# 3 WAy TOOLPOST for lathes



## bazmak (Sep 17, 2015)

For everybody who does not have a QCTP like me and probably uses a 4 way
It gets too cluttered,the most tools i mount at the same time is 2 and then its regular changing and packing etc.In this months edition of Model Eng W,shop
i saw this 3 way and decided to make it,tailored to suit my specific range of tools,then if it prove useful you can make more and you have a QCTP but 3 at a time.I had a slice of cast iron 32 thk x 105 did.IDEAL.I wanted to use steel but 
ihad the CI and its easier to machine
I first drilled and bored in the 4 jaw sc and faced to thickness
I then marked out ,dims to suit the lathe and hacksawed to shape
I wanted to rough mill in situ in the lathe (see video on other thread SC4 )
I then set up on the angle plate and finished milled on the mill the 12w slot x 11mm deep was dimentioned to give me centre height for 4 no homemade tools
I then drilled and tapped for M6 capscrews etc.Ohotos are self explanatory,time will tell if this familey grows.I can see parting off tools and boring bars with a HSS set and ny new diamond tool


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## xpylonracer (Sep 18, 2015)

That's a very old design, Dave had this serialised in ME about 30 years ago, those who built them soon found 3 is better than 4.
Emgee


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## bazmak (Sep 18, 2015)

thanks for your reply.It is the first time i have seen it and saw its
potential.Having a number tailored to suit a range of tools
makes it a hybrid QCTP regards barry


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## goldstar31 (Sep 18, 2015)

I have tried to post in reply to Baz's interesting contribution- without success. Any comments would be- err- welcome

Norman


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## goldstar31 (Sep 18, 2015)

Merde! Merde, Merde!


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## bazmak (Nov 15, 2015)

I found the 3 way post very successful and used it all the time.With 2 tools loaded in the 4 way i just swapped toolposts and so decided to make another
to give me more scope as a hybrid QCTP.This one was made the same but from mild steel not cast iron.Photos and text self explanatory.Has anybody out there made/use one ??


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## deverett (Nov 16, 2015)

I made 2 4-way toolholders to the GHT design.  As usual with GHT tools, it was very well designed.  It was extremely rigid and had positive indexing stops.  My idea was to have one loaded with general purpose tools for ferrous materials, the other for non-ferrous metals.
In practice, I very rarely changed the toolholders over because I had all the tools with pre-made up packing easily to hand and it was just as easy to change the individual tools and packing as change the toolholder.
Wish now I'd kept the old system, but reluctantly, I changed them for a QCTP of the Dickson type.  Having said that, the 3-way toolholder seemed to have a lot of advantages over the traditional 4-way, as bazmak has discovered.

Dave
The Emerald Isle


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## bazmak (Jan 30, 2016)

I found i was using the 3 way tool all the time and the 4 way loaded with 2 tools .The 3 way is more labour intensive than the 4 way so decided to make
a 4 way/2 way dedicated to parting off with 13x2.5 blade and boring with my set of 10mm boring bars.Any more for my family will probably be on these lines



[URL=http://s1327.photobucket.com/user/bazmak47/media/two%20way%2004_zpsmjsc6tpm.jpg.html]
	







[/URL]


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## compressor man (Jan 31, 2016)

Bazmak, that toolpost with the slot for the parting tool is among the best ideas I have seen in a long while. I am going to try and make one of these for my mini lathe. 

I have been planning to make a 4-way tool post for my brothers Craftsman lathe to replace his lantern style post. I have been wondering though, is there a trick to determining the height in which to cut the slot to hold the cutting tools? Surely with all of these great looking tool posts here someone has discovered a bang up way to find this out.

Chris


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## 10K Pete (Jan 31, 2016)

Height/size for QCTP slot? Pick the biggest tool you'll use for the machine
and then make sure the holder will allow that size tool to be centered up.
Then add some more!

