View Full Version : Boring head question

Black Forest
04-05-2011, 03:05 PM
I have this Rohm boring head that came with my mill.

There is a knurled ring just above a dial with numbers on it. When I turn it the round dial with the numbers on it rotates but I can not see any movement in any of the parts.

What am I missing? I have never used a boring head and I don't know if this is a piece of junk or a good one.

04-05-2011, 03:16 PM
That appears to be a boring and facing head. When the spindle is running and you hold the knurled ring the tool moves in or out depending on the direction the spindle is rotating. Definitely not junk and very useful when needed.

04-05-2011, 03:17 PM
Yeah that's junk, send it to me for disposal ;)

What you have there is a very nice boring and facing head. You'll need to find the manual or someone who knows how to work it, but basically the knurled bit is held still while the body it turning, so that boring bar will traverse out and face the surface of the part.

There will probably be a button or switch to start the facing action. The stops can then be set to end the operation at the correct diameter. Some head also have fast return. By synchronising the Z feed with the rotation it's even possible to cut tapers with it.


Black Forest
04-05-2011, 03:33 PM
There are a bunch of boring bars mounted on the dovetail mounting blocks. Long and short. Probably ten of them.

Alistair Hosie
04-05-2011, 03:46 PM
I'll give you a quid for the lot delivered with a 99 guarantee parts and labour :DAlistair
ps I think you knew all along this was not junk:D

Black Forest
04-05-2011, 03:56 PM
I have no experience with boring heads. I did not think it was a piece of junk for two reasons. The name Röhm and it feels good. But I have no clue what all the parts do. I googled the name and number I found on it but got no results. I went to the Röhm site but could find no boring heads at all.

Tomorrow I will call them and ask about the tool.

04-05-2011, 04:12 PM
Most of these heads have a similar working activation. The knurled ring with the numbers on it you were asking about sets the feed rate when facing. Rotate it to what feed you want. Then either on the knurled ring or above it will be a threaded hole. A lot of these used heads seem to be sold without the stop lever. It is just a long rod threaded at one end. You hold this rod stationary as the boring head is rotating in your spindle. This activates the feed mechanism. The little "T" stops on the ruler below the normal, circular dial set where you want the automatic feed mechanism to disengage. Otherwise, they work just as any other plain boring head if you keep that long, threaded stop rod uninstalled (or not held stationary). Some use a complex gearing mechanism I'm not particularly informed on to provide the automatic feed. Others use a ratchet like mechanism.

04-05-2011, 04:20 PM
One of the better tricks I read of is for quickly enlarging your hole to get it in the range for final boring passes. You use a shorter rod for the stop-lever. Then you set the head and bore like normal. Now, you don't need to stop the spindle on your mill to enlarge the setting. You just grab that rod slinging around and hold it a little bit as the slide feeds out. You let it go and bore like normal again. Hold the rod again, bore again, etc. etc. until you're getting close.

I made a sewer coverplate once out of steel that needed 2-1/2"+ diameter holes in it. All I had was my RF31 mill/drill and a 2" boring head. I drilled up to 3/4" with twist drills. Then plunge-cut with endmills up to 1-1/2", which is the largest I own. After that, I had to use the boring head. Without an automatic head such as you have, it took a very long time. Bore. Stop machine. Reset head. Bore. Stop machine. Reset head. Over and over up to 2-1/2". It was tedious, and I've remembered the above trick in my head ever since. I would love to have one of them, but so far can't justify the expense.

Alistair Hosie
04-05-2011, 05:28 PM
Schwarzwald like all your buys you've done well buddy this is a nice piece of kit. Alistair

04-05-2011, 10:15 PM
So- it will likely take a lot of turns of the knurled wheel to change the position of the cutter noticeably.

04-06-2011, 03:38 AM
This is a re-badged D'andrea head. The dovetail tool holder gives it away.

I believe it's U95 model. It's an Italian company, still in business but that model has been replaced.

I don't have a manual, but they show up on Ebay often so you might persuade a seller to sell a copy of a manual.


Black Forest
04-06-2011, 05:57 AM
With the confidence gained from you all I went to the shop. The boring head has three speeds that I can tell. It does not have a rapid return that I can find and not an automatic return. If I want to return the cutter I have to reverse the spindle. Of course I am not sure why I would want a rapid return or even an automatic return!!

Now I have to find an excuse to bore a hole using my new to me boring head.