8020 ErectorSet Router...

[diyengineer]

It will require M5 and M3 SHCS to secure the Hiwin and THK rails to the 1530 series 8020 extrusions. Some of the more typical hardware used with 8020 is their economy T-nuts. Since the size I require is not offered I made the decision to create my own. It's very straight forward. A simple matter of a few cut fender washers, hex nuts, and a bit of tack welding. Split lock washers will be located under the head of the SHCS in the rail itself. We will see if this arrangement maintains a tight screw or requires frequent attention.

Your #1 shop for Aluminum T-Slotted Extrusion hardware

Cheap T nutz.

[Senna]

I have read this thread until my eyes have bled. When I seen that you chose 8020 it drew me in. You have a mighty fine machine. Congratulations on the excellent build. I myself am in possession of quite a bit of discarded 8020 (stuff thrown away at work) and am planning on doing a machine in the near future. Thank you for the inspiration. Also your art work rocks

Thank you for that...! Anything I can do to help your design/build move forward please don't hesitate to ask. There are certainly a plethora of 8020 machines that have been built and are being built so the info for pretty much anything you might encounter is here in the forums.

I hope to see your build thread start up soon...!

Steve

[Senna]

I've been wanting to do a auto zero touch plate for quite some time and I finally got the bit between my teeth yesterday and today. I first tackled the hardware... an aluminum touch plate (+) wired to Input terminal 11 and an alligator clip (-) that clips to the tool bit wired to GND on my C10 breakout board. I then went into Mach3 and under Config / Ports & Pins / Input Signals and scrolled to PROBE... checked Enabled for Pin 11 and checked Active Low.

Next I found a super VBscript written by Kent Janes... the same KENT that designed and makes the excellent plexi-dust shoe. His VBscript however was written to work specifically with the Blue Screenset which I do not run. I have a custom screenset I created and didn't want to switch so after looking at his code... I determined all I needed to do was change a lookup variable he used to a constant (the constant being the thickness of my touch plate) and plug that directly into Plate_Offset =. Once I did that all was well with the script.

Using MachScreen I copied the Auto Zero Tool button from the 1024 screenset to Screen 1 of my custom screen. That Auto Zero Tool button has a User Defined: 707 function tied to it which when clicked will run the auto zero VBscript. Now that the Auto Zero Tool button is on my screen I went to the pull down menu for OPERATOR/Edit Button Script. I clicked on the flashing Auto Zero Tool button and a script window popped up. I copied and pasted the modified VBscript into the window and clicked Save.

That's it...! It worked perfectly the first time I tested it. I ran twenty test runs to insure repeatability and it was spot on...!

There have been numerous reports of the Z axis making unexpected plunges with other Auto Zero scripts. These unexpected plunges cause damage to the material and breakage to bits and can be dangerous if your hand happens to be it the way. Kent figured out it was a timing issue and fixed the plunging phenomena completely. This is what is happening in Kent's script...


This Auto Zero routine is used to zero the Z-axis using a touch probe.
The probe must be ungrounded when this routine starts.
The user is given 15 seconds to touch the probe to the bit.
Once the bit is touched, the z axis will be moved up then down by a small
amount to let the user know that the touch was successful. The routine
will then pause for 1/2 second to allow the user to move the probe to the
top of the workpiece. The system will then move the probe downward until
it contacts the touchplate. Once touched,the z-axis DRO is set to the
plate thickness.
The z-axis will then be moved upward by the distance specified as
Final_Back_Off constant.

I was using the paper feeler gauge method for zeroing to my surfaces previously... this new touch plate addition will be a JOY to use...!

Steve

[jharvey407]

I just read your post about the touch plate. I thought I would explain how I have it set up for comparison.

I also have the aluminum plate and alligator clip, but I don't have to use the alligator clip because my entire machine has a common ground, so the body of the router and the bit are ground.

I simply wired my touch plate to and input pin, and set it as Z home switch.

I use Mach's ref function on the diagnostics page. I place the touch plate on the work surface, jog the tool above the plate and hit Ref Z. The Z axis moves down until it touches the plate, grounding the Z home input and Mach sets the DRO to .25.

I do have to jog the Z axis up before I pull out the plate.

I wonder if there are pro's and con's to the two different methods.

I have been using this method for over a year and have not had any trouble.

James

I've been wanting to do a auto zero touch plate for quite some time and I finally got the bit between my teeth yesterday and today. I first tackled the hardware... an aluminum touch plate (+) wired to Input terminal 11 and an alligator clip (-) that clips to the tool bit wired to GND on my C10 breakout board. I then went into Mach3 and under Config / Ports & Pins / Input Signals and scrolled to PROBE... checked Enabled for Pin 11 and checked Active Low.

Next I found a super VBscript written by Kent Janes... the same KENT that designed and makes the excellent plexi-dust shoe. His VBscript however was written to work specifically with the Blue Screenset which I do not run. I have a custom screenset I created and didn't want to switch so after looking at his code... I determined all I needed to do was change a lookup variable he used to a constant (the constant being the thickness of my touch plate) and plug that directly into Plate_Offset =. Once I did that all was well with the script.

Using MachScreen I copied the Auto Zero Tool button from the 1024 screenset to Screen 1 of my custom screen. That Auto Zero Tool button has a User Defined: 707 function tied to it which when clicked will run the auto zero VBscript. Now that the Auto Zero Tool button is on my screen I went to the pull down menu for OPERATOR/Edit Button Script. I clicked on the flashing Auto Zero Tool button and a script window popped up. I copied and pasted the modified VBscript into the window and clicked Save.

That's it...! It worked perfectly the first time I tested it. I ran twenty test runs to insure repeatability and it was spot on...!

