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Wimberley lathe tool holder

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alan frost08/11/2014 01:56:25
137 forum posts
3 photos

My interest was piqued by a comment in a recent thread about the superiority of the Wimberly tool holder over even the diamond tangential tool holder. Looks to me as if the comment might be accurate. It looks very "makeable" but its all time and I have the usual time overdraft. Anyone know of a UK supplier. I have n't been able to locate one after a cursory ( meaning I swore a lot) search.

Vic08/11/2014 10:38:51
2255 forum posts
11 photos

The Wimberley presents the toolbit at a completely different angle and requires several faces to be ground on the toolbit.

Tangential tools only require one face to be ground.

The Wimberley looks easy enough to make though.

http://www.wimberley-tools.com

Vic08/11/2014 10:49:19
2255 forum posts
11 photos

Manual here if it helps:

http://www.wimberley-tools.com/user-manual-110309.pdf

Jon Gibbs08/11/2014 10:54:04
738 forum posts

I may be wrong but turn the Wimberley through 90 degrees and it looks as if you've got a presentation that is almost identical to the tangential tools - but perhaps switched from right-hand to left-hand?

Michael Gilligan08/11/2014 11:16:17
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14011 forum posts
608 photos
Posted by Vic on 08/11/2014 10:49:19:

Manual here if it helps:

http://www.wimberley-tools.com/user-manual-110309.pdf

.

Many thanks for posting that, Vic

MichaelG.

Michael Horner08/11/2014 20:27:36
202 forum posts
55 photos

Hi Alan, can't help with a supplier. Sorry.

Vic. Read through the manual and picked up on the extract below. I have noticed this on my tangential tool (one I have made). I have moved on to Crobalt but the cutting flank does seem to scuff up but is more durable than m42 HSS. Normal HSS was a waste of time. Anybody else have this issue?

Cheers Michael.

"When I was using a tangential toolholder, I was very dissatisfied with flank wear. In order to clean up flank wear, you cannot grind the flank; you must grind the rake surface and quite a bit of material may need to be removed. I would be interested to know if others have had this same experience".

Vic08/11/2014 20:42:13
2255 forum posts
11 photos

I'm using plain old HSS in my Tangential holder and it's been fine for most things. The hard skin on Cast Iron bar was an exception though! I've got some solid carbide rod I could use in one of my holders for hard stuff but it's difficult to sharpen even on a green grit wheel.

Versaboss08/11/2014 21:39:37
417 forum posts
50 photos

As it was possibly me who provoked this thread, I'm obliged to show a bit more...

I tried my luck with the famous tangential toolholder also, but had some difficulty with the clamping - the screw or a part of the holder always coming in conflict with the work. So I started making a Wimberley clone. The first one was mostly scrap, then they became (slowly) better... I admit that the HSS bit is not as easy to grind as for the t.t.h., but mainly because I upscaled up to 10 x 10 bits. The original W.t.h. uses a tiny (3/16" I think) bit, a size I don't even think of using!

The easiest way to make one is starting with a bit of steel, about 25 mm square and 35 mm long. Mill one side off at an angle of 20 degrees, then mill the tool slot diagonally on this side, also at 20 degrees. A vise with a rotating base helps a lot for that - or set the vise oblique on your mill table. Next is drilling a hole, in my case 10 mm, in the upper left corner of the steel block, and stop when the drill reaches the tool slot. Don't forget the holes fot the clamp screws - either just vertically or inclined so they are perpendicular to the tool slot. Finally silver solder the stem into the 10 mm bore. You can use a square one turned down to 10 mm, or say a round 12 mm, which you mill flats on after soldering.

A word again to the tool bits: I found the best method for grinding the steep primary angle is using a thick spacer on the horizontal grinder table (which usually is around axle height). The height should be so that the grinding point is between 1 and 2 o'clock on the wheel, This should result in an angle of about 28 degrees (20 for the holder, 8 for the relief).

So now some pictures:

dscf1221 (medium).jpg



The first two usable holders, for 10 and 6 mm bits.

dscf1222 (medium).jpg


The smaller, front view

dscf1226 (medium).jpg

A larger clone for mounting directly in a Tripan holder, with 10 mm bit

dscf1229 (medium).jpg

here seen from the tool bit side.

Well, enough for the moment!

Kind regards, HansR.

alan frost08/11/2014 22:38:02
137 forum posts
3 photos

Thanks for inputs. What I liked about the Wimberley was the holder seemed far less likely to get in the way than with the t.t.h and it seemed so suitable for chamfering and , "round overs" as the Wimberley site calls them. Another tool change saved.

As I said it seems very makeable but its all time and I suspect I shall carry on with insert holders and a QCTP unless I can get a ready made one. Not being a modeller I don't do that much turning despite having several lathes .That's not the paradox it sounds as I just like lathes and other m/c tools for themselves , and restoring them, and as a sort of investment. May sound odd but for instance I have a pretty well tooled CVA toolroom lathe (£ (half an ML7)-very cheap and delivered free ,quite important at a ton and a half , which I hope to get into the £2000 class with a good restore and paint job . Its a runner but I might yet find problems when I really get into it but there ain't much that ain't fixable..

My trouble is a massive time overdraft and I hardly ever sell anything . Hence my current 100 sq ft shed build.The lathes were quite busy converting temporarily my S/H Honda power barrow into a mini "readimix bowser" for that job. I also know quite a few the same who would say "snap". Wimberleys etc promise to be time savers but they also require time to make. Suppose if I keep chasing my tail I might eventually vanish up an orifice but I'm enjoying it. To paraphrase a fellow traveller "You might be doing plant engineering mainly but its a lot more fun when you're doing it on a Holbrook, CVA, Smart and Brown or what have you."

