drilling steel on an angle

[elementFe]

Lessons learned:
*You can't necessarily get machine cutters in a small town, even a busy seaport town. Apparently those things come from jobbers, not stores.
*When you DO finally find one, twenty miles away, you can't do accurate, nice looking work with machine tools on a cheapo Grizzly drill press. It's just not that steady or accurate: I'm tempted to post a youtube video of the wobble...it would be nice to dance to, but sucks for steel work.
*There's no substitute for real (read, "expensive") metalworking tools.
Options are to spend another day chasing around looking for a drill press to use, hiring a machine shop and waiting....

Considering that consistency can often hide inaccuracy (as long as the inaccuracy is consistent) perhaps I'll change the layout, punching straight through, and using a hand drill and lots of fluid, torque the hole sideways enough for the bar to pass through on the correct angle. Not what I'd wanted, but there's something to getting the job done.

The big question is, how much slop is acceptable?
*sigh*
...decisions like this are what make me, the C.E.O, worth the big bucks. Perhaps I'll vote myself a multimillion dollar bonus at the end of the quarter.

[arftist]

Don't give up yet. Yes, things like endmills and other machine shop tooling are best purchased from MSC or McMaster-Carr, both of which ship the same day for delivery (in most cases) the following day. A Grizzly is a bit week for this operation.

One of the ealier suggestions would still work though. Using a die grinder, with a small ball end cutter, make an impression in the stock, about 1/2 diameter deep. Work slowly and carefully, keep both hands on the tool at all times, and above all wear safety glasses. Next, with a hand held drill motor, drill a pilot hole through the stock at the required angle. 1/8" or 5/32" would be apropriate. Realize that a bit that small must spin fast, well over 1000 rpm or it will break easily. Also, with a small bit, very little feed pressure should be used. Note that many common drill motors, especialy those with a 1/2" chuck are too slow. The work is possible with such a tool, but the likelyhood of a broken bit is dramaticaly increased. The next step is to drill to the finnished size.

If this fails, there is still another, yet more difficult method.

[arftist]

Slot drill was the name for it in the UK when I served my apprenticeship way back in the mid last century (Thanks for reminding me about that detail, may have to change my description to 'Old Fossil' now)

Other locations may well know it by other names,

As for the 4 flute end mills, (some may have more than 4 flutes, the numbers of flutes also alter with sizes but to quote Biggundoctor "A 4 flute is usually smoother when plunging" I personally have never come across one that you can plunge cut into solid material as the end is flat, with a slight recess in the centre that governs how far you can cut vertically into the material,and the centre of the tool is solid, and so will bottom out when the tooth depth of the cutting end is reached, smoothness of cut can also depend on rates/relationships of speeds and feeds, sharpness and cutting angles on tool's edges, materials being cut, and rigidity of workpiece and tool mounting.


We use the method I described above to drill many thousands of angled holes a year. The endmill doesn't need to drill through, just spot a small flat, large enough for a twist drill to start correctly. The fact that it is entering the work at an angle provides plenty of "relief".

On a further point as to names of tooling here in the UK, again Biggundoctor mentioned "Get a center drill (combined drill, and countersink in some catalogs),a #5 or #6 has a 1/2" shank. These drills are short, and stiff, keeping them from walking on you I use these all the time at work for angled holes."

We call these Combination centre drills, but originally they were known as Slowcombe (Slocum) Drills,

To Quote again "The center drill will get you a pilot hole made which you can follow up with a regular twist drill" and they are perfect for that, however take care as the small diameter end portion is prone to breakage.

These combination drills were more commonly used on lathes to assist supporting longer pieces of work being turned.

They will also produce a chamfered (Angled) front to the hole, this angle is the same as the angle on a lathe centre used in the tailstock of the lathe, the pilot on the drill allowing the centre to clear the end of the lathes tailstock centre, this allows the piece to be securely supported at the end some distance from the lathe's chuck whilst turning long parallel lengths, a steady (travelling or fixed) can also be used to aid rigidity throughout the cut being taken.

By definition an end mill is for milling/machining flat areas then you get other types of cutters, slab mills, side and face cutters, slitting cutters, dovetail cutters, T slot cutters etc, the clue is in the name, hence slot drills are for "drilling" into materials to the full depth of the flutes on the tool, and mills are for milling areas.

We are travelling into the realms of engineering now and most people do not have the machinery available to use these types of tooling correctly, it is also fairly expensive to purchase new, and need to be used with care to be safe.

