Startup Issues

[Richard Rumancik]

Hi David; welcome . . .

Has anyone else had issues with airflow on the larger format machines?

David, I'd like to introduce you to Barb Macdonald. She is another forum member. You might have some things in common. Do a search on the term "big bed epilog" and read through what problems she had.

(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).

I think the problem stems from the fact that you can use your blower to exhaust smoke, or as a hold down, but not both. And if you try to do both you might not do either very well. You can get a light suction if you sacrifice air performance but it is not a vacuum hold down as you see with CNC routers. I and others gave Barb some suggestions in the thread mentioned above. I am not sure that she has really "solved" it though. Read through that first. You might want to PM her if you have questions.

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.

Weights and masking tape. Which are not very good solutions. Weights often get into the way of the cutting or carriage, fall off the material, etc. Tape does not stick well to birch. I have not tried magnets as my table is aluminum. I have pondered better solutions for birch as well as it gives me problems. You mention a torsion box – not sure what you have in mind exactly. I currently have a 4" raised frame on my table with the vector grid sitting above (works with a lot of the fixtures I make). But I currently don't have access to the underside of the grid from the front. (I don't know what your grid looks like but I use a simple 3/4" x 3/4" aluminum xy grid.)

If I modified my box to allow access to the underside, I could secure the plywood from the bottom to the grid. What I would do is lay the warped material on the grid, open up my Corel layout, and laser five or ten quarter-inch holes in the sheet in the scrap areas. If they are out of focus and cut poorly it is not important. Then (without moving anything) drop a pin or screw through the holes and tension from underneath (with a weight or ?) (Nuts/bolts would take too long I think.) Then when the sheet is "flat", refocus. If you try something like this let us know how you did it and your results . . .

Sometimes I make "relief cuts" before I start cutting the parts out. Takes some time but other solutions do to. If you cut the sheet in the scrap area it will often flatten it out. Then you do the final focus.

Also check around and find the best source. The cheapest source might not be the most cost-effective. There is good plywood and bad plywood.

3) 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. . .

I know how you feel . . . Corel was designed as a tool for artists, not technicians or engineers. Basic drawing operations can be very difficult at times. You will have to develop work-arounds for some things. In most CAD programs you can "snap" to lots of features but Corel 11 can't even find an intersection of two lines.
I do my accurate design work in CAD and import as dwg or dxf. I understand why you don't want to do this. So you will need a bag of tricks. Some you will have to discover/develop yourself. (Feel free to ask though.) But you should check out some add-ons available at places like oberonplace.com and isocalc.com. There might be other sites that have some good scripts that will help you do the things that Corel forgot to put in.

Good luck and ask questions . . . one suggestion though . . . if you put a single question in a posting it will stay on track better. So just ask a question a day.

[David Fairfield]

Yeah Corel... I feel your pain. Its not even the industry standard for graphic artists. Adobe Illustrator is. Not sure why the laser industry chose Corel as their standard. Using Corel is like trying to use Adobe with a sinus headache.

For me when it was a choice between using Corel or figuring out the software conflicts with Adobe Illustrator and the laser's processor, I chose the lesser of two evils and stuck with Adobe.

Dave

[Scott Shepherd]

I'm with you David. I come from the CADD/CAM world and learning how to draw in any graphics package has been frustrating to say the least. Simple things like drawing a line in the right place from scratch puzzles me, or trimming an element. Two things that are key to CAD and yet, not so key in Corel. I just can't get my mind around having to draw something and then move it to the right place. I want to draw it in the right place from scratch. It's twice as many steps to draw it and move it, as just drawing it in the right place.

Trimming is out there, but boy is it a challenge some times.

All in all, I think you really have to change the way you draw things. It's just two different beasts and if you try and apply CAD practices, you'll be frustrated. My advice is to just start learning it from scratch and pretend you didn't come from CAD.

[Doug Griffith]

Here is something you might find useful:
http://debece.net/pages/propts.htm

Here is a useful CAD tool for both Illustrator and Corel:
http://www.kandusoftware.com/product...product=Bezarc

Smart Guides are a beautiful thing in Illustrator. So is Transform, Align and Pathfinder.

[Rob Bosworth]

Dave, other than the noise of the inexpensive exhaust blower, that blower should do a fairly good job of evacuating your effluents.

In any exhaust system, airflow is restricted in every corner, ripple, reduction or length of the ducting. If you are using some spiral wrapped flex ducting in your exhaust path, that will cut down on airflow efficiency. Each 45, 60 or 90 degree elbow will greatly reduce airflow. The longer the run to the outdoors, the more ooommmpppphhh your exhaust system will need to push the smoke out.

Reducing the the diameter of the ducting from 6" to 4" also restricts the flow. I try to run as much 6" ducting as possible, and only neck things down near where it has to be necked down.

