Epilog Mini Blurry Engraving (Backlash Issue) ?

[chris szlachetka]

I recently started running more Al and have noticed very blurry text. I run my machine at 600/1200 DPI, 100% power and 65 - 100% speeds depending on the coat/color. The blurriness starts to show its ugly face at around 75% speed.

I was on the phone with one of the Epilog techs trying to help locate the issue. I've tightened up a quite a few different spots hoping to figure this out. Long story short I think it may be the iko linear carriage assembly. If I place my finger under the metal frame that houses the lens, I can feel a very tiny click/backlash when very lightly pulling up & down. I've tried to locate the preload adjustment screw, but can't seem to find it looking at my machine or online. If you know where I can find this little set screw, please comment below.


Thanks

[Kev Williams]

Ironic- I was looking for just such a screw on my GCC only 2 hours ago, I even went so far as to dump ball bearings all over the place (ooops)... My rail guide has quite a bit more than what I'd call "very tiny" backlash. However, it's not really affecting the engraving, I was just curious if I could snug it up. So now I had to remove the whole rail assembly...
After locating all the bearings and reloading them into the guide--
railguide.jpg
I smeared some grease over the ends to keep the bearings in place and re-assembled it, then packed the bearings with fresh grease.

In doing all of that, there was no lash adjustment of any kind that I found.

But even being able to rock the lens head up & down, there is virtually no side-to-side slop, and I'm sure yours is the same way. If you're getting 'double vision' on the SIDES of text, it's (IMO) likely not the rail guide. If your double vision is in how the text lines up from top to bottom then up/down backlash may be the problem.
-or-
I posted up just the other day too (more irony), same machine started engraving very badly, this is a before/after pic-

be7.jpg

-the top line thought might be due to my rail guide, but turned out the mirror on the gantry was loose...

It's probably okay, but how tight is your X belt?

Do you have a backlash adjustment in your software? All 4 different software drivers for my 4 different machines have backlash adjustments of some kind. My GCC works great up to 80% speed, but 90 to 100%, text starts getting fat, especially at the edges. It's a simple matter of adjusting the backlash from zero to -2....

Finally, does that machine have servo steppers with an encoder strip or disc? If so, the encoder may be need cleaning...

good luck!

[chris szlachetka]

Thanks for the reply ! My belt was the first thing they had me tighten up, still not much of a difference in the text at higher engraving speeds. I also ran a q-tip on the back and the front side of the encoder strip. What I find strange is when I engrave the same word spaced properly 8 times in the same row all but the first word is blurry. I've checked and leveled my machine to be within .005" - .014" flatness from corner to corner. I've even run my dial indicator and 123 blocks as the leveling points to set my numbers. I'm with you on the side to side slop vs the up & down engraving results, but this is the only thing I could find left on my machine that's loose that could cause blurriness at high speeds. My next step is to start working my way back into the left panel and finding anything to tighten up. If you can think of anything else I'm all ears. As for the being able to edit the Epilog software/postprocessor file, I don't see any access to it ?

[John Noell]

A fairly common problem with the Mini is the ribbon cable to the encoder strip reader. One quick easy test is to switch cable ends. (It does not use all the wires so this changes to a new set of wires.) If a wire in the cable is broken (due to constant flexing) and making intermittent contact, it can cause the symptoms you are seeing. Of course, other wires may also be going or gone but often swapping ends is a (temporary) cure.

[Kev Williams]

As for the being able to edit the Epilog software/postprocessor file, I don't see any access to it ?

Here's the adjustments on my 4 machines:

My LS900 has a section in the print driver for some tests. The page isn't very forthcoming with the info, but the "send test file" is how backlash is aligned on this machine...
900test.jpg
The test file is a job that engraves a series of 12 (I think) rows of vertical dashes. Line 1 starts out with the hash marks not lining up well at all, around line 6 is near perfect, and around the last line they're misaligned bad again. My job is to get a magnifier and decide which row of lines are aligned perfectly to my eye, then enter that line number in the prompt box. (My line has been "5" since day one, and every time I've tested it's still the best...)

My GCC Explorer has the adjustment on the page size ("paper") page, it's the "image tuning" slider. I only have to adjust from zero if I'm running 90% or faster. (When I first got it, it liked +4, then I adjusted the belt tension, and it's been close to zero ever since)
GCCtest.jpg

My old ULS driver, the adjustment is the "tuning" slider, very much like the GCC...
ULStest.jpg

My Triumph is adjusted on a parameters page, "carving backlash". These are the machine's default settings, not mine by the way. This machine is very "manual" based, and I have different settings for every 50mm/second increment from 150 to 800mm/sec... I spent a lot of time dialing it in, but even though it's a 35x51" machine designed for cutting, it engraves as well as any other machine I have!
TRItest.jpg

I've never messed with an Epy or even seen and Epy driver page, but since every machine I HAVE messed with has a backlash adjustment in the driver software, I believe hiding somewhere in your print settings is a "tuning" feature of some sort... If so, I hope I've helped locate it

[Darren Wilson]

Hello Chris,
How did you go? Did you fix your fuzzy engraving?

[chris szlachetka]

"A fairly common problem with the Mini is the ribbon cable to the encoder strip reader. One quick easy test is to switch cable ends. (It does not use all the wires so this changes to a new set of wires.) If a wire in the cable is broken (due to constant flexing) and making intermittent contact, it can cause the symptoms you are seeing. Of course, other wires may also be going or gone but often swapping ends is a (temporary) cure."

Hi John,
Very interesting... I have a bunch of jobs to complete right now and will continue to engrave slow till I'm ready. I might look into ordering a new ribbon just in case something does go wrong. This machine is still very new, but I guess anything can happen. Thank you for the input !

[chris szlachetka]

Thanks Kev ! I'll look into this as well.

[chris szlachetka]

Darren unfortunately not yet, but working on it.

[Darren Wilson]

I had similar problem...caused by mutiple issues. Linear strip was damaged (replaced), ribbon cable worn (flipped around) and tube was tired (replaced). Hopefully you issue isn't caused by tube.

[Kev Williams]

Chris, WHY I believe there must be an adjustment somewhere in your software has come more to light since my guide-rail grease job--

As I noted above, I had the backlash adjusted to plus-4 when I got the machine, and after adjusting the belt, zero adjustment was needed--

Well, after a few jobs and running-in the new grease, we were noticing smaller characters were a bit on the fat side-
It seems that the grease has itself taken up some the slack in the system, and as of now I have the backlash tuned at minus-7!
I assume as the grease slowly works its way out, the backlash numbers will have to be adjusted accordingly

Just shows how little things can affect the final results!