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.