Interesting results.

I also did the "take out the pivot play" thing on a Picador. Discovered that the darn thing worked better with things "as delivered" slack. With the play taken out there isn't quite enough clearance angle at the a back of the flute with larger drills. From memory the effect starts to bite around 3/8" – 7/16". 1/2" drill ended up really sharp on the edge but barely, if at all, cut once fully engaged due to the back of the flute rubbing. Poor thing got a 5 years + stay in the box after that before I decided to give it another go following the instructions rather than improving things. Sometimes the maker does know better and sometimes crude works where precise doesn't.

Essential to make arrangements to accurately and easily adjust the distance between drill jig base and grinding wheel without things twisting and sliding every which way. Mine sits on a scrap of 1/4 plate bolted to the bench with 10 gauge side-plates to keep the jig straight. Wort thing then is getting the projection and angle of twist right. That darn location finger is rather un-useful. Mine gets done more or less by eye with the finger as a reference rather than a stop. I found a narrow, 1/2" or so, cup wheel more reliable than just using the side of a normal wheel.

When it comes to drill setting and location the cheap plastic, but rather decently performing, one in the original Plasplugs multiple sharpener set is the best I've seen. Positive stop for the projection with a sliding Vee gauge to set the angle of twist. "Grip the drill gently in the Vee holder and lightly push it forwards against the stop then turn until gauge is at it's lower point. Then tighten up the drill holder so that it is firmly held." Drill holder fits in the grinder proper both ways up so none of this business of trying to set the second edge exactly 180° to the first. Just grind one side, flip the whole darn thing and do t'other one. Genius. Why aren't they all made that way. Pity flexi plastic construction and trying to make the thing for thruppence three-farthing when fourpence ha-penny would have been a better budget makes getting best results a minor art.

In the process of making the missing bits for my "wallet came out smoking" Clarkson drill sharpener attachment right now. 3 years marinating in t'cupboard is about par. Be interesting to see how well the professional option works.

Clive.

Very interesting, following with interest as I'm in the market for something to do a better job than I do at present…

Bill

As requested shifting Clarkson drill sharpener discussions from Dereks Cup Wheel thread of 12/08/2020.

Starting at the beginning the Clarkson system uses a 6 jaw chuck with long sloped jaws to hold any drill from about 2.5 mm to 16 mm, 1/8" to 5/8" diameter. The chuck jaws are about 2 1/2" total length so as to grip the spiral lands in a stable manner.

Setting up merely requires the cutting edge on the wheel side to be set level with its outside end, i.e the full diameter of the drill, 1/2" proud of the chuck jaws. The instructions say that there is a setting gauge to make this easier. I've never seen one or a picture of one. The chuck mounting shaft is free to rotate in its carrier casting with an indexing device at the other end to select the second edge. Obviously it is bored out to give the drill shank somewhere to go. The carrier casting pivots up and down on a shaft fixed into the main support post. The pivot shaft is set at an angle to the chuck carrying post so that swinging the cutting edge upwards grinds the correct clearance on the drill.

Assuming the chuck carrier shaft is set to as to give the correct point angle the only requirements for a correctly backed off drill are :-

1) the pivot shaft and chuck carrier shaft be at the correct relative angles

2) the drill cutting edge is the correct distance from the intersection of the shaft centre lines.

So far as I can see the shaft centre lines are in the same plane which is perpendicular to the cup wheel face.

Hence given the shaft angles it should be relatively easy to replicate the sharpening geometry with a simple post support. Some means of applying controlled small cuts is essential. Already present if fitted to a T&C grinder. Otherwise some sort of screw or micrometer controlled slide will be needed.

The actual Clarkson implementation is angularily more complex to incorporate tap lead grinding.

Photos show the device moved clear of the grinding wheel so a drill can be put in the chuck. Grubby wheel is still flat so not due for dressing. Yet!

Whole thing on Clarkson

Side View

Top View showing indexing device, shaft angles and spring loaded pin that sets chuck position

The calibrated cam-plate device next to the pivoting handle isn't used for drill sharpening.

Clive

Bill

Not quite. The grinder table angle is irrelevant. All that matters is that the drill is at the right angle to the grinding wheel to give the desired point angle.

