Pantograph

I decided to take a few minutes and start on the pantograph castings.  My normal method, honed so many years ago on the only other casting I started  (and haven't finished yet) I painted it before I started milling it down.  Made sense to me then.  I decided to do it again and see if it works.

All my primer spray cans were plugged or empty...  So I blew on some high temp bbq pit paint.  I traded off my pit so no need for it any more.

 

Beautiful

The black parts were not in need of fettling.  But the spindle arm was.  I spent 20 minutes or so smoothing out the flash.  Some spots, it was really proud and I had to tap it down a bit so the file would cut easily.

That spindle arm still has a big gate / sprue on it that will be ground down tomorrow or Friday, then filed flat to match the rest of it.

I haven't decided on the final color.  I have some gray and some blue.  I may even have hammered green.  I need to dig in the stash and see what's available. Man this is starting to get exciting!!  

What can a pantograph do?  Well, it reduces or expands whatever you run the stylus over.  This one can shrink by a few different amounts depending on where you put the holes.  1/2, 1/4, 3/8 IIRC.  I could engrave letters and numbers, or make torx holes, or whatever I can make a template of.  Pretty cool machine.

Here's a good overhead view of one running.  

I have some leeway on making the base for it.  I'm not sure quite which way I'm gonna go on that.  Maybe an aluminum plate or maybe dig for an old cast iron drill press table.

The original used a sewing machine motor to run a spindle.  I  found a spindle motor that runs at 12K rpm.  It has a built in ER11 collet and comes complete with a DC driver, a few cutters, ER11 collets in multiple sizes and the two mounting holes will work perfectly on the spindle arm.

I can hardly wait to get started machining on it.  The heat broke a week or so ago.  Shop isn't bad at all unless it's really humid.  It's only in the mid 90's now.  Cool edge to the breeze most days.  This evening reminded me of summer nights in Lubbock county 40 plus years ago.  Nights were cool on the caprock.  Even in the middle of summer, getting into the mid 60's at night was not uncommon.