Milling curves

I am fortunate to have a Volstro rotary milling attachment for my Bridgeport. It is like having a rotary head milling machine. It will cut circular faces and do angular cuts in any direction. All in the xy plane, of course.

I must admit to thinking that there would be dozens of YouTube videos, but perhaps they are just too basic a technology. There is a thread elsewhere on this forum, but to be honest I have no idea where I saw the idea of using ballraces, but they are just used as a shortcut to avoid the need to turn, harden and temper buttons, not rolling like on a filing rest.

Brian

Personally I regard filing buttons as disposable. I make them from low carbon steel and never harden them; it's only a few minutes work. My procedure is to hacksaw away as much as possible. Then use a coarse file to get within a few thou of the buttons, without actually touching them. The a finer file to remove material until the file just touches the buttons. Finally a smooth file to finish the profile and then draw file after removing the buttons. The little ends on these connecting rods were done using filing buttons:

Andrew

On thin plate-work, and assuming matching radii, I often use a washer as a filing template rather then revolving button.

It won't work for thicker, quality pieces like those connecting-rods... unless your filing is rather more accurate than mine!

Unless you need to use filing-rollers directly on the work-piece very often, they could be simply of mild-steel and allowed to spin on the shank of a bolt (preferably to a screw), held by lock-nuts tightened just enough to allow free movement.

Can you show me pictures of how this works?

I've googled filing buttons and had zero useful results.

Filing guides shows me knife making file guides.

I have absolutely no idea how you would use bearings / buttons to guide files on work.

The mentions of it are so full of knowledge that the reader understands the principle that they are impenetrable.

I'm sure it's really simple. .. Probably, but not the faintest clue how.

Can you show me ?

Round about the eight minute mark in this video **LINK**

Rob, that is a stunning video on hand filing for clock making.

The patience involved must be truly immense to achieve such pristine results by hand.

Certainly not within the realms of normal workshop practice, at least not in my metalwork class lol.

It shows that hand work is superior to machine work for many things and I couldn't imagine writing the programme to mill out those complex shapes on a CNC whirligig.

In my shop CNC always said for crunchy nut cornflakes

Amazing skill on show in that video. I like videos like that. They actively make you want to break out the files and have a go.

You only need the most basic equipment decent vice, good files and a keen eye well within any ones workshop.

How do you think all the quality guns ever made were done and to a far greater quality in fact more like a totally different league working to microns polished. Video is left rough after the draw filing. Currently theres only three people alive with the know how.

Video he has left way too much meat on and using finishing files (be there all week), would still be using a bastard at that point before going to 2nd cut he certainly isnt doing it for a day job.

Attempt 2 (well, a few failed bodged betwixt then and now) 0.5m steps, "etch a sketch" guided by the DRO. Quite pleased.

Tremendous amount of setting up involved, but really quite logical, I can see I need to improve my setting up accuracy.

Think the steepest curve is the learning curve.

Roy,

I believe you said you had a belt grinder. One way to get a radius id to scribe the arc, then grind to the line.

I like your humour

Would have to agree with many others that for a "one -off" it would be quicker to use a hacksaw and a file.

As others pointed out it takes far longer to set up for a job than it takes to do it [my experience,anyway. ]

If you want to cut gears,you will need a rotary table,but no need to have it motor driven. Great help available on this site regarding this subject. How do I know ? Ask me ! Thank you Brian !!

My advice,for what it,s worth : buy a few hand tools and get used to them first before getting involved with machines. Remember MACHINES NEVER SLEEP !!.And they dont come cheap either.