Screwdrivers dressing

[oldhippy]

This should put your mind at rest. Click on this link.

http://members.iinet.net.au/~fotoplot/sdriver/sdriver.html

 

[ramrod]

2 hours ago, mcass said:

Be sure to blunt the tip

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macss....please explain this. blunt in what way? i've not heard of this.

[mcass]

All I mean is to make sure the tip is perfectly flat. You don't want to sharpen the angles of the blade like a knife blade, to an edge. When you break a tip, you are getting into thicker metal the further up the blade you go. When you sharpen them, you need to do both sides of the blade at the angle which will thin it back out and then sharpen the very tip at a 90 degree angle, as flat as possible with a very fine stone, to get the width you need to match the screw head openings. That's all I mean when I use the term "blunt".

[ramrod]

ah....got it. makes perfect sense.

[Scouseget]

On 6/21/2016 at 1:57 PM, Marc said:

 

If you find that you are regularly suffering from chipped blades then it might well be worth exploring the possibility of adjusting the temper of the blades. If you get it right you not only get more resiliant blades which are less likely to scratch movement plates, but you also gain an understanding of heat treatments for steel on a macro or even micro scale. Useful stuff.

This makes perfect sense, however I have a couple of questions regarding this:

Why on earth don't they come correctly hardened and tempered, given that this was a very expensive set of screwdrivers?

How should we go about doing this, i.e., what type of torch should be used, what color should we heat the steel up to for each step, what is the quenching medium, etc? 

Regarding the sharpening of the screwdrivers, it seems to be agreed that the tip of the blade shouldn't touch the bottom of the screw slot, thereby ensuring that the blade jams against the side of the screw slot thus helping to prevent it slipping out - am I right in this or is this some fanciful notion that idealists propose whereas the real practitioners don't actually do this but rather have sufficient dexterity to ensure it doesn't slip out even when the blade bottoms out?

If we really should ensure that it doesn't bottom out, then can I assume that, providing the blade has been properly sharpened and sloped, then all we need to do is grind the bottom back sufficiently until it clears the bottom of the screw, and should we do this each and every time we encounter as screw with an extra wide slot? 

There's a lot to this hobby isn't there? Who would have thought we would be learning metallurgy, sharpening, heat treatment,  etc., and that's just for the screws, then there's the movement itself - yikes! Or at least crikey as Steve used to say!

[jdm]

27 minutes ago, Scouseget said:

This makes perfect sense, however I have a couple of questions regarding this:

Why on earth don't they come correctly hardened and tempered, given that this was a very expensive set of screwdrivers?

Good question. If you notice, "haute holologierie" at some point is an exercise in rationality twisting, or futility. A perfect 1st world timekiller / moneymaker.

[ramrod]

If the screwdriver blade isn't supposed to bottom out in the screw head, that is one rule I break with regularity. Every screw I've driven in my life has had the driver blade bottom out. I'll continue that way. I don't have a problem with the blade coming out while turning.

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[TimFitz]

I spent the day literally watching paint dry. I was using black lacquer to fill in the engraving on a pocket watch case to make it stand out. I will send pictures when it is finished.

In the mean time I was looking for screwdriver sharpening stone holders on the net. The sticker shock was amazing.

So i said to myself, "Self" your only watching paint dry, make your own, you have a sharpening stone and some wood. So I made this from scrap wood while watching paint dry. I'm happy with it & it cost nothing. It is perhaps not as pretty as Bergeon but they have enough money.

[Cad101]

And it does the job just as weļl 

[oldhippy]

Good for you it looks nice.

[dman2112]

Nice Tim. Excellent job


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[vinn3]

very nice tool ! it is a good way the make the  flat sides paralel.  a usefull tool to find [ or invent] would be one that hollow ground the tip before honing.   part of the concept of "100% contact in the slot"  vinn

[deeclee]

Very nice! Way to be creative. Cheers.

[OmarHaltam]

[emoji1303]

[Brian3]

That looks perfect Tim, great job!

