Epilog Legend 24EX issues

[Keith Downing]

Finally got the recharged tube and repaired RF unit back for this older Epilog Legend 24EX I'm bringing back to life. Everything is re-assembled and I'm ready to test it BUT, now something strange is going on with the Y axis.

When I restarted the machine for the first time (it had been about 4 months) the carriage slammed into the back of the machine. I tried going to "Service" mode to move the X and Y axis to test and again it started pushing towards the back of the machine. I've cleaned and checked my connections and now it just "stutters" when it tries to move the carriage on startup.

Is this usually a connection, sensor, motor, or something totally different?

I'm going to give Epilog a ring tomorrow, but I have a sneaking suspicion this machine just stopped being supported since it's no longer listed in the online knowledge base. So any help would be appreciated.

[Brian Book]

Hi Keith .... although I don't have an Epilog .... I experienced a similar situation when one of my Stepper Motor Wires Broke

Brian

[Keith Downing]

Thanks Brian, I'm checking wires and connections tonight.

My worst fear is that it was something simple like a loose connection or a broken wire...but that it has now caused a motor to burn up.

[Joe Pelonio]

Remove and spin the motor by hand. I had to replace it in mine years ago when it did what yours did, and the shaft had bent and was binding. This was a known problem, and the replacement was beefed up. It was on warranty then, about 2007.

[Kev Williams]

Based on my experiences--

To start--I've never seen a stepper motor do anything it wasn't "told" to do. Meaning, they don't just go for no reason. If the head moves beyond its boundaries and slams a wall, it's because that's what the stepper thought it was supposed to do. I've been thru many stepper issues over the years, 3x on my lasers, all were broken-wire/bad connection issues. When connections are iffy, the stepper will act erratic and 'crazy', usually making lots of racket, because they seem to be trying to go both ways at once. When doing this the stepper is losing position badly, and if the bad connection 'catches' and the stepper works correctly again, the gantry can hit a wall because it was too close to the wall in the first place based on where the controller thought it was...

On startup, hitting the wall could simply be a limit switch not working. These switches are always exposed to the smoke & soot, and after sitting for months the crud may have compromised the switch.

Another possible issue, hopefully not, is the controller isn't working right--

You say it just stutters on startup now-- have you moved the gantries by hand away from home position? If not, SLOWLY move the head to the middle of the table... If your Y axis is trying to start up and it's against the wall, it'll just keep trying to move towards the switch. Move the gantries and see what happens on startup, let us know...

[John Noell]

I thought the Epilog Legends all used servos, not steppers. No? I loved the fact that my Mini (which said "Legend" on start up) could be rapidly and easily positioned by hand (using the perfectly aligned coaxial red dot). I miss that feature on my stepper controlled Chinese machines.

[Kev Williams]

My GCC has servos, I DO love them! But they come with their own headaches, in the form of encoder strips or discs. If they get cruddy, all kinds of goofy stuff can happen! My machine started misplacing steps badly one day...
be2.jpg
be4.jpg

After a good cleaning:
be6.jpg
-no problems since!

So if the machine in question has servos, could be encoder related...

[Keith Downing]

Thanks for the all the help guys.

I spent most of yesterday following wires and trying to think of every possibility that could be causing the issue. Couldn't find a thing wrong. So this morning I got my camera out to take a video of the startup process to post for help...and it worked normally.

So it's a mystery, but the laser is apparently working again.

I have a feeling that I'm going to be learning a LOT about exactly how this machine works over the coming months, but fingers crossed this was just a loose wire and hopefully the problem won't come back again.

[Bill George]

You more than likely have a broken or marginal wire or wires to that motor or the encoder.

[Keith Downing]

You more than likely have a broken or marginal wire or wires to that motor or the encoder.

Thanks bill, where's the encoder located? I'm new to the servo motors.

[John Noell]

At least on my Mini, the encoder is a small strip of plastic running along the top of the gantry.

[Kev Williams]

If you have an encoder disc, it'll be under an end-cap right on the servo motor...

[John Noell]

Video for Legend 36XT encoder strip here. Epilog instructions here.

[Keith Downing]

Thanks John, the video was helpful and I'll clean that up tomorrow.

One random question: If I try to focus the machine on a piece of plywood smaller than half an inch thick (without the big grid table in the laser); the table/bed hits on the edge of the machine as it is coming up BEFORE the item comes into focus. Is this the intended behavior? Or is something setup or adjusted incorrectly with my bed?

Obviously I could always use the big grid table when doing thin stock, but it seems like that would be mentioned in the manual if that was absolutely necessary.

[Kev Williams]

There's a bit of a flaw in how the guy cleaned the encoder strip--

as he mentioned, there a bazillion 'hash lines' along the encoder strip, just like those on the disc in my pics- the flaw is he ran a Qtip 'against the grain' of those hash lines. While this will clean the strip, those grooves can trap pieces of the Qtip cotton...

It's tedious, but you need to clean the strip 'with the grain' to get those grooves good and clean...