Pete


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## compressor man (Jan 31, 2016)

10K Pete said:


> Height/size for QCTP slot? Pick the biggest tool you'll use for the machine
> and then make sure the holder will allow that size tool to be centered up.
> Then add some more!
> 
> Pete




I think I did a poor job of explaining my question. I am wanting to make the slot so that a cutting tool (in this case a 5/16) will be at the right height when placed in the slot and tightened down. I was wondering if there was a clever trick for determining that height.


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## 10K Pete (Jan 31, 2016)

Well, there are really two ways to mount a tool. I should say two sides of
a tool to choose from, commonly. The bottom, which is the 'normal' way,
and the top, which is, I think, the better way. 

All the QCTP holders I know about have a slot for the tool and the set
screws are through the top of the slot. So the tool registers on the bottom
of the slot. That means that the holder height is different for each tool size
used.

Let's do it the other way around and use the top of the slot to register the tool
bit, and put the set screws through the bottom.

Now any tool put in that slot registers the same, within some minor adjustments
for the actual placement of the tool edge. But no compensation is needed
for the bit shank size!!

Ok, now how to determine the 'right' height. Let's assume you've put a blank
holder on the tool post. For the first case the holder needs to be set high
enough so the bottom of the intended slot will be below the center line
by the thickness of the thinnest tool that will be used. If it's a 5/16" tool
then the bottom of the slot needs to be 5/16 below the lathe center line.
There needs to be enough adjustment so the tool can move up to allow
for the tool point moving down when sharpened.

For the second case the holder needs to be set low enough so the top of the
tool will be at the lathe centerline, with enough adjustment to go up when
the tool is sharpened.

So, it all references to the lathe center line. That line will determine, along
with the dimension of the tool, where the slot is cut. It's simple maths
and takes a lot less time to figure out than its taking me to type this!!

So for your 5/16 tool, put the holder on the post. Using a center in either
end of the lathe, mark the holder for the center line. Then mark the other
side of the slot 5/16 lower than that. Cut slot.

I've never typed this much! Sorry.
Pete


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## bazmak (Jan 31, 2016)

all i did was determine the height from the top of the compound or uside of the toolpost.- the tool dim gives the dim from the bottom of the tool post to the bottom of the slot.On the sc4 i needed 18.3mm from underside of tool post to tool centre height.I set the 12.7 slot at 2o for top rake and tool at correct height with the blade projecting nom 15mm.Pushing the tool in or out changes the tool height slightly but not enough to worry about
The 18.3mm is now my constant for tool height.For a 10mm tool the height from bott of toolpost to bottom of slot is 8.3mm.I made it 8mm which allows for slight shim if need be
However its not important.I spend time getting the tool height right and then leave it in.A no of tool holders each holding a no of tool and they are all set correctly,i just change tool holders


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## goldstar31 (Feb 1, 2016)

Opinions will always differ. Such is the challenge of model engineering!

I agree with Bazmak especially about his three way tool holder. It avoids stabbing hands when old and using a small lathe! 

However, for somebody less experienced than Baz, I would suggest the old fashioned system of building up tool holders out of mild steel blocks and using bolts to join the bits up. Dear old Sparey described something similar in his Amateurs Lathe book  and I've still got a rear parting and lathe tool thing  which was built up to the articles of Martin Cleeve.   When push comes to shove, you can add shims or machine and spend precious little money in the process.   The trick, I believe, is to reduce the characteristics from some cheap jack, badly machined QCTP.  OK, I have one that came with my 'new' little ML10 and will have to discover whether this one is suitable for machining or merely aiming at the neighbour's cat!

Again, in Pandora's Box, there is a Cleeve swing boring tool holder that poor old Kenneth C. Hart took out a provisional patent. yonks ago. Still available from Hemingwaykits and described in Cleeve's Screwcutting in the Lathe.  Again, it is fabricated. Also in Pandora's Box of goodies is a rear parting tool but, woe trice woe, it isn't canted as in my George Thomas one which has moved from lathe to lathe -over the years.

My opinions, of course.