The factory Clarkson set up has the table at 15° for drill sharpening because that makes calibration easier for the tap grinding function which has the table at a different angle anyway.

Clive

An interesting subject where no system has ever really become the definitive route for the hobby market

I had one of those picador type things but it was too fiddly for me

Used a great one from B+Q years ago which was fabulous for the 48 hours that the grinding stone lasted but the spare stones were about a fiver for two

The multisharp uses the same sort of simple stone system, the big problem is you put a gutter into the stone really fast once you start doing a few drills

Lidl cheapo ones for a fiver tend to have two spare cup stones

Grinding drills by hand helps to keep your eye in for when you need to grind a special cutting tool

It's a real whatever-works-for-you thing where hand sharpening gives the least hassle for an acceptable return

Edited By Ady1 on 13/08/2020 05:53:32

The lands look too wide to me on the Unknown Make New(ish) Four Facet Commercially Ground; pictured above, also I understood the grind lines between clearance angles should be parallel on a correctly ground 4 facet drill.

Emgee

Great picture of the setting gauge. Many thanks.

All drawn up and ready to make next time I'm on t'mill.

Clive

On 24 October 2024 at 13:24 Chris152 Said:

On 26 December 2018 at 16:57 peak4 Said:

I’ve been having a bit of a play this afternoon as the weather wasn’t up to much.
Rather than hijack the other thread, which was asking specifically about the Sealey SMS2008 drill sharpener, I thought I’d start a new one for a quick comparison.

Maybe others could contribute some ideas and photos to this thread, so that it could be used for reference and learning.

Doubletop-Pete commented, in the above thread, that he felt that his Sealey was taking off too much metal; so was mine out of the box, albeit a second hand box.

Hi all, I’ve tried to access Doubletop-Pete’s thread but it doesn’t seem to exist anymore? I just received an SMS2008 and it seems to cut off too much metal on the first cut, and the chisel isn’t properly centred after the second side. I’d like to try to adjust the wheel position – can anyone advise how to do this? The manual says nothing about it.

Thanks, Chris

Sorted – just undo the grub screw on the shaft and it moves!

The Clarkson drill grinding attachment seems to fetch about £500 or more for a good one with the bits that go with it. I went for the Brierley and was lucky to get one with all the accessories for just under £1000. It is so easy to use and very quick even for drills of 1.25″, and 1, 2, & 3MT. The various cams and levers make the process simple and various point forms can be done.  The biggest problem I had was getting wheels balanced, even some new wheels were so far out it was a problem. A J & S balancing way sorted that out, it was then that I was able to see how far out the wheels really were. Even with the wheel only slightly out it would show as small lines on the drill face, not enough to matter but I knew they were there. The Brierley has a wheel carrier that can be balanced, then fitted but the Clarkson has no provision for wheel balancing, which seems strange.

I had a picador but this was hopeless on a bench grinder with an out of balance wheel. Noel.

If you grind a secondary point angle on the drill stays sharper longer as you are halving the angle on the outside corner of the dril where the most work is done and heat generated. This I believe comes from our friends over the pond some time in the middle of the last century and is also reputed to give a more polished finish to the hole.

Thanks to this thread I kicked myself into actually sharpening several of my poor drill bits this afternoon. I’ve had the Sealey 2008 for a good while and have used it occasionally in the past but never thought much of it.

Bits would often chip badly almost straight away after sharpening which now makes sense and after today I probably will do them by hand in future.

On closer inspection (thanks to this thread!) every bit would end up with 1 face slightly longer than the other. I stripped and cleaned everything including the holder but the outcome was still the same.

The finish was pretty rough but good enough for a drill bit and I ended up having to not fully grind the bits, once the face was full and all traces of chips removed I had to keep swapping sides and checking it until I could get an even grind on both flutes.

Obviously needs more investigation although the holder doesn’t seem to grab the bit evenly for some reason.

But then going by me luck I’ve probably got a dodgy one!!

I’ve got a Picador type, but never really got on with it. Others do, so have more skill and patience than me.

Being heavy handed, melted the plastic drill holder in a cheaper “Will sharpen anything” device.

Having made a Worden, that is now used to four facet grind drills; good results every time. But obviously at a cost in time, effort and cash, which is repaid in the ability to sharpen most tools accurately and consistently.

Howard