The TINKER is a compact, versatile, and easy-to-use Tool and Cutter Grinding Jig that will enable you to sharpen milling cutters, lathe tools, twist drills, reamers, circular saw blades, etc. on your bench grinder.
INTERESTED? Why wouldn't you be? The cheapest of the Taiwanese T&C Grinders start at about 4 times the size and 30 or 40 times the cost of a set of TINKER drawings, and you can go on up from there. Most other hsm-type T&C Grinding designs are much more complex, critical and time consuming to make and use, and/or less versatile. In my understandably biased opinion, the TINKER tops them all, especially for the average home shop machinist.... but it could also earn its keep in any jobbing machine shop, tech school shop, R&D toolroom, tool & cutter grinding shop, etc.
The TINKER looks simple - and it is simple, both to build, and to use. We can supply you with a set of the most comprehensive working drawings and user instructions you're ever likely to get your hands on.
SHARP CUTTERS GIVE ACCURATE WORK AND GOOD FINISHES.
THE TINKER WILL GIVE YOU SHARP CUTTERS.
Let's look at the TINKER Tool and Cutter Grinding Jig, and some of the questions you are likely to have about it:
The TINKER Tool & Cutter Grinding Jig was invented and patented in the early 1970’s by Norman W. Tinker of Nottingham, England. He had been developing and refining the design for more than 10 years when I got interested in it. It is a tested, proven and practical design, easy to make and easy to use.
I ordered a set of drawings from Mr. Tinker about 1982 or so, and built two, in collaboration with friend and fellow home shop machinist Roy Bickerstaffe. We were impressed with its simplicity and its utility for guys like us, so much so that I later arranged to be the North American agent for the design. (Added March 2011: Norman Tinker died a few years ago, and I bought all rights to the design from his estate.).
What is the TINKER?
The TINKER is the answer to a maiden's prayers, particularly if she happens to be a hsm, gunsmith, machine shop owner, vocational school teacher, etc.
The TINKER is about as big as a basketball. It teams up with any ordinary bench grinder to provide the small shop owner with a highly versatile tool and cutter grinding (T&CG) capability. All you need, then, is your bench grinder, an appropriate grinding wheel for same, the TINKER, a common base, and a space about 2 ft. square. You don't even need a cup wheel, although one can be used.
What sort of a Grinding Wheel will I need?
A standard white Aluminum Oxide wheel of 60 grit is fine. I use a half inch wide, 6" dia. straight wheel from Norton. The abrasive spec on it is 32A60K5VBE, correct for high speed steel and hardened carbon tool steel. You can use a cup or dish wheel if you want to, but it is not necessary to do so for the normal run of work.
Is it Hard to Build?
No. The TINKER utilizes two identical castings*, one machined just slightly different from the other. One is called the Foot, and the other is referred to as the Standard. Most of the machining throughout the TINKER is not to critical limits. The only parts of the whole job that must be done to tight limits are the Toolholder (shown with a 2 fluted end mill in it, in the photo above), the Toolholder Guide Block (a 1-1/2" sq. x 3" long block that the Toolholder passes through), and the hole in the round boss on the Foot and Standard.
With the exception of machining the Foot and the Standard, the TINKER could probably be built entirely on a lathe that will spin a 6" diameter workpiece. To machine the Foot and the Standard, you will require the use of a larger lathe, or a shaper, or a milling machine. The Foot and the Standard are not hard to machine, but do require access to suitable equipment - if not at home, then perhaps through a friend, or at night school, or at a local machine shop. No tricky setups or difficult operations are involved in machining the Foot and the Standard.
(The castings are shown in the photo below.)
The Tool holder is 7/8"ø x 7-1/2" long. To get that #2 MT socket in there right requires not only a #2 MT reamer, but also a lathe with a spindle bore greater than 7/8", and/or a good-sized 4-jaw chuck; the proper performance of the finished TINKER depends upon virtually perfect concentricity between the O.D. of the Tool holder and the #2MT socket in its nose. This is one of 3 similarly demanding tasks noted above that are involved in the building of a TINKER. The rest is pretty easy work.
The TINKER is not a complex item to build, nor will it take you a great deal of time. Obviously building time will vary from one maker to the next, but I think that any hsm who puts his mind to it could have a basic TINKER in service within a month of receiving the drawings, working on it in his spare time.
Anyone who builds himself a TINKER and devotes some time to becoming proficient in its use will find his efforts well rewarded. (T&C grinding is a branch of the machinist's trade, and as such, demands some skill development - you do not buy the expertise with the machine, whether it be a TINKER or a Cincinnati!)