I believe the "red" 1.5 hp. dust collector has a 6" dia. inlet on it. I believe Harbor Freight sells an adapter to that inlet that allows you to neck down to two 4" dia. inlet connections. This adapter is in a Y configuration, and causes less restriction of airflow than a T connection.

If you have an end cap or directional vent cover on your exhaust outlet, that will cause restrictions.

I agree with your assessment of the noise of your dust collector/ exhaust blower, but there is not much you can do with it but to isolate it and sound dampen the unit. But they are cheap.

I have run that exhaust blower on a number of Epilog 36 EXTs. Using it on both the 4" dia exhaust manifolds and the newer designed 6" manifolds. If everything is clean and SMOOTH, it does a pretty good job of evacuating smoke and debris.

As far as the downside exhaust match ups on the machine, I will let the boys at Epilog handle those questions.

Good luck. I think the 36 EXT is a really nice machine. Maybe too big for most applications, but pretty darn nice.

[David Brasfield]

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

Thanks, Doug.

I have some magnets, but don't use the etching table much yet since most of the work I have done so far required etching and cutting. I wonder how well those non-adhesive backed flexible magnetic strips would work. I haven't played with any of the magnetic material yet.

We have CS3 on one of the Macs, but only use it for graphics so far. I will have a look at it.

Thanks,
David

[David Brasfield]

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,

Hi, Peck!

You actually did some test cuts for me before I bought the laser. I really appreciated Epilog's willingness to work with me.

I'm not worried about a refund from the rep, I think he was doing what he knew to do. I do think you guys might want to give him some instruction about exhausting the larger machines.

I also understand that the vacuum created under the tables is minimal, but some of what would have been available is lost when the internal ports and the table ports don't match up. A potential fix for you to consider would be sliding ports. Could be a good selling feature. Just being able to adjust airflow dynamics within the enclosure (say with baffling similar to an auto's AC system) would do wonders. Just some ideas. It's the engineer in me

Thanks for the tip on the nozzle, I assume that I can just rotate it to change the height?

The new blower system should be plenty quiet to have in the shop, and the total distance from center of the laser to the wall is less than 10 feet. Quiet isn't such a huge issue with me, because when the ShopBot is running, ear protection is mandatory (cutting, vacuuming, dust collection all at the same time), but we still like quiet whenever we can get it. Also, the 1hp "red" blower is brush type, vibrates across the floor unless we put it on foam, so it would probably self-destruct in less than 100 hours of operation anyway. Something else the rep should consider in the future.

Besides all that, who wants a loud vibrating red thing screaming and moving around sitting next to such a classy machine. That just doesn't seem right

Thanks,
David

[David Brasfield]

Hi David; welcome . . .


David, I'd like to introduce you to Barb Macdonald. She is another forum member. You might have some things in common. Do a search on the term "big bed epilog" and read through what problems she had.

I think the problem stems from the fact that you can use your blower to exhaust smoke, or as a hold down, but not both. And if you try to do both you might not do either very well. You can get a light suction if you sacrifice air performance but it is not a vacuum hold down as you see with CNC routers. I and others gave Barb some suggestions in the thread mentioned above. I am not sure that she has really "solved" it though. Read through that first. You might want to PM her if you have questions.

Weights and masking tape. Which are not very good solutions. Weights often get into the way of the cutting or carriage, fall off the material, etc. Tape does not stick well to birch. I have not tried magnets as my table is aluminum. I have pondered better solutions for birch as well as it gives me problems. You mention a torsion box – not sure what you have in mind exactly. I currently have a 4" raised frame on my table with the vector grid sitting above (works with a lot of the fixtures I make). But I currently don't have access to the underside of the grid from the front. (I don't know what your grid looks like but I use a simple 3/4" x 3/4" aluminum xy grid.)

If I modified my box to allow access to the underside, I could secure the plywood from the bottom to the grid. What I would do is lay the warped material on the grid, open up my Corel layout, and laser five or ten quarter-inch holes in the sheet in the scrap areas. If they are out of focus and cut poorly it is not important. Then (without moving anything) drop a pin or screw through the holes and tension from underneath (with a weight or ?) (Nuts/bolts would take too long I think.) Then when the sheet is "flat", refocus. If you try something like this let us know how you did it and your results . . .

Sometimes I make "relief cuts" before I start cutting the parts out. Takes some time but other solutions do to. If you cut the sheet in the scrap area it will often flatten it out. Then you do the final focus.

Also check around and find the best source. The cheapest source might not be the most cost-effective. There is good plywood and bad plywood.

