[milhead]

After reading many posts and spending lots of hours on CNCZone and other sites I've started my first CNC machine.

My friends all think I'm nuts but my girlfriend is so far supportive as she will get come finely cut craft wood.. (assuming that I am successful). I'm just a builder and currently the machine is my goal...

[joecnc2006]

What size Machine are you planning?

[milhead]

Well, I pretty much designed and fooled around with a small z-axis, Building from the top down... I've learned a few lessons about using a router to cut the plastic (Including sending a peice sailing across the garage)...

Here is near the finished peice... I'm now working on the gantry section and
mounts for the z-Axiz...

Currently I'm using a section of 1/4 threaded rod with a tapped block of
nylon for the nut. I'm not sure how this will hold up. For the remaining screws I'm switching to the popular 1/2-10 Acme screws..

[milhead]

What size Machine are you planning?

My Z-axiz came out 6 inches wide... I was hoping for maybe a 20" travel on the gantry (x-axis I think) and maybe 30" on the bed for the gantry to travel..

[joecnc2006]

Well, I pretty much designed and fooled around with a small z-axis, Building from the top down... I've learned a few lessons about using a router to cut the plastic (Including sending a peice sailing across the garage)...

Here is near the finished peice... I'm now working on the gantry section and
mounts for the z-Axiz...

Currently I'm using a section of 1/4 threaded rod with a tapped block of
nylon for the nut. I'm not sure how this will hold up. For the remaining screws I'm switching to the popular 1/2-10 Acme screws..

you may want to use some tubing or some way to lock the possition of the bearing so it does not slide along the u-bolt to the sides, here is what i did om my cnc Model 2006.

[milhead]

Thanks for the suggestion Joe, I will add the tubes when I take it apart to paint it (I've decided on purple as it's my girlfriends favorite color and I'm going to need all the compassion I can get, she is just realizing the time I'll be putting into this)...

[joecnc2006]

as soon as you get the machine finished cut her portrait and stick it to the side of the machine, and tell her that way you can be thinking of her while using the machine... LOL

[milhead]

Tonight (while hiding from the snow.. near portland).. I got the basics of the Gantry put together...

Looks like the finished product will allow a width of about 18 inches... I've not worked out the length.

Here is a question for all the CNC fans out there.. Which axis typically is represented by the carriage sliding on the gantry... Y or X?

I also need to get to work on the electronics, but am eager to complete the mechanism first.. I'm not too worried about the electronics part.

Miller

[Mike F]

Generally, though not always, the longest, horizontal axis is X, the shorter of the two horizontal axes is Y and the vertical axis is Z.

Mike

[ger21]

Here is a question for all the CNC fans out there.. Which axis typically is represented by the carriage sliding on the gantry... Y or X?

The Z axis moves along the Y axis, the gantry moves along the X axis.

[joecnc2006]

Tonight (while hiding from the snow.. near portland).. I got the basics of the Gantry put together...

Looks like the finished product will allow a width of about 18 inches... I've not worked out the length.

Here is a question for all the CNC fans out there.. Which axis typically is represented by the carriage sliding on the gantry... Y or X?

I also need to get to work on the electronics, but am eager to complete the mechanism first.. I'm not too worried about the electronics part.

Miller

Generally most people use the gantry for Z and Y because the bed is the longest x axis, Look at it as if you were standing on the left side looking at the machine and reading a set of plans.

[Madclicker]

My X and Z are on the gantry. I think the only real convention is that the Z axis is up/down.

[milhead]

Well I was able to spend several hours on the Gantry mechanism over the weekend.. It looks like I'll have about a 20" x 30" travel for y, x respectivly,
Give or take an inch...

I have learned the desire to have a machine in order to spit out parts for a
second machine, I think all of the error that is introduced in this mechanism
so far has been done so by me and my router...

As a result I took a 2 hour side bar and slapped together a router table
out of the MDF, I'm using my old Craftsman workhorse as a base.. This
Thing is a real time and error saver, I think I've only taken the router out
of the table once since I built it.... So now I'm kicking myself for not
building one years ago..
I've always looked at them in the store and thought it would be useful... Well it cost a whopping $4.00 to build... (*add a few screws,
some glue, a few biscuits, and two C-clamps to hold the fence in place..)

On a sad note, Cutting off some bolts caused my Dremel to die. The one
I've had since high school (20+ years I think)..