[TimFitz]

5 hours ago, Brian3 said:

That looks perfect Tim, great job!

I had a wood shop teacher in high school named Mr. Hammer (no really!) who said I should not plan on being a carpenter as a career! He was probably correct.

[Tmuir]

Like many things in horology there seems to be disagreement as to the best way to sharpen screwdrivers.

One point of view is to hollow grind them and the other is to have the sides flat.

I've seen on a few websites and books dead against hollow grinding screwdrivers, but the BHI recommends it and so does the books on clock repair by John Wilding.

Is this just one of the many topics that people need to agree to disagree about, or is it the case that hollow grinding is better for the larger screws on clocks and a flat surface is better for the smaller screws in watches?

This way also makes sense to me as larger screwdrivers used on clocks should not need as much maintenance as the smaller ones used in watches and its much easier to resharpen your watch screwdriver on a diamond hone or oilstone than it is to hollow grind them as this is something you can do at your workbench.

[oldhippy]

There has already been a good debate about sharping screwdrivers on this forum. I'm sure if you do a search you will find it and there are many different opinions.

[vinn3]

the hollow grind proceedure is done so that  "the  sides are nearly parallel" at the slot depth and honing gives you only a slite wedge affect at the slot width.  OR  what ever it takes to get a tight fit in the slot.  Not a big deal !    vinn

[anilv]

In an ideal world you should have both types. Hollow ground ones will be used but when normal force is not sufficient then the flat sided ones take over as it takes greater force before breaking! In reality this only matters if your working on the top drawer movements like Patek etc. to avoid screw slot damage/ marking. 

So if you have means to sharpen screwdrivers both hollow and flat sided... it makes sense to hollow ground the smaller sizes and flat grind the larger ones.

Personally flat sides have worked for me, but I haven't gotten my hands on a Patek  yet!

Anil

 

[clockboy]

 

 

Just a quick review of the “Horotec Screwdriver sharper”  I have always tried to keep my screwdrivers sharp & in good condition but found that despite this I was still (on occasions) getting slips. Some of it this may well be my method of handling them but also I noticed that many pro,s use screwdrivers that have different shaped blades. After some research I found that this is because many use a “Horotec Screwdriver sharper” (or equivalent) but unfortunately the cost does carry a prohibitive price of £175. However feeling plush last month I purchased one & after waiting a few weeks for it to be in stock, today I have started to use my re-shaped screwdrivers.

 

My initial impression is that this tool offers a very quick method of shaping/reshaping your screwdrivers & it really does give them a round shape not the usual V shape.  see below:

 

 

 

This round shape defiantly gives more stability on the screw. There is however a few issues to be aware of.

First: It is adjustable for the different screwdriver blade widths via altering the distance between the two rollers. As yet I am not sure if this is necessary or at least a critical adjustment as the final de-burring & tip flattening of the screwdriver blade seems to be more than adequate to make a good stable tight fit on the screw head. 

Secondly:The tool is supplied with three holders for the different screwdriver shaft diameters (4.3mm, 4.8mm,5.3mm) This works great for my most used screwdrivers which are Horotech. However my lager screwdrivers (from 1.6mm) are Swiss A*F & their shaft diameters is too large. So for now I will still use these with the old shaped blades but eventually I will change them for Horotech. 

Finally: I suspect I will still also need conventional shaped screw drivers as well so this is pricey for an amateur but …… I do like tools.

 

Del

 

[Watchtime]

Thanks Del, nice tool, I found this ...great info

 

 

[transporter]

Oh gosh I just use a grinding wheel on my dremel, takes about 5 secs a head

[SSTEEL]

17 minutes ago, transporter said:

Oh gosh I just use a grinding wheel on my dremel, takes about 5 secs a head

 Not ideal is that.

[Watchtime]

Just my personal feeling but I think hollow ground does make a lot of sense as the tip of the screwdriver goes all the way into the cut of the head instead of just hitting the sides....