2017 POTD Thread Archive

Since I needed to roll the 4x6 drop saw into the main shop to cut quite a bit of metal for this summer's main fabrication project, I thought it was time to complete all the mods I wished to perform on this faithful tool.

dropsaw_1.jpg

Some of the mods were performed a few years ago, like hman's drywall mud pan shavings catcher which actually works quite well. The big improvement this time was the folding work table for cutting in the vertical position. Right now it's stowed and out-of-the-way for drop saw use.

dropsaw_2.jpg

I also tweaked the hydraulic down feed mod that was done earlier. It seems that it's impossible to completely get all the air out of such a system, but since most of that air seems to be at the ends of the piston stroke it doesn't seem to matter that much.

The two big advantages of the hydraulic down feed over the factory spring: you can easily lock the saw's movement so you can position the work at the correct spot and you get a better cut because the down feed is more consistent especially cutting tubing and angle iron.

The shelf below holds tooling for the saw, which is all located on the saw itself do it doesn't get lost.

dropsaw_3.jpg

Here you can see the saw in vertical mode, with the cutting table down and a wooden seat held with the vise. Trust me, for bigger jobs it's a lot more comfortable to sit on that board than to sit on the vise. While it will never be as nice as true vertical band saw with a big heavy table, it only takes about 10 seconds to setup like this and it's already proven to be quite handy. I don't have room for another saw anyway...

And that completes the mods for this saw as I'm pretty happy with the way it works now. Most of these mods I would classify as extending the capabilities of the saw, not fixing a bad design or polishing a turd. Sure, a bigger drop saw would cut much faster and already have a hydro. down feed, They are also are bigger, heavier and more expensive. This saw is small and light enough to easily roll where I need it and once you go through the initial setup does a nice job in cutting the small stock I use in my hobby work.
 
I made my first Printed Circuit board on my cnc mini mill tonight and I’m over the moon!!!

It took nearly a month in learning the EAGLE cad to design the board, learn how to setup the PCB-GCode (an add-on for EAGLE) to create the GCode but I the result was promising.

PC221919s.jpg
As usually I used tools I own to do the job and results are far from perfect.
For instance I tried to use some bits my dentist gave me.

PC221911s.jpg

Although they are good to grnd a tooth they do not last long in etching a board.

Started nicely

PC201904s.jpg

But lasted only 15 minutes.
3 bits later I decided to make my own bit from a broken one.

PC221909s.jpg

I hand grinded it to a shape that will not break and started etching the board for the 3rd time.
The bit lasted through the whole process and was replaced by the tiny drill bit to make the holes.

PC221916s.jpg

In case you wonder how I supported on the mill, I just used a wooden block secured in the vise

PC201900s.jpg

I milled it to be level and left an edge higher to align the copper

PC201897s.jpg

and with some drops of glue I secured some copper board on it
PC201901s.jpg

I think if there are people interested, I might make a full tutorial on how to etch a copper board on a cnc mill giving all the details

Thanks for reading

Petros
 
Last edited:
That's down right inspiring. I know I for one would be interested in the entire process, if for no other reason than to understand the hardware/software for a plasma table that I eventually want to build. Great job on getting something that complex right the first time. Mike
 
That's down right inspiring. I know I for one would be interested in the entire process, if for no other reason than to understand the hardware/software for a plasma table that I eventually want to build. Great job on getting something that complex right the first time. Mike
Mike the hardest part was to familirise myself with the eagle CAD as you need to work on 2 levels:
You design the circuit (shematics) using a library of components

Schematics.jpg

Then, from the schematics you arrange the components on the board in a logical (?) arrangement and connect them with lines that would be the copper stripes. That's where the fun begins as you test the CADs intelligence (when it does the work automatically and makes stupid routes) with yours that is MUCH MORE EFFICIENT.

Board.jpg

From there you ask the program to create the gcode for etchig it and another gcode for drilling it. It does and shows how the final board will be marking areas that the tool will pass many times.

FinalEtch.jpg

After that its a simple matter on supporting a copper board on the machine, load the gcode USE THE RIGHT ENDMILLS and etch it.

PC221914s.jpg

I will make a full tutorial on that process as it is very nice to use the CNC mill to make such a delicate work.
STAY TUNED

Petros
 
Last edited:
Petros, You might want to take a look at ecad.io.

Now that Eagle is an Autodesk product, they have added this utility that converts the pc board mask to a dxf file which can be imported into a CAM program. If you are using Fusion 360 for CAD/CAM, you can import directly into Fusion.

I prefer to mill away all the copper which is not part of the circuit traces. For cutters, I start with a 1/4" carbide end mill, followed by 1/8", .060" and .023". If I wanted to have the distance between traces smaller than .023, I would use a 15º carbide engraving tool which could take me down to separations of around .005". Here is an example of a pcb used to scale an outboard motor tachometer output to interface with an aftermarket digital tachometer.
.Divide by 3 Circuit.JPG
Divide by Three.JPG
 
Petros, You might want to take a look at ecad.io.

Now that Eagle is an Autodesk product, they have added this utility that converts the pc board mask to a dxf file which can be imported into a CAM program. If you are using Fusion 360 for CAD/CAM, you can import directly into Fusion.

I prefer to mill away all the copper which is not part of the circuit traces. For cutters, I start with a 1/4" carbide end mill, followed by 1/8", .060" and .023". If I wanted to have the distance between traces smaller than .023, I would use a 15º carbide engraving tool which could take me down to separations of around .005". Here is an example of a pcb used to scale an outboard motor tachometer output to interface with an aftermarket digital tachometer.

VERY INTERESTING, and very convenient. I use Fusion and I will have a look at that ASAP.
Thank you RJ
 
Greg,
Thanks for the tip. I checked out Tubal Cain’s video on shear tools and will give it a shot.
Definitely gaining on it. I'm realizing that while I thought I had a pretty good handle on 3-D relationships and shapes, I've got a way to go. Once I ground the first angle 8º THE RIGHT WAY, the rest was pretty easy. I think I need to tweak it a bit for shearing on the face, but I'm pretty happy with the progress I made once I got the bit ground correctly. I stopped the cut mid-radius to capture this picture--I just couldn't believe the improvement in finish. There's definitely some chatter marks on the finished disk, but I think those will buff out. Now, to figure out how to protect the finish.

IMG_0815.JPG
IMG_0814.JPG

IMG_0816.JPG
 
Last edited:
Glad we could help, total coincidence that I saw his video just before your post.
Greg
 
Back
Top