Circles????

[leggman]

After not messing with my homemade plasma table for about 18 months I finally have the desire again to get it working.
I am using various programs ( 123D Design, QCad), etc to draw simple parts and using sheetcam to generate g codes.
Yesterday I drew a simple rectangular plate and ran it through sheetcam to create a g code. Today I loaded it into mach 3 for a simulation and when I hit start it started cutting large circles???
I am new to all of this. After building my table two years ago I ran the roadrunner program and it ran great until I ran out of code lines ( I still have not paid the registering fee to mach 3)
I really believe I can get this sorted out but I hate to keep throwing money at it (the sheetcam fee was 150.00) if it's not doing any good.
As always any help and/or advice is greatly appreciated. Thank you.
Dave

[djreiswig]

Are you using the correct post processor?

[robertspark]

https://warp9td.com/index.php/faq/faq-g ... irdCircles

[acourtjester]

Thanks for the reply, and answer, members again show why this is a great site to belong too.

[msimpson99]

When working with a new machine, I will add some sort of marker or pen holder so that I can test the machine making some simple cuts (marks). That way you dont have to waste consumables or stock.

[Ironken]

When working with a new machine, I will add some sort of marker or pen holder so that I can test the machine making some simple cuts (marks). That way you dont have to waste consumables or stock.

I use an Easyscribe available here on this forum to test accuracy and layout. For me, sharpies, etc. create too thick of a line to measure against.

If you have a Hypertherm Duramax torch, it fits right into your existing torch.....easy peasy.

[msimpson99]

I have a ton of various ways of marking things, Pens, Markers (Ultra fine works well), dry erase, and plate markers. I still use a pen or marker when testing a new machine.

On a brand new build things can go south until you get the machine operating properly. I have crashed the pen or marker hard, and would rather damage a cheap marker than an expensive scribe.

In any case it does not matter what you use, it is a step that must be done on a new DIY build.

[Ironken]

Sounds like you know what works best for you. I would have a hard time pulling an accurate measurement with calipers on a line created with a marker.

[acourtjester]

This talks about a pen marker. I have since built (3-D printed) a simpler one
viewtopic.php?f=129&t=17080&p=99328&hil ... ker#p99328

[msimpson99]

I think we are talking about two things. I am talking about using a pen or maker in a pen holder for break-in and initial testing or trouble shooting.


For alignment, I use a whole set of different procedures to fine tune each axis.

[acourtjester]

I think drawing squares is a better method for measuring axis movement. First you have X and Y size and then corner to corner measurement for squareness of the table travel. then an extra treat is drawing a circle in the square to see if it touches each side equally. but do use a fine tip pen for smaller line. The larger drawing makes for more correct measurements too.

DSCN3662.JPG

DSCN3661.JPG

[msimpson99]

I have a write up using these parts to make a very precise pen holder.

longpenpartst.jpg

Its based on the brass hobby tubes that fit one inside the other.

_MG_9225.jpg

I have used simpler ones. I even have a couple commercial pen holders.

I was looking through some of my older videos, and found this.
https://youtu.be/zPDTyza8XZA
It was one of my very first pen holders.

Here is brass pen holder on my KRmx02.
https://youtu.be/HwGdwPZBHBc


In any case here is my writeup for a pen holder.
http://www.kronosrobotics.com/diy-cnc-pen-holder/