[40fordcoupe]

I'm not sure if this is the correct forum, but here goes.

I have created a drawing in CAD for an absolute encoder. I can output in DXF file format. I want to have this engraved on glass The person who has the laser engraver says he can only take BMP or JPEG file formats.

Question what is the best way to convert DXF to Bitmap? I only want to do this one application so buying an expensive software program is not an option.
Thanks in advance for your help.
Bob B.

[ger21]

Hit the print screen button while the drawing is on the screen. Paste into Paint, and save as .bmp

[One of Many]

The scale will need to be adjusted after doing that.

Keeping it 1:1 may not be simple, but your frieinds software may have this function. If not, a first article can get you close, then make minor scale adjustments after a known dimension from the first part.

DC

[40fordcoupe]

Thanks to both of you.
I can put a one inch scale in the corner of the drawing and adjust the size as needed.
Bob B.

[sidi_steve]

Hello Bob,

One thing you can do to set scale is draw a square around your object. For example, if your encoder is basically a circle with a diameter of, say, 2" then you can enclose that in a 3" by 3" square. Then, after your conversion, you can use that box to crop the image, then scale to a 3" x 3" image.

Steve

[40fordcoupe]

Then, after your conversion, you can use that box to crop the image, then scale to a 3" x 3" image.

Steve

Good thought Steve thanks,
Also I could just leave the squares on the drawing to make sure what is coming out of the laser engraver is sized correctly and it will make communication with the person who has the engraver easier. I can tell him to fit as many of these things as you can on say a 9.5 by 12.5 inch piece of glass.
Bob

[ger21]

An image doesn't really have a "scale". The size just depends on the dpi it's displayed at. Ideally you just want it to be the highest resolution possible.

[One of Many]

An image doesn't really have a "scale". The size just depends on the dpi it's displayed at. Ideally you just want it to be the highest resolution possible.

True and there in lies the problem. At some point in the process, it will need to be scaled in order for the Laser to follow a path relative to the part intended. Be that the image before it gets into the laser control or after and most certainly before it is cuts a final part. Probably in a rastor to vector conversion.

DC

[sidi_steve]

Well said DC.

I realize that my explanation (for the process of including a bounding box of a known size in order to set "scale") was a bit brief.

So, when trying to convert a vector based image to a raster based image, for the purpose of engraving, it is good to find out what the highest resolution (dpi) that the goal process can handle.

Working with pixel based software, like photoshop, one has the ability to work in the desired dpi, to crop to an area defined by a bounding box of a predetermined size and then set the size of the remaining image to the prescribed value.

In this way, if the end user imports the bmp or jpg into the engraving software at the highest supported res, then the size of the desired part should come out as close as possible.

Steve

[One of Many]

Well said DC.


So, when trying to convert a vector based image to a raster based image, for the purpose of engraving, it is good to find out what the highest resolution (dpi) that the goal process can handle.


Steve

I thought rastor was the image and vector was the dimensional information for motion control? So, Wouldn't that be a Rastor to Vector conversion.

We had a laser engraver for a while and it could do both conversions.

BTW, the laser engraver caught on fire when the operator fell alseep and no gas was flowing to eliminate the condition. Sad, very sad a total loss. I had big plans for that thing! (flame2)

DC

[40fordcoupe]

Hello again,
I have since called the laser manufacturer and was told that their software can accept a DXF file. The person that owns the laser engraver is not a very computer savvy person. For that reason I was trying to make it simple for him. I do realize that what is on the screen represents a bitmap. The suggestion to draw a square around the encoder pattern suits the situation just fine.
He will understand that it is a 3 inch square and will adjust the output accordingly. Also I understand that it will not be exactly 3 inches. If he gets it to plus or minus 1/32 that with be sufficient. Whatever the error is it can be compensated for. I'm very grateful for all the very thoughtful comments.
If this does not work (and I think it will) I will go over to his place and show him how to import a DXF file.
Thanks to everyone,
Bob B.

[sidi_steve]

The following is a quick list of suppliers of low cost laser engravers. I don't know the best way to maintain a list here, but if people find other suppliers with websites, seems like this would be a good place to put them. This list is not an endorsement for any of the websites or suppliers, just what I have stumbled on or been lead to...

Low Cost Laser Engravers:

Ink Express
IE300 laser engraver
http://www.iehk.net

Jinan Hengxing Computer Equipment Manufacturing Co.
Rabbit HX40A
http://www.hxlaser.com/en/index.htm

Red Sail: HF Laser
3040B
http://www.hflaser.com/jgdbj.html

Wuhan Huahai Photoelectron Co.
H40w Laser Engraving Machine
http://www.huahailaser.com/eng/cpjj2.asp?id=173

Sorry guys... this shouldn't be in this thread. I will put this in it's own thread once I extract my head from my... (chair)

[rbthntr64]

Does anyone know of a program to convert a .jpg to a usable file for engraving? I would like to convert this pic;

[40fordcoupe]

Does anyone know of a program to convert a .jpg to a usable file for engraving? I would like to convert this pic;

Try this site http://www.brothersoft.com/downloads/jpg-to-dxf.html