PDA

View Full Version : Restoring a Mini 24



Dan Wilhelm
07-01-2014, 7:25 PM
I've recently acquired an Epilog Mini 24, 40W laser cutter that has had a fire in the cutting chamber. I'd like to try to restore it to a usable state, but it needs some significant restoration. Once I got a lot of the burned crap out and most of the fire extinguisher residue cleaned up, I put some power to it. It homed the y-axis, but the belt is melted though on the x-axis which prevented it from fully starting up. As far as I can tell, the laser diode, power supply, motors, and controls are all operational.

I know as of now that I need to replace the left belt bracket on the y-axis, the auto-focus plunger, the x-axis belt, and the air-assist tubing. It would probably be a good idea to just replace the entire x-axis because it is going to take a lot of cleaning to get running smooth again. The exhaust manifold and engraving table are both warped from heat, but I know a pretty decent metal worker that might be able to restore them.

My question is, where can I buy the parts that I need to restore this thing? It's one of the pre-2010 models, so I think it uses some different parts than the current generation Mini. I emailed tech(at)epiloglaser(dot)com, but they have yet to respond to me. If I am able to restore the laser, I'd also need the original Epilog drivers/software. I don't want to take any money out of Epilog's pocket, but if they are unwilling to sell me parts, do I have any other options?

Robert Walters
07-01-2014, 8:17 PM
I'm sure epilog will sell parts if they have them available, this IS how they make money.
You are not taking money out of their pockets in the least.

Since you said the engraving table is warped...

If your friend can work miracles, make sure that the table is tested on a granite surface plate and a dial indicator.
also ask epilog what is the tolerance of the table, then you will have something to measure against and see if you are within that spec.


That will tell you for sure if it's true or not, you don't need to go thru the whole restoration process only to find out that you have to do it all over again because the table isn't flat.


*I* would pull out the entire wiring harness and bench test every wire/connection point.

Fire has a funny way of doing unexpected things, and the last thing you want to do is not be unaware of an open, short, or worse of all intermittent connection. Yes, it might be a PITA, just take *LOTS* of photos before pulling it out, take photos of the connectors themselves and what they plug into as well. that way when/if you get tired/frustrated you can look back at the photos.

In a laser engraver I would not be surprised to take 80-150 photos, including of how the wires are run in the machine and at various angles.

I would inspect PCB's for lifted components, etc. While they may have been protected from the flames, they might not have been from the heat.

I would also inspect/photograph before spending one dime in parts. you never know what you might find till you do a full tear down.

Good luck!

Joe Pelonio
07-01-2014, 8:21 PM
Epilog responds faster to a phone call. To find the exact replacement part you would have to determine their supplier and most of the parts you need are custom made for them, and they probably can sell only to Epilog by contract.

Dan Wilhelm
07-01-2014, 9:07 PM
Actually, this laser is built differently than my GWeike. The part that is warped is the "pan" that the different cutting services sit in. It has rulers that fold down around its perimeter. The previous owner was using the expanded metal grid when the fire happened, and that thing is wrecked. I didn't even notice that the pan was warped until I removed it from the Z-axis mounts.

I'm actually an electrical engineer and an electronics hobbiest in my spare time, so I'm fairly confident that the wiring and PCBs are in good shape. I have removed the laser diode and power supply, opened them up, and cleaned out as much of the fire extinguisher residue as I could. I didn't open any sealed parts of the laser diode, though...don't want any contaminants getting in there.

Where I left it this afternoon was deciding whether or not to drill out the rivets that hold the exhaust manifold into the chassis. I can't get in the manifold to clean it without drilling out the rivets, so it's probably going to happen. The plastic parts of the exhaust ports in the "pan" are melted, so they will have to be replaced at a minimum.

Pete Simmons
07-02-2014, 8:56 AM
"the auto-focus plunger"

Leave it out. Easy to focus without it and gives more head clearance for odd shaped objects. With it installed you will jam it up against some uneven piece of material.

Good luck with the rebuild.

Bill Munroe
07-02-2014, 9:07 AM
Pete, I realize this sounds incredibly ignorant, but how do you focus without the plunger? Thanks!

Dan Wilhelm
07-02-2014, 11:21 AM
"the auto-focus plunger"

Leave it out. Easy to focus without it and gives more head clearance for odd shaped objects. With it installed you will jam it up against some uneven piece of material.

Good luck with the rebuild.

