Author Topic: Insert Boring Bars - any hints or tips please?  (Read 5906 times)

Offline b.lindsey

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Re: Insert Boring Bars - any hints or tips please?
« Reply #15 on: August 31, 2018, 02:50:57 PM »
Check the A. R. Warner Co. They have single boring bars in various sizes that use their HSS or Carbide inserts. They have good quality tools and in sizes suitable for smaller machines as well.

Bill

Offline propforward

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Re: Insert Boring Bars - any hints or tips please?
« Reply #16 on: August 31, 2018, 02:53:03 PM »
Purely by chance I happened upon this site just now, with this tool with HSS inserts.

https://www.arwarnerco.com/Kit-13-3-8-inch-Boring-Bar-C-p/kit-13.htm

So I'll keep that in mind, but I'm still going to look into grinding my own tools first - I did have success with that on external turning tools, so with some direction maybe I can get where I want that route.

EDIT: Timing! Thanks Bill - appreciate the heads up.

Stuart

Forging ahead regardless.

Offline b.lindsey

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Re: Insert Boring Bars - any hints or tips please?
« Reply #17 on: August 31, 2018, 03:00:49 PM »
Mine is the same size but uses the triangular inserts.

Bill

Offline Chipswitheverything

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Re: Insert Boring Bars - any hints or tips please?
« Reply #18 on: August 31, 2018, 03:05:46 PM »
Hi Stuart, very much second Dave's recommendation of looking up what Geo. H. Thomas has to say about kit for boring smaller holes, he covers the subject in a very effective way with gear that can be made cheaply in the home workshop. He gives a lot of detail on tool forming and the holders. 
 You don't necessarily have to grind the boring tools from HSS, silver steel ( drill rod ) will turn and shape quite easily and is fine for many jobs when properly hardened and tempered.  I mostly use this type of tooling, down to little boring tools about 1/8" wide, good for forming a really true hole to start a reamer, for instance on something that warrants that attention.    The two larger bars with the brown ends are from a design by "Martin Cleeve" in a 1960's Model Engineer, a BMS shank with a H & T silver steel end, the HSS tip secured by a screw inside the tapered end.   ( Apologies for rather rubbish photos! )     Dave


« Last Edit: August 31, 2018, 03:08:54 PM by Chipswitheverything »

Offline Steam Haulage

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Re: Insert Boring Bars - any hints or tips please?
« Reply #19 on: August 31, 2018, 03:19:15 PM »
 :old:
I know that a debate rages often occurs between advocates of HSS and carbide inserts. With that in mind when I had the opportunity to have a newly equipped workshop I made what has turned out to be an irrevocable decision asnd settled on Carbide.
As has been said the main problem for the hobby user is cost, any mistake can work out expensive. However I looked back at various machine shops I had acquaintance with in the UK. (I have never worked as a machinist but in most cases I had access to the shop records to see their buying patterns.). One thing became pretty apparent, with few exceptions the Manager/ Superintendant had elected to use only one make of inserts, and again mostly the same makers tool holders. After a few enquiries I found they had built good relationships with the suppliers and had access to a deeply knowledgable body of information.
I don't believe we have any chance to build these sort of relationships but I have done my best to garner such information as I need from the two or three suppliers I use.  So far I have been able to bore cylinders fulfilling the main criteria for such work, e.g. parellism, roundness, fine finish, adopting methods suggested by them.
I settled on Kennametal and have no regrets.
So far I have spent out a sum well within the limits set by SWMBO, and as far as inserts are concerned where I have bought packs of 5 I still have 3 or 4 of each type. Possibly enough to se me out.
Jerry
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Offline Baner

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Re: Insert Boring Bars - any hints or tips please?
« Reply #20 on: August 31, 2018, 04:14:08 PM »
Glad you found the info useful Stuart.

I managed to muddle GH Thomas's books. The one with Boring tools is called 'Model Engineers Workshop Manual'. Had a look around and it seems to cost a fair bit more these days than what I paid for it. :(
If you like I can probably scan the chapter on boring tools and send it to you.

Dave.

Offline jonesie

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Re: Insert Boring Bars - any hints or tips please?
« Reply #21 on: August 31, 2018, 05:29:08 PM »
i have that same set and they work great.i use them all the time.would highly recommmend.

Offline propforward

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Re: Insert Boring Bars - any hints or tips please?
« Reply #22 on: August 31, 2018, 06:16:45 PM »
Glad you found the info useful Stuart.

I managed to muddle GH Thomas's books. The one with Boring tools is called 'Model Engineers Workshop Manual'. Had a look around and it seems to cost a fair bit more these days than what I paid for it. :(
If you like I can probably scan the chapter on boring tools and send it to you.

Dave.

