Startup Issues

[David Brasfield]

Hi, Folks.

I have been lurking for a few weeks now. There seem to be a lot of knowledgeable people here.

My wife and I sold our technology-based business of 18 years back in the summer of 2006. In 2003, I built a nice wood shop for us to do piecemeal projects, cabinetry, whatever came up. It was to be a nice change from owning a high-stress business that had to be operational 24/7 (that part of our business was 12 years of hell, no matter how many employees we threw at it).

Once the business was sold, we took off a year (plus) and didn't do much of anything. We have eased into the woodworking and done surprisingly well. At one point before we sold the technology business, I swore that we would never take the woodworking business, high-tech. That has been a tough boot to eat...

Anyway, on to the problems.

1) The exhaust blower that was provided by the rep with our laser is noisy (112db - worse than a router), and totally inadequate for the job. It is one of those "red machines" from Harbor Freight. I am sure that the Rep wasn't trying to get anything by me, he worked hard for the sale. I just don't think he realizes that particular blower won't do the job for a machine that size and power. I should have had issues with him reducing both 6 inch ports down to 4 inch to start with. The machine makes a lot of smoke. I have ordered a 2hp 1500 cfm blower with proper sized ducting. The "red machine" claims 914 cfm. I think "claim" is the operative word here, and it makes no mention of the static pressure in the specs. Regardless, it doesn't move enough air, and you will go deaf without ear protection. Has anyone else had issues with airflow on the larger format machines?

My shop wide vacuum system is a 3hp system from Oneida, and it is only slightly louder than the air-conditioning system.

2) Holding material flat. We use a good deal of baltic birch in varying thicknesses. Since our system has the air assist cone (long), and we do a lot of cutting, I am concerned with keeping stiff material as flat as possible. (It would also be nice to have enough airflow to remove the smoke out of the vector grid). The "Vacuum hold down" doesn't hold anything, and probably won't, even if the ports under the table lined up with the ports in the back side of the enclosure (below the flutes). (Note to Epilog. Providing different port configurations for machines with different focal points would be a great idea, or even better, offer re-positional ports, that might make vacuum hold down more effective.)

So, has anyone come up with a good method for keeping materials flat on the table? I have a half dozen ideas in my head, none of which I want to implement if someone already has a decent fix they wouldn't mind sharing.

3)<rant> Is there a mind meld feature in CorelDRAW? I have used a lot of different CAD packages, and X3 is good for text and bitmaps, but is completely non-intuitive for dealing with (what are to me) basic functions such as precision size, placement, and combining/cutting/manipulating vectors. I've been doing electronic engineering since 1982, and CorelDRAW is beating me up. Most advanced engineering packages seem to have a logical "feel" or "operational signature" to them, even printed circuit board layout systems, electronic simulation systems, and unix for that matter. CorelDRAW feels like "Windows" to me, maybe that is the disconnect - too many software designers, each with a different idea of how things should work. </rant>

Seriously, does anyone have any good sources of "How To" for CorelDRAW?

Sorry for the long post. Nice to meet you all!

David

[Darren Null]

1) I also have noise and airflow problems on my machine- partially solved by masking-taping all the vents except those ones venting hot air away from the laser and power pack etc. Also, check connections/filters etc. You will be amazed at how fast your filters can cack up.

2) Vacuum tables- tape over all the holes that aren't required to hold your piece down. Failing that...masking tape. Lots and lots of masking tape.

3) Precision size- there's a size/scale/rotate docker that covers pretty well all the size things you need. I leave mine open all the time & it's the most frequently used tool in there for me

Placement- I have a default page that is exactly the same size as my bed; there's coordinates in the lower-left corner and if you have a page frame you can snap bits to the edge.

Combining/cutting/manipulating vectors- search the board...there's lots of different ways of doing things, depending upon what you're trying to achieve, and there are correspondingly lots of hints and tips on SMC. Also lots of addresses for Corel tutorials and howto videos.

[Rodne Gold]

If you use guide lines , the grid and the snap to features of Corel , it will make it act more like something like ACAD. Use and get to know the align and distribute features as well and combine this with the properties bar and you will have all the features you need in terms of other CAd packages.

[David Fairfield]

Holding material flat-- once you know where the laser lines are going, you can put metal washers, nuts, flat files, etc down on the wood that isn't cut. Tape works too.

In order to know where the lines are going to go, you can run the laser with the red dot on, and the lid up so it doesnt fire. Or you can cut a scrap paper sample.

