Engraving on Rowmark stock

[pedals]

I am thinking of buying a Shark instead of a traditional engraving machine, and wonder if anyone has used them in this way to make signs and so forth on standard 1/16" engraving plastic, where the objective is to just break the surface to show the contrasting color underneath. It seems, from everything I can discern, that this should be no problem, but have any of you had experience that would prove otherwise?

[wolffie]

I have yet to receive my shark plus, it hasn't landed in Australia as yet.
However, from what I have read, it should handle that kind of material well.
Cheers
Wolffie

[sk8nmike]

I've seen several examples of engraving and carving on multilayer material. You will want to use a good quality engraving bit though.

[GARYR6]

Well, It might be my choice if I was only going to doing a few of the multilayer signs. There is a reason sign shops use an engraving machines to do that kind of work. It is because they excel at high levels of precision with repeatability.

[pedals]

I spoke with a tech support man at New Wave and he told me candidly that the best machines in the Shark lineup are the standard Shark and the Shark Pro HD. This makes me believe that the smaller table size of the entry level unit means less flexing in the middle of the gantry, and therefore more accuracy and repeatability. The Pro HD is probably beefed up to the point where it also gives that level of accuracy.

My intention is to use one of these machines to engrave the lettering on license plate frames, and probably a few signs. Since a dedicated engraving machine with a 12" x 12" table costs over $8000, and these Sharks come in well under that, I naturally wondered "what's the big deal with the engraving machines?" I can only guess that the regular engraving units are able to do a better job on diamond drag scribing and very small, intricate graphics. Since that's not what I want to do at all, does the license plate frame work sound OK as a Shark application? With just the standard Shark, I could engrave three frames at a time, making this a great production unit. Another plus: no sawdust...until I do my first job in wood, that is.

[gary z]

I used my HD to engrave 1/8th inch lettering in colored anodized aluminum. I did use a two flute 60 degree V-bit and had to fuss a little with my Z axis set point. Once set it did well.

[Freedom747]

When we owned an awards store, 10 years ago, we did a large volume of signs, name tags, etc., out of Romark material. It was great to work with, but could 'melt' if the engraving tool was dull. We used the .060 material, and normally had great results. I would think you could adjust your feed rate and get the job done with the Shark.

[jimsworkshop]

Some very good questions were asked in this thread, but I didn't see any good answers. I tried to do some name tags with my Shark Pro and had very disappointing results. I tried using a brand new 90 deg V-grove bit and Vcarve Pro and I ended up with melted plastic in the corners of the "E" and the center of the "e" was just gone. I tried using PAM (the cooking spray) and that helped considerably, but the results were still no better than a 6 or 7 on 10 point scale.

I also tried a ball nose 1/8" bit (brand new HSS), and the results were really ugly.

I've used up a 12" x 18" sheet of material trying all sorts of different deas but with no better than "7".

I think that when the software goes back over each letter is part of the problem, but the slight pause in the corners when the bit changes from all X motion to all Y motion is also causing melting.

I'm using a BOSC Colt in my Shark and I have tried speeds from 1 thru 6 (max) with not a lot of differece.

What is the silver bullet, guys? What is the correct bit? Speed?

Any other suggestions to try?

[BillK]

I have made quite a few signs in that type of material on my shark pro plus. I prefer the 1/8" thick material because it tends to remain flatter and you can cut it a little deeper. A lot depends on the material. I have run 12 inch square signs with a 1/8 two flute bit on speeds 3 and 4 with no problem, then switch to another sheet and have problems. Most times when I have color smearing I'll use the set command to recut about .005" deeper and that cleans it up. I've tried single flute with mixed result, it really seems to be the material, not the cutter in my experience.

[wolffie]

I have had good results with both the 2 colour plastic as well as multilayer material where the second layer at both sides is aluminium.
Cheers
Wolffie