Thank you - I appreciate that and will take you up on the offer if you can do it. I ordered the other book you mentioned from the UK, but Model Engineers Workshop Manual seems very much more rare. I'll PM you an email address. If the file is large I can send you an upload link to use also.
Stuart

Forging ahead regardless.

Offline propforward

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Re: Insert Boring Bars - any hints or tips please?
« Reply #23 on: August 31, 2018, 06:19:43 PM »
i have that same set and they work great.i use them all the time.would highly recommmend.


This is very good to know - thank you.


Thanks everyone for your inputs - very helpful all of them. I've decided to "tread lightly" initially, and start with ground HSS rod (just ordered some). I may then order one of the nice HSS insert holder bars, but the ground blanks is an inexpensive starting route, which once I have had some success will give me confidence to go a bit more advanced. Most likely now is the time to make that tool grinding jig I've been promising to make for myself, which at the same time will be more practice before going to far on my engine castings.
Stuart

Forging ahead regardless.

Offline cwelkie

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Re: Insert Boring Bars - any hints or tips please?
« Reply #24 on: September 01, 2018, 01:51:51 AM »
A little late to the party but for what it's worth I very much second using the GHT holder for small boring bars and other cutting tools that only come to mind after you have the versatility it offers.  This holder is an extremely good solution for holding carbide boring bars such as those made by Micro 100; all it takes is an adapter sleeve to suit the bar's diameter.  They are pricey but they have become my go-to boring bars for small holes ... they are stiff beyond belief for a given diameter.

Besides - it's a nice little project!
Charlie

Offline zeeprogrammer

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Re: Insert Boring Bars - any hints or tips please?
« Reply #25 on: September 01, 2018, 02:34:57 AM »
I got the Accusize S06M-SCLCR2 / M2.5x6/T8 17211 from amazon.
Looks similar to the one you posted but about 1/3 the price.
I haven't used it much so I can't give a review.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline propforward

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Re: Insert Boring Bars - any hints or tips please?
« Reply #26 on: September 01, 2018, 02:53:23 AM »
Oh yes - absolutely. Definitely looking into that. I think that might be a good add. Going to try grinding a few HSS tools first, and go from there, but that accusize tool is a nice price for what you get.
Stuart

Forging ahead regardless.

Offline john mills

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Re: Insert Boring Bars - any hints or tips please?
« Reply #27 on: September 01, 2018, 01:30:54 PM »
it is good to see you are going to grind your own boring bars from high speed steel ,in small sizes they can be very sharp and cut very easily .can be used for small holes 1/4 " is not the smallest holes any hole for precise position should be bored even if finished by reaming.I use lots of turning and boring bars made with brazed on tips made from plain grades of carbide .they must be ground with the right type of grinding wheels.they can be shaped with small radii and can be very sharp and will produce good finish.mild steel shank can work as good as any thing at a fraction of the cost.when you see the shape on high speed steel that work you could try the brazed on tools.Most of the commercial  tools i have seen are only semi finished and need to refinish ground be for they can be used.The problem these days lots of tip are coated grades and don't suit silver soldering.I spent lot of time on milling machines  when i used lots of plain grade inserts seco s25m was a favourite of mine.with CNC machines then indexable inserts are essential  but at home and in manual machines often brazed on tips are very usefull . 

Offline propforward

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Re: Insert Boring Bars - any hints or tips please?
« Reply #28 on: September 01, 2018, 01:34:21 PM »
Yes indeed - and armed with some info that Baner kindly sent me, I have some new tooling to make. The excerpt he sent me is really thorough and helpful. It has an introductory passage that rings very true:

“I suppose that many workers start off with their first lathe and a “set of tools” which, in my case, were forged carbon steel and included a “boring tool” which looked like a miniature golf club, and was just about as useful for its purpose. Every attempt to use it involved grinding something off it somewhere so that, in the end, it resembled nothing so much as Harry Lauders walking stick! To give a beginner one of those tools and expect him (or her) to bore successfully any hole that comes along is enough to put him off for life. I can quite understand why so many workers adopt the  drill and “poke a reamer through” technique”.

Stuart

Forging ahead regardless.

Offline john mills

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Re: Insert Boring Bars - any hints or tips please?
« Reply #29 on: September 01, 2018, 01:51:23 PM »
50 years ago as an apprentice we started grinding tools instructors would grind drills so we could practice.
working as an engine re conditioner most of the machines were special and had there own sharpening jigs and lapping divices.line boring tools still hade to be ground brazed on carbide ,the pin borer was solid carbide .in those days indexable tips and tools were limited on what was available an the work i did then didn't have much to do
with them .I gess thats why as apprentices at school they spent a lot of time with what shapes were required . 

 

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