Blower noise-- optimal solution is place the blower unit itself outside. You can build a simple hutch for it, or buy a plastic outdoor play house from Toys R Us. Additional benefit of having the fan outside is you have only suction on the interior portion of your air duct, which means if there is any leakage at your joints, air goes into the duct, but no smoke goes out.

HTH
Dave

[David Brasfield]

If you use guide lines , the grid and the snap to features of Corel , it will make it act more like something like ACAD. Use and get to know the align and distribute features as well and combine this with the properties bar and you will have all the features you need in terms of other CAd packages.

Thanks for the reply, Rodne.

I was working on a simple project last night, using the features you mentioned (correctly, I thought), making parts for a box with finger joints. When it came time to join all the objects, there was misalignment between the squares (fingers) and the rectangle (box side), even though all positions and sizes were done with 1/1000 precision. I finally found part of the issue by zooming until I could see that the vectors didn't match.

I manually matched the lines, and never got the vectors combined enough to remove the unwanted portions of the squares. Weld didn't help as it simply removed square objects from inside the rectangle (and other strange things).

For what it is worth, the first project I did with X3 involved doing a trace of a bitmap, cleaning it up, then doing a simple vector cut. I kept sending the job to the laser, and it would do nothing other than beep and display "Done". I finally rebooted windows, opened Corel and the same file, hit print and it worked perfectly. Is it possible I am aggravating a known issue with X3?

Just thinking out loud...

David

[David Fairfield]

For what it is worth, the first project I did with X3 involved doing a trace of a bitmap, cleaning it up, then doing a simple vector cut. I kept sending the job to the laser, and it would do nothing other than beep and display "Done". I finally rebooted windows, opened Corel and the same file, hit print and it worked perfectly. Is it possible I am aggravating a known issue with X3?

When stuff like this happens, check your print driver settings. When this happens to me its because I either mistakenly drew my vector lines larger than .001 and have the driver set for vector only, or because the lines are the correct with and I set the print driver for raster only.

It was about a year before I ran up against most of the potential conflicts and came up with solutions for them. Still finding a few new ones!

[David Brasfield]

Holding material flat-- once you know where the laser lines are going, you can put metal washers, nuts, flat files, etc down on the wood that isn't cut. Tape works too.

In order to know where the lines are going to go, you can run the laser with the red dot on, and the lid up so it doesnt fire. Or you can cut a scrap paper sample.

Blower noise-- optimal solution is place the blower unit itself outside. You can build a simple hutch for it, or buy a plastic outdoor play house from Toys R Us. Additional benefit of having the fan outside is you have only suction on the interior portion of your air duct, which means if there is any leakage at your joints, air goes into the duct, but no smoke goes out.

HTH
Dave

Thanks for the reply Dave - good name by-the-way

I can do what you suggest with thinner materials, but I haven't found anything thin, but heavy enough to hold down even 1/8 baltic birch, much less 1/4, 3/8, 1/2 ....

It looks like I will have to design a torsion box fixture of some sort that will hold the edges from the bottom. It's already spooky enough to watch the plywood change shape slightly from the heat of cutting it. I've been pre-cutting the pieces close to the final project size on the table saw, but for jobs like the ones I did yesterday where I cut 30 x20 inch sheets of 1/8 BB into 630 1 inch high numbers per sheet, you have to worry about a part falling out and wedging up enough to catch the cone as it comes across.

I have been manually focusing on what appears to be the highest point of the sheets, but that point can change as the sheet moves from the heat.

On the blower, I am hoping that simply swapping the ductwork and the blower with the universal brush type motor (LOUD - same type motor as used in routers), with a real induction motor and proper size ductwork, will solve the smoke and noise problem. The new blower is rated at 1500cfm @ 9.6 inches static pressure, and 62db noise level.

David

[David Brasfield]

When stuff like this happens, check your print driver settings. When this happens to me its because I either mistakenly drew my vector lines larger than .001 and have the driver set for vector only, or because the lines are the correct with and I set the print driver for raster only.

It was about a year before I ran up against most of the potential conflicts and came up with solutions for them. Still finding a few new ones!

I did indeed check line size and the print driver. Both are actually mentioned in the Epilog manual (which I did read )

I have had Corel crash several times when I was editing nodes. I have already learned to save often, and under different file names, and that the "recover" function - doesn't

David

[David Fairfield]

I did indeed check line size and the print driver. Both are actually mentioned in the Epilog manual (which I did read )

I have had Corel crash several times when I was editing nodes. I have already learned to save often, and under different file names, and that the "recover" function - doesn't

David

Yeah mysterious stuff does happen. Epilog's tech support is really good, call them up and ask when you run into a problem. Most of the time they have you back in business in minutes.

