Yet Another Tangential Tool Holder

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Yet Another Tangential Tool Holder

This topic has 35 replies, 11 voices, and was last updated 3 January 2012 at 09:34 by michael howarth 1.

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11 October 2011 at 21:51 #76149
Sub Mandrel
Participant
@submandrel
After some thought and a frustrated attempt at making a tangential holder, I realised I could make one froma much smaller (1/2″ square) bar, as long as I didn’t mind angling the holder a little when cutting to a shoulder. Lot’s of brain ache in setting the angles (I used simple angle vice, set slightly skew-whiff to the X-axis of the mill and clamped the work at an angle to get a third degree of freedom. All done by eye! The cutter takes 1/4″ square HSS and took 1/16″ cuts in nasty stainless, giving a good finish with 4-thou feedrate. For size the clamp bolt is M4, cutter height is 5/16″ to suit my mini lathe.

I need to file down the end of the clamp a bit more to give better clearance when facing – I realise I don’t need such a big lip to secure the bit anyway. So here are the pics:

No drawings yet, but I could do some.

Neil
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11 October 2011 at 21:51 #11834
Sub Mandrel
Participant
@submandrel
… this one may be familiar!
11 October 2011 at 22:47 #76150
chris stephens
Participant
@chrisstephens63393
Good show Neil,

Welcome to the Tangential Tool Owners Club.

Proper clamps look so much better than the original (well if not original, shall we say the latest round of interest over the last few years) designs from USA using just a screw.

I have one general question, why is it that everybody who has one of these tools loves them but they are still not more widely known? When I used demonstrate them at MEX and Ally-Pally loads of people have come up and asked for details because they have never seen them before, little realizing that the idea is at least 130 years old. Perhaps some folks are just slow learners?

chriStephens
11 October 2011 at 23:03 #76151
Geir
Participant
@geir
Very nice, looks solid and clean. A drawing would be much appreciated.

Geir
12 October 2011 at 12:44 #76160
Ian S C
Participant
@iansc
There is one described in vol 1 (1898) of Model Engineer. Ian S C
13 October 2011 at 22:03 #76224
Sub Mandrel
Participant
@submandrel
I thinned down the end of the tool to 1/32″ and took a skim from the back of the clamp clamp is hard up against the whole length of the toolbit. It works for facing now.

I managed a 3mm(!) cut in mild steel on the mini lathe, but only took a short cut as I worry about the motor working that hard at low revs.

Geir,

I’ve made a start on a drawing. It’s amazing, it HARDER to draw one than make one, especially if this is going to be a drawuing that can be followed.

I discovered a large slab of 1/2″ steel in my bandsaw though. I fancy taking a 5/8″ strip off the end to make a non-cranked version. If I do I’ll photograph each setup.

Neil
22 November 2011 at 19:23 #78353
chris stephens
Participant
@chrisstephens63393
Hi Neil,

Since you mentioned Tangential tools on the other topic, I thought I would tell of a new use I have found for mine. I now use the tool to rough turn car gearbox shafts, where the needle rollers have worn part way through the case hardening, so that a new bearing sleeve can be fitted. Saves using very expensive Titanium Carbide tips for the rough stuff, so that I now only have to use them for the finish sizing.

chriStephens
23 November 2011 at 04:07 #78390
BERTO
Participant
@berto
Hi , I have been using one of these for a couple of years now and still think it is the best thing i have purchased for my lathe .

The company i purchased it from ais Eccentric Engineering .

I watched a clip on youtube and was hooked !

They have now revised the design and i urge you to look at thier website as it may give you some more ideas as to making your own .

Unfortunately they will not be adding the smallest version to the modified line-up at the moment so if i want these for my lathe i will have to make them myself .

Regards .

Ian.
23 November 2011 at 08:37 #78396
ady
Participant
@ady
I bought a cheep one off fleebay and it was pretty clever, and very useful.

Unfortunately it had been made out of some kind of cast metal and the neck snapped after about a week when I got a dig-in.

So a good quality one is pretty essential, whether you make or buy.

I can see Neils grin from here as that swarf falls away, a nice job.

Edited By ady on 23/11/2011 08:38:57
23 November 2011 at 12:12 #78405
chris stephens
Participant
@chrisstephens63393
Hi Guys,

Nice to see that the commercial one’s designer has seen sense, he must be reading this site.

chriStephens
24 November 2011 at 19:51 #78502
Sub Mandrel
Participant
@submandrel
I can’t understand why they advertise the smallest one for mini-lathes, when the second one up is for 5/16″ tool height. For my mini lathe I normally use 5/16″ square HSS and single thin shim, so i imagine that their second toolm would be ideal?

Neil
25 November 2011 at 00:11 #78524
BERTO
Participant
@berto
I believe it is to keep tool overhang to a minimum .

The larger unit has more material behind the cutting tool and this means there is a larger distance between tool tip and toolpost all be it probably around 10mm maybe a little more .

There are some benifits to the smaller unit as the cutting tool is small and easier to work with on small items , it does though get hotter quicker than a larger piece of tool steel as it simply has not got the surface area to sink as much heat away.

You can also use these to cut threads as the grinding instruction come with the toolholder and seem reasonably simple .

Regards..

Ian
25 November 2011 at 00:23 #78527
chris stephens
Participant
@chrisstephens63393
Hi Neil,

Or you could just make your own for a few shillings and get it to suit your lathe exactly. Do remember that the tip height can be adjusted much more easily than standard tooling, no more shimming. There are loads of plans about, or you could try the mini-lathe group.

chriStephens
25 November 2011 at 19:23 #78571
Sub Mandrel
Participant
@submandrel
Hi Chris – er… gentle reminder – that’s my home made one in the picture at the top of this thread

Ian – good point.With my design I found you can’t really turn above 2 1/4″ diameter, another 1/4″ or so would be handy. With plain HSS I use a right hand tool sideways to be able to go up to the full 7″ diameter, but you can’t turn very thick things that way..

