Not getting any adjustment?

Help for setting up and using
daedelus
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Re: Not getting any adjustment?

Post by daedelus »

Looks like I have found the problem. Looking at your original file, it contains a lot of arcs (G2 and G3) which this autoleveller version does not yet support. Sometimes arcs work without problems, sometimes not.

It does say this under 0.5 on the downloads page and even in the latest 0.7.7 version, they are not supported. This causes problems with straight line segments after it encounters an arc as it does not break down straight lines like it should do without arcs in the file which explains why you get no Z adjustment in the middle section of your file.

What a lot of people have done in the past is break down arcs into small lines around the circumference instead of arcs and in fact, many PCB / gcode programs produce small octagons for pads instead of arcs.

Having a quick look at Marcus's code, he does break down arcs successfully but the distance between the start and end points of an arc is measured "as the crow flies" rather than measuring the length of the segment around the circumference. This is OK for small arcs as the difference is negligible but for bigger arcs it will not be too accurate.

For now, try to stick to straight line segments (G0 and G1)

best,
http://www.autoleveller.co.uk/. Software to probe and adjust a GCode file for PCB's or any probe-able surface.

http://www.autoleveller.co.uk/cnc-probe-guide/. A short guide to setting up the probe.

-James
booski
Posts: 51
Joined: Sat Oct 19, 2013 4:46 pm

Re: Not getting any adjustment?

Post by booski »

Is that so?

So simply put, autoleveller doesn't account for round pads?

And that any future designs I create should have square or octagonal pads?

Unfortunately, the program I used, CamBam for outputting my files doesn't allow for arcs to be broken down and simply outputs them as is and I haven't seen any other pcb-gcode software that is really any good unless you can advise?

Cheers for looking into it though!
daedelus
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Re: Not getting any adjustment?

Post by daedelus »

You are correct about the software not accounting for round pads. However, it should not cause so much of a problem so I shall have a look and see if I can apply a quick fix for this before I start my next project of a good gcode parser.

The video on the home page of the case being engraved was made by "Mad Professor" using CamBam. There are a lot of fairly big arcs in this design but on the original post on mycncuk forums: http://www.mycncuk.com/forums/computer- ... are-4.html the Prof explains how he did it:
Daedelus: Regarding the G2 and G3 moves, I made a new Post Processor within CamBam, and there is an Option called "Arc Output" this was selected to "Convert To Lines".

Now all the G2 and G3 arcs are turned into lots of small lines, suitable for your probing software.
I dont know CamBam myself but hopefully that makes sense.

If you try this, you might want to send the new gcode to me to check. I would hate to think you are ruining another board.

best,
http://www.autoleveller.co.uk/. Software to probe and adjust a GCode file for PCB's or any probe-able surface.

http://www.autoleveller.co.uk/cnc-probe-guide/. A short guide to setting up the probe.

-James
booski
Posts: 51
Joined: Sat Oct 19, 2013 4:46 pm

Re: Not getting any adjustment?

Post by booski »

Well, I've just had a look at Cambam. Unless you change the post processor, the 'default' setting is used.

So, I changed the default setting for 'convert to lines' and voila!

I overlaid the original and converted to line g-code outputs in cambam and immediately saw the difference, can hardly tell the difference between the original and converted.

In the future I will just have to remember to include that change or just simply change the default of the default.
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