Sunday, December 28, 2014

Grinding Fixture for Handle End of Awl

I am making small runs of a custom Awl for shoe making and the least critical operation can be hard to get done in a proper manner.
After the last batch of 80 I decided to make a small fixture to use on the disc grinder.

As we know the disk grinder is a very dangerous tool. It spins so quietly and can be such a monster if not treated with great respect.

That was part of my motivation, I needed a fixture that would allow me to concentrate on the operation.

This was a fun project in that I got to use my Old School Drafting techniques and tools.

The finished project needed to be low to the grinder table and get close to the edge of the disc.

The other requirement was to grind 4 sides which without the fixture is just a wild guess.
 In position for grinding...
The steel axis rotates the square alum to the next position.

The grinding angle is about 3 deg. so for now I just eye-ball it.

Friday, November 28, 2014

Weaver Heritage Leather Splitter Improvements

I picked this Splitter up from Tandy back in 2007
It was hard to get used to and adjust so over the years I have made changes to tune it in, now it is a better machine and easier to use. As with any machine it takes time and practice to get good results, but as with some machines it requires improvements too.

I put a more accurate pointer on the hand lever because cutting the same thickness on more than one piece requires resetting the blade for each piece.

The radius on the curved piece of steel did not match the radius of the handle so I had to correct that by grinding it down.

The blade must be shimmed to get it parallel to the roller.

I use several thin steel shims and move them around while slowly tightening teach of the two screws. You must watch the gap between the blade and the roller; you will be surprised at how easily it is warped out of parallel with the slightest change in torque.

Sharpening the blade is tricky but I have the answer; 8" x 12" x 2" granite surface plates are cheap and well worth the investment. it will be THE flattest thing in your shop and will become the last word for straight edge sharpening. With a piece of 800 - 1200 sandpaper clamped to it you will be amazed at how easy it is to tune up this very wide blade. YOU CAN SLICE THE END OF YOUR FINGER OFF WITH THIS BLADE SO BE CAREFUL!
Although no one want's to admit it you know that any unsupported part of the blade will cause a sharpening mess. I am able to get razor sharp results with this method.
I added a couple of compression springs; a vast improvement to the how the machine operates.

I also added a couple of oil holes for the roller pin.

Monday, November 17, 2014

Sherline Mill & Lathe DRO Display A - B Box

I have posted about using a single DRO display box for both of my hand turned lathe & mill.

I got the bug to create an A - B box to do the switching instead of plugging and unplugging the 4 wire telephone jacks.

This is an expensive little switching box however it is worth it to me.

I modified an off the shelf Radio Shack aluminum box so that the phone jacks could come in from the bottom and be protected from the machining mess. There are two types of phone jack so this is actually a little bit of a problem; the narrow ones (4 pin) for the handset are used by Shereline.

After the prove out I fabricated an aluminum cover for the underside.

The 4, 12 pin switches are the cost hit for this design.
Maybe there is someone with a better understanding of whats out there or better yet could create an electronic switching circuit and do what this does?

Sunday, March 9, 2014

Sherline Lathe & Mill with MX3660 driver

Months after buying an old Denford / Sherline mill and lathe from the Detroit Public Schools auction I have finally got the CNC lathe running. I tried to make the old Denford driver work... a waste of time. The goal was to add the CNC lathe to my arsenal of machines; having several years of experience on the mill I really wanted this addition.

I went ahead and bought what appears to be one of the best drivers out there, the MX3660 from AutomationTechnology Inc.Wishing to build out the enclosure myself I was very pleased with their help when I ran into problems.

The MX3660 is a compact unit that drives any three axis. I had been looking for a 3 axis driver in one box but most are one axis per box? So I am very happy with the size, built in options, DIGITAL aspects, and ease of wiring. I also bought a 48vdc power supply and 3 NEMA 23 hybrids from them.

I designed this 12" x 6" x 5" enclosure with on - off switch and indicator lights and X, Y, Z, and AC receptacles. I didn't have the nerve to wire the 25pin receptacle so it plugs direct into the MX3660. Also powered a little 12vdc fan (on the left) just because.

After careful assembly I was ready to complete the machining center. I decided to add the lathe to the rolling bench already dedicated to the mill. The reason I got the 3rd motor is so that I can someday (if necessary) get into thread turning or Rotary Table work.

I welded up a small table to suspend the lathe over the LCD screen. I had assumed that I would use a second computer for the lathe but then I ran across a 15 year old 25pin A - B box! So with a single load of Mach3 (using different start-ups) I have one computer and two drivers (with completely different pin-outs,) but by switching from A to B and opening either the Mill or the Turn versions of Mach3 I can jump between machines and the different loads of Mach3 are saved unique.

Ultimately I like the drivers under the table and the whole thing is contained on the one rolling bench.

Someday I will either take the driver out of the old Sherline computer box or better yet get another MX3660! But for now I think I will leave it and start making stuff again!


Someday is here!

After careful consideration I saw that the A-B box was between the wrong components, and so I built one that would go between the MX driver and either machine instead of between the computer and two different drivers.

Obviously the 12 year old Sherline controller buried inside a huge old computer box was annoying and having perfect success with the MX I decided to swap it out with one of those office style Dell computers with XP I got used from the Grosse Pointe Public School system. .

The middle row is the XYZ in from the MX, above and below are the XYZ out to one machine or the other. Finding the 12 pin switches was a little trouble but the physical and visual logic of the design is hard to beat.

 Huge amount of soldering.

Up for lathe, down for mill.

The rear view; old XP computer on the right, MX in the center, and the A-B box on the left.

Now I am very happy with the this new set-up, the MX is of course smoother and more quiet on the mill then the old Sherline too.

The whole machining center is more compact and I got to throw out the other computer after stripping the guts out of it.

Automation Technology Inc
Automation Technology Inc
Automation Technology Inc.
Automation Technology Inc.
Automation Technology Inc.
Automation Technology Inc.
Automation Technology Inc.
Automation Technology Inc.
Automation Technology Inc.