I know how you feel . . . Corel was designed as a tool for artists, not technicians or engineers. Basic drawing operations can be very difficult at times. You will have to develop work-arounds for some things. In most CAD programs you can "snap" to lots of features but Corel 11 can't even find an intersection of two lines.
I do my accurate design work in CAD and import as dwg or dxf. I understand why you don't want to do this. So you will need a bag of tricks. Some you will have to discover/develop yourself. (Feel free to ask though.) But you should check out some add-ons available at places like oberonplace.com and isocalc.com. There might be other sites that have some good scripts that will help you do the things that Corel forgot to put in.

Good luck and ask questions . . . one suggestion though . . . if you put a single question in a posting it will stay on track better. So just ask a question a day.

Hi, Richard!.

Thanks for the lengthy reply. You're right, I should have broken it down to multiple threads :-)

I have read all of Barb's (my wife's name as well) blower experiences. She has been through the ringer. I will get my system to do what I need and pass on what I learn to her in the next few weeks. I have a really nice shop-wide all metal (the welded thick wall piping and branches) system with automated gates. I will send some pics when I get a chance. I'm kinda proud of it

I have the vector cutting table and etching table from Epilog. The torsion box concept is simply because they will remain flat under pressure, the issue was how to fasten down materials of varying size. If acrylic does allow me to vector on top of it without leaving smoke and resin on the ply, then I can come up with a simple way to fasten the boards down with some kind of low-profile fastener. My first effort may simply be either a rigid aluminum frame to which I can attach a 1/2 inch piece of sacrificial acrylic, or maybe a frame made from ply. If the acrylic works, then I will make a template drawing and vector a bunch of holes in it for airflow and for the fasteners.

I built a large storage building about 5 years ago. I designed it with two hinged 8' x 10' X 6" doors on the front. I used my own torsion box design, and even though the doors weigh about 500 pounds each, they have never drooped even 1/8 inch. I'm not a mechanical engineer, but I have this thing for torsion box designs

As for the ply I have in stock, it was all A/B baltic birch left over from a large purchase back in 2004. I think I have 1 sheet of 3/4, 4 sheets of 1/2, and 8 sheets of 1/8 left. It is as flat as you will find. The shop is fully air-conditioned. That is why I am anticipating problems with material far worse than I am dealing with now.

I am completely with you on finding intersects in Corel. I spent over 2 hours last night trying to figure out how to create sub-paths from existing paths before I found "extract subpath" on the tool bar. Why they left it out of the list of options when you right-click a node or vector, beats me. I am still wasting a lot of time "hovering" the mouse to figure out what the icons on the tool bars are. Some are obvious, a few. Then 5 minutes into creating some subpaths, the program simply "went away", leaving me looking at a basic windows screen with no open programs. The first night I used it, all of the toolbars disappeared, so I had to google info on resetting program defaults. Since last night, I have lost the ability to select a vector by clicking on it, in object mode

I will spend some time today looking at add-ons.

Thanks,
David

[David Brasfield]

Yeah Corel... I feel your pain. Its not even the industry standard for graphic artists. Adobe Illustrator is. Not sure why the laser industry chose Corel as their standard. Using Corel is like trying to use Adobe with a sinus headache.

For me when it was a choice between using Corel or figuring out the software conflicts with Adobe Illustrator and the laser's processor, I chose the lesser of two evils and stuck with Adobe.

Dave

I hear your pain :-)

I have a a couple of nice Macs and CS3. Assembly is my native language (shows my age), and unix is my best friend. I don't think I will ever forgive Bill Gates for stealing CP/M, stripping it of a decent file system, replacing "/" with "\", and taking away its ability to handle reentrant system calls, then calling it MSdos... (no offense to the windows aficionados' out there).



David

[David Brasfield]

I'm with you David. I come from the CADD/CAM world and learning how to draw in any graphics package has been frustrating to say the least. Simple things like drawing a line in the right place from scratch puzzles me, or trimming an element. Two things that are key to CAD and yet, not so key in Corel. I just can't get my mind around having to draw something and then move it to the right place. I want to draw it in the right place from scratch. It's twice as many steps to draw it and move it, as just drawing it in the right place.

Trimming is out there, but boy is it a challenge some times.

All in all, I think you really have to change the way you draw things. It's just two different beasts and if you try and apply CAD practices, you'll be frustrated. My advice is to just start learning it from scratch and pretend you didn't come from CAD.

All I can say is amen.

My first real project was a simple, precisely even spaced group of squares and rectangles that I wanted to intersect, then remove unwanted lines. I figured most of it out, only to find that trimming one line is a time consuming effort, and I have a bunch of them to do. I am sure (I hope) that there is a trick to it. I would like to find it soon.

David

[David Brasfield]

Here is something you might find useful:
http://debece.net/pages/propts.htm

Here is a useful CAD tool for both Illustrator and Corel:
http://www.kandusoftware.com/product...product=Bezarc

Smart Guides are a beautiful thing in Illustrator. So is Transform, Align and Pathfinder.