However Blacksmiths were the forefathers to the Engineers, and this type of joint was being made before machinery was available, but this application that the original question was posed about may be a finished welded application as opposed to a forging problem.

I look forward to seeing pictures of the finished project as I am intrigued by the sizes/types of materials stated as to finished proportions, methods of assembly etc. If the 1" x 1.5" is solid, it is going to be quite weighty.

Thanks to Biggundoctor for his prompts, and apologies for the long windedness of the post

We use the method I desribe above to drill thousands of angled holes a year. The endmill only needs to create a small flat in the work, enough for a twist drill to be properly started. The fact that the endmill enters the work at an angle adds extra "relief". In tube or pipe, a center cutting endmill will readily peirce at an angle.

[BIGGUNDOCTOR]

Here is a down and dirty way to do this. Take a cutting torch, and blow a slot in the bar at roughly the correct angle. Take a tube with the appropriate inside dimension and weld it at the correct angle in the bar. Take an angle grinder and grind it all flush. Either that or just clean up the hole if ya got a steady enough hand.

Look for the center drill (combination drill), that will do what you want, even with a wobbly Grizzly. MSC is a good company to deal with. Some others that I have used when I had my shop were Enco, and J&L.

Hey John B, don't worry about the expansive explanation, it's all good info. As to the 4 flute endmills bottoming out. Some are made that way, and others have a center cutting tooth geometry. Kind of like a 2 flute endmill with 2 extra teeth added on. I use center drills for a lot more than lathe work due to their rigidity. The size he will need will have about a .125" pilot, so I think it should hold up fine for this application.


Machine tools do not need to be expensive. I have bought most of mine for $0.10 on the dollar. I know a used machinery dealer who has picked up several Bridgeport, and it's style, mills for as little as $500. Lots of shops closing which means lots of surplus machinery on the market. The Bay Area of California has been losing shops for quite some time now. I once walked past 6 machine shops to get to the one that was being auctioned off. I just saw an ad on the local CL for a lathe, and a surface grinder - $500 each. They are out there, just like anvils, you just have to look for them.

[peacock]

I don't know exactly what you are wanting to end up with so this may not work. Could you drill the holes a 90 degrees then forge the tendons at the angle you need? angled tendons are not nearly as hard to do as drilling angled holes. Set the sloulders at the angle you want on two sides set the inside of tendon to match the sides leave outside of tendon flush. Make a monkey tool that will fit your hardy hole. Heat up your stock stick it in the monkey tool hit other end of bar as you pull the bar over to the neede angle. The bar will upset at the shoulder as the tendon moves to the center of the bar. It all sounds hard to do but is much harder to explain than it is to do. One or two pratice bars and you will be on your way.

[elementFe]

I don't know exactly what you are wanting to end up with so this may not work. Could you drill the holes a 90 degrees then forge the tendons at the angle you need? angled tendons are not nearly as hard to do as drilling angled holes. Set the sloulders at the angle you want on two sides set the inside of tendon to match the sides leave outside of tendon flush. Make a monkey tool that will fit your hardy hole. Heat up your stock stick it in the monkey tool hit other end of bar as you pull the bar over to the neede angle. The bar will upset at the shoulder as the tendon moves to the center of the bar. It all sounds hard to do but is much harder to explain than it is to do. One or two pratice bars and you will be on your way.

I kind of wish this was a forged joint, I know more or less how to do that- got a great lesson at the last NWBA conference from Mark Aspery.
These are 1/2" round bars passing through 1/2 x 1" flat bar on a 34 deg. angle, everything on this railing system is tight and crisp, no forged work.
The end mill really did do what it was supposed to but there was enough wobble in the drill press (Griz floor model, 12 speed) that the flat that it ground was oversized. If I ran it far enough down so that I could center punch the center of the flat, there was too much slop around the 1/2" drill hole- is that clear as mud?

[peacock]

use a smaller end mill or drill the 34 degree hole in a 1/2 or thicker piece of plate clamp that to your railing part and use that as an angled drill guide. clamp it realy good so it don't walk off the correct spot. if you can set it up with a hardend drill bushing will be even better.