Pete, I took the plunger off my Gweike, and it included a focusing tool that works just fine. I don't think that's possible with the Epilog, though. There isn't really a "lip" on the lens holder to manually adjust the focus length like there is on the Chinese lasers. Plus, I'd trust Epilog to execute auto-focus better than the Chinese do.

Pete Simmons
07-02-2014, 11:27 AM
I have a small V shaped spacer (came with Epilog Mini) that slips over 2 pins on the lens carriage and is held in place by 2 magnets.

Bill Munroe
07-02-2014, 12:02 PM
Thanks guys. I got my Epilog second hand and didn't get a "tool". I'll check out their site.

Pete Simmons
07-02-2014, 3:01 PM
Manual focus. Lotsa dirt but the lens is clean!

292276

Kev Williams
07-02-2014, 9:08 PM
Man, you guys are too hi-tech for me!

Here's my focusing tool... ;)

http://www.engraver1.com/erase2/focus.jpg

Dan Wilhelm
07-02-2014, 9:27 PM
Epilog tech support got back to me today with some CAD drawings including BOMs. That's helpful for determining the names/part numbers of the parts I need. I responded back with a slew of questions that will probably take them a while to answer.

I tried to remove the exhaust duct today, but even after removing the rivets, the duct is not removable. It looks like the frame was built around the duct, so I would have to completely disassemble the frame to remove it. How critical is it for the ducts on the engraving table to be flush with the plastic sliders on the rear exhaust duct? If I can't remove that thing to flatten it, it might be a deal-breaker.

Also, Epilog just directed me to buy CorelDraw when I asked about their software. Are the job control plug-ins and drivers free from Epilog?

Tim Bateson
07-02-2014, 11:15 PM
...Also, Epilog just directed me to buy CorelDraw when I asked about their software. Are the job control plug-ins and drivers free from Epilog?

Epilog doesn't use "job control" . Just a specialized print driver. Just like sending a Corel file to a printer, but in this case to the Epilog laser.

Dan Wilhelm
07-03-2014, 8:10 PM
Got some good work done today. Turns out that the part of the exhaust duct that is warped is removable from the rest. I got that taken off, and my metalworking friend is going to fabricate another one for me this weekend. I also cleaned up the x-axis and found that I really only need the parts that attach directly to the focusing lens...everything else is in good shape. I might get out of this thing only having to buy a new focusing head assembly and a cutting table. It'll still probably run $1000, but far cheaper than a new Mini 24.

Bill Cunningham
07-20-2014, 7:29 PM
Or just measure it ... Sometime I use my focus tool, but other times its just as quick to grab the tape measure and bring the table/part up to 2" from the lens. Your lens is most likely a 2" focus..

Dan Wilhelm
07-22-2014, 5:49 PM
Are you Kellie or Steve? Either way, do you sell Epilog spare parts? I think I've determined what I need, but it has been over 11 days since I sent in a list of parts for a quote, and Epilog has yet to get back to me. I shook the tree earlier today, so we'll see if they respond. If not, I guess I might need to look elsewhere.

Dan Wilhelm
08-04-2014, 8:03 PM
Well, I finally got my parts order in today. Ended up getting a whole new cutting table, several parts for the X-axis, and one part for the Y-axis. I'm reasonably confident that I can get this up and running, and for what I'll have in it, I will have paid about 10% of the original price for the laser.

I got quotes for the Epilog brand air compressor (air assist) and rotary axis. I decided to not pull the trigger on them since I'm not 100% sure that I can get the laser running. Do you all that own Epilog (or Trotec, Universal, etc.) use the OEM air compressor for air assist, or do you have an alternative? The price I was quoted seemed excessive for a 30 psi air compressor.

Paul Phillips
08-05-2014, 1:52 PM
Dan, not all air is created equal, you can find a small cheap compressor that will output the same volume and PSI but it will need to be properly filtered as they typically put out moisture and oil vapor into the air line which you definitely don't want to get onto your lens, the manufacturer supplied units (western ones at least) usually come with the proper filters already installed, thus the increased price.

Gary Hair
08-05-2014, 2:06 PM
For the price difference between what the manufacturers want for an air compressor, you can buy a decent compressor and a really good filter/dryer and still be money ahead. There is nothing special about what the mfg's want to sell you, they just mark it up as much as they can.

Dan Wilhelm
08-05-2014, 7:01 PM
For the price difference between what the manufacturers want for an air compressor, you can buy a decent compressor and a really good filter/dryer and still be money ahead. There is nothing special about what the mfg's want to sell you, they just mark it up as much as they can.

That's what I figured. Any suggestions on compressor/filter combinations?

