Not an even cut

[Gunny Rogers]

While etching glass I discovered something unusual. I am not cutting on an even plain. For instance, On a piece of glass I was trying to etch the capital letter "R". on the first attempt the only thing that was etched was the slanted part of the R. If it was even all the way across the letter it would have been OK. But I tried six times to get the whole letter to get etched, each time attempt I lowered the bit, but even at the sixth attempt I wasn't satisfied with the letter. Is there some adjustment that I can make to make the machine cut level?

[highpockets]

What bit are you using? What depth of cut are you using?

[Rcnewcomb]

Have you leveled your spoilboard recently? If not, that might help.

[4DThinker]

The bit may be slipping up as you cut. Glass is a very hard surface, and may be resisting more than your steppers, or bit tightness can handle. Just a thought.

[Gunny Rogers]

1. I'm using a diamond tipped bit at a depth of .001. As I said I get only a partial etch on the glass.

2. How do I level the "spoilboard"? I haven't seen or heard about this adjustment. Please enlighten me as to how to level my "spoilboard".

3. I'm very meticulous about tightening my bits so I don't think that is the problem.

[SteveNelson46]

1. I'm using a diamond tipped bit at a depth of .001. As I said I get only a partial etch on the glass.

2. How do I level the "spoilboard"? I haven't seen or heard about this adjustment. Please enlighten me as to how to level my "spoilboard".

3. I'm very meticulous about tightening my bits so I don't think that is the problem.

It's not an adjustment. It's a procedure to skim a small amount of material off of the top of your spoilboard so it is co planar with your router/spindle. YouTube has lots of different examples. Just search for "Leveling The Spoilboard"

[FixitMike]

Is your diamond tipped bit spring loaded? If so, you can use a much larger engraving depth, and the end will move in and out to suit the precise height of the material you are marking. Very, very, few spoil boards will be parallel to the gantry movement to within .001". Myself, I start with a depth equal to half the total spring movement and change it if necessary.

[mtylerfl]

...Myself, I start with a depth equal to half the total spring movement and change it if necessary.

Good tip, Mike. I don’t think I’ve heard that one before (ie, starting with depth of half spring travel).

[FixitMike]

Good tip, Mike. I don’t think I’ve heard that one before (ie, starting with depth of half spring travel).

I ran some tests with a diamond drag bit on acrylic. There did not seem to be much difference in the appearance with different pressures. So it apparently is not an important setting, at least with acrylic.

[Gunny Rogers]

First off I don't have the equipment to shave off .001 of the spoilboard. I will got on face book and looks at some of the ways that on there. Maybe I'll just place a couple of sheets of paper under the low side of the material and lift it, hopefully that will level it enough.

[mtylerfl]

First off I don't have the equipment to shave off .001 of the spoilboard. I will got on face book and looks at some of the ways that on there. Maybe I'll just place a couple of sheets of paper under the low side of the material and lift it, hopefully that will level it enough.

You MUST purchase a spoilboard cutter to surface your spoilboard flat. This is always done and is done with a certain amount of frequency to assure a flat surface for accurate cutting of all projects. This is especially important for what you are attempting. Engraving is especially sensitive to variations in “flatness”.

If you have questions about how to skim your spoilboard, and/or need Bit recommendations etc, there are plenty of folks here that can help!

[Leo]

Gunny,

What is your machine? I tried to search 141001, but that is not enough information to find your machine.

Knowing what you have will help us to better understand how to help you.

If it is any sort of a standard CNC Router, we can help you to understand how to "level" your machining platform - spoilboard -

This is imperative to good quality precision work. When you are talking .001, then that is precision.

What make is your machine, so we can look it up.

[mtylerfl]

Hi Leo,

Back in April of this year, Gunny mentioned he has a Piranha CNC

[Leo]

OK, then yes certainly doable for the spoil board.

[barryc]

I really fail to understand why the CNC make/type would make any difference whatsoever to levelling a spoilboard. Taking a skim cut is taking a skim cut.