[LazyMan]

I need to engrave small letters into an aluminum panel and standard engraving bits are not working out so well because of the variation in height. Has anyone ever used this bit? Diamond Drag Engraving Tool Spring Loaded | eBay

Everything I have seen is pretty expensive. Any recommendations would be appreciated.

[alan_3301]

I'd give it a try. I'm ashamed to say what I spent on the widgetworks engraver, and I felt like a chump when I opened the package and saw how simple it is.
Unless it has alot of play between the body and the tip, It has to work well. Even for what I paid it has too much play (I feel)

Look at the one on the tormach site, It looks like it weighs a pound, and is only $60 or so. Too bad it's 3/4 shank.

[BMcCaskill]

Looks just like the $18 MSC tap guide I've been using with great results.

Tap Guides - Tapping Accessories | MSCDirect.com

[wesviddaurri]

I know this may sound funny but my company has used center drills for engraving for years. Our Makino cell uses a #4 center drill, .010 deep, 14000 RPM, 200 IPM. Works like a champ. You can adjust the "Z" depth for letter and number size or use a different size center drill.

[neilw20]

Consider how PCBs are held down dead flat with a brush.
I've made one out of an old car washing rotary brush.
PCB Drill-router.MOV - YouTube

[LeeWay]

On my plasma cutter I use a drill mill and a foot on a floating head. I use the floating die grinder head because a plasma table can get bumpy on not particularly level after a while. The floating part exerts just enough weight from the axis to cut well. The foot adjusts the depth of course. I just bend up some all thread into a loop on one end and used nuts on what was left upright. You don't need a floating head on a surfaced table, but a rotating bearing right beside the cutter would also hold that down.
The brush Neil shows is pretty neat as well, but might damage the surface after it gets loaded up with chips. An air blast might prevent that though.

I have been using the drill mill on my mill for engraving for years with great result and good longevity. I also searched around like you and thought I really wanted or needed a diamond tip, but carbide works very well too. Those are still about $25 each, but are worth it to me.

[neilw20]

I just grind up single point cutters from broken 1/8" carbide pcb drill shanks.
A few gashes on the green grit wheel, and a little practice does it well.

http://i399.photobucket.com/albums/p.../Engraving.jpg

Blackening is done by wiping on powder coat and baking in oven just till it starts to melt.