I found a bit of 1/8″ HSS the other day, so I might make a small one as well.

Neil
30 December 2011 at 14:22 #80830
Billy Mills
Participant
@billymills
Found a very interesting description of a tangential toolholder in Turning & Mechanical Manipulation Volume 2 by Charles Holtzapffl ( reprinted by Tee Publications).

Page 535 shows the device with a round toolbit ground with a single flat and then the author’s

version with a triangular bit. The original was used in the Portsmouth Block Factory (1802) to turn wrought iron pins. Another version had a centre hole through the bit and was used for wood turning. So Marc Brunell and Henry Maudsley could well be the source of the Tangential tool concept around 1803 when the factory started production so it may have been going for over 200 years!

The same book p996 has further material, an illustration of a toolholder on p998 is almost identical to the pictures in this post, the book was first published in 1843!

The three volumes cover a vast range, the sections on screwcutting and the problem of producing leadscrews are very interesting.

Billy.
30 December 2011 at 15:42 #80832
chris stephens
Participant
@chrisstephens63393
You mean this one;

http://www.archive.org/stream/turningmechanica02holtuoft#page/998/mode/2up

I tend towards the notion that the true grandfather of the tangential tool is the swan neck as shown here;

http://www.archive.org/stream/turningmechanica02holtuoft#page/984/mode/2up

but some inspired chappie in antiquity thought to make a holder that takes a small piece of the best tool steel in a cheaper metal holder. I doff my metaphorical hat to him.

chriStephens

PS it just goes to show that Model Engineers are a bit behind the times, “it’s been about for 200 years, so perhaps it’s nearly time to try one” could be the watch word(s)

Oh, and if I don’t speak to any of you before the coming big day, let me wish you all a Happy Easter.
30 December 2011 at 16:35 #80833
Billy Mills
Participant
@billymills
No Chris, it’s before that at p535 , the page is headed Brunel’s Cutter. This is the earliest that I’ve seen at around 1803 when the Block Works started making blocks.

Happy New Everything,

Billy.

PS for those that have not seen the books they contain loads of interesting ideas.
30 December 2011 at 16:49 #80834
michael howarth 1
Participant
@michaelhowarth1
Has anyone ever invented a tangential parting off tool….or is the geometry all wrong ?
30 December 2011 at 17:58 #80843
chris stephens
Participant
@chrisstephens63393
Hi Billy,

Ah ha, seems like another project for the “tuit” list.

Hi Mick,

Never seen one, but that means not a lot. There would be some advantages, especially if normal bevelled parting blades were used but standing up, wide edge forward. Depth of cut would naturally be limited, but for small work it might just work.

Just had a nudge from the memory banks, Ifanger make them.;

http://www.ifanger.com/fileadmin/Webmaster/Produkte_EN/B_01/020111_Parting%20tools.pdf

Looks like another reason to mill some HSS!

chriStephens
30 December 2011 at 19:58 #80863
Jim Greethead
Participant
@jimgreethead
Sudden thought: would it be possible to braze a carbide tip onto a piece of 1/4″ x 1/4″ mild steel to use with a tangential tool holder?

Maybe a discarded indexable tip ground on a green wheel.

Might have a go when the dizzy season slows a bit.

Jim
30 December 2011 at 21:56 #80876
Mark Bus
Participant
@markbus97330
Hello everyone,

Here in the States someone has developed a new toolholder.It’s called the Wimberley or Wimberly toolholder. If you Google that in you can get to his website.

Mark
31 December 2011 at 00:14 #80884
chris stephens
Participant
@chrisstephens63393
Hi Jim,

I have not tried to braze a lump on, but do use a solid square piece of carbide instead of HSS, it works particularly well on cast iron and when turning down case hardened steel gearbox shafts.

chriStephens
31 December 2011 at 00:49 #80885
Billy Mills
Participant
@billymills
The interesting bit about the Brunel Cutter is that the toolbit is round. The Appendix article shows a clearance flat ground almost vertical so that the cutting edge is straight, not oval. It might be that the flat lasts longer than the oval. Very simple to do, old drills spring to mind.

The Holtzpeffl triangular tool is very much like a parting tool however there is the issue of the length of unsupported blade being longer than a conventional approach however if it cuts as well that could be well worth trying as the cutting forces are along the blade rather than across. The basic tool must have merit, Charles Holtzapeffl was a very clever man and a very experienced lathe maker.

Anyway following Brunel and Maudsley’s footsteps some 200 years later is interesting. The Block Factory is well described on wikipedia.

Billy.
31 December 2011 at 01:17 #80886
Billy Mills
Participant
@billymills
Hi Mark – welcome,

The name is Wimberley, the website is here. I think that there is very little difference between this tool and all of the others given that it all started 200+ years ago. If you have a look back on the Tangential tooling posts there has been quite a bit said about this kind of tooling, most of the “angles” have already been tried.

With such a long period between conception and rediscovery it is possible that something has been lost in the years between. Brunel and Maudsley were both brilliant engineers, they were setting out the World’s first specialised “production line” so when they did something there is every chance that we can learn something from their methods. In this case it could be the extreme ease of maintaining and changing Brunel Cutters for wood and iron.

Billy.
31 December 2011 at 01:34 #80887
chris stephens
Participant
@chrisstephens63393
Hi Billy,

I have just watched the sharpening video for the Wimberley, and whilst I applaud the chap for trying something “new”, sharpening of a Tangential wins hands down. Grinding one face using a jig compared to two, or three, on a specially marked grinder rest has to be easier.

chriStephens
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