Newbie with a 3020

[Daven]

PM'd some info over

Dave

[Leon]

Bubbles!! avoid at ALL costs, they kill tubes VERY quick (as Mike can attest) it's often best to leave the machine on but unplug the extraction to reduce noise. That way the bubbles tend to form a lot less.

I can't over emphasise this, bubbles in the tubes cause more issues than all the other reasons put together!

So you actually leave the machine turned on 24 hours a day, just with the extraction off? That would never have crossed my mind, doesn't it wear anything out? Mine is in an upstairs room, so might annoy the neighbours sitting there humming all night! It'd be a nice payback for their teenage son playing his guitar at 7am though...

Running without air assist, this is going to soot up the final lens, and it will require cleaning, this has to be done very carefully as they have a fine coating on them (they look like glass but they are in fact a metallic salt) Zinc Selenium.

Very light touches with a virgin cotton bud and some Isopro alco will sort it though.

OK, I'll get that sorted.


Thanks for all the help so far, I think with a clean lens and some air, I'll almost be there. I'm not looking forward to aligning these lenses though. I'm sure it's easy enough, just slightly daunting for the first time.

[Daven]

So you actually leave the machine turned on 24 hours a day, just with the extraction off? That would never have crossed my mind, doesn't it wear anything out? Mine is in an upstairs room, so might annoy the neighbours sitting there humming all night! It'd be a nice payback for their teenage son playing his guitar at 7am though...

Cut the 2 pin plug off the pump, fit a 3 pin, and plug into mains rather than socket on machine?

Re the anoying neighbours son - buy a drum kit

Dave

[Spooky]

Where abouts are you Leon? if your within driving distance of me I can pop over and help with your alignment?

Dave's quite right, I use a 3 pin on my water pump right into the mains,same with my extraction.

best wishes

Dave

[Mike]

That lens will likely be very sooty if you haven’t had the air on, consider yourself lucky if your belts and rollers haven’t distorted due to the flame heat.

On my machine the power to the water pump originally came from a socket on the machine, to run the water continuously fit a standard UK plug and plug the water pump straight into the wall, that way its on all the time and you don’t have to wait as long to let the bubbles run through the system. This was on Chris’s advice, you may want to check with him that the pump you have is continuously rated.

You may already have damaged the laser tube if you have been running with bubbles, but get the other things sorted first, before trying a new tube.

Clean the final lens, you have to drop the air cap off first and then unscrew the retainer, its pretty straight forward.
Also take the final mirror off the top of the cone and make sure it’s clean, actually when you take the top mirror off you can see how dirty the lens is beneath it.

I have become particularly anal about checking the air is on and there are no bubbles in the tube before using the machine. I would recommend you do the same.

I just did an alignment check on my machine last night, I modified the mirror holders on my machine to make the alignment process easier, so I can’t be much help here. There are other threads here that cover it though. Apparently there should have been a DVD with the engraver, but I never got it.

As a quick check you can put some tape across the hole on the cone and fire the laser once to make sure you are at least hitting the cone in the middle of the hole. Check it at all four corners of the bed and take the mirror and lense off before doing this so that they don’t get dirty or marked.

[Leon]

Cut the 2 pin plug off the pump, fit a 3 pin, and plug into mains rather than socket on machine?

I'll get that sorted then.

Where abouts are you Leon? if your within driving distance of me I can pop over and help with your alignment?

Right up in Middlesbrough, bit far away I think! I did wonder if there were any engineers up this neck of the woods though?

That lens will likely be very sooty if you haven’t had the air on, consider yourself lucky if your belts and rollers haven’t distorted due to the flame heat.

I hope not...

You may already have damaged the laser tube if you have been running with bubbles, but get the other things sorted first, before trying a new tube.

I've always got the bubbles out before starting, the smaller ones were more recent, and we've turned it off whenever they've appeared.

Clean the final lens, you have to drop the air cap off first and then unscrew the retainer, its pretty straight forward.
Also take the final mirror off the top of the cone and make sure it’s clean, actually when you take the top mirror off you can see how dirty the lens is beneath it.

This is the next thing on my To-Do list. I can't see any instructions in the manual, but I'll have a look and see if I can work it out.

As a quick check you can put some tape across the hole on the cone and fire the laser once to make sure you are at least hitting the cone in the middle of the hole. Check it at all four corners of the bed and take the mirror and lense off before doing this so that they don’t get dirty or marked.