[John B]

I kind of wish this was a forged joint, I know more or less how to do that- got a great lesson at the last NWBA conference from Mark Aspery.
These are 1/2" round bars passing through 1/2 x 1" flat bar on a 34 deg. angle, everything on this railing system is tight and crisp, no forged work.
The end mill really did do what it was supposed to but there was enough wobble in the drill press (Griz floor model, 12 speed) that the flat that it ground was oversized. If I ran it far enough down so that I could center punch the center of the flat, there was too much slop around the 1/2" drill hole- is that clear as mud?

That is a little different proposition to your post#12 which makes the material appear to be 1" x 1.5" (one and a half inch) and this is a whole different ball game and makes more sense than the larger former size stated. And in that case I would go with what peacock suggests, but I would go with a bar thicker than the 1/2" to use as the guide bush

Are the 1/2" bars going to be welded and ground flush or what?

(mini rant)Forge work can be tight and crisp when done correctly by the way, it's is only in recent years (post 1940's)that distressing or hammered finishes have been introduced to suggest things are hand forged to unknowing customers. If you left any unintended hammermarks on a piece in those days you would incur your master blacksmith's disapproval to put it mildly, nowadays it seems to be perceived it must have hammermarks in to suggest it has been handmade by a blacksmith, its called distressing, well it certainly distresses me, haven't people heard of hammer control and flatters? (rant over)

[Sam Thompson]

That's an interesting point, John. The only time anyone makes anything 'perfect' nowadays is as an apprentice. In some ways I think that making stuff look rough in the belief that it will look old is a bit of an insult to our antecedents. There's a few hundred years between badly-made and worn.

[John Larson]

The only way to do this job reliably IMHO is to clamp triangular piecs top and bottom so that the drill bit enters and exits perpendicular to the faces of those added triangles. If you can band saw the triangles quickly than they are sacrificail and no need for hardening. Maybe you can tack weld them in place. That will prevent slippage.

[nuge]

(mini rant)Forge work can be tight and crisp when done correctly by the way, it's is only in recent years (post 1940's)that distressing or hammered finishes have been introduced to suggest things are hand forged to unknowing customers. If you left any unintended hammermarks on a piece in those days you would incur your master blacksmith's disapproval to put it mildly, nowadays it seems to be perceived it must have hammermarks in to suggest it has been handmade by a blacksmith, its called distressing, well it certainly distresses me, haven't people heard of hammer control and flatters? (rant over)

I think one of the most appealing aspects of working hot steel is the ability to impart texture, hammermarks being an overused motif. But, if done skillfully, with thought and maybe a good dose of restraint it is effective. To leave toolmarks leaves a story. The industrial revolution is over, the machines won. When children visit my shop I often ask them if they prefer the textured metal or the mill finish and it's always the bumpy one. Its tactile. And interesting. Smooth is a texture we maybe know too well. Bring on the imperfections.

[Dr Dean]

The only way to do this job reliably IMHO is to clamp triangular piecs top and bottom so that the drill bit enters and exits perpendicular to the faces of those added triangles. If you can band saw the triangles quickly than they are sacrificail and no need for hardening. Maybe you can tack weld them in place. That will prevent slippage.

That's a great idea! The triangles would need to be clamped very well, I will keep this in mind the next time I need to do something similar.

[John B]

I think one of the most appealing aspects of working hot steel is the ability to impart texture, hammermarks being an overused motif. But, if done skillfully, with thought and maybe a good dose of restraint it is effective. To leave toolmarks leaves a story. The industrial revolution is over, the machines won. When children visit my shop I often ask them if they prefer the textured metal or the mill finish and it's always the bumpy one. Its tactile. And interesting. Smooth is a texture we maybe know too well. Bring on the imperfections.

Nothing wrong with texture, as I said in my mini rant

If you left any unintended hammermarks on a piece in those days you would incur your master blacksmith's disapproval to put it mildly,

Texturing was done, but done for a reason as part of the design/specification not as an excuse for poor hammer control

[nuge]

Well, there are no unintended marks on that Paley bench. It surely speaks to a smith's skill to execute those long tapers and flowy lines with nary a divot.

[Mark Aspery]

Can anyone out there walk me through the basics of drilling steel on an angle?
Making infill panels for a stairway- it seems no end of obstacles to drilling accurate, consistent holes on about a 34 deg. angle- wish I could just punch em!
My drill press is set for the angle, but getting it to actually drill in the right place without wandering to the side is baffling...
Thanks for any suggestions!
Andy G.

I would drill a square bar on end as deep as you can go and then cut slices of the bar at the angle you desire. The hole will now be at the desired angle in the slice when the slice is held horizontally.

Hope this helps.