Alan

Bazyle08/11/2014 22:38:36
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4724 forum posts
186 photos

You could simulate this with one of those common milling flycutters witha round shank and a corresponding round boring bar holder. Might try that.

Clive Foster08/11/2014 23:31:32
1840 forum posts
59 photos

The Wimberly geometry is essentially that produced by the left hand bend version of the old style J&S, Armstrong et al square toolbit holders. The angles may well be a little different but that is hardly important given that, in general, pretty much any reasonably close angle will do so long as the tool is good and sharp. Correct and best angles are more about tool life and chip control e.g. breaker grooves than actual cutting.

Novel it isn't. The modified and multipurpose tip geometries in the manual are anything but new and can, of course be put on a conventional, flat mounted tool too. As I recall matters I was shown this sort of thing way back around 1972 at RARDE by either Big Den Everitt or Eric Hopekirk. Both considered it a rather old fashioned emergency expedient for when tool steel was in short supply. In their view, and mine ever since, you grind the tool angles to suit the job and change tools as required not struggle around with a sort of do anything tool. Rotating the tool post to change the cutting point or do a quick'n dirty chamfer could be vocabulary enhancing!

"Automatic" setting of projection when tip height is correct is a feature of all toolholders with built in rake.

Clive

Vic09/11/2014 09:43:06
2255 forum posts
11 photos

It is indeed reminiscent of the old Armstrong holders but once again the angles used are different. Probably of little interest to production turning but once again it could be of use in the hobbyists arsenal of turning tools, particularly those that don't use insert tooling.

Michael Gilligan09/11/2014 11:50:56
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14011 forum posts
608 photos

Apologies if this is drifting slightly off-topic ...

Those with an interest in unusual tool-holders might like to look at two of the patents that I mentioned in this thread.

MichaelG.

Jon Gibbs12/09/2016 11:29:55
738 forum posts

Since this thread I've made my own Tangential toolholder and experienced the main problem cited by the proponents of the Wimberley i.e flank wear and not being able to simply grind it off directly.

So, I took some time to read up on the Wimberley and have made my own. This turned out to be a bit tricky as it involves a compound of 3 angles rather than the 2 of the tangential toolholder and mine involved silver soldering the head to the stem as shown by Versaboss above.

As I see it the BIG advantage of the Wimberley is pretty clear when used in anger in conjunction with a QCTP. It doesn't extend below the bottom of the QCT holder and so there's no need to unmount the toolbit from the holder or QCT holder to sharpen it. A quick touch up on the grinder can return you to the lathe PDQ - grinding off the flank wear easily.

To sharpen the Tangential toolholder obviously you need to remove the toolbit completely and mount it in the sharpening fixture before remounting it in the toolholder which all takes time.

The disadvantage of the Wimberley is that there's no single grind. The optimum grind for hogging material isn't suitable for use for square shoulders and you really need the second grind from the manual (http://www.wimberley-tools.com/user-manual-110309.pdf) which means you either need 2 Wimberleys or to be swapping toolbits around losing some of the advantages in the process.

So, I've come to the conclusion that possibly the ideal is one Wimberley and one Tangential toolholder. The Wimberley really excels at shifting material and the Tangential is great for squaring up shoulders.

HTH

Jon

Neil Wyatt12/09/2016 12:21:59
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16568 forum posts
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Does anyone else feel they suffer from the Wimberley extending too far out in front of the toolpost, or are you using lathes of above 3 1/2" centre height/long cross slides?

Neil

Neil Wyatt12/09/2016 12:23:12
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Moderator
16568 forum posts
687 photos
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Also, my tangential problem has been cheap HSS chipping away from the tip when used in a tangential holder.

With decent HSS this isn't an issue.

Vic12/09/2016 13:09:41
2255 forum posts
11 photos

I bought some decent HSS from Cromwell tools when it was on offer and it's proved to be pretty good. I think it's something like 8% cobalt?

MW12/09/2016 13:41:22
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2050 forum posts
51 photos
Posted by Vic on 12/09/2016 13:09:41:

I bought some decent HSS from Cromwell tools when it was on offer and it's proved to be pretty good. I think it's something like 8% cobalt?

I would concur, a former british aerospace toolmaker recommended them to me when i worked under him, they are a bit pricey but they do deliver.

Michael W

Jon Gibbs12/09/2016 13:55:40
738 forum posts
Posted by Neil Wyatt on 12/09/2016 12:21:59:

Does anyone else feel they suffer from the Wimberley extending too far out in front of the toolpost, or are you using lathes of above 3 1/2" centre height/long cross slides?

Based on my homemade holders I think the two are pretty similar in terms of overhang but that's based on two samples of one wink

Here are mine side-by-side...

Obviously the Wimberley doesn't suffer from "hang-down" as well but is potentially less rigid because it has a silver-soldered joint in my version.

It's worth noting that the clearance angles and back-rakes of the two geometries are also different.

The Wimberley has a roughly 20 degree back rake (14.4 degrees in each direction) and 8 degree clearance (variable but this is the recommended grind) whereas the Tangential has a 13 degree backrake (30 - 17 (12 degrees in each direction)) and 12 degree fixed clearance.

I also try to use M35 (5%) or M42 (8%) Co HSS toolbits

Jon

Edited By Jon Gibbs on 12/09/2016 14:18:07

Vic12/09/2016 14:17:15
2255 forum posts
11 photos

My mistake, the Cromwell bits are 10% Cobalt.

**LINK**

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