Thanks for the links Doug!!

David

[David Brasfield]

Dave, other than the noise of the inexpensive exhaust blower, that blower should do a fairly good job of evacuating your effluents.

In any exhaust system, airflow is restricted in every corner, ripple, reduction or length of the ducting. If you are using some spiral wrapped flex ducting in your exhaust path, that will cut down on airflow efficiency. Each 45, 60 or 90 degree elbow will greatly reduce airflow. The longer the run to the outdoors, the more ooommmpppphhh your exhaust system will need to push the smoke out.

Reducing the the diameter of the ducting from 6" to 4" also restricts the flow. I try to run as much 6" ducting as possible, and only neck things down near where it has to be necked down.

I believe the "red" 1.5 hp. dust collector has a 6" dia. inlet on it. I believe Harbor Freight sells an adapter to that inlet that allows you to neck down to two 4" dia. inlet connections. This adapter is in a Y configuration, and causes less restriction of airflow than a T connection.

If you have an end cap or directional vent cover on your exhaust outlet, that will cause restrictions.

I agree with your assessment of the noise of your dust collector/ exhaust blower, but there is not much you can do with it but to isolate it and sound dampen the unit. But they are cheap.

I have run that exhaust blower on a number of Epilog 36 EXTs. Using it on both the 4" dia exhaust manifolds and the newer designed 6" manifolds. If everything is clean and SMOOTH, it does a pretty good job of evacuating smoke and debris.

As far as the downside exhaust match ups on the machine, I will let the boys at Epilog handle those questions.

Good luck. I think the 36 EXT is a really nice machine. Maybe too big for most applications, but pretty darn nice.

Hi, Rob.

Thanks for the reply. The blower is the 1hp version and has a 4 inch inlet, and sits less than three feet away from the laser. The only turn in the system is the tee between the ports on laser. Exiting the blower is a straight run of pipe out the wall that doesn't even have a screen over the end to keep the wasps out :-) It was just too small to begin with. I should have made a more in depth query regarding the exhaust requirements before I bought the system. I seriously doubt that particular blower meets the CFM/static pressure requirements Epilog publishes for that laser.

On the 1.5hp blower you are talking about, does it use a "universal" brush type motor, or a regular induction motor? The model I have is 94029 from Harbor Freight.

I am well pleased with the Epilog so far. I just need to de-ugly the exhaust system

David

[Barb Macdonald]

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.
OMG.
Well, Peck, maybe I can expect a refund? The recommended specs supplied by Epilog were woefully inadequate, and I mentioned this several times, in my postings regarding my myriad exhaust issues, which continue to be ongoing. I spent, all told, $6000.00. I still don't have enough exhaust. The bigger tables must be much more difficult to exhaust. I've seen the smaller beds, the specs supplied by Epilog were the SAME as for the small beds. I followed Epilog specs for the first installation, then went to the big noisy blower, both on the roof. Epilog sent me a new front grate. It helps, a little bit. I still have smoke hanging in the cabinet. The only way to improve it would be to make all material thicker, or at least further down in the bed, so that the ports are more opened. I need to make a thick false bed. That's my next fix.
IF I'd known how much exhaust I actually required when I first bought the machine, I would not still be having these issues today.

I don't mind spending $$. I do mind wasting 'em.

sorry, needed to rant.
Thanks
Barb

[Barb Macdonald]

I have an epilog legend ext 60 watt.

merci!

b

[David Brasfield]

I followed Epilog specs for the first installation, then went to the big noisy blower, both on the roof....
.....

sorry, needed to rant.
Thanks
Barb

Hi, Barb

The "noisy" part is what keeps getting my attention. There is no reason that a larger blower with an induction motor should be very loud. My 3hp dust system will aggressively pull chips and dust out of 3+ machines (table saw, router, shaper, ShopBot, Miter saw) running at the same time. The vacuum system itself is only slightly louder than the air-conditioning.

My point is that moving a reasonable amount of air does not mean making a lot of noise. Again, that makes me wonder just what is sitting on your roof.

Does your blower operate on 220/240 volts, or on 110/120 volts? If it is a blower that utilizes a "universal" motor (one with brushes), then it is going to be LOUD. An example of a small "universal" type motor would be similar to the one used in a kitchen mixer. Larger ones are used in old style (and some new ones) shop vacs and in all hand held routers (LOUD).

The other problem when you mention noise, is the other primary issue with universal type motors, and that is efficiency. They aren't, and don't produce nearly as much power as a standard electrical motor of the same HP rating. Manufacturers love to play with the numbers, especially with devices that utilize universal (brush type) motors. The main advantages of universal type motors is that they are cheap to produce and smaller than a standard motor.

David