View Full Version : Boring Head

12-29-2005, 09:42 PM
How does a faceing and boring head work such as when you are doing and inside recess? What makes the head move? Thanks

12-30-2005, 02:11 AM
I'm no expert here, but...To initiate feed, boring and facing heads may have a grip ring that is held by the machinist, or a method like a rod or clamp that is held stationary against a fixed machine member. This fixed ring has internal gear teeth that mesh with a gear on the part of the head that spins which turns a feed screw (think like a planetary gear set, but with just the ring gear and one planet gear fixed to a shaft). There are varying degrees of complexity and adjustment, but I believe they are all variations on this theme...

About the simplest one may be an early Chandler such as in patent number 2 356 651.

Go to:


and enter 2356651. Click on the "images" tab and you will see the patent. Look at figures 6,7, and 8 and I'm pretty sure you'll get the picture (pun intended).

You will need a tiff viewer of some sort, if you have Quicktime on your computer the tiff images should open for you.

I have some other interesting boring/facing head patent numbers but they aren't with me now and they're all pre-'76 and can't be searched by text. Hope this helps...

Ian B
12-30-2005, 03:01 AM

To add to what abn wrote, most boring heads can face inwards and outwards, but the internal gearing always rotates the feed screw in the same direction - you get the 'inward' or 'outward' by mounting the cutting tool on one end of the slide or the other.


12-30-2005, 08:56 AM
I would have to look to be sure, but the boring head we have at work you run in reverse to get it to move the opposite direction. Obviously you turn the tool over when cutting that way.

George Barnes
12-31-2005, 01:29 PM
Here is a boring and facing head that I built from a casting kit that came from one of the model supply houses. I think that it probably originated in the U.K.. The feed to the facing part of the operation is initiated by the pin engaging the star wheel on the lead screw. Depending on which pin is engaged, the feed is either inward or outward.


I'd be interested in seeing how this is done on the unit that Metal Lathe Accessories sells the plans and casting kits for.

01-01-2006, 09:12 AM
The MLA boring head is on the same principle as yours. The boring head only feeds in one direction though. You hold the feed ring and each click gives you about .0025 outward feed. Turn the tool around to feed inward or outward.


01-01-2006, 10:14 AM
I've used 2 different types. The Chandler has a gear drive that works in both directions with gear driven by holding a ring at the top. The Enco has a ratchet arangement. It only works in one direction but has 3 different feed rates. I prefer the smoother gear drive.