Engraving on Brass plates

[Tom Bachman]

I need to, if possible, engrave some names on some brass plates. The plates are 3/4" x 2 1/2" and the letters are going to be about 1/8" tall.

First off, I know it's possible, but how do I go about this? Can I do this with a very sharp 60* V bit? How deep do I set it to cut? How's the best way to hold it down?

[feinddj]

Diamond drag bit is the way to go. Spring loaded, you adjust pressure on the bit by your depth. Mine is by Widgetworks


David

[Tom Bachman]

OK, which type? I'm assuming there are rotating and non-rotating (a search brought up the non rotating). What size. And where to buy?

BTW, Thanks for the info.

[Tom Bachman]

If I get the non rotating type, do I just turn the router off and let it go? Any other info would be greatly appreciated.

[jerry_stanek]

Yes you don't run the router.

[Tom Bachman]

OK, thanks.

I just bought this one. For the price, I figured I couldn't go too wrong.

http://www.ebay.com/itm/Diamond-Drag-Engraving-Tool-Spring-Loaded-1-2-Shank-/151246231316?pt=LH_DefaultDomain_0&hash=item2336fa5714

[Xray]

That is a decent bit, I have one.
You are capable of adjusting spring tension on these, probably about medium will do. You would set you file with a very shallow depth like .008.
You touch the bit to the material where it just starts to compress and zero the Z there, should etch out the lettering just fine. And for sure, don't turn on the router else you'll ruin the bit - Its pretty cool to see & hear the machine run without noise.
Hold down is another matter and will require improvising on your part. Since there is very little force/friction applied with a drag bit, you could use double stick tape. What I use is hard to describe but simple, it is an improvised, adjustable jig board. Basically a piece of mdf that uses 4 blocks to secure work pieces. 2, the bottom and far side, are permanent and just screwed into the mdf at the edges. The other 2 are adjustable, they snug in to whatever size the workpiece is and you secure them there, also with screws.
The whole thing is screwed to the spoilboard. Probably not the optimal method for small metal plates, but works great for plexiglass. I think I'd try the double stick method 1st and see if that works.

[Tom Bachman]

Xray, thanks for the feedback. I am thinking about doing an MDF holder where I recess the brass plate and have it snug on all four sides. I also designed a way to apply vacuum (shop Vac) to it. We'll see what it takes to actually hold them down once I get the drag tool. I'll post some pictures if my jig actually works. :D

[Tom Bachman]

That is a decent bit, I have one.



Xray, what parameters did you use to set this tool up in the database. Assuming it is 60*(30*on side angle) Yes/no. What "Flat Diameter" did you use?

The ad does not give those specifics of the bit.

[Tom Bachman]

I got the bit today and ran my first engravings. The bit works great and I can now see even more things that can be done with the ShopBot. Totally impressed/enthralled with the quality that it can produce.

[Chuck Keysor]

Tom, can you post some pictures. I haven't paid much attention to diamond drag engraving, for whatever reason. But I am curious to see how your engravings turned out. Thanks, Chuck

[Tom Bachman]

Not a great picture but I did "Albert "Joe" Gosch". The other ones you see were done "professionally" by the local trophy shop. The plates are 3/4 x 2 5/8. The lettering is about .16 high

http://img.photobucket.com/albums/v281/toms94/other/DSC_4852_zps44a4bb4f.jpg (http://smg.photobucket.com/user/toms94/media/other/DSC_4852_zps44a4bb4f.jpg.html)

[Chuck Keysor]

Tom,,,,, you know, this is at the borderline, where I really can't tell the difference between your engraving versus that done with an engraving machine. I was really hoping to see a side by side comparison. Can you try another picture? Or can someone else provide a good close-up showing the best traditional engraving on brass versus what the diamond drag bit will produce? Thanks, Chuck

[Tom Bachman]

Chuck, If I were to get my magnifying glass out, I'd have to say that my engraving is not quite as sharp as the professional engraver. But it is more than acceptable for this project. And with some more experience, I believe I can improve. Not sure about the Z-zeroing, amount of tension I should put on the point or the depth I should be setting in my toolpath.

If anyone here can make suggestions, I'd be more than happy to hear from you.

[mikeacg]

Tom,

What settings did you finally use in the set-up? I have a drag but haven't tried it out yet...

Mike

[Tom Bachman]

Tom,

What settings did you finally use in the set-up? I have a drag but haven't tried it out yet...

Mike

Mike, when I selected the "Engraving" tool path the default drag tool came up as the tool. Whatever the default settings for the tool is what I used. IIRC, the depth was set at .03. I've read elsewhere that some use .008, that seems really slim to me. .03 seemed more logical to me. As far as the tension on the tool itself, mine has a Allen screw to adjust, I left it fairly loose.