Norman


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## bazmak (Feb 18, 2016)

Changing the tool posts is very easy so I machined up a couple more blanks
with the idea of of machining the stations as I need them
I had bought a set of 9 boring bars and at a later date bought a boring head
This came with another set of boring bars.They would get little use in the boring head so I machined a station on the 4 way to accept 12mm dia bars
now they will get much more use on the lathe for recessing et

c


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## xpylonracer (Feb 19, 2016)

Hi Bazmark
You could turn and then slit lengthwise an eccentric bush so all tools could be used from the same holder by rotating the bush to bring the tool to centre height. The existing screws would clamp the tool shank by closing the slotted bush.

Emgee


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## bazmak (Feb 19, 2016)

I agree emgee,however there is no need.The larger boring bars are
concentric with the 12mm dia and automatically are on centre height
The smaller boring bars are eccentric to the 12mm dia and can be rotated
to achieve centre height,and by raising the nom 1mm or so also produce a top rake for the tool.Will let you know my thoughts when I start to use them


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## goldstar31 (Feb 20, 2016)

Barry,
          I've ticked a 'like' because I have an eccentric boring bar which you have suggested.
Mine- no it is not 'mine' comes from the George Thomas book.  GHT in his usual pedantic way, could slide the boring bar to minimise vibration.  

Having said all this, I also have a Martin Cleeve Swing tool holder.  It was a thing which I always wanted to try but continued family illness and recent death have put things back.  However, one materialised with the purchase of a very second hand little  Myford ML10.
The lathe itself has to be collected. 

Gulps a little but I've just blown the inverter on my Myford Super7B and I'm returning it to single phase for the time being.

Makes a change from the complexities of Probates, Deeds of Family Variation and Enduring Powers of Attorney - in 3 languages.  

Continue with your accounts please. 


Cheers

Norman


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## goldstar31 (Feb 20, 2016)

For those interested, this was a David Lammas design and originally appeared in Model Engineer. After David died, a Chris Heapy  put this and many other useful things on the net. Then Heapy gave up and a Japanese gent traced the article again and it is on the net . In my opinion, the Heapy series of articles would eradicate a lot of requests being repeated and repeated. For a newcomer, it is gold dust.

What there is or was the drawings for three different sizes  and the castings  were still being sold by Blackgates Engineering by my old friends - Phil and Jackie. 

Norman


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## xpylonracer (Feb 20, 2016)

Norman

The Dave Lammas designs included a Sine Table, I bought the castings for that from a small foundry in Scotland, they did most of DL castings at that time, also bought a slab of cast iron to make a boring table for my Bantam lathe, good quality easily machined castings.

Emgee


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## bazmak (Feb 20, 2016)

any drawings or photos please.Just a note,i tried out the smallest boring bar
boring to 15dia from 13 dia hole.I had to grind the tool at the underside
to give clearance at these small sizes and also grind more front and side top rake.I assume when I use the larger sizes on larger diameters it will not be necessary to grind additional clearance
Also on a previous toolholder I fitted the TP in posn and drilled/bored from the lathe to get centre height exactly.This caused problems with the cutting tip
being higher than CL with these boring bars,so I made a 12dia boring bar
with HSS insert for this station which also uses the 10mm dia boring bars
hopefully I now have enough of all I need to bore.Boring but true


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## goldstar31 (Feb 20, 2016)

Barry,
         I attempted to resurrect the Martin Cleeve articles as my wife's old associate Dr Bill  Bennett did with George Thomas's.
I ran foul of copyright with Model Engineer and simply suggest where the information can be found.

As I said, I acquired the Cleeve tool recently and my boring gear is probably a lot smaller and neater from GHT's book- the Model Engineer's Workshop Manual. My opinion- for what it is worth- is that Thomas designed his stuff expressly for model maker's lathes whereas what you get 'from the shop' is probably clumsy and difficult to sharpen. Quite a lot of my so called inserted tool tips are broken little centre drills. I haven't quite got the hang of how to 'do them' on my tool and cutter grinders.  

My tooling- incidentally- is not exhibition quality but suffices for my modest needs.


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