Kevin Gregerson
08-05-2014, 10:37 PM
Get the machine up and running first then look at the compressor. Also double check the back wall of the machine to see if its straight as most Lasers are pretty much toast once that goes bad. Second piece, the compressor is really only needed as a way to keep the optics clean on epilogue machines and even then it's really only for when you are working with materials that put out a fair bit of smoke. If you are doing a ton of cuts on smoky materials like wood sure. But if you are using it for only anodized aluminium, no machine needs a compressor attached to it. I say wait till you go through a lens or mirror then look at air assist. The price of air assist compressor is usually equal to 5 or ten lenses. So unless you are planning on going through a set of optics annually or more. It's not exactly going to pay for itself especially when you can pretty much add it to your shop compressed air along with a dryer and oil separator for less.

Gary Hair
08-06-2014, 1:07 AM
That's what I figured. Any suggestions on compressor/filter combinations?

Get an oil bath compressor if you want a fair amount of volume and relatively quiet. They are a bit more than a typical compressor but a lot quieter. If you can put it in the garage, or away from your work area, then you can get away with anything that is in the 30 gallon tank size range. I have a 60 gallon, 5 hp, electric and it puts out more air than I'll ever need for the laser and still has enough to run my glass sandblasting cabinet, way overkill for any laser usage. The filter I have for my diesel powered rotary screw is made by these folks - http://tsunamiusa.net/ - I think it's this one - 21999-0082.
If you got the same version but lower cfm, it would work really well for separating oil/water for your laser. Here is one for $130 http://www.filters.com/Air-amp-Gas-Filters/Tsunami-Air-Systems/Tsunami-Automatic-Water-Separators/21999-0390-Tsunami-Compressed-Air-Filter-System-Water-Separator-w-Float-drain-20-Series

It's not rocket science but the manufacturers want you to think it is...

Mike Null
08-06-2014, 7:09 AM
My first machine didn't have air assist. I got by just fine but I have built in air assist on my Trotec and wouldn't buy a machine without it. If you're going to cut anything it's a real asset; particularly with acrylics.

You can rig a supplemental unit without a lot of hassle. Get the machine running--then address the compressor question. Gast is the standard for this type compressor so keep your eyes peeled for a used one.

Doug Griffith
08-06-2014, 10:02 AM
...Second piece, the compressor is really only needed as a way to keep the optics clean on epilogue machines and even then it's really only for when you are working with materials that put out a fair bit of smoke. If you are doing a ton of cuts on smoky materials like wood sure. But if you are using it for only anodized aluminium, no machine needs a compressor attached to it. I say wait till you go through a lens or mirror then look at air assist. The price of air assist compressor is usually equal to 5 or ten lenses. So unless you are planning on going through a set of optics annually or more. It's not exactly going to pay for itself especially when you can pretty much add it to your shop compressed air along with a dryer and oil separator for less.

Air assist is not only there to keep the optics clean. It prevents flare up and helps remove incinerated material from the kerf. I would not cut wood or acrylic without it.

Dan Wilhelm
08-06-2014, 6:24 PM
So you guys just use regular "shop-type" compressors then regulate the air down to 30 psi? I have a pancake compressor for some air tools I have, but that thing is loud as holy hell...and total overkill for air assist on a laser.

I was thinking you could get a much smaller compressor that just put out 30-ish psi. That is what comes with the Chinese lasers. I know they are just aquarium pumps that aren't really rated for continuous use on a laser...but it seems like a more reliable, but still similar, option would be available.

Kevin Gregerson
08-06-2014, 7:16 PM
Air assist is not only there to keep the optics clean. It prevents flare up and helps remove incinerated material from the kerf. I would not cut wood or acrylic without it.
Some people swear by it, and if you are doing volume by all means. I've never had flare up issues on acrylic and I've done all the way up to 1/2 inch cast without any flare up(at least on the top) with 50 watts.

Now if you are talking HDPE, Nylon, Delrin, kapton Films, vhb tapes. Air assist is necessary.

Glen Monaghan
08-07-2014, 12:07 AM
There are some small "industrial strength" compressors that are generally highly regarded, such as some of the Gaast line. Dee recommended a "salon" compressor and likes hers. I'm on my third one (warranty replacement) because the plastic one-way valve keeps self destructing. They said they wouldn't replace it again... I also have one of the Harbor Fright air brush compressors, which works well but gets scorching hot if I don't put a small fan close by, blowing across it.