I run Adobe Illustrator on my Epilog, and I have a whole laundry list of do's and dont's. Some combinations of settings and dimensions will produce wierd results.

Take notes as you go along. I made a form to fill out for each job so that I can go back and reference things like which settings work for which materials, what settings gave me problems etc.

Can't really help you much with Corel, butfrom my Adobe experience, you also want to check the dimensions and orientation in the driver. They gotta match your document specs of your artwork otherwise the machine gets indigestion

The dimension & orientation issue is real easy to overlook. Also, the human operator's frame of mind while you are getting ready to hit the start button can be a bit ...ah... impatient. Helps to slow down and take 'er easy!

Dave

[Joe Pelonio]

Since your experience is with CAD, why not use it to create your work files, then just import them into Corel for sending to the laser?

For keeping thin wood flat an option I use at times is to apply a few bits of thin double sided tape and attach to a sacrificial piece of thicker acrylic or other material.

[David Brasfield]

Since your experience is with CAD, why not use it to create your work files, then just import them into Corel for sending to the laser?

For keeping thin wood flat an option I use at times is to apply a few bits of thin double sided tape and attach to a sacrificial piece of thicker acrylic or other material.

Hi, Joe!

The reason for the Corel learning curve is so that I can help my wife with it. She will eventually take over the more creative side of things, and I want to be able to quickly do whatever touch up is needed on a project without inter-program conversion issues added to the mix. I also want to be able to take her work into my systems for doing CNC work. So I basically need to incorporate her into "my system", since I handle the technical side of things. I am creative, but my skills lend me toward turning a "onesy twosy" item into wholesale ready items, and doing large complex jobs.

On using the acrylic sacrificially, is that an issue when cutting, such as leaving residue or trapping smoke? How many times can you re-use a piece? I am wondering if it would be worthwhile to take a thick sheet and cut a lot of holes for airflow...

Thanks,
David

[Joe Pelonio]

I've cut a lot of things with the same piece, it ends up with some shallow cuts in it is all. I never have problems with residue or smoke with my powerful exhaust. I often used "dead soldiers" which are 1/4" acrylic with lots of shapes already cut out, that I have laying around from previous jobs before the recycler show up.

[David Brasfield]

I've cut a lot of things with the same piece, it ends up with some shallow cuts in it is all. I never have problems with residue or smoke with my powerful exhaust. I often used "dead soldiers" which are 1/4" acrylic with lots of shapes already cut out, that I have laying around from previous jobs before the recycler show up.

Thanks much, Joe.

That also gives me an idea for a simple torsion box where I can fasten down the thicker stuff from the underside.

David

[Doug Griffith]

re #2: For thin stuff, even 1/8 ply, samarium-cobalt magnets work well. They are unbelievably strong (and expensive). You can get them from McMaster-Carr. A way to get them for free is to rip apart old hard drives that are laying around. I've found 2 large magnets in every hard drive I've tried. The etching table on an Epilog is magnetic. I do not know about other manufacturers.

re #3: If you were to use Adobe Illustrator, there is a plug-in suite called CadTools that has all sorts of precision bells and whistles. I'd be lost with it. The Adobe interface is also very intuitive.

Doug

[Peck Sidara]

David,

Most reps have a few different selection of exhaust systems; from the cost-effective loud units that sit next to the laser system to roof mounted systems that aren't as noisy due to its location to high end self contained units that cost several thousand.

If you haven't owned your EXT for too long, talk to your rep and see what he can do in regards to a credit or a refund. Epilog has a recommended flow rating and a drawing of the ideal exhaust system in the manual. There's just so many routes you can go. It's just a matter of what you're willing to spend.

With that being said, your new exhaust system should do the trick. Keep the plumbing as straight and short as possible.

The stronger the exhaust the more smoke will be removed and the better the vacuum suction will work. If the material you're using doesn't cover the entire bed, cover the rest using scrap wood, plastic, aluminum etc.

The vacuum suction isn't designed to keep rigid substrates flat. When used properly it's to assist in keeping thin flexible materials flat and from moving.

If the wood you're working with still isn't flat with the above pointers and your new exhaust system, try adjusting the nozzle on the cone lens to where there's enough clearance at the high points. Your beam and cut quality isn't likely going to change by adjusting the nozzle up an 1/8" or so.

HTH,