There have been numerous reports of the Z axis making unexpected plunges with other Auto Zero scripts. These unexpected plunges cause damage to the material and breakage to bits and can be dangerous if your hand happens to be it the way. Kent figured out it was a timing issue and fixed the plunging phenomena completely. This is what is happening in Kent's script...


This Auto Zero routine is used to zero the Z-axis using a touch probe.
The probe must be ungrounded when this routine starts.
The user is given 15 seconds to touch the probe to the bit.
Once the bit is touched, the z axis will be moved up then down by a small
amount to let the user know that the touch was successful. The routine
will then pause for 1/2 second to allow the user to move the probe to the
top of the workpiece. The system will then move the probe downward until
it contacts the touchplate. Once touched,the z-axis DRO is set to the
plate thickness.
The z-axis will then be moved upward by the distance specified as
Final_Back_Off constant.

I was using the paper feeler gauge method for zeroing to my surfaces previously... this new touch plate addition will be a JOY to use...!

Steve

[Senna]

Ah... my router mounts are insulators... wood & HDMW... so I need to clip the GND wire to the bit. I suppose I could attach a GND wire from the router to the 8020 frame and then attach the breakout board GND to the frame too. Then I would just have the plate to fool with during a zeroing op. But since I've just implemented the zero plate I really have nothing to fall back upon for comparison. I did 20 test runs and have ran a few more showing off to neighbors... but it's really new to me.

There's so many areas to dabble in when you get bitten with the CNC. I'm certainly NOT expert in any of them. The touch plate is truly the one addition I've been wanting and I'm excited to have it functioning perfectly on my machine. I'll try grounding my router to my frame and see if I can get results where I clip to the 8020 and not have to clip to the bit itself. Hmmm... is the armature of the router conducting through the bearings to the router body so this would work??? Where's my multimeter...

Steve

[RicknBeachcrest]

I just got an order (t-nut stock) in from 8020 surplus and was looking through their promo booklet ... Things you can make from 8020. And I saw your router in there.

Rick

[Senna]

Hey Rick...

Yeah... it's just a matter of taking a good picture and sending it to them. Seeing it in a slightly different context of a catalog and not within a dedicated CNC forum does tickle the ego a bit though... I must admit...!

Steve

[newpatch]

Nice build Senna,

I'm currently designing mine and reading lots of info.......

I have a question on your machine. What is the length of your y axis rails? (the axis going towards and away from you)? And what is your working area?

The reason I'm asking is because I'm planning on getting 47" rails like the ones you have and want a 36" working area. My gantry support columns are designed to be 12" wide but I'm thinking it might be too wide....I'm guessing yours is about 8in? (the width of both bearing blocks on the y axis)



newpatch

[Senna]

Hi newpatch...

The Y axis rails are 985mm or 38.7795". The bearing skates or the distance you have red lined on the side view picture is 7". MY max Y axis cutting distance is 28". Now I understand you want to extrapolate a cutting distance by using these numbers... but you also have to take a few other things into consideration... like your leg or feet design and attachment... the gantry bottom rail design... the AB nut attachment bracket design and location... your stepper mount design... the Z axis design cantilever and the total length of your leadscrew travel. All of these will additionally impact the travel distance.

I've attached a pic that shows my base design and in the side view I have a ghosted profile of my gantry. I've placed the ghosted gantry profiles at max fore and aft travel. As you can see... it's the leadscrew length, the stepper mount, and stub feet locations that are my limiting factors for Y axis travel. Just wanted to point this out so my 28" of travel with a 38.7795" rail wouldn't give you bad information to design off of. Many factors need to be considered...

I'm also attaching a PDF of the same image if you want to better explore the drawing...

Steve

[newpatch]

Thanks Senna,

I knew there was more too it. I just don't have the experience yet to figure it out.

I saw in your pic the rails hung off the frame. I'm curious why? I remember reading somewhere to buy the rails and build your machine around them, which is kind of what I'm doing now. My first parts for my machine came in yesterday. A pair of THK HSR20 rails $85 shipped. Not bad considering I saw others in the $190 range. I was surprised at the condition, tightness and smoothness of the rails. I guess that's why they cost so much brand new. Not sure when I'll finally get all the parts but from some the posts here it took several months before starting the builds.

I'm curious if you tried milling aluminum yet and the results?

Anyway thanks for your reply!
newpatch

[Senna]

The rails hang off the frt about 1" and the back about 5/8"... and that's because the 2 lengths of 1530-8020 aluminum I snagged from eBay in a auction were 75". I cut those in half and did some additional slight trimming to square the ends. I ended up with 4 lengths 37-1/4" which I double stacked and plated to create the base sides. The gantry doesn't get out to the ends so no flex issue... I didn't even want to contemplate cutting steel rail. It's just one of those compromises you have to make when you are designing and building.

At some point I plan to extend the Y & X axis so the Y axis rails will move to a new wider gantry head piece and new longer linear rails (size depending on what I managed to win at auction) will be installed on new 8020 side rails.

I have milled alumimum. I was quite pleased with the results BUT I have to say... even with my cyclone vac and dust shoe... my shop looked like a 70's disco after a glitter party...!!! The swarf was everywhere... still cleaning up several months later!

The guy you want to chat with about milling aluminum on a self-built CNC is Louie Atienza... try reading through this... lots of aluminum examples and info. http://www.cnczone.com/forums/diy-cn...d_another.html

Steve

[newpatch]

I got a laugh out of "70's disco after a glitter party...!!!"

I've read many Louie Atienza threads and posts..unfortunately, they're very long...but very informative. I'm glad I'm taking my time with my build and reading a lot...

I can sympathize on "I didn't even want to contemplate cutting steel rail." From the looks of my THK rails I got yesterday, I can tell you it wouldn't be pretty. Especially if you don't have the proper comercial cutting machines...


newpatch