I've just done this today, and the laser spot is hitting the top right of the hole from about 50mm away from Mirror 2, so my alignment's definitely out! I'm guessing this is why cuts in the bottom right corner haven't been going through the material. I've not got the right size Allen key though, so I'm gonna go pick one up tomorrow hopefully.


Any tips on getting the laser cone off would be great!

[Leon]

Right then, to update:

Turning the blower on has fixed the flame issue, so that's sorted (who'd have guessed it eh!)

I've got a bigger tub for the water and that seems to have fixed any bubbles.

I managed to get the lens cone off, and I've cleaned that and the final lens. There was a bit of dirt on it, but generally looks OK. There's a very small (pinhead) mark on it, but it's about halfway from the centre. I cleaned it again, but the mark remained.

However:

The alignment is still out.

I bought the allen key to adjust Mirror 2, and put masking tape over the entry to Mirror 3 and fired a low power shot at it. When the laser was at the top-right of the bed, the spot was bottom left of the tape. So I adjusted Mirror 2 until it was OK. Then I moved it to the bottom right of the bed and fired it again. This time it was to the right of centre, so I adjusted the mirror again, and went back to top-right. Out of line, left of centre again. Fixed it, went bottom right, right of centre again!

Every time I fix it at one side, it's pulling the other side out of line. I even tried adjusting to 'centre-ish', to get both ends as close as possible, but it's still not right. What can I do now?

On the last test-piece I did, which was a 60x40mm grid, all of the vertical lines are OK, maybe 0.2mm variance in the gaps between them. However the horizontal lines (those cut travelling from left to right), are all out. I've measured the gaps between each of them, at both ends:

From Line A to B, left side of bed: 40mm
right side of bed: 40.5mm
From Line B to C, left side of bed: 42mm
right side of bed: 41mm
From Line C to D, left side of bed: 39mm
right side of bed: 40mm
From Line D to E, left side of bed: 40mm
right side of bed: 40mm

This seems very odd, that I'm getting more variation at the left side of the machine, closer to Mirror 2? Surely any alignment issue would be increased the further away from Mirror 2 the lens head is? And also more variation in the more central lines?

On this last cut as well, the machine didn't actually cut anything, it just engraved the top of the MDF, which was odd?

It's getting quite frustrating now, I'm using this machine for the most basic of jobs, and I'm having to throw away nearly half of every sheet I'm cutting. Are there any laser engineers in the North-East?

[Spooky]

Hiya leon,

That sounds like the tube is out of level, this will cause the beam to exit the tube at an angle, very unusual but possible. Have you ever moved the mounts that the tube sits in?

Do the mirror test on mirror 1 where the beam exits the tube and see what results you get?

There are a couple of things that can cause this but have a look at Mirror one to start with then we can go through a few more ideas if it's not that (there are a limited number of things that can cause it and none are too serious)

best wishes

Dave

ps:remember to move the mirror adjustment tiny amounts at a time

[Leon]

That sounds like the tube is out of level, this will cause the beam to exit the tube at an angle, very unusual but possible. Have you ever moved the mounts that the tube sits in?

Do the mirror test on mirror 1 where the beam exits the tube and see what results you get?

There are a couple of things that can cause this but have a look at Mirror one to start with then we can go through a few more ideas if it's not that (there are a limited number of things that can cause it and none are too serious)

ps:remember to move the mirror adjustment tiny amounts at a time

No, I've never touched the tube, too wary of damaging anything! We do have to tilt the machine quite regularly to get the last air bubbles out of the right hand end of the tube, would this knock it out? We're lifting the whole left end of the machine.

I'll check on Mirror 1 when I get in from work tonight.

All the adjustments I made to Mirror 2 were very small incremements, maybe 1/16th of a turn at a time.

[Spooky]

Hiya Leon,

You want to be looking for around 2 to 5 degrees of turn on mirror adjustment if possible, just enough to actually feel movement on the screw.

Lifting the end of the machine may well cause alignment problems, I found a good way to bump out the bubbles is by finger pinching the rubber hose water inlet then letting go quickly, the tiny boost in pressure it causes is often enough to kick the bubbles out. The rubber tube is silicon rubber so the pressure on the water (fractions of a PSI) will increase in the tube due to micro expansion of the silicon, that's usually enough to just knock those bubbles on their way.

Don't adjust any mirrors further along the chain until you are sure mirror 1 is ok, even if all the others are aligned bang on if you then adjust mirror 1 it will throw all the others out

let us know how you get on with mirror 1 and I'm sure we will get you sorted out

best wishes

Dave