Forming screwdriver tips

[Tatume]

Do any of you have an economical, easy to build, design for a fixture that can be used to cut parallel flats on screwdriver tips? I have in mind using stones or diamond stones to do the actual cutting, but I need a guide to do a good job. Any help will be appreciated. Thank you.

[country gent]

A square of steel aluminum or brass with a hole drilled it and filed in a tear drop shape with a set screw clamp bit in parallel to top and bottom and use on grinders rest. a piece of 1/2" thick 1 1/2 wide 1 1/2-2" long should work well.

[Der Gebirgsjager]

No, Sir, nothing ready-made comes to mind. I've made many special purpose screwdrivers to fit specific screw slots. I used to buy a handful or two of the cheapies on sale in the bargain bins. I tried grinding them, but found it better t put them in a bench vise and cut the parallel sides with a file-- no guide or fixture at all, just by eye. This is hard to explain, but one has to develop a kind of stiff wrist filing technique, not only for this task but other jobs as well, and you just get there by practice. It helps to have a very sharp, new file-- a pillar file seems to work the best.

[uscra112]

For 60 years or so I've done this simply by holding it against a bench grinder, judging parallelism and thickness by seaman's eye. Maybe it's an acquired talent, like sharpening twist drills free-hand, but that's how I do it. These newfangled disposable-tip bits require the use of a handle that you don't much care about, of course

[KCSO]

I use a bit grinding table on my grinder. Got the basics from Grizzly and modified it for lathe bits and screwdriver bits. I use a wooden guide that replaces the cross slide in the guide and is angled for a drill bit.

[Scrounge]

This one won't be as easy to build as Country Gent's tool, but it will, with proper setup, let you grind just about anything that can be ground by hand. Harold Hall is one of the gurus of the Model Engineering fraternity in the United Kingdom.

http://homews.co.uk/page145.html

[John Taylor]

I use a spin jig in the mill and 1/4" carbide end mill. Cut one side then turn it 180 and cut the other side. Measure the thickness and move the table 1/2 the amount you want to take off. Smaller end mill for smaller blades. I have a few sets of Forester screw drivers with round shanks and they get re-cut several times a year. Less heat than grinding. Also have made a few custom screw drivers from spring steel.

[rancher1913]

https://www.amazon.com/100-Piece-Security-Ratcheting-Screwdriver-Vanadium/dp/B0744BTGJ8

upper left corner, is that what your talking about?

[Tatume]

I haven't done any machine work since I was in high school 50 years ago. An X-Y table for my drill press might enable me to do what I need, but I need advice before spending any money. To re-cut screwdriver tips the way I want them, the cuts should be flat and parallel. I don't want to hollow-grind tips.

Some of my screwdrivers have square shanks, and some have round shanks. An inexpensive pair of of Vee-blocks that I can clamp in the X-Y table should hold both types. They run from the mid-$30 range to hundreds of dollars. For what I want to do that seems excessive. Is there a bit I can buy that will cut a simple 90-degree groove? Then I could make a Vee-block set good enough for what I want to do. The groove does not need to be very deep; my screwdrivers are small.

Then I will need an end mill bit. Amazon has inexpensive bits for around $15, or carbide bits starting around $30.

My thought is to make the Vee-block so it rests on the bottom of the X-Y table jaws, before the jaws are tightened. The screwdriver tip will stick out slightly past the side of the table jaws. That way I can remove the screwdriver and replace it without losing the depth of cut setting. Then I will adjust my quill stop so the end mill barely touches the screwdriver bit, and make a cut. I'll then loosen the vice jaws, turn the screwdriver over, and make a cut on the other side. If the thickness of the screwdriver tip is good, I'm done. If it is too thick, then I'll do it again.

Does this sound like a workable plan? Can you recommend specific bits and an X-Y table? If it is a bad idea, please say so.

Before I buy new stuff, I'll probably put a WTB ad in the swappin and selling forum.

Thanks, Tom

[country gent]

I just purchased a x-y table from grizzly the 6 X 18 model Its good and has adjustable gibs to play can be taken up. Its a t slot table so either a vise or make your fixture to bolt align in a tee slot.

You definitely will want carbide for better screw drivers. their hardness will dull HSS quickly. Remember most shops look on end mills as expendable or consumable tooling.I have used a lot but by far the one brand I really like is OSG but they are pricey.

Doing the hollow ground style would require only one set up cut first side the raise up and move over to second side. This would allow the bit to be cut plunging and easier on the drill presses spindle. Im not big fan of end mills in a drill press, hard on the spindles and normally not locked in as solid as a mill collet. Take light cuts wear appropriate PPE and be careful.

