tolerance of blades...I ended up putting extra emphasis on using the white nylon insertion tool and really pushing hard when installing a new blade...I know it's an elementary description but worked well for me.

 

[jagsouthern]

Likely not the blade but a worn cutting strip.

 

[Joseph44708]

Your cutting speed could be too slow, allowing the material to buckle under the blade and pull up from the cutting strip.

 

[Goatshaver]

I had to cut another sheet this morning. It's only on one particular shape this is happening. I even rotated the image 180 to see if that would change anything. Set my blade and pressure to where I have it for these types of cuts. Test cut worked fine so I proceeded to to the whole sheet.
First row was good, second row looked good but I noticed when it got further up the position has changed and this time my entire blade holder was being pushed up. I stopped the cutter and re-seated the blade and holder and made sure it was deep enough again. Started cutting the last half of the sheet and the blade got turned back again, blade holder didn't physically move out of the holder, just the gray screw part moved about 1/8th turn back.

I cannot even understand why this would be happening. I cut other things right after this shape and had no issues at all. It's very strange. Could be a worn blade holder?

 

[balstestrat]

It could very well be so.

 

[Lindsey]

I had to cut another sheet this morning. It's only on one particular shape this is happening. I even rotated the image 180 to see if that would change anything. Set my blade and pressure to where I have it for these types of cuts. Test cut worked fine so I proceeded to to the whole sheet.
First row was good, second row looked good but I noticed when it got further up the position has changed and this time my entire blade holder was being pushed up. I stopped the cutter and re-seated the blade and holder and made sure it was deep enough again. Started cutting the last half of the sheet and the blade got turned back again, blade holder didn't physically move out of the holder, just the gray screw part moved about 1/8th turn back.

I cannot even understand why this would be happening. I cut other things right after this shape and had no issues at all. It's very strange. Could be a worn blade holder?

Could it be a media issue? I know you got good results in the 1st few rows, so it would be normal to rule out the media...but maybe the way the media is travelling/passing through the Summa is causing the problem. Maybe watch the media (from both sides...input side and output side) and look to see if it's rising or pushing the blade or blade holder. A simple trick to try would be to slow the cutting speed down. To the slowest speed.

 

[Joseph44708]

Too much pressure and not enough blade can cause premature wear of the blade holder.
This happened on my cutter and it would not cut deep enough on one side.

 

[Goatshaver]

Could it be a media issue? I know you got good results in the 1st few rows, so it would be normal to rule out the media...but maybe the way the media is travelling/passing through the Summa is causing the problem. Maybe watch the media (from both sides...input side and output side) and look to see if it's rising or pushing the blade or blade holder. A simple trick to try would be to slow the cutting speed down. To the slowest speed.

Possibly. I did change my overlam recently but I'm on my third roll and now just having problems. I'll try slowing it...I've moved my pinch rollers around a little but still the same result.

 

[Goatshaver]

Too much pressure and not enough blade can cause premature wear of the blade holder.
This happened on my cutter and it would not cut deep enough on one side.

Yeah I might have to adjust some things. I'm playing with different pressures for it now. The blade holder is definitely moving. The last sheet I just cut it actually got deeper the more I cut.

 

[Goatshaver]

I just cut one sheet. All circles and the blade holder adjustment piece is definitely moving. The cuts started great, pretty ideal and as it moved up the sheet the cuts got deeper. The blade got turned out about 1/8th of a turn from where it had started. I'm going to only assume this is a worn blade holder now and this is the result.

 

[Raum Divarco]

I had to cut another sheet this morning. It's only on one particular shape this is happening. I even rotated the image 180 to see if that would change anything. Set my blade and pressure to where I have it for these types of cuts. Test cut worked fine so I proceeded to to the whole sheet.
First row was good, second row looked good but I noticed when it got further up the position has changed and this time my entire blade holder was being pushed up. I stopped the cutter and re-seated the blade and holder and made sure it was deep enough again. Started cutting the last half of the sheet and the blade got turned back again, blade holder didn't physically move out of the holder, just the gray screw part moved about 1/8th turn back.

I cannot even understand why this would be happening. I cut other things right after this shape and had no issues at all. It's very strange. Could be a worn blade holder?

On a lot of plotter tools depending on a variety of factors i use thread tape on the caps to add more friction to hold to depth i set with the rotation of the cap.
This isnt uncommon for plotter type tools.
Sometime the thread pitches male/female are looose and sometimes they wear.

 

[Joseph44708]

Just a thought.
Take blade holder off cutter and take the adjuster completly out of holder and check to make sure the tiny O ring is seated on adjuster.

 

[Goatshaver]

On a lot of plotter tools depending on a variety of factors i use thread tape on the caps to add more friction to hold to depth i set with the rotation of the cap.
This isnt uncommon for plotter type tools.
Sometime the thread pitches male/female are looose and sometimes they wear.

This was it! Put a little thread tape on it and it was nice and snug, felt secure and then cuts improved greatly. Great suggestion as this helped so much!

 

[Raum Divarco]

This was it! Put a little thread tape on it and it was nice and snug, felt secure and then cuts improved greatly. Great suggestion as this helped so much!

Good to hear.

 

[Goatshaver]

So I got it to work with a few sheets and now I'm back to the same issue again. I don't know what is happening. Cuts start out good and then the depth goes away. I've tried multiple pressures, adjusting my blade depth, using a new blade, with no real success. Out of a sheet of 100 stickers I get about 25 good ones then the rest of the sheet has to be trashed.

I had no problems for months and now all of a sudden almost every job I do full die cuts for is garbage. I wish someone with a summa plotter could tell say how they're doing full die cut stickers. No one can seem to answer this question with any kind of technical info that I can use to figure this out.

My process had been. To do the test cut until I got a decent cut through the sheet and the test square popped out fairly easy. My pressure has been set to 285, as that's what seemed to work well for this and blade is out further due to cutting through. It would just be enough to barely cut through the other side, so the stickers would stay in and not fall out and then I could easily pop them out on a table.

 

[gabagoo]

Maybe you should just go to one cut and cut them up manually as I don't think the d-140 was designed to to what your doing

 

[Goatshaver]

Maybe you should just go to one cut and cut them up manually as I don't think the d-140 was designed to to what your doing

I've gone back and forth on this. While it's not meant to do them, I've seen several people state they are doing these types of cuts on their summa. I do two cuts that are just deep enough to just break the backer slightly and then I can pop them out. However no one can seem to say how they do it. I just found a way through trial and error.

Unfortunately I do a lot of these cuts and it seems my blade holder was worn beyond use. A new holder works better but still not ideal. I was sold this machine as being able to do these types of cuts only to find out that it's much more difficult than I thought.

I think my next purchase will be a Graphtec since it is better designed for doing these types of cuts. I'm just losing productivity and reprinting stuff I shouldn't have to reprint.