Not an even cut

Gunny Rogers
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Not an even cut

Post by 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?

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highpockets
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Re: Not an even cut

Post by highpockets »

What bit are you using? What depth of cut are you using?
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Re: Not an even cut

Post by Rcnewcomb »

Have you leveled your spoilboard recently? If not, that might help.
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Re: Not an even cut

Post by 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
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Re: Not an even cut

Post by 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.

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Re: Not an even cut

Post by SteveNelson46 »

Gunny Rogers wrote: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"
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Re: Not an even cut

Post by 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.
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Re: Not an even cut

Post by mtylerfl »

FixitMike wrote:...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).
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Re: Not an even cut

Post by FixitMike »

mtylerfl wrote: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.
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Re: Not an even cut

Post by 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.

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Re: Not an even cut

Post by mtylerfl »

Gunny Rogers wrote: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!
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Re: Not an even cut

Post by 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.
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mtylerfl
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Re: Not an even cut

Post by mtylerfl »

Hi Leo,

Back in April of this year, Gunny mentioned he has a Piranha CNC
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Re: Not an even cut

Post by Leo »

OK, then yes certainly doable for the spoil board.
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Re: Not an even cut

Post by 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.

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