Drill Sharpeners Compared.

[Michael GilliganParticipant @michaelgilligan61133]

Excellent link, Bill

Thanks !

MichaelG.

[bernard towersParticipant @bernardtowers37738]

I seem to recognise that article, it must be where I got my info from.

[PlasmaParticipant @plasma]

made a new chuck to hold drills smaller than 3mm.

[Neil LickfoldParticipant @neillickfold44316]

Thanks for the images Bernard.

I was shown that trick as an apprentice in 1982. The only difference was to add a small radius on the outer edge. The angle on the edge of the drill I use is about 15 deg per side. So about 1/2 of what you have shown. It does improve the surface finish of the hole, and it also seems to drill a straighter hole as well. The radius edge is used where we don’t have a reamer of the size required ,but do have a drill bit of the desired diameter.

The limit today, is the wear of the very centre of the drill.

Cobalt HSS drills do last alot longer than the standard hss alloys that are out there in the cheaper grades these days.

The more accurate the outer angle is created, the better the drill will be to size and roundness.

[Jan RaapParticipant @janraap84676]

Interesting thread.

I have a Brierley ZB50 which I have just got working in the last week. It is not completely finished yet, I still need to refurb the light with magnifying glass and also clean and paint the optional motor (I believe it is for split pointing).

I bought my ZB50 in 2023 and it looked like this.

 

It was completely stripped off paint and repainted.

The additional motor that still needs to painted.

 

[Jan RaapParticipant @janraap84676]

 

 

First time using it.

 

 

[Jan RaapParticipant @janraap84676]

First drill bit.

 

 

 

 

[noel shelleyParticipant @noelshelley55608]

Hi Jan, I have a ZB25 and a ZB32 and the instructions for their use. They look very similar to the ZB 50. If they would be any help to you let me know. Noel.

[Jan RaapParticipant @janraap84676]

Hi Noel, thank you.

I have a selection of manuals and they all differ slightly.

I have the two ZB50 manuals from here (I uploaded one).

http://vintagemachinery.org/mfgindex/detail.aspx?id=12088&tab=3

 

It seems like the basic principle between the ZB32 and ZB50 are the same. However, it looks like there is a key difference in setting up the drill for grinding.

As far as I can tell you need to lock the ZB32’s head (no oscillation) and place the stop in the Green stop (for a RH drill) on the chuck.

 

On the ZB50 it specifically states that the head needs be unlocked to allow oscillation when setting up the drill bit.

The ZB50 instructions:

 

[BazParticipant @baz89810]

Seems the wording for ZB 50 is slightly different but it all boils down to the same thing, the drill land rests on the blade, the chuck is locked in either red or green slot and chuck is tightened. The operation of all machines is the same, I believe the cams will fit all machines. Have you got or are you aware that a special wheel is available, three quarters of it is coarse grit for large drills and the other quarter is fine grit for small drills.

[Jan RaapParticipant @janraap84676]

I was wondering why the grit was different.

Here is mine.

[Jan RaapParticipant @janraap84676]

My drill setting guide is also different.

I think on mine, you just set the drill to the nearest marking on the setting guide according to the drill’s diameter.

[Jan RaapParticipant @janraap84676]

Reading the translated manual, it is confirmed. No Vee gauge is required on my machine.

I should have read the ‘Sharpening large diameters’ bit before I tackled my 2″ drill bit.
Maybe it wouldn’t have overheated so much…..

[noel shelleyParticipant @noelshelley55608]

Hi Jan, The V gauge is not really needed as all you do is express the drill dia in 1/32″s eg 3/8″ (10mm) is 12, above 1/2″ (13mm) just use 16 or a figure that give the clearance you need. I take it your wheels are new ? The lines on your regrind are caused by the wheels being out of balance, common on old and worn machines. Only by careful balancing will you stop this and some wheels can be a long way out. There is also the risk an out of balance wheel will come off. Do you have a set of cams, and the steadies, plus the diamond dresser that normally come with the machine ? Best wishes Noel.

[Jan RaapParticipant @janraap84676]

Noel, thanks for the reply.

The dish wheel is new, the main grinding wheel is not. I did balance the wheel, then dressed it. I should have balanced it again but was too excited to use the machine. I also found if you go slowly on the last few passes, there are less lines on the grind.

Hopefully, I will get a chance to balance the wheel again tomorrow after dressing.

I do have a few cams.

2,4,6,8 Green and 7 red.

I also have the round shank drill steady.

I do not have the original MT holders – my machine came with shop made MT holders and sleeves.

The OD of the MT holders have been welded and machined down so that they fit in the Brierley head.

 

I also have the countersink grinding attachment which I would like to try out. Not really sure how to use it.

 

[noel shelleyParticipant @noelshelley55608]

I see you are using coolant, is this specifically made for grinding ? On the smaller machines a spray mist was used and I thought it used water. The hole in the top of the extended motor shaft cover was to mount said equipment. My ZB32 did not have the spark catcher ‘ so I made one of light gauge 25 x 50 box section. I also had trouble holding the motor shaft to tighten the wheel mounting due to the hole in the shaft cover being badly worn. The hole in the cover was near enough size to tap 1/4″ BSP and I cut one side off a steel male x male 1/4″hydraulic adaptor and screwed it in, the hexagon enabled it to be tightened . This held the lock pin true.