WHAT IT IS NOT
The TINKER is not intended to rival a dedicated, purpose-built T&C Grinder by such legendary builders as Norton, K.O. Lee, Cincinnati, Oliver, or Brown & Sharpe. Nor does it have the cost, weight, and bulk of a "real" tool and cutter grinder - a significant advantage for the guy with a 12' x 12' shop, like mine. But with it you can accurately sharpen cutters that you can't do freehand.
What will it do?
The basic TINKER T&C Grinding Jig is terrific for sharpening the end of end mills and slot drills. This operation is easy to learn to do well, and can be done very quickly. In my opinion, even if all you want to do with it is to sharpen end mills and slot drills, this capability alone would justify building a TINKER. Set-up time is minimal, and once the TINKER is set for this operation, you need only change the Tool holder collet to suit the shank diameter of the cutter you want to sharpen at the moment. Slot drills I have sharpened on my TINKER take no back seat to factory new cutters - they cut like a razor on both flutes, and they leave an impeccable finish on the work.
As you probably know, the end cutting teeth of end mills and slot drills are sharpened with a "fish tail," or slight dishing toward the center. The TINKER does this automatically, without any "setting up" beyond correct assembly: one bolt in the right one of 2 holes - simplicity itself. For those who don't know why such cutters are sharpened thus, it is fully explained in the TINKER User Instructions, which come with the working drawings and instructions.
The basic TINKER will also sharpen the side cutting teeth of end mills, slot drills, and similar cutters. This requires a bit of skill development, but is not difficult: just don't expect (although you may get) perfect results the first time.
The basic TINKER will also let you sharpen the following cutters: slab mills, tee slot cutters, counterbores, countersinks, woodruff cutters, and some other cutters.
The basic TINKER, with simple adapters which you can make as needed, will also sharpen circular wood saws, slitting saws, and side and face milling cutters. Norman Tinker says so - I've never tried this type of work because I don't own any side and face milling cutters. But if he says it, you can believe it, and if you want to, your TINKER will let you do it. The capacity limit for wood saw blades will depend on the set-up used. More than one way is possible, but suffice it to say that sharpening a 9"ø saw blade would be routine, and a 24" blade (that is not a misprint) would be entirely possible, with a bit of finagling.
Why do you say The TINKER is easy to set up?
The TINKER is set to produce any desired relief angle by offsetting the Toolhead above or below the grinder wheel center height. This is done via a simple-to-make, simple-to-use Setting Gage (just a piece of 1/4"ø CRS with some graduations cut in it) which permits direct setting of relief angles for right and left handed, straight and spiral toothed cutters. There is no need to refer to tables. No calculations are required. Once set to produce a given relief angle, the TINKER will produce that angle on a cutter of any diameter. This means that if you want to sharpen several end mills of different diameters, one after the other, you can do so without further adjustment.
Another useful feature of the TINKER is that the Toothrest Finger is attached to the Toolhead. Thus, when the Toolhead is raised or lowered to set up a desired relief angle, the Toothrest Finger moves with it, undisturbed, and remains set to the correct height. The whole operation is completed in a matter of seconds. A separate gage (very simple, takes about 10 minutes to make), allows you to set the Toothrest Finger EXACTLY on Toolholder center height in about 5 seconds flat.
How are Cutters Held?
Cutter shanks are held in a sliding Toolholder, the end of which carries a #2 MT socket. You can make yours different if you want, but that's what the drawings show, and what we recommend.
A set of #2MT bushings which you can make for yourself will take tool shanks up to 5/8"ø, or factory-made #2MT collets can be bought in any size desired up to 1/2"ø. I made my TINKER's Tool holder nose to take Myford #2MT collets, because I already owned several of these, in all the right sizes, for my Myford lathe. (#2MT collets of other makes besides Myford can be had, and will do fine. See note at end of price list.) The drawings include details for a nose cap dimensioned to suit Myford collets, exactly as mine is made. My friend Roy B. made his (and you can too) per Tinker's original design, using the solid steel bushing type; these are also fully detailed in the drawings.
What about Cutters with Larger Shanks?
The drawings give broad details of a larger Toolholder capable of taking cutter shanks up to 1"ø. Some builders have made their TINKER with an R8 socket, thus enabling them to use R8 collets from their milling machine. (More ideas re this are given in the one-time TINKER Newsletter, which you get with the TINKER drawings.)
The TINKER will sharpen other cutters, too.
The Lathe Tool Bit Grinding Attachment permits grinding lathe tool bits, e.g. small parting tools and screwcutting toolbits for 60º Vee, Acme, and other thread forms, where known angles have to be produced with accuracy. Twist drills from about 3/4"ø on down can also be sharpened with this accessory.
With the addition of a small pin chuck, e.g. the Eclipse #160 or Starrett #240 pin vise, small drills from 1/8"ø down to #80 can be sharpened direct from the main Toolholder. I'd just as soon not have to prove that the TINKER will sharpen a #80 drill, but with the right stone, and care, there is no reason to think it would not.