What's your opinion, Do I add the cost of a new fangled Dremel tool to
my running total that I attribute to the machine? Or are tools overhead
that get accounted with rent, lights and Kerosene (to make the garage
not freeze).

[milhead]

The photos above show a peice of 1/8 MDF on top of the base, this is NOT what I'm planning to use here... I'll have a 24x36 3/4 MDF top for the
table with two largish peices of angle iron running the length to keep it flat.

I'm not sure how to measure a torsional defection of the table yet but I'm
sure that I'm going to have a problem with it. I'm content for now to allow
the table to have some torsional flex but be rigid enough that I can adjust
it out when I set it on a hard flat surface...

A torsion box of some sort will probably be a result of my next round. I like
Joe's as it accounts for both torsional flex in the base as well as loading
flex on the large X axis rails.

Having a machine that can cut the ribs sounds like good fun...

Mil

[milhead]

Has anyone come up with a good cheep way to guide wire
for cheep?

After poking around the commercial sites for a while I think I'm going
to try using a section of Stanley Fat-Max tape measure with my 10
z-axis wires and 20 gantry wires.. Either I'll tape the wires on at intervals
(cheep links) or use some sort of loosely braided string...

I think the concern is that if the wires get around the edge of steel
tape it will be a short time before it cuts through the insulation...

I'll see if home sells replacement tapes, I hate to hack up a good one..

Miller

[Weldtutor]

I think the concern is that if the wires get around the edge of steel
tape it will be a short time before it cuts through the insulation...

To protect the wire insulation you might run the wires through some "split plastic loom" that is taped to the Fat-Max blade.

[milhead]

I played with it some during lunch, The loop that the tape will make is approx the diameter that the tape has... I think my first attempt will be to tape at about 2-3" intervals some trailer wire...

I'm not sure if it will work, The wire has to compress around the bend or create a slack bulge. All of the commercial chains hinge in the middle of the cavity for this reason...

[paulC]

Lots of ideas around cable carriers here.
http://www.cnczone.com/forums/showthread.php?t=25257
Paul

[milhead]

Well, I deviated from the all wood system for the base, I took some scrap
iron from the nasty garage and a rented Home Depot welder and welded a
square to hold the two end peices and to support the table.

Aside from converting four spots of my MDF jig into char with appropriate
flames the resulting frame came out very true (Or at least as much as I
can tell with my good carpenters square).. The folks in the other apartments probably dont see alot of welding in the mini garages here...

Oh well.

I put the base and the gantry drive together.. There is a tad of rack
possible but I have to tweak pretty hard to get a barely noticable movement..

I know that any visible movement will spin the dial on my caliper.. But for
my first attempt an any of this apparatus I'm pretty stoked.

I now have the motors and drives attached for all three axis..

My last box from All Electronics also came this week so I thinking of
starting the electronics but am still having fun building so I worked a
bit to template, rough cut and route out the palstic for the cutter mounts.

I need only now to reassemble the Z axis and the basic mechanism will be
complete.

I've got a long list of honey-do's so my Saturday may be CNC-Free

But the electronics, limiit-switches, e-stop and motors will soon be
assembled...

[milhead]

I've got the Z and Y axis wired an operating but am having pretty severe noise
issues with the limit switch circuitry.. Straight wires are not going to work and my
vision of a nice single wire bundle is a joke.

I think I'll have to run the 8 limit wires (x, y, and z, limits as well as the
emergency stop button) through a sheilded cable and may even have to use
some common-mode rejection circuits in order to get clear signals.

Tonight I'll focus on the noise it to see if it's a grounding problem or if
I really need to add some circuitry to reject it. I have added capacitors on the
controller end and while it works great for a single wire, when I have all 3 motors
running I will get false limit switch firings.


My girlfriend is starting to hint that there will be a limit to the amount of house
space that I consume with the thing.. It's back inside for wireing and nearly
consuming the 10x6 foot table... Suddenly I'm on a timeline, The garage is a very
cold place and kerosene is expensive to heat it.


The amount of wire I'm adding to the thing is kinda daunting...

but... It's eating through most of the wire I've beem packing around for years which
may not be a bad thing.,

In the photos below I'm able to move my test tool (18V DeWalt Drill) around pretty
well at lower speeds (< 75 IPM) but at higher speeds The motors loose steps or
stop all together...

The next steps are to complete the electronics assembly and then mount my Sharpie
felt tip marker (not so damaging test tool) for a real test...

Mil