I didnt purchase the table for milling but to do hole patterns when the bridgeport is tied up with something else.

[Tatume]

Doing the hollow ground style would require only one set up. Cut first side, then raise up and move over to second side. This would allow the bit to be cut plunging and easier on the drill presses spindle.

That makes a lot of sense. Thank you. What type of bit would be best?

[Scrounge]

I haven't done any machine work since I was in high school 50 years ago. An X-Y table for my drill press might enable me to do what I need, but I need advice before spending any money. To re-cut screwdriver tips the way I want them, the cuts should be flat and parallel. I don't want to hollow-grind tips.

Some of my screwdrivers have square shanks, and some have round shanks. An inexpensive pair of of Vee-blocks that I can clamp in the X-Y table should hold both types. They run from the mid-$30 range to hundreds of dollars. For what I want to do that seems excessive. Is there a bit I can buy that will cut a simple 90-degree groove? Then I could make a Vee-block set good enough for what I want to do. The groove does not need to be very deep; my screwdrivers are small.

Then I will need an end mill bit. Amazon has inexpensive bits for around $15, or carbide bits starting around $30.

My thought is to make the Vee-block so it rests on the bottom of the X-Y table jaws, before the jaws are tightened. The screwdriver tip will stick out slightly past the side of the table jaws. That way I can remove the screwdriver and replace it without losing the depth of cut setting. Then I will adjust my quill stop so the end mill barely touches the screwdriver bit, and make a cut. I'll then loosen the vice jaws, turn the screwdriver over, and make a cut on the other side. If the thickness of the screwdriver tip is good, I'm done. If it is too thick, then I'll do it again.

Does this sound like a workable plan? Can you recommend specific bits and an X-Y table? If it is a bad idea, please say so.

Before I buy new stuff, I'll probably put a WTB ad in the swappin and selling forum.

Thanks, Tom

I did a HS machine shop class in 1973, my senior year of high school, and just read about machining until 2008, when I bought one of the Harbor Freight 93212 7x10 mini-lathes. Couldn't remember enough of the class to really do all that well with it. Made some blade guides for a bandsaw, and some odds and ends. One day, when I was griping about it, SWMBO suggested I take another class. That was December of 2014. I started the class in February 2015, and have been attending part-time ever since. Also been building my own small machine shop in the back room. When I got done with the bookwork and handwork portions of the class, all the lathes were tied up, so I started working on the milling machines. Finished that about 1.5 years ago, and started the lathe finally. I've successfully cut some threads, and butchered some more, and I'm maybe a dozen small projects and parts from being done. Health problems have slowed me down, mine and my spouse, and the Covid-19 thing, but I've learned a tremendous amount, and it's been fun. Many of the projects took me up to 7 tries to complete. Once I learned how to feel the correct tension when measuring that number started lowering. This is setup for what follows:

For the 90 degree cuts, get an angle vise, and set it at a 45 degree angle. Clamp your block in it, and cut straight across it. You'll have a small shallow v grove. You can widen and deepen it if needed. Or you can remove most of the material you want go with a hacksaw, and finish with the end mill. then cut it in half, and you have two matching V blocks. A good X-Y table will be almost as expensive as a mini-mill, btw, and your drill press bearing aren't designed for milling. They don't like sideloads. So if you use it, you're going to wind up wearing out the bearings. You can do a lot of what you need to fix your screwdrivers the way you want them with hand tools. Hacksaw, files, hammer and chisels. Back before machine tools were invented, that is how things were done. Archive.org has books on that in their American Library that you can download for free. It's called "benchwork" in several of the old books on machining. Burghardt, Colvin, Stanley are names to search on. The HF mini-mill and mini-lathe are about $700 each new right now. They go on sale for about $600 once in a while. I got a very used mini-mill from Craigslist a few weeks ago for $350.

https://www.amazon.com/s?k=x+y+table&i=tools&hvadid=77721858535386&hvbmt=be&hvdev=c&hvqmt=e&tag=mh0b-20&ref=pd_sl_4beonpcn2q_e The amazon link lists a bunch of x-y tables, most of which are aluminum. They'll work for a while, but they're not very strong. There are a couple of cast iron tables there, too. Cheap ones tend to be sloppy, but you can fix that if you want. I've not seen the Wen x-y table in person, but the one Wen tool I've owned lasted for about 50 years before I finally broke the poor thing.