Substitute a good 0-3/8"ø drill chuck on a 3/8" or 1/2"ø straight shank, and you can do drills up to 3/8"ø, again direct from the Toolholder, probably about as good as a skilled machinist can do them offhand. The Newsletter gives yet another method of sharpening drills up to 1/2", which N.W. Tinker discovered after I issued my TINKER drawings in the Summer of 1985.
Add the simple Cam Plate and Follower Accessory and you have a method of tap grinding! I've only done a few taps this way, holding them in a 3/8" drill chuck. It works fine, and is not difficult, but it does take some care in setting up.NOTE: A certain amount of operator skill and technique must be developed for consistently good drill sharpening results. It is only fair to say that drill grinding is not theTINKER's strongest point, and if you just wanted a drill grinding machine, a purpose-built unit such as the Darex Drill Doctor would be a better choice than the TINKER.
Norman Tinker also showed a dedicated set of Tap and Die Holders in his drawings. These I did not make, but they are shown in my drawings. (Obviously, to grind a threading die, a small mounted point will be required.)
The Radius Grinding Accessory will let you grind lathe toolbits to known convex and concave radii. Its use takes some care, but it does the job. If you need to grind a radius of say 0.175", it'll do it, or close enough to keep most of us happy, anyway. (NOTE: This item could also be modified and built as an entirely separate accessory for your bench grinder.)
The Reamer Sharpening Attachment replaces the entire Guide-Toolholder-Toothrest Bracket assembly. This attachment is really a set of dead centers of 5/8" center height, in which can be mounted any cutting tool with center holes at each end, such as a reamer, etc. The between-centers capacity as drawn is about 9.5"; this could be increased somewhat at the builder's option.
There are also drawings for a Wheel Dressing Tool, which can be used from the Toolholder for accurate dressing of the grinding wheel, and miscellaneous minor items.
How do I set up my TINKER once I get it built?
The TINKER is set up on a flat base beside your bench grinder. This base can be a 1/2" steel plate, or a sheet of good plywood overlaid with sheet metal. Typically the base is 12" x 18". The grinder sits on the left, the TINKER on the right. Several holes are provided in the base to permit bolting the TINKER down (one bolt) wherever a particular operation calls for it to be placed relative to the grinder.
A COMMENT ON THE NATURE OF THE DRAWINGS:
The drawings are printed on standard 8-1/2 x 11" paper, with a sufficient margin on the left hand side so that if you want, you can put them in a 3-ring binder for easy reference. Explanatory notes appear right on the drawing they apply to, so the info you need is right where it should be - you don't have to flip back and forth from text to drawing. These notes will save you hours of time through not having to try to read the designer's mind.
If you follow my notes, you will also not need to waste your time thinking up shortcuts - they're already built right into the drawings. (No doubt you'll think up shortcuts of your own, too.) You will also avoid having to scrap and re-make parts, and/or having to re-draw some part or parts to find out where to put something, or stand around in the middle of the shop wondering what to do next! Working from a set of drawings and notes like this is somewhat like the two of us talking face to face, me having just made my TINKER, and you now working on yours.
If you have any questions not answered above, phone me at (604) 885-4780. I am usually at home. (You won't waste your nickel on a telephone answering machine, because I don't have one.) If no answer, try again in a couple of hours. Be persistent and you will get me. One further point: I operate on more or less normal business hours, and on Pacific Time. Please do not call before 9 AM my time.
In late August '86, feedback solicited from the first 200 TINKER builders was boiled down into a one-time TINKER Newsletter, a copy of which will be sent with your TINKER drawings. This Newsletter includes drawings for making a set of precision grinding wheel flanges with adjustable balance weights, info re protecting the TINKER from grinding dust, an idea for easier adjustment and calibration, and a lot of other good information.
A NOTE RE COLLETS: If you don't want to make your own #2MT solid steel adapter bushings, you can buy #2 MT collets in the sizes you need. 1/4", 3/8", and 1/2"ø should cover most cutter shanks, but they can usually be had in any size from 1/16 to 1/2" by 1/64" increments (also metric sizes 2 to 13 mm by 1/2 mm).
* NOTE: You can order #2 MT Collets from suppliers such as Little Machine Shop. Travers Tool Co. Inc.,
in NY (1-800-221-0270), also sells suitable #2MT collets. Such collets are drawbar operated, whereas Myford
collets (which I used) are tightened into the spindle socket via a screw-on nose piece at the front of the collet.
Before you start making your TINKER, you should have in
your own hands the collets you plan to use in your TINKER.
The Mini-TINKER is a more recent development from N.W. Tinker, the inventor of the TINKER Tool & Cutter Grinding Jig.
