Boring bar/head

I have been given a job to bore some 45mm holes.

So was thinking about this boring bar **LINK**

Is this a good cjoice or should I be looking at something else?

No reason why it should not do the job, I use a nice French made 4" boring and facing head on my Bridgeport but there is no change out of £300 or more if buying new. Your chosen head will no doubt last you a lifetime.

I have one, it works straight out of the box. I think the smallest bore size with the bits supplied is about 10mm dia, but if you ground your own, then they could be smaller.
BobH

I advise you to get the metric version so you have the finer adjustment.

Emgee

Petro1head,

One of my boring heads is exactly the same as the one in your link and I consider it a perfectly acceptable bit of kit. I've never been able to achieve what I think is a "decent" finish with those carbide tipped tools, though, but I suspect that's more down to my inexperience or incompetence. If you want a super-fine finish, I would encourage you to invest in an insert-type boring tool or a named hss tool. I have a small Sandvik hss boring tool, which gives excellent results, without too much practice.

John

Note the boring tools seem to be out of stock. These ones with interchangeable shanks are much better for the hobbyist who might change machines. Mine is fixed but luckily the same on both mill and lathe but if I ever got an R8 machine it would add to my retooling costs.

.

Agreed.

They can then also be used in a lathe tailstock as a poor mans taper turning attachment if light cuts are made.

Nick

Cheers for the replies. I was going to buy the metric version

So are you saying the tools that come with that bar are not the best?

I cant see any other boring tools on the ARC website.  Looking elsewhere I see you can get indexable tools.  What about HSS?

Edited By petro1head on 08/04/2017 13:13:43

I have an 8mm shank HSS tool that came I think from RDG. I use it in my small Arrand boring head. But I also get reasonable results using the standard carbide brazed tools as available from Arc. You need to fiddle round a bit with the rake setting.

Being new to boring heads can you expand on this please

I was given a Boring Head with a set of Boring Tools from a local Machine Shop. It was given to me because " I don't know what's wrong, it chatters". I traced the chatter down to the R8 Shank was undersize. I replaced the R8 Shank and it works very well.

The set of Boring Bars I received look like the picture in the Arc-Euro ad - the shanks are plain diameters with no flats. At first I thought to put flats on the Boring Bar shanks so the set screws would not cause dings in the shanks which would make it horrible to remove the m from the Head. Then I realized there was no way to put the Boring Bar in the Head and assure the cutting surface was parallel with the Head motion (as mentioned by John Haine above). I did put flats on the shanks, but the solution was to measure the shank diameter of the Boring Bars. I then put each Boring Bar in the Mill Vice horizontal and rotated the Boring Bar axially until the cutting face of the Carbide was exactly 1/2 the diameter of the shank diameter below the top of the shank (easy to do with a Dial Indicator). I then milled a flat along the shank to a width equal to the set screw size. I can now place a Boring Bar in the Boring Head and slightly jiggle it as I tighten the set screws and it is always aligned correctly. Plus the dings do not prevent the Boring Bar from sliding out freely.

Of course the Boring Head in a Mill is only as good as the clearance in the Quill (unless you lock the Quill and feed using the Knee).

Another one of those "I did it quicker than the time it took to write this project".

Bruce, Cleveland, Ohio

Just to clarify - I wasn't suggesting in my post above that the supplied boring bars weren't any good [Arc wouldn't sell them if that was the case], just that I couldn't get a good finish with them. Oh, and I didn't get my boring head and bars from Arc, so maybe I'm comparing apples with pears.

John

Snap! have a set like that but came in the plastic carry box used it once so far... can't remember what tho' ( see other thread about losing memory ​ ) mine is metric too, IIRC I titivated the point to a fine radius with a diamond lap & it gave an acceptable finish, worth the spend.

George.

See Bruce's reply above.

I now always look very sceptically at offers with several 'cutters' along with the basic tool. Often, one decent quality cutter, bought separately, exceeds the 'assumed' value of the 'offer pack' where one does not need all the 'specials' (or even all but one!).

I have, before now, thought 'If only I had not bought that '***' item, as I will likely never use it...' Or if I need one, I would buy a better quality one than the one on offer. Special offers are not always what they immediately appear to be cracked up as!

Regardless of whether these particular examples are good quality or not, their basic tool geometry is rather crude. An indexable boring bar offers the benefits of higher top rake and chip breaker, resulting in lower cutting forces and likely better finish. Spend a little more and you can get something like this. The ground finish inserts (**GT) are good for small machines and are fine for steel unless you are taking very heavy (by our standards) cuts.

Murray

Edited By Neil Wyatt on 09/04/2017 08:35:25

Have used for decades the cheap brazed on carbide in first link all made by same company, however they will need reprofiling and sharpening sold as steel or cast iron.

Mainly used on aluminiums they don't generally leave a respectable finish on most steels due to the flex. More you try to correct the worse it gets often showing up as chaff marks.
One respectable strong boring bar would be 4 times the price as the carousel.

I don't think it matters what a boring head is, metric or imperial, as i always use a DTI for adjustments, its easy and gawd knows what the divisions are on some of these far-eastern made heads. The cheapo bars that come with them are very roughly made, i have a set and all the tips were at different angles to each other, very sloppily brazed on.

A trick i was shown before, and works very well if the holes aren't too deep, is to use a slot drill in the boring head, with the point/corner as the cutting edge, before you pooh-pooh it, try it.

The job I am doing needs to have a good finish so where do I buy decent cutters. I machining Aluminium

Use an indexable lathe boring bar the same size shank as the holes in your boring head. For aluminium i would try a tip with a radius rather than a sharp point though.