All ShapeOko, All the Time

At least thats what it feels like to me. But I’m having fun, mostly.

Over the past few days I’ve done more stuff to my ShapeOko. Here is all the stuff that I can remember, and some pictures.

Warning, very long.

1. First off (no pictures) I grabbed some 2x4s, cut them into three 4 foot lengths, jointed one edge and then ran them through the planer so they were all the same width.

I screwed these to the bottom of the MDF base for my ShapeOko and now it’s really stiff. Not very much deflection, so that’s a good thing.

2. Since the base is pretty stiff now, I chased some more accuracy (no pictures). I took my indicator and base and checked the height of the rails at both ends. They were all within .005″. Imagine my surprise. I also realized that I did the 10″ travel check incorrectly. So I set the steps per revolution back to the default and setup and did it again. This time I interpreted the results correctly and it appears that when I tell it to go 10″ it goes 10″ +/- .001″. So no real change needed.

I then clamped my dial indicator to the Z axis (see below for details) and ran it across the table the short way. It was off about .018″ in 6.5″, so I adjusted the rails to fix that up. Of course this assumes that the table is flat, which I’m sure it’s not completely, but it’s good enough for now.

3. I thought I had a bad Z axis motor, so I ordered another. I swapped the motor and discovered that it behaved exactly the same as the one that I thought was bad! So I guess it’s just that the threaded rod and nut are not very well machined. Sigh. Oh well, now I have a spare stepper motor in case I manage to burn one out.

4. I bought the Acme Screw Z-Axis upgrade from Improbable Construct. He made a forum post a few days ago saying they would be $10 off and that he probably wouldn’t make anymore for a while. Since I was not happy with my Z axis anyway, I dropped the $65 and ordered it on Thursday. It arrived on Saturday and I mounted it right up! It works great and now I can set the rapid value to 1400 instead of 800 and it works.

Acme Screw Z Axis Upgrade
Acme Screw Z Axis Upgrade

5. I made an air deflector/dust shoe mount for the router. This was a hassle and a half, though it shouldn’t have been. The part is a square with two holes in it. You wouldn’t think it would be that difficult to mill, but I had no end of troubles. I drew up the part and generated three programs in CamBam – one for each circle and one for the profile. Unfortunately when you send an M30 command to the GRBL Shield it appears to treat it as a soft reset. So it lost my zero and when I tried to send the second circle it took off across the table. Which is always my favorite thing. Time to hit the reset button on the GRBL Shield!

So I fired up vi and joined all three programs together. But apparently the GRBL Shield was in some weird condition when I sent it – and it plunged the tool into the material and took off at a 45 degree angle! Man I have got to get that E-Stop button wired up! It was getting late on Saturday night at this point, so I just turned it all off and went to bed.

Today I ran the program up in the air to make sure it was all fine. It was so I started milling a part. It machined the two holes and was about 1/3 of the way done with the profile when the X axis locked up solid. WTF? Since this is open-loop control, the GRBL Shield has no way to know that the X axis didn’t complete it’s move and it kept sending motor pulses. The Y axis then started it’s move and cut a groove right up the middle of the part before I could get to the reset button!

I tried sending some X axis commands and it was not moving, so I powered down to see what the deal was. One end of the X axis was moving fine, the other end was not. Locked up solid. How is this possible?

I turns out that when cutting Acrylic the swarf that gets tossed and blown all over is very hard and non-compressible.  A tiny piece of swarf got under one of the V wheels and kept it from turning. I find it highly ironic that this happened while I was cutting out a part that should solve this problem.

Apparently the third time is the charm. I fired up the mill again and this time I watched the V wheels like a hawk, tooth brush in hand to clean any swarf out of them. I managed to get a part this time! Huzzah!

I mounted the plate to the lower motor mount with some 1/2″ spacers. The gap is where the air from the fan in the router will get deflected. Here are some photos of the plate mounting.

Plate - bottom view.
Plate – bottom view.

Note, one screw is missing. I only had three of the proper sized screws around – I’ll have to pick up another tomorrow.

Side view.
Side view.

Here you can also see the 1/4″ aluminum rod I pressed into a hole on the mount. This allows me to mount my dial indicator for squaring up material.

Mounted to the mill.
Mounted to the mill.

All mounted up with a piece of 1-1/4″ plumbing fixture for dust collection. I still need to get some brush material to mount around the bottom of the plate.

Dial Indcator Mount.
Dial Indicator Mount.

Since the spindle lock is spring loaded, and does not really lock the spindle tight I wanted to have a more rigid mount for my dial indicator to enable me to square up my vice jaws or blocks of material. This works great.

6. I also made some hold down clamps. I actually did most of the work on these using my table saw. I ripped a strip of 3/8″ plywood, cut it into lengths and mitered the ends. But I used the mill to cut the slots and just wrote up a quick program in vi to do it. Worked out slicker than snot too!

Hold Down Clamp.
Hold Down Clamp.

7. I took some hose that I had and ran it up and over for the dust collection. I don’t have a picture, but I took some video. I’m going to have to get some different hose apparently, check out the awesome noise it makes!

So that’s not really going to work for me. I’ll have to get some real vacuum hose or something.

All in all though I’m pretty happy with the mill.


Running total costs.

All Shapeoko CNC Mill Posts.

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