Cobbling some bits and bobs together!
|Henry Brown||28/01/2020 20:23:32|
107 forum posts
Now I have a mill I’m thinking about sharpening the ends of cutters. I’ve looked at the various kits that are available but they seem to be very expensive and in some ways over complicated so I got to thinking what I needed and what I could cobble together.
An X – Y axis would be good and some method of setting the clearance angles, a smallish (0.25Kw?) 240V single phase electric motor to mount a cup type grinding wheel on and to index the cutter I thought I’d get a couple of Stevensons blocks so I can use my ER32 collects as that covers most sizes I presently have.
I’ve done a bit of ebaying and come up with this for £23.
It may want a bit of fettling on the X – Y axis and I’ll remove the vice part and add a piece of flat plate with a guide for mounting the Stevenson blocks should be easy enough to engineer. It seems a good way to get the basics and won’t break the bank if it doesn’t work. ARC have the Stevensons blocks so next time they have an offer I’ll order them.
The Worden T&C rest seems to have the way forward for the clearance angles so I’ll need to think how they can be incorporated with the X – Y axis device. When I get it I’ll make the decision how to do this.
I can easily fabricate some sort of frame to mount the motor and X-Y table.
Any suggestions for a relatively cheap motor would be appreciated and, of course, constructive comments before I spend any money!
|Clive Foster||28/01/2020 21:34:24|
|1992 forum posts|
Don't even think about a cheap cross vice for X-Y movement. They are very sloppy and the screws far too coarse for a sensible job. The effort involved to get suitably good results is totally disproportionate to the gainProbably too much movement anyway.
I'd be thinking in terms of simple rod, bearing and carrier systems which can be found insanely cheap via E-Bay. This one uses 6 mm diameter rods and is around £20 for 8" / 200 mm lengths.
Loads of similar choices. Even "proper" flat bar and ball bearing carriage systems of adequate strength can be found for about twice the price. That said I'd use something like the Igus range with plain, plastic bearing flat top carriers riding on wider alloy bases which, frankly, is both expensive and overkill. But nicer.
If you only want to sharpen and, possibly, re-gnash the end faces there have been a goodly selection of simple mount designs to use in conjunction with an ordinary bench grinder published over the years in ME, MEW and other magazines. I started to collect designs before finally deciding to sort out the Clarkson I'd obtained "velly, velly cheap". Hafta say that overall I felt the Brooks design published in MEW back in early 1993 was the one most worth making as being close to a proper, basic T&C grinder without extreme effort. If you go that way consider buying in rails and bearings, won't need the carrier extrusions tho', similar to those in the picture rather than making the functionally identical components shown in the Brooks drawings.
Or you could just follow the Howard Hall system described in his book. Simple, pretty comprehensive and effective.
If I wanted to do something quickly and not too expensively I'd be looking at the Stevenson's ER32 Sharpening fixture from ArcEurotrade **LINK** . Unfortunately out of stock right now but if you are in a hurry the design details of this sort of cutter carrier be found pretty easily on the internet. Albeit with a 5C collet. Frankly if you seriously wanted to home brew there is sufficient detail on the Arc site. To me home brew would be way too much effort to save £55 these days. But 30 years back ...
Edited By Clive Foster on 28/01/2020 21:42:28
|Clive Foster||29/01/2020 01:33:16|
|1992 forum posts|
On further reflection there is no real need to use collets to hold the cutters as the number of shank sizes is limited. Clarkson use simple bored cylinders made a nice fit on the shank with a grub screw or two to hold them.
If its good enough for the pros its good enough for us.
Never seen the sense of using relatively expensive collets in relatively expensive holders to position cutters close to grinding wheels where they will inevitably be showered with abrasive dust. Doesn't seem a good way to treat them.
Plain cyiinders are easily made in the lathe so replacement is simple if they do suffer.
619 forum posts
I would stay clear of those Asian cross vise, X-Y tables, you want precise movement in all planes with no shake or wobble.
You want a very fine in feed, an absolute maximum of a thou, and a very coarse cross feed wiping across the wheel, why some T&CG's have a handle rather than a wheel.
I agree with Clive's points above as a starting point.
|1158 forum posts|
I have one of those Asian cross vises, and I agree with Clive, mine too is sloppy and is seldom used. Harold Hall has several pages on Tool & Cutter sharpening, see here, his simple grinding jig is not difficult to make. If you already have ER-32 collets, Stevensons blocks work very well, I use mine often.
|Henry Brown||29/01/2020 08:03:01|
107 forum posts
Thanks for all your replies! Ok, so I'll ditch the idea of the X - Y vice and have a rethink. I hadn't realised the rod and bearing system was likely to be a cost effective solution so will investigate that further.