Doug Griffith
08-07-2014, 11:36 AM
Some people swear by it, and if you are doing volume by all means. I've never had flare up issues on acrylic and I've done all the way up to 1/2 inch cast without any flare up(at least on the top) with 50 watts.

Now if you are talking HDPE, Nylon, Delrin, kapton Films, vhb tapes. Air assist is necessary.

I have had flare up with acrylic more often than once. Most often when nesting parts tight and the area between them is very thin. Also, paper backing exacerbates the issue. My point being, air assist is required in many situations so it should be recommended no matter what. Dan's machine that he's restoring probably caught fire in the first place because there was no air assist. That, and the operator left the machine unattended. HDPE and nylon cut (or should I say melt) bad but air assist helps remove the slag. Delrin cuts great and I doubt it needs air because it does not tend to flare up. I use air anyways because it's there and safer to run with it.

Dan Wilhelm
08-14-2014, 9:22 PM
Progress report: I have all of the parts I think I need to restore this thing. I have now re-built the entire X-axis with a new back plate, auto-focus plunger (hey, it was cheap), belt, and air hose. I bought an entirely new cutting table, so it just needs to be bolted in. The most major repair I have left to do is replacing the left X-axis mounting plate on the Y-axis. That is going to require removing one of the Y-axis belts and linear guide rails...not looking forward to it. I also have a new Molex connector for the rotary axis plug in the cutting table. Just need to re-wire the connector and attach it to the cutting table.

I bought a new final mirror and focusing lens assembly. Out of curiosity, I removed the lens and mirror from the old assembly and cleaned them with DNA. The surfaces are clean now, but they are both discolored. There are no scratches or fractures in the lens. There are few minor scratches on the mirror, but I rotated it when I put it back in the frame so that the scratches aren't exposed any more. But the old lens is pretty severely discolored compared to the new one. The old one has some rainbow type discoloration, and is generally darker than the new one. Is this normal for a used lens? Do you guys think it is still serviceable? I plan on keeping the new lens, but if I can get some use out of the old one, it'd be great to have a spare.

Dan Hintz
08-15-2014, 7:14 AM
The rainbow discoloration is the AR coating, though it's likely you have a burned lens considering what it has been through.

Dan Wilhelm
08-15-2014, 9:51 AM
What material are Epilog lenses made of? I've never heard of a lens 'burning.' Usually, IR lens material is fairly heat resistant and the worst that could happen is thermal stress fractures.

Dan Hintz
08-15-2014, 11:30 AM
What material are Epilog lenses made of? I've never heard of a lens 'burning.' Usually, IR lens material is fairly heat resistant and the worst that could happen is thermal stress fractures.

Zinc Selenide, same as all of the other lenses in these machines... by "burned", I simply mean you've cooked the AR coating and/or thermally stressed the lens. They're cheap, I'd buy a replacement to have on hand anyway, so use the old one until you can determine it's truly junk.

Dan Wilhelm
08-15-2014, 8:33 PM
Gallium Arsenide also works as an IR lens. I wouldn't say they are "cheap," especially from Epilog. That was my plan anyway. I was going to fire the laser up with the old lens in, and if I only had focus/power problems, then I would change the old lens out for the new one.

Dan Wilhelm
08-16-2014, 7:28 PM
Got everything installed, and tried my first power-up today. The laser cooling fans powered up, but nothing really happened. The control panel display shows about half solid rectangles and nothing else. The green light on the power supply and all four red lights on the main control board indicating that the voltage rails are OK are lit up. The bottom light next to the RJ-11 cable on the laser is lit green and the top light is lit red. There is a button on the control board, and when I hold it down for a few seconds, an amber LED lights up for a couple of seconds, then a green LED flashes twice. None of the buttons on the control panel change anything.

When I powered up the laser before tearing into it, the Z and Y axes homed, but an error was displayed on the control panel because the X-axis couldn't move (melted belt). I seem to have taken a step in the wrong direction. Any suggestions?

Dan Wilhelm
08-18-2014, 6:18 PM
After some troubleshooting with Epilog tech support, they say that the control board is bad. All of the power rails are energized, but there is no "boot up beep." I must have done something during cleaning or re-assembly because the board was working before I took everything off. The only thing I can think of that might have killed it is when I was moving the X- and Y- axes around after putting them back together, I saw the voltage rail lights on the control board light up. Apparently, the servo motors act as generators when you move them manually and will feed voltage back to the control board. It's plausible that this voltage fed back onto the 1.5 or 2.3V rails and fried a chip. Kinda bad design if you ask me. It would be trivial to put diodes or opto-couplers on the control board to prevent back feed voltage from the motors.

