Sketchup Follow-me tool acting funny

I’m making a marble tic-tac-toe game to practice Sketchup and cutting with my CNC mill.

I’m having an interesting problem. I’m trying to make little cups for the marbles to sit in. I make a circle on the surface, then a circle into the material. I then make the perpendicular circle into a fragment and rotate it around using the Follow-me tool.

For some reason it only gives some of the cup shape. I’m missing the lower portion and some other fragments. Any ideas?

Source: xo5

So I tried to do it by subtracting or adding the object from outside as Paul M suggested. For some reason, in this Sketchup drawing I can’t get the follow-me tool to work at all.

CNC Mill made from Polyethylene

polyethylene plastic mill

I spent some time getting the electrical going for the Polyethylene mill.

The electrical is a Nema 23, 3-Axis.

I wired it up with some nice long wires so I can add the drag chains later. I decided to just run it for a while before installing the drag chains.

I just used a dremel as a spinle motor. Not perfect but when you think of it, it’s great value overall.

It runs nice.

3D CNC milling


Today managed to cut a 3D part using my CNC mill (rather than 2.5D like the other stuff I’ve done so far).

Here are the source files: balsaholder

I did the design drawing up in Google Sketchup.

The file was exported from Sketchup to STL format using an STL Exporter plugin in Sketchup.

The STL was processed into g-code using FreeMill.

The g-code was then run in the CNC machine to produce the part.

If you get this error in FreeMill, it's because you have to run the program as admin. Cannot find the c:Program FilesMecSoft CorporationFreeMILL emp.acl file. Do you want to create a new file?

I got stuck on Freemill for a while. You have to run it as administrator (right click then “run as admin”). If you don’t it will fail when you get to the end because it tries to write the g-code into it’s own program directory where there isn’t sufficient privilege for the program process.

I used pretty well all of the defaults of FreeMill except I put in the specific dimensions of my endmill (1/8 diameter, ball radius 0, length 1).


Part dimensions: The measurements of the part do not match the measurements of the drawing from Sketchup. I suspect I have to calibrate the machine (Mach3) or there is something wrong with how I made the g-code.

The 4 1/2″ measure in Sketchup is 4 1/16th” on the part. The 12 1/2″ measure in Sketchup is about 12 1/8″ (measured with ruler). So those two came out a little shy.

I find this puzzling because the 1×1″ square in Sketchup is 1 3/8 x 1 7/16″ (1 3/8″ side is in the direction of the 12 1/2″ measure).

Something is fishy that the 12 1/2″ came out shy but the 1″ along the same line came out long.

Feed Rate: It took really long. Next time I will us a feed rate that is much faster. I’m supposing next time I’ll try a feed rate that is about 5 or 10 times faster. I was running on full override and it was still crawling.

Holes: It seemed to miss the holes. I think I made them right in Sketchup but they didn’t come out on the part.

Multi-pass: The g-code is quite simple. It removes all material in one pass. When it made the edges it plunged about .6″ and cut across the board at that depth. I will look in FreeMill to see if there is a feature to have it remove material in layers.

Clamping: I had to move a clamp and the workpiece shifted a bit. The piece has to really be clamped well. I’m going to get more hardware for clamping.

Dust: This is still an issue. I don’t like lording over the piece with a vacuum. I went out and got some hose so I vacuum near the spindle automatically. I wound up with some 1 1/4″ ID pool hose. It’s pretty light and flexible. I got enough to mount it on the machine. I now need to make a mount for the spindle and a mount for the base so I can just plug the vacuum in when I want.

“Make your CNC” book basec CNC

I’m just in from my friend Benoit who made a CNC router. Benoit, Guy and I met up to have a Google Sketchup lab. Benoit gave is a brief walk-through on how to use Sketchup. He also showed us how to use the Phlatboyz Sketchup plugin to generate g-code from a Sketchup file.

I’m pretty excited as it looks very promising for 2d work!

We had a chance to run his router a bit and jog the motors around.

Turns out Benoit is into painting! Here’s a quick video of jogging his cnc router and some pictures.