Experiment Engraving Machine Dials

Gallery, Projects and General > Project Logs

<< < (2/10) > >>

awemawson:
It's been a useful exercise in that I've learned a few things :

... diamonds don't conduct electricity so no use trying to use my LED 'Z Height' setting gauge to set tool length :scratch:

... I must have used ceramic bearings in my air turbine all those years ago - the spindle & collet are electrically isolated from the body so again no point in trying to use the LED Z height gauge ! :scratch:

... my lubrication / misting system for the air turbine that passes oily air through the bearings to keep them alive works, but using WD40 is messy and needs refining somehow :ddb:

... my HUGELY expensive Heidenhain TS511 automatic probe does (JUST!) clear the 4th axis tailstock in use on automatic tool changes without breaking it's nifty little ruby precision ball off :ddb:

When the diamond arrives I'll make another one - but it's been a learning exercise

So where does this dial go - here:

philf:
Andrew,

I'd forget the diamond and use tungsten carbide for most materials. I chipped my diamond (forgot to set Z zero!) and thought I'd try a point ground onto a broken carbide end mill. I've never had to regrind it and I've done a lot of engraving with it - much on to stainless.

I've got plenty of 1/8" shanked broken or worn out cutters so I can grind up different angles for different hardnesses. (They can also be ground into rotary engraving tools but that involves a lot more work.)

Drag engraving doesn't seem to take paint or filler as well as rotary engraved. Maybe because it's very shallow and the surface finish in the engraving is too smooth.

My diy tool height setter doesn't rely on conductivity and works very well.

Cheers.

Phil.

awemawson:
Phil, thanks for that tip :thumbup:

So encouraged by your suggestion I steamed up the Clarkson T&C grinder, found a green grit wheel and modified a broken 1 mm carbide end mill that had a 3.17 mm shaft.

That completed I made another steel doughnut, went through the origin set ups again (LED sensor OK on carbide :thumbup:) and engraved the new disk.

Oh so much better than the rotary engraver, but obviously shallower. I need to experiment with tip angle - this one was about 40 degrees included angle as far as I can measure - and was completely arbitrary.

I suppose the sharper I make it, the deeper it will cut but the more likely to break

philf:
Andrew,

I usually use a 90 degree included angle on hard materials and 120 degree on soft. You may find that 90 degrees will give you a wider mark than 40 even at the same pressure although I've not done any scientific comparisons varying angle and pressure vs width of mark.

This example was a test in a piece of brass before I risked it on a trophy.

Have you got some backlash in your dividing head? In the 4th image the gap between 50 and 51 looks smaller than the rest. Or is it an optical illusion?

Phil.

awemawson:
I'll do some experiments. I've no idea what the steel is that I was engraving, but it's certainly not plain mild steel. Cleaning up after boring, my normal de-burring tool wouldn't touch it - I think that it had work hardened - or maybe it was pre-hardened stock :scratch:

Navigation

 Message Index

Go to full version