Sunday, January 11, 2015

Sherline Mill - Break Press Bar Fabrication

I wanted a full length bending bar for my bench top break press.Over the years I have wanted an uninterrupted single bar so this is how I made one on the Sherline.
I started out with some old school drafting.
Lots of trig to get from here to there.
This crazy 60deg happy accident was discovered by setting the steel stock into the T slot.
I decided to just go for it. I know that the angle will not be exact but the goal was to have a crisp straight line and any angle less than 80 deg. is fine; its around 60 deg.
I made the 3 hold-downs out of a single piece of 0.75" alum. hex.
My basic feed & speed for steel on the Sherline is 0.004" - 0.005" cut and about 5 ipm.
The Sherline is simply not stiff enough to take a heavier cut and that is why I hand write simple code to get me thru what would be a long hand crank process.
The 3 clamps obviously had the opportunity to be out of alignment, and so after a few passes I had to tighten the left side and loosen the right side to tune to bar into square.

Saturday, January 10, 2015

Sherline Mill - DIY T - Nuts

I ordered some of those A2Z T nuts a few years ago and I really like them. The Sherline T nuts don't make any sense to me; they protrude just above the deck surface, are far to short, and are difficult to slip in with out looking closely.

It looks like A2Z went out of business but the T Nuts are still available for $5 - $6 each.

I decided to make my own.
First I had to decide on my own set of dimensions, and as with any DIY project you can be more precise. So I made my own choices regarding how loose to fit them.

I started out with the dimensions of the slots in the table, then the dimensions of the A2Z, and lastly the dimensions I wanted to target. 
I used the dimensions at the bottom of the sheet, the red are the dimensions I achieved, .

I always try to work in long strips and make an over sized "blank" or extrusion. I had to turn down the heads on three 10-32 screws so I could clamp my strip stock directly to the table.
The dimensions are good!
I divided up the strip stock into equal parts around 0.550" long, cut them with the band saw, and finished then on the 1" belt sander. 

PORTER-CABLE Bench Belt/Disc Sander Detachable dust collector

After 29 years on my Craftsman belt - disk sander including a bearing replacement about a decade ago I wanted to replace it with a direct drive.
The only consumer direct drive that didn't cost lots of money is the P/C. I've read a lot of bad reviews so I hope I got a good one?

I made a detachable  dust collector because some times you need to pass a long item over the surface and it was a good challenge.

I modified the intrusive dust collector provided an then taped some high power magnets to the inside or the chamfer on the left of the cover.

I folded up this 0.030" steel cover.
Snaps on and off with ease.

It is a quiet machine and that is important to me.