Reply with QuoteWay Cool! Have to use this idea.
Bill
DIY Z axis 0 plate. It works perfect!
Someone on here mentioned that the Shop bot comes with a Z axis zeroing tool made up of a plate that you set on your material. You run some kind of "Zeroing routine" and the tool comes down an touches the plate and calculates the material top of stock location and sets the tool zero to be at the top of stock.
Well I made my own, and it's so simple it's silly.
I made a small .125" thick plate from aluminum. I took the +5 volt wire off my Z axis home switch, extended it and tied it to the plate. I set my z home switch in turbocnc.ini file to normally open and the home offset to .124". My router has an aluminum body so it is grounded.
To set the tool height, I chuck in the tool, set the little plate on my material, under the tool, then I home the axis. The z axis slowly moves down towards the plate. When it touches the plate, it stops, thinking it hit a NO switch, and sets the z height to .124". The 1 thou difference seems to be the time it takes for the tool to stop. I raise the tool, remove the plate, and if I send the z to 0" it stops perfectly on the top of the materail every time. I han just barely slide the material out from under the tool, it leaves just the slightest mark. I love it.
I will make a plastic pocket, attached to the z axis to hold the little plate so it can ride along and be insulated from things while not in use.
Here is a picture
Eric
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Last edited by balsaman; 04-09-2004 at 11:13 AM.
I wish it wouldn't crash.
Way Cool! Have to use this idea.
Bill
Definitely cool!
I one of those things where you say "Doh, why didn't I think of that!"
Good work Eric.
I'm probably stating the obvious but for those with insulated routers, you could rig up an aligator clip to attach to the bit.
Or would this be electrically harmful to something?
That would work fine.
Eric
I wish it wouldn't crash.
Great Idea !!!
I will have to do this
Great idea Eric.
If the tool overtraveled into the plate, you could design a spring loaded the plate to allow for that.
Bill.
Eric would you mind me showing my tool set switch here? I will have to get it photographed. I tried one photo and the light was not good enough? My switch is a different animal completely so it will at least give a variety, .....just say the word.
Mike
No greater love can a man have than this, that he give his life for a friend.
I've also done something like this with my 'nearly completed' machine. I've done a permenant
system, where I've constructed a spring loaded touch sensor just to the side of the table. This
sensor is exactly the same height as the spoilboard, so after I've flycut I can adjust the sensor
accordingly. The feed is to pin 11 of Mach 2 and ground is through the frame (the spindle is double insulated). I'm about to run a macro the moves the tool to the sensor. The only thing I haven't worked out yet, is how the automatically set the height when it touches. Apparently I should use the 'digitise' method. Has anybody done this in Mach 2?
I'll post some pictures of the machine in a few days or so. I'm rather proud of it.
Turmite, go ahead.
Krsykes, I would like to see some pictures
Eric
I wish it wouldn't crash.
Nice idea Eric
as for my impatience and related promised pics...
It's been an hour now and no pics posted yet!
Very nice simple implementation. What Feedrate do you use when probing the tool? I would imagine that with this system, the slower you run it down the more accurate it will be.
A little spring loaded system like they use on the big machines would be nice to keep from breaking bits in case they touched down a bit hard, but you're not making this for Joe Schmo, you made it to make your life easier. You know, the more I look at this system, I am in love with it's simplicity.
Great job on a very useful tool!
My name is Electric Nachos. Sorry to impose, but I am the ocean.
http://www.bryanpryor.com
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)
It aproaches the plate at around 10" per minute. It does not hit hard, and stops instantly. It will not break a bit unless something is very wrong(wire broken off the little plate, software settings messed up).
Eric
I wish it wouldn't crash.
krsykes my system is Mach2. I have the macro already done. I will try to email it to you or post it in the files section over on the y Mach2 forum.
Eric I will try to get the pics today. It is basically a micro switch mounted to the table that I machined some add on parts for. It sounds like exactly what krsykes has done, except I used a shotgun barrel!
Mike
No greater love can a man have than this, that he give his life for a friend.
That is fantastic. I had wondered if it could be done like that, that is how the CNC machines I have used in the past worked.
I am going to check the Mach2 forum to see if you have put up the macro yet. With a spring loaded switch, do you have it set to plunge quickly, then retract a bit when it hits the switch then plunge slowly and stop again when it hits the switch? This is how the tool probe's I am familiar with work. Very accurate because the second plunge is slower.
co
yukonho I had to use my brother's digital camera and then he had to email the jpeg to me for the pics. I have been waiting for over three hrs for the email and he lives 1/4 mile away. I will go to the shop and get the macro and will put it up by 2:00pm central time.
Mike
No greater love can a man have than this, that he give his life for a friend.
Great, thanks.
If you cant post it, could you e-mail it to me? That would be great. It is so cool to add a feature like this to a home made machine. Just approaches "real machine" status with every addition.The spindle on off and Estop are my latest additions and I love em.
cant wait to do this one
co
yukonho believe it or not I couldn't see on my computer at the shop.No...seriously I forgot my glasses and couldn't see it.
I did find it in my email folder I have dedicated to Mach2.
You will have to edit it to fit your needs and the feed rate needs to be about what has been posted so far of 10" min.
Here tis!
code "g31 z-10 f10"
While IsMoving()
Wend
code "G92 Z0"
code "G0Z3"
While IsMoving()
Wend
code "g92z0"
I have a deep z so I put in the z-10. This script restes the z axis to zero in the last line. If you will notice the fifth line down is a z3" move up. You can edit that for whatever you would like. I don't have to have a know distance from my table height but from the centerline of my a axis. I hope this helps. I will post the pics as soon as they get here from cyber mail.
Mike
edited to add ( make sure you write it exactly as shown as in Caps spaces etc. I made the mistake of having 1 space in between ( and) like before the a in and, and it wouldn't work.)
No greater love can a man have than this, that he give his life for a friend.
Sweet concept Eric. I love it when simplicity reigns. Now we need to think of a similar device which will work on conductive stock like steel or aluminum. I suppose one could insulate the touch pad with a piece of teflon, or better yet, how about a phenolic block, with an inset of brass, machined to an exact height? The phenolic would be oil resistant and dimensionally stable to boot. You could have different shapes for other than flat stock, such as a v-block for round stock, a rod probe for recesses, etc.
Just thinking out loud, here. Thanks for sharing this with us!
how about a peice of PCB?
Bill
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