I am very aware that grinding tools subjects the associated equipment to fine grinding dust, that was the downside as I quite enjoyed the setting up and subsequent finish on the freshly sharpened tools! I was thinking back to my days in the tool sharpening room back when i\ was an apprentice and we used a proprietary device, I can't remember the manufacture, similar to what I described and it did have a lever that took the cutter past the wheel at what ever speed was required.
I hadn't really wanted to use the bench grinder as mine tends to be rather abused although another one would be a cheap way to do this, maybe I'll look out for a more powerful one and use the one I have for this with new wheels.
I do have Harold Halls book on cutter grinders, I needed a refresher course after some fourty odd years away from the tools. I'm fine with grinding my own lathe tools as I did that a lot anyway as we had lots of applications where standard tools just wouldn't do.
So, again, thank you for the replies, watch this space as they say...
|Russell Eberhardt||29/01/2020 08:14:42|
2531 forum posts
+1 for the Harold Hall T & C grinding jig. I made one years ago and it does everything I need.
|John Haine||29/01/2020 08:19:04|
|2833 forum posts|
Now you have a mill tha Acute grinder is a nice project. Upgrade your grinder with a CBN wheel.
|355 forum posts|
Give it a try. Make a new fine leadscrew if you need it. If it does not work you have learned a lesson, not lost a lot of money and have some parts you can repurpose.
See here >> Why
|Clive Foster||29/01/2020 10:32:37|
|1992 forum posts|
Generally the various "home brew" cutter holder systems will work just as well on a T&C style grinder as they do with a bench grinder. As usual its a case of folk making the best use of what they have and staying within what they can afford.
Around the time I decided that building a new workshop meant I could have the space to "go with the pro" by using the Clarkson I read an article about using the smallest B&Q grinder as the motorised wheel head for a T&C build. Apparently an effective and economical solution. Presumably similar 4" wheel machines can still be found at low prices.
As you know, when it comes to X-Y movements on a T&C grinder normal practice is to have one screw controlled axis to set the position and cut whilst the other is lever feed for the grind movement. The professionals use a rack and pinion for the lever feed. The Brooks design uses a chain and sprocket, cheaper and just as effective. Wire pull systems are said to be inadequate.
To my mind the one real weakness of the Brooks design is the rather slender column carrying the wheel head. A larger diameter would seem more sturdy. Especially if you used a smallest size bench grinder for the wheel head instead of the, rather lighter, small motor chosen for the original design. I suspect something similar to the Clarkson see-saw arrangement would be more appropriately sturdy and less challenging to build accurately but significant design re-thinking would be needed to incorporate wheel head swivelling or equivalent capability.
My back of the envelope sketch would probably be rather Clarkson style with fixed see-saw, albeit single ended, carrying a motorised wheel head made form a small grinder with Brooks style round bar slide X-Y table on a centre pivot. Dunno whether I'd go for Clarkson style cutter carriers and mounts or just make up a bolt on version of the Arc jig with simple bored cylinder cutter holders rather than expensive collets.
Bottom line is there are a lot of ways of coming up with something that (mostly!) meets your needs and budget. Always going to be something that really needs a Mk2 version (which never happens). My usual practice with anything is too steal ideas from everywhere, chisel off the serial numbers, paint it purple (well not really) and let folk believe that I'm a really clever fellow for thinking it all up.
Edited By Clive Foster on 29/01/2020 10:34:37
|Nicholas Wheeler 1||29/01/2020 11:33:06|
|301 forum posts|
I'm about half way through building HH's basic grinding rest, and will be using an ER32 spindle in his fixture. That's because I already have it and the collets, so will save a huge amount of time and material making more parts that will do the same job.
I don't expect to use the thing much, and how will grinding dust affect the collets when they're fixed in the chuck?
ER collets are cheap to buy, and consumable parts any way.
|Howard Lewis||29/01/2020 11:52:59|
|2730 forum posts|
If you want to sharpen cutter, they need to ,be accurate. A drill with unequal lips will cut oversize, and not all well if the lips are are different heights.
Ditto, for End Mills and Slot Drills.
You need to make something that is reasonably precise.. I am not suggesting a Quorn, but maybe a secondhand Worden or Stent would suffice? You may not use it a lot, but the results will so much better than free hand or with a sloppy device, with questionable advances. A ME 40t p[i screw thread makes a good micrometer advance.
You can use it to grind lathe tools as well as drills End Mills and Slot Drills.
And once you have experienced four facet sharpened drills, you will never want to go back!
|Douglas Johnston||29/01/2020 13:59:46|
670 forum posts
I was recently needing a device to produce a fine feed for a grinding set up and had a look at a cheap way of providing an accurate feed. A look on ebay provided a micrometer head with a rounded spindle for about £5 from China. I have bought one but may have to wait some time for it if air transport out of China is suspended during the current health crisis.
|Clive Foster||29/01/2020 14:22:42|
|1992 forum posts|
I've always felt it impossible to overstate the ability of abrasive dust to get into places where it its least wanted, most likely to cause damage and hardest to completely clean out.