Are you in the UK ?  Noel.

[Jan RaapParticipant @janraap84676]

Yes, I am using coolant. My machine came with a coolant pump and tank (it was filthy, probably never been cleaned).

In regards to the coolant being specifically made for grinding, it depends on which datasheet you read 🙂

I have some Castrol Cooledge BI coolant so I used that.

The first data sheet would suggest it is not made for grinding.

 

The second datasheet

 

 

The third datasheet

 

So maybe it is not exactly made for grinding, but it seems like a general-purpose coolant that could be used for grinding. I am using the same coolant on my Jones & Shipman 540 grinder.

 

Luckily, the hole to hold the shaft was all good on mine.

Today I have rebalanced the wheel.

I took photos of a drill I had previously sharpened (with the grinding lines) and then reground it again after the wheel had been balanced.

 

Before

After

 

A bit of an improvement but there are still slight grinding lines/marks. I don’t think it will affect the drill’s performance.

 

Finally, yes I am in the UK, sunny Wiltshire!

[Jan RaapParticipant @janraap84676]

The promised photos of the countersink attachment.

 

 

 

With the sleeve pulled back (the operation is similar to the wheel dressing attachment).

 

It seems like it has got its own ‘built in’ cam. I guess you tighten the attachment in the chuck and then rotate the countersing attachment’s handle instead of the machine’s head handle. I am guessing the mark (line) on the attachment must be used for setup.

 

I have attached a better copy of the countersink’s marketing blurb (the only information I have on the countersink attachment).

 

[BazParticipant @baz89810]

Castrol Cooledge will be fine for the Brierley, regarding the countersink tool it is held in the chuck with the chuck locked from rotating, from memory it only does single flute countersinks, conventional three flute ones can be sharpened using the appropriate cam and the lowest setting on the relief dial. Your latest drill sharpening looks good. Do you have any of the other accessories with your machine?

[Jan RaapParticipant @janraap84676]

This is all the accessories I have.

The No 2 Cam is still on the machine.

Also shown is the additional split point motor that still needs to be paint stripped, painted and refitted.

In the translated manual, it is called ‘cross sharpening’ probably a translation error.

 

 

 

[BazParticipant @baz89810]

Looks like you also have the sub land grinding attachment, the black thing just above the row of green cams, this is handy for grinding lands on step drills.

[Clive FosterParticipant @clivefoster55965]

Concerning the single lip countersink sharpener I’ve often wondered whether the necessary feed on a device conceptually similar to the Brierley could be produced via screw thread of appropriate pitch.

Basically the idea is that by turning the device through a full circle the cone behind the cutting edge would be ground back to provide functional relief angle. Obviously the starting point needs a certain offset to generate the tip. My imagination isn’t up to visualising the 3D geometry needed to get the offset right so I’ve never had the bottle to try. I think the actual feed needed over almost a turn could be measured directly.

After several sharpenings the cutter would need to be re-gashed but judging by the life of mine I can’t see it being pressing problem in the home shop.

Clive

[Jan RaapParticipant @janraap84676]

So, gather round, fellow tinkerers, as I recount a tale of excitement, questionable decisions, and one spectacularly bad idea.

A few days ago, I took a look at the old grinding wheel from the point-splitting motor on my trusty Brierley ZB50 drill grinder. It had that “seen better days” look about it – the kind of look that makes you think, “This probably shouldn’t spin at high speed near my face.”

Naturally, I conducted the ring test. Hung it on a screwdriver shaft, gave it a light tap, and… nothing. Not the reassuring ting of a solid wheel, but the dull thud of something that might want to kill me. To confirm, I grabbed another (larger) wheel and tapped that – ring-a-ding-ding! Just as expected. Tried the suspect wheel again – no ring. Conclusion? Wheel’s bad. I ordered a replacement from Zoro. So far, so good. Safety first, right?

But then, mistake number one: I didn’t immediately destroy and bin the old wheel. Instead, I set it aside, where it silently awaited its chance to shine in this tragic comedy.

Fast forward to yesterday. I finished wiring up the VFD and got the point-splitting motor mounted. A moment of pride! Naturally, I wanted to show off this fine piece of engineering. Took a video of the startup, but without a wheel or holder installed, it just looked like… well, a motor spinning. A bit anticlimactic, really.

Enter mistake number two. “What harm could it do,” I thought, “to pop the old, KNOWN BAD, grinding wheel on just for a quick video?” Surely, the universe would grant me this tiny indulgence.

Spoiler: it did not.

The wheel, unsurprisingly, came apart.

Thankfully, I emerged unscathed, though my dignity remains in pieces alongside the wheel. In hindsight, this was one of the most idiotic decisions I have ever made. And that’s saying something for someone who owns a VFD and thinks “quick video” trumps “basic safety.”

 

[noel shelleyParticipant @noelshelley55608]

Your a lucky man Jan ! It could have ended so much worse ! Noel.

[derek hall 1Participant @derekhall1]

Yes you are a lucky man Jan!

Thanks for the video, just think of the damage and danger if those guards were not in place – at least the guards did the job….

Any dud grinding wheel that I find I immediately break it up with a hammer. However I can understand you being very keen to see your new toy in an action and accidentally fitting the dud wheel…

Glad you are ok though

[Author]

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