Monitor Steam Engine

[mklotz]

Cheap Harbor Freight drills have their place, too.  Last time I was in the Perfumed Palace I picked up a set of their left-hand drills for a measly $6.40 ($8 and 20% coupon).

http://www.harborfreight.com/left-hand-drill-bit-set-13-pc-61686.html

In my shop about the only use for left-hand drills is drilling out the relatively rare stuck or broken screw.  Since I regard this as drill abuse, I really don't care if I destroy a drill with each job.  Might as well destroy cheap drills.

Actually, after examining them, they're reasonably ground and look to be made of genuine steel, not Mazak. 

[Flyboy Jim]

Jim,
My chart shows #38 for 5-40 and #37 for 5-44 for 75% thread in aluminum.
If you use the #37, let me know how it goes.

I didn't know until today that my tapping chart that came with my Sherline equipment was based on a 75% DOT.

I don't have a #37 yet. My #38 should be here tomorrow. I made the 5-40 nut for my first wobbler using a #36 that I had.  It was a little sloppy, but worked fine for the threaded pivot pin and spring. I threaded the pivot pin for my Elmer's #25 today and that worked good once I turned the first few threads off on the lathe. I'll make a proper nut tomorrow for comparison.

I'm with you about drill bit sets. I bought a screw length set 1/16" to 1/4" to get started. They seem to work pretty good, but I've only been ordering good bits in individual sizes since then. Now based on my new knowledge from today it looks like I'll be ordering more for doing 65% DOT threads. 

All in all a good day today! 

[b.lindsey]

Just a comment on drill sets. I have a full set of fractional, letters and numbers at work though not used that much these days. Here at home I have a set of number drills (1-60) and a set of fractional up to 3/8" by 64ths. Between the two sets at home I would say I use the number drills about 90% of the time and the fractional only 10% and even then a far fewer number of those. When you think of drilling undersize for reamers and all the tap drills for hobby sized screws, the number drills are needed far more often.

Bill

[zeeprogrammer]

All in all a good day today! 

Lucky man.
I'm still recovering from last night's festivities. Whew...these youngsters know how to party.
Well...I still know how...but 'able' is another story.

Probably a factor in today's tap disaster.

Silly kids. They got in an argument of who I sounded most like. Jeff Bridges or Kevin Costner.
I don't know how many times I had to say "hey careful man, there's a beverage here".
Last week it was a couple of dental technicians. Wanted me to call their mom as Kevin and wish them a happy birthday.
(By the way...inside my own head I sound like Kermit.)

I need a zee quote. Something other than the 'crap', 'drat', 'rats', and 'fooey'.

Just saw your post Bill. I agree. The number set gets used much more often. The 1/64s some. The alpha rarely.
And thanks for your reply about drill bits. Supports what I was thinking.

[crueby]

Better kermit than the swedish  chef or beaker!