That said if you have suitable collets and are confident that personal care combined with relatively low use will keep them in good condition despite the hazards of grinding use then go for it and use them. Conversely if folk don't already have collets and holder(s) it seems silly to buy a set and subject the precision components to abrasive dangers when something easily and cheaply made will do the job.
Back around 2008-2010 or thereabouts when I seriously considered building a T&C grinder or at least an endmill sharpener I probably looked at approaching 40 articles and designs from numerous sources. Around 20 were considered worthy of scanning and saving to computer files for further consideration and, if selected, printing out ready for manufacture. (I tend to write on drawings as I go so never work directly out of a magazine or book.) As I recall it the Cannon Endmill Sharpener designed by Colin Pape, published in MEW May & June 2004 got the vote for a simple end sharpener along with the Brookes for the T&C grinder. Both seemed to offer a good balance of easy build using materials I had, or could easily get, with decent functionality without excessive work. Nothing else seemed to hit the spot for me.
Don't recall any total lemon designs. Choice being a matter of balancing what it did, how much effort to make and whether I'd actually be happy to use it. The in between "more than a simple end sharpener but less than a basic T&C grinder" designs never hit the spot for me despite being perfectly capable on their own terms. YMMD.
Although I frequently recommend Howard Hall designs there is no way I'd make them for personal use. Different philosophies mean most of Howard Halls work would be "fingernails on blackboard" for me to use.
The Brookes is basically "Quorn Lite" with much simplified construction. The Bonelle is a similar device, objectively a superior and better engineered design, much closer to "full Quorn without castings", but rather more work to make. The effort needed to make a proper Quorn being, frankly, outrageous given how much its likely to be used. (Probably not at all in reality. I'd not want to shower grinding dust over all that hard work. Especially not after making a nice box too.).
I too intended to go four facet for drill sharpening taking inspiration from the Plasplugs drill setting and flip over Vee block carrier for the drill holder. Not sure where the back of that envelope went!
The Stent always seemed a sprawling design to me taking up too much bench space. Effective though it is the Worden always seemed over-driven by using punched and bent metal sheet for the main structure to keep costs under control. That pesky price / performance / how can the retailer make a profit thing again.
|Howard Lewis||29/01/2020 14:39:18|
|2730 forum posts|
My experience of Plasplugs, and other "plastic" drill sharpening gadgets has not been good. Which is what started me looking for a "proper" cutter grinder. Initially a Quorn, until the realisation came of how complicated it would be!
The Worden beat the Stent by a short head on the basis of less, or easier machining. Mine now has additional accessories, one or two to Hemingway designs, (some modded ) and others of my own design.
Not that it sees a lot of use, but when needed it does a good job.
To try to keep abrasive dust from where it should not be, after use it is brushed with a pastry brush whilst a vacuum cleaner nozzle is held close to the brush. The rods on which the table slides need to be cleaned with a rag from time to time, to keep it running smoothly.
It has ground Drills, End Mills and Lathe Tools at various times, so that they cut satisfactorily afterwards.
Makes a far better job of it than I ever could.
Making it and the accessories was a most satisfying activity.
|Clive Foster||29/01/2020 15:50:28|
|1992 forum posts|
I generally agree with you about the (non)performance of the cheap plastic and other low end drill sharpeners. But the device in the original Plasplugs 4 in one multisharp system is unreasonably good given what its made from. Very acceptable results if you don't force it.
However the flip-over Vee-block'n clamp drill carrier along with the associated drill projection and alignment device are things of genius. All the problems of drill setting normally associated with swing across the wheel sharpening eliminated in one swoop. OK inherently limited capacity range, probably cover no more than 1/4" or so diameter change, so you'd need several. But it just works and the cutting edges are at 180° every time.
|Anthony Knights||29/01/2020 21:42:23|
|309 forum posts|
Nothing wrong with using a cross vice to get the X-Y movement you require. No point in using expensive precision devices when you're going to spray them with abrasive dust. I have used one for years. I recently removed the vice and fitted a T slotted table which became available when I upgraded my mini mill/drill. I am presently rebuilding the whole grinder assembly.
|Steve King 5||29/01/2020 21:46:15|
|67 forum posts|
Very nice i like that.
|Henry Brown||30/01/2020 07:49:49|
107 forum posts
|Clive Foster||30/01/2020 11:02:04|
|1992 forum posts|
Nice job Anthony.
Your cross vice must be way tighter than mine. Reckon if I tried that something would dig in and wreck the wheel inside 6 months!
I was always told that leadscrew feed for the grinding movement on normal tools was too slow and too lacking in feel to work well. Is this actually an issue in practice or merely a "safest(?)" generalisation.
I've only ever used hand fed systems whether by lever or directly sliding the tool either against a guide or free hand. Hafta say I'm scardy cat with grinding wheels.
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