engraving on baltic birch ply ?

[ian stewart]

Hi

I have had my 60W laser for a month now

experimenting with birch ply

cutting great !

now trying to engrave
following the gold method gone for 150 dpi initially

images seem very dark and deep ?

power of 40 speed 400 is this about right ?

do I have to adjust scan gap? what is it ?


Is birch ply good for engraving ?

can anyone help





I have learnt so much reading past posts thanks to you all


Ian

[Tim Bateson]

Hey Ian. I'm envious of the 60watts. :o
Yes it can be given a descent burn. In my case with multiple passes and/or at a high DPI.
No it doesn't burn as easily as other woods.
That's my experience.

[Frank Corker]

Ian, try to talk in full sentences, makes it much easier to read. Next update your profile and include the make of laser/wattage, then you will have a better response. All of the lasers here seem to vary from brand to brand, they have their own unique issues.

Birch plywood is nice and bright, if your image has gone too dark and too deep, then you simply have too much power. Epilog will recommend that you engrave say 45 speed to 100 power, which is great if you want neatly defined lettering. Engraving a picture at the same setting may result in severe burning of the surface.

Right now you are doing tests, yes? Then you should start say with the 300 dpi. This is an all around dpi setting which many use because it gives fine results. Start your engraving at speeds of 100%. Power should start at somewhere around 30% and increase in multiples of 10% with each image, until you find a satisfactory result to suit your machine. As you engrave each image, add a piece of text which states what power setting that you used.

Ten laser engravers with ten identical machines will also rarely find the same result. Machines vary in power even between 60w lasers and other 60w lasers. They do not always put out the identical power, maybe from long use or just bad luck. Fact is, everyone should do their own experimenting otherwise the advice that you are getting will be of little use.

[Steve Clarkson]

That's a scary eyeball you got there dude.......

I found baltic birch engraves fantastically........but my photos were really dark at Epilog's suggested settings, so I basically cut the power in half and they came out great.

I totally concur with Frank's recommendations......it's also nice to know where you're from.....

[Joe Pelonio]

With wood I find that placing some transfer tape over it before engraving keeps the oils in the wood from coming to the surface, for a much cleaner image.

[Frank Corker]

Joe I was discussing this point earlier with Dave Russell-Smith, would you recommend doing that even if the wood has been treated with either wax or varnish? I must admit I haven't had the problem, but any signs of blooming, I just lower the speed and do it twice.

[ian stewart]

Well thanks for all that

so it seems I must experiment


sorry to upset you Frank I have updated location my sinature does not seem to show up ?


anyone enlighten me as to what is the scan gap is

[Frank Corker]

Ian I wasn't upset mate, just trying to help you in the long run, no damage done.

[Allen Isakson]

chinise laser U.S.A modified and i love it. I do many photos on baltic birch.
I run mine at 60% speed and 40 power. I will prefinish the wood then burn the photo, I like it deep and dark, afterwards i wash it with a tooth brush and water, brightens it right up and the detail is incredible. facial fetures are carved out and my cliants love the way they turn out.
I think the bottem line is if you custumer is happy with the end result

[ian stewart]

HI

I have tried varies powers amd speeds some results quite good

However all attemps have some detail missing
I am not sure if I am expecting too much

I have attached a file with the image in ready for engraving
saved it as v12 hope this is ok

The detail that is missing is circles on the upper boys shirt
The shirt just comes out black


Any comments gratefully received

[Steve Clarkson]

Ian, can you post a picture of your results? That might be more helpful to see rather than the Corel file.....if it's a settings issue.

[ian stewart]

Thanks steve I should of thought of that


here is a quick snap of my very first attempt


I have modified post and added original picture

[Joe Pelonio]

Joe I was discussing this point earlier with Dave Russell-Smith, would you recommend doing that even if the wood has been treated with either wax or varnish? I must admit I haven't had the problem, but any signs of blooming, I just lower the speed and do it twice.
Mainly bare wood, I have not seen a problem with sealed surfaces.

[Steve Clarkson]

My guess.....which is all it is.....is that the upper boy's shirt pattern didn't engrave because the bottom part of his shirt is too dark. Try adjusting contrast/brightness etc. to lighten up that area before engraving. Sometimes the picture won't look right on your computer monitor in order for it to engrave better.

[Tim Bateson]

You have to be part photographer and part graphic artist. Depending on the software being used - I would dodge the darker areas and slightly over burn the lighter areas.

Yes, you may be expecting too much. The results of a photograph on wood can be dramatic, but do to the substrate - the wood; you can't expect to get true photo quality. Most engravable materials just can't handle the range of gray scale you see in a real photograph. This varies depending on the species of wood, as well as every other type of substrate.

Practice, practice, practice.

[Allen Isakson]

This is the pic from my photograv. All the detail will be there

[Michael Hunter]

The depth of engraving has a huge effect with Baltic ply -
In the top ply, the engraving will be a nice tan colour with fairly good contrast to the wood surface.
Hit the glue line and you get a black engraving.
Into the second layer and you get dark brown.
- and so on ....

It's possible to get really good effects by engraving a piece at different depths. Problem is though, that the ply varies from sheet to sheet, so you have to do all the tests again every time you pick up a new piece.

[ian stewart]

This is the pic from my photograv. All the detail will be there


Thank you for that Allen

hopefully tomorrow I will try engraving that
I will let you know how I get on

[ian stewart]

I have done a bit more investigating

The image from photgrave that Allen posted is fine and has all the detail but
it is at 96dpi ( is this phtograve choice for wood ?)
and it is massive in size 17" X 23"

I can produce a similar image using the gold method and stucki


I lose the detail when I resize to say 6" x 4" and set dpi to 150


I have come to the conclusion that I can not engrave this picture at 6" x 4" and still show the detail on the shirt ??




I am therefore confusaed not sure if I am getting the best out of my laser


Would someone be kind enough to post a small image about 3" x 3" THAT ENGRAVES WELL in three states


as taken with camera
ready for laser
engarved on wood


then I can compare each stage of the process with what I am achieving
THanks again for help

[Dan Hintz]

Ian,

You have a 1632 x 2208 pixel image (total pixels are what counts in the original image, not size or dpi). At 250dpi engraving, that gives you an image size of roughly 6.5" x 8.8", plenty big to etch.

17" x 23" and 96 dpi are irrelevant values, just like 1 mile is the same as 1.6 kilometers... either way, it will still take you 2,000 steps (pixels) to get there. One way says you've traveled 1 mile, another way says you've traveled 1.6 kilometers, but you know it still took a foot-numbing 2000 steps.

[Tim Bateson]

Good explanation Dan.
Ian, if you do use PhotoGrav, resize it before PhotoGrav, but never after.