Lets start a "Tip of the Day" thread...

[David Somers]

Hey everyone1

Have you by any chance checked out the second thread at the top of our engravers forum? Titled Sticky Threads?

It is a combination of some of the "running threads" SMC has set up for us. It is called a Sticky Thread because it stays at the top of the forum listing. I believe Keith created it so that all those "standing threads" would stay at the top of the thread list.
You might check it out and see if what you wanted is contained in there? Of if you want to ask Keith to move this thread under it as well so it stays up by the top.

Dave

[Rodne Gold]

the loupes will sow you a lot of things

1) the heat affected zone around the mark.. what you think might be blurry engraving might be heat damage to the periphery of the laser mark.. prompting another strategy to minimize this .. heat affected zones should be minimized by the laser .. ie you want the best mark without the civilian casualties...

Then just looking at the surface of the mark , you can see all the himalayas there . smooth is always better , you can see the slag deposits , remelts , banding , power fluctuations there and take steps to minimize by fiddling with setting

Then there is the lining up of bidirectional engraving , a loupe will show you plainly the overshoots and most machines have a correction factor

then there is curve and square engraving , a loupe will show up nibs of incomplete or over fast circle or jerky curves , it will show you how the laser deals with the corners of squares , ie power ramping

It will also illuminate line spacing , you might be using too heavy a y axis overlap .. adding more heat into the material

It will also show exactly what marking process you are using , ablating material , annealing , colour change , foaming , bonding etc and see exactly where those marks can be improved

then of course , edge quality is paramount and a loupe helps big time there , you can see the striations and determine whether they are due to the motions system , too much remelt and solidify , are the striations even on all edges or just in some places

you can also see the quality of the front and back edge of the cut , ie too much slag , more air oressure needed ,

Also the flame polish effect is clearly visible, and you can see how smooth it is , frosty places indicate too much air assist and cooling

A loupe is also great to see the characteristics of test marks on new substrates etc.. helps put you in the ballpark as to what settings to use or if indeed attempting the job is viable

[Bruce Volden]

I too do many knives. I built a "jig" and lasered rule marks along it's ends and sides to aid in positioning as these are custom made knives and no 2 are uniform!
I also used a 3/8" forstner bit and drilled into the "jig" in various areas and inlaid some rare earth magnets to hold positioning at the correct spot.
Now I just slap the knives on the jig and GO!

Bruce

[John Blazy]

Gotta love them magnets. If I were to do my grid over again, I would mortice in a few magnets for added holding power with magnets over top of the material. The thicker the material, the less magnetic pull on my existing steel bars inset into the grid. COme to think of it I will side grind into my grid to slip in a few 1" long ones.

[Gene Uselman]

That is pretty cool Evan. I use blue masking tape for that same purpose.

Here's my latest tip: Easily do polished bevels in acrylic with a simple angle jig on the bed. The bottom edge of the jig has a lip to hold the material. I just rotate all the pcs of this Candylam four times and all edges are beveled. Any size can be done based on how large you make the angle block.

Attachment 341590Attachment 341591

Hi John- what is candy lam, please? Thanks Gene

[John Blazy]

Candylam is a newly developed acrylic that I had to make to compliment my other dichroic laserable acrylic products that are under development (cant give any more info due to forum rules, but if you become a contributor for as little as six bucks a year, you can access the Lumberyard forum and read ALL about it under the "machineable Opal - need feedback" thread).

Anyway, I started a thread a couple months ago asking for a purple laserable acrylic cuz I couldnt find any out there (since found Acrilex, but still not close enough), then I remembered buying some metallic fabric, planning to contact cement it to plywood, then lasering it, and wondered if I could actually laminate it to the back side of acrylic. So I did a small test pc, and it bonds great to acrylic. Then I ordered about 3 yds of each color and figured out a way to laminate in a continuous 48" wide process on 4 x 8 sheets of clear. Then I discovered that it burns from any underside flashback heat, so now I have to fill the back with a special polymer, and now it cuts great.

I do Cobalt, Lime, Fuscia, Purple, silver and gold. Pretty neat stuff. Look for a banner ad on SMC when these products are ready.

[Klaus Madsen]

My tip would mainly pertain to people who do awards, which is mostly what I do. I cover the table with a large sheet of paper masking and laser an accurate rule for lining up plates, acrylics, glass plaques, etc. at the proper position. Helps to perfectly align multiple plaque plates, and especially when doing running several jobs at once. It also acts as scratch prevention for acrylics. Also for acrylics, I use the paper masking for positioning by lasering the outline of the acrylic onto the masking. I change it out every couple of months on the machine I use for acrylics. On the ULS lasers I cover the entire table. On the Fusion, I just use an 8-inch wide piece and to the top and left sides because the table is so large.

Why haven't I come up with that idea myself In other words, that is a great idea, thanks.
Have you made the white rulers yourself or did the come with the machine ?

[Kev Williams]

A tip about having your laser make rulers-- When you're done, align it against a known 'real' ruler to check the results. You might be surprised...

[Brian Leavitt]

The rulers with the black numbers are part of the machine. They're good for putting plates up against, but I don't like to use them for horizontal positioning unless I'm using the top left corner of the machine.

I set up my lasers' offset and scaling using a machinists rule so my lasered ruler is 100% perfect in relation to the top and left sides of the machine. Even with western-made lasers, they're not necessarily perfect when you get them.

[John Blazy]

Got another tip for everyone, that I haven't really heard of before, although its been alluded to. Actually two tips - first, is if you just bought a laser one of the most asked questions is "what power / speed settings do I use for XXXX material?". Ignore those suggested speed / power charts - use them maybe as a start guide, but you need to make your own chart based on all the variables of YOUR machine, with YOUR materials. Materials vary so widely, I always do test ovals most of the time and record the optimum setting. Material variability is like cast vs extruded acryic, baltic birch vs same thickness of other plywoods (that may have exterior glues, which require more power).

Second tip that has really helped me recently. Just because 1/4" acrylic cuts fine at 18mm / sec @ 100% power, doesnt mean the edge quality is optimum - it likely has the "coin edge". I have recently been slowing down my laser to get better polished edges. Cutting your speed almost in half really makes a nice edge, if you have the time. I cut some 3/8" composite laminates today (top has 3/16" cast acrylic) and decided to run 3mm / sec @ 100%. Edge looks nearly buff polished.