Anyway, new control board on the way and fingers crossed.

Dan Hintz
08-18-2014, 8:48 PM
The only thing I can think of that might have killed it is when I was moving the X- and Y- axes around after putting them back together, I saw the voltage rail lights on the control board light up. Apparently, the servo motors act as generators when you move them manually and will feed voltage back to the control board. It's plausible that this voltage fed back onto the 1.5 or 2.3V rails and fried a chip. Kinda bad design if you ask me. It would be trivial to put diodes or opto-couplers on the control board to prevent back feed voltage from the motors.

It's possible you were back-powering the LEDS through the body diodes, but it shouldn't pose a problem... something else toasted the board.

Kevin Gregerson
08-20-2014, 11:34 AM
After some troubleshooting with Epilog tech support, they say that the control board is bad. All of the power rails are energized, but there is no "boot up beep." I must have done something during cleaning or re-assembly because the board was working before I took everything off. The only thing I can think of that might have killed it is when I was moving the X- and Y- axes around after putting them back together, I saw the voltage rail lights on the control board light up. Apparently, the servo motors act as generators when you move them manually and will feed voltage back to the control board. It's plausible that this voltage fed back onto the 1.5 or 2.3V rails and fried a chip. Kinda bad design if you ask me. It would be trivial to put diodes or opto-couplers on the control board to prevent back feed voltage from the motors.

Anyway, new control board on the way and fingers crossed.

Double check your connections and sensors to make sure you don't have any bad grounds or shorts while you are at it.

Dan Wilhelm
08-20-2014, 4:30 PM
Got the new board today, installed it, and everything seems to be working. I haven't yet fire the laser, but the red dot pointer works fine. The motors sound like they are running a bit rough, but that may just be from not moving for 6+months.

Can anybody send me a picture of an intact rotary attachment plug in the back of their cutting table? Epilog has tried twice to send me the Molex for that connection (mine melted in the fire), but they have sent me two different incorrect connectors. I'm pretty sure its a standard Molex, so I was just going to buy one from DigiKey or something. Problem is, I don't know exactly what the correct intact one looks like.

Dan Wilhelm
08-26-2014, 8:00 PM
Well, hit a milestone today. I successfully fired the laser. The power output is low which I'm hoping I can fix by putting the new lens assembly in. However, I can't really test anything until I get the exhaust situation fixed.

I realized that I don't have the duct adapter for this laser. I tried taking the one off my GWeike, which would probably work, but the mounting hole pattern doesn't match. I bodged it on just for testing purposes, then the crappy exhaust fan motor included with the GWeike crapped out on me. I ended up running the test just using a vacuum for smoke removal (light engraving on plywood...didn't even make it through a ply).

Is there a standard size for the duct adapter on an Epilog, or do I need to order that part from them? I don't mind the expense...just don't want to bother them unless necessary. As for replacing the exhaust fan, I've been reading up on here, and the Harbor Freight dust collectors seem to be the low-end standard. I see they run about 60 dB for noise, but I don't know how that compares to the noise of the laser itself (which I consider pretty loud).

Dan Wilhelm
09-03-2014, 5:42 PM
Did my first paying job on the Epilog today (three nameplates on LaserMax). I screwed up five of them before I got three good ones. I did all of my testing to get the power levels right in the back left corner of the cutting bed, and everything was working fine. When I went to make the 2" x 8" nameplates, the engraving was a lot lighter towards the right, and it didn't cut all the way through like it did during testing. After screwing up the original 3, I went through and leveled the x-axis to the cutting bed.

I started a new batch to the right of the first 3, and it still wasn't engraving deep enough. I hit the stop button halfway through the 2nd one and that's when I noticed the problem. I had the red dot pointer on, and saw the red dot on the wall next to the laser (still don't have the side panels back on yet). I adjusted the 2nd mirror down a little bit, restarted the job, and it worked like a champ. I got 1 usable nameplate out of that second batch, then had to reprint the first 2. I tried engraving over the second screw-up by just restarting the job, but apparently I bumped the material during the adjustment process because the engraving was off by about 1 mm.

Anyway, I'm now confident that everything is operational and properly aligned. The best news is that I did the whole job with the old lens and final mirror. I'm still going to keep the new one I bought just so I have a spare. If anybody is interested, I can post some before and after pictures of the restoration.

Ed Maloney
09-07-2014, 10:59 AM
Pictures would b e great.