OTH, nothing about this is economical, and it can get addictive. I've got 3 lathes, two milling machines, a shaper, 3 drill presses, two bandsaws, not counting the hand-held model, and a 3-d printer... so far. Oh, yeah! 4 bench grinders, several angle grinders, and lets not talk about the number of hand tools. ;)

[Green Frog]

As a certified "Seasoned Citizen" the state of Virginia lets me audit all the classes I want, including machine shop classes. About 10 years ago I took a bunch of them, and got to where I could efficiently turn perfectly good raw stock into scrap. I got busy with other things and have neglected the bench lathe and horizontal mill in my basement for about the last decade... I'm about due to get them dusted off and get back to ruining perfectly good material! [smilie=l:

Froggie

[Scrounge]

As a certified "Seasoned Citizen" the state of Virginia lets me audit all the classes I want, including machine shop classes. About 10 years ago I took a bunch of them, and got to where I could efficiently turn perfectly good raw stock into scrap. I got busy with other things and have neglected the bench lathe and horizontal mill in my basement for about the last decade... I'm about due to get them dusted off and get back to ruining perfectly good material! [smilie=l:

Froggie

I resemble that. Got more equipment gathering dust, I believe, but a STRONG resemblance! I'm now officially retired, too. Not sure if that's seasoned, or well-done. Oh, no, probably not well done, or I'd be better. My instructor did tell me I was becoming a good machinist, though. I hope she was telling the truth, not trying to keep my spirits up. It's after 7pm, been up since 9:30am, and just now putting my socks on. I need to get off here and go work on the shop. Y'all have a great day!

Bill

[Tatume]

Just to let folks know, I've spent the time practicing and can now grind my gunsmith screwdrivers with nice flat sides and the thickness that I want. I've found that 0.028" tips work well on my post-war S&W side plate screws, and 0.025" tips fit pre-war screws snugly. These cover much of my needs. Thanks for all the encouragement and suggestions.

[Drm50]

Brownells has the jig for Drill press. I never needed one before but can’t see good enough anymore. I’ve got a cigar box full of broken tip gun screw drivers of all brands. Don’t have a full set of anything any more.

[pietro]

.


K.I.S.S. :bigsmyl2:



http://www.finegunmaking.com/page16/files/00233-screwdriver-grinding-.jpg

[indian joe]

Pietro
whydidntithinkofthat?

[W.R.Buchanan]

Come on Man! that's too easy!!!

Randy

[Brass&Lead]

pietro - I like that idea!

[bangerjim]

I use my 12" slow-speed (300 RPM) grind water stone to give me perfect hollow ground sides and a square end. Made a jig to do all the accurate positioning work.

The slow water stone will never burn steel. I use this same stone to give perfect hollow grinds for my plane blades, wood lathe tools, and cutting tools. You cannot get that perfect machine grind by hand!!!!!!!!! The wife loves the perfect hollow grind I put on her kitchen knives.

[uscra112]

TatumeEnd mills were made and ground to cut on the END.....hence the name. Yes, they will cut somewhat on the side flutes, but the grind angle is all wrong and will cause severe chattering....even in a sturdy milling machine!

:holysheep There's only about ten generations of toolmakers, machinists, CNC programmers, and process engineers who will be amazed to learn THAT.

Reason to not use mills in a drillpress is that the chuck can easily come loose from the spindle taper due to the intermittent side loading. The mounting method is only intended for axial loading in compression. (NOT that I haven't done it from time to time, using very small mills taking light cuts in aluminum.)

[uscra112]

Still, end mills are not really recommended for pure side cutting due to chatter and poor surface finishes.

????Please. Let's not confuse/misinform the non-machinists in the audience. 100.000% of end mills are designed for and used for cutting with the side flutes. A tool ground for cutting only on the end is called a drill. Many end mills aren't ground to cut on their ends at all. I've had a hand in removing kilotons of aluminum from billets and forgings to make airframe parts - ribs, flap tracks, spars, engine and landing gear mounts, seat brackets, und-und-und. All using the side flutes of end mills. End mills are today being used to rout out openings in the carbon-fiber-composite skins of the F-35. (Been there. The final mission of my career in aerospace was at Lockheed in Fort Worth.)

A historical tidbit: End mills came to be called that because they were mounted at the end of the machine tool spindle, as opposed to being set in the middle of an arbor. 'Least that's what my mentor in the machine tool industry told me back in the '70s. He was old enough that he might have been there.

[bangerjim]

whatever