Re-designed and simplified for the smaller lathe/mill user, the Mini-TINKER is ideal for the home shop machinist who uses smaller cutters, and/or does not need all the capabilities of the regular TINKER Tool & Cutter Grinding Jig.
The Mini-TINKER can be built to take cutter shanks up to 3/8"ø. If the Toolholder is limited to 4" overall length, you could go to a 5/8"ø cutter socket; alternatively #1 or #2MT sockets could be used.
The Mini TINKER is a simplified, smaller, and somewhat less versatile version of the TINKER Tool & Cutter Grinding Jig. It uses no castings, the frame being instead built up from 3 pieces of 3/8" steel or aluminum plate. The 3 pieces are rectangular or triangular in shape, and can therefore be readily milled, or even hacksawed and filed to shape. Assembly of the frame pieces is via 1/4" socket head cap screws, so the Mini-TINKER doesn't even require any welding.
Customers wishing to build the Mini-TINKER will be supplied with a set of Tinker's own drawings, re-dimensioned in inches, and showing North American threads. You will also receive an edited (= improved) version of his Construction Notes and User Instructions, into which I have woven some of Tinker's comments to me about various aspects of the Mini-TINKER's design and construction.
I do not plan to make a Mini-TINKER prototype here, and then turn out a whole new set of drawings of my own, replete with copious and helpful notes. Therefore, those ordering Mini-TINKER drawings must order a complete set of regular TINKER Drawings as well. By studying these, plus the Mini-TINKER drawings and notes as above, you should be able to build the Mini-TINKER without difficulty.
Go to the How to Order page for full information on how to place your order for a set of TINKER drawings.
While waiting for your TINKER Drawings to arrive, contact your local Norton Abrasives supplier and ask for a copy of the excellent Norton book, Toolroom Grinding.
TINKER PLANS: Complete Working Drawings and user Instructions for the basic TINKER and all accessories plus the TINKER Newsletter:US Customers: US$40.00 ppd . Add US$7 for Mini-Tinker plans, if wanted..
Canadian Customers (includes postage and applicable taxes):
$40.00 AB SK, MB, QC, YT, NT, NU
$43.05 NB, NL, ON
$43.80 NS, PE
Canadian Customers (mini-Tinker plans): (includes postage and applicable taxes)
$7.00 AB SK, MB, QC, YT, NT, NU
$7.53 NB, NL, ON
$7.67 NS, PE
Customers outside US or Canada: C$50.00 airmail ppd; mini-Tinker plans $8.
TINKER CASTINGS: Castings are not REQUIRED for this project, although having a set of castings would be a significant convenience.( I used to offer a pair of unmachined gray iron castings for the TINKER T&CG Jig, but the cost of having the castings made got so high that I ceased to offer them in 2011. However, TINKERS have likely been built without the use of castings, because I have sold many more sets of plans than castings. So if you want to build a TINKER, order the plans, and go from there.)
If you think you would prefer to build the mini-TINKER, add the appropriate amount, and ask us to send you the Mini-TINKER Drawings when you order the regular TINKER drawings.
(You will need the info in the TINKER drawings, even if you ONLY plan to build the Mini-TINKER.)NOTE: One customer said he plans to build ....."both the TINKER for general shop use, and the Mini-TINKER for very small cutters that drive me nuts to hand sharpen (#2 counterbores and smaller, form tools for HO gauge wheels, and the like). The Mini-TINKER will probably end up with a small cup wheel on a dedicated spindle and base, with a magnifier, while the larger TINKER will be used with my 8" bench grinder."
Added August 2009:(The following is probably superfluous, in view of all that has been said above, but I will stick it in here anyway.)
A customer recently asked some questions about my drawings for the Mini-Tinker, and I replied as you see below.
"...I've been reading about the Tinker Tool & Cutter Grinder, and I think the Mini-Tinker will serve my purposes. Are the plans for it hard to read and understand?"
"Do I need to buy the plans for the full-sized TINKER in order to understand the Mini-Tinker?"
You need the drawings for the full-sized TINKER not so much to understand the Mini-Tinker drawings per se, but to avoid certain minor pitfalls, and to know how it works, how to sharpen various types of cutters, etc.
"Did you improve the plans when you brought out the full-sized TINKER?"
The full-sized TINKER came before the Mini-Tinker. The plans for the full-sized TINKER were very detailed, and included not only a lot of helpful notes on making it, but also several pages of notes on using it. I drew up the mini-Tinker plans several months later. Since the drawings for the full-sized TINKER were already available, and included lots of helpful info, I decided that the simplest way to provide how-to notes for those wanting to build the Mini-Tinker was to supply them with a set of TINKER drawings as well.
Best, Guy ...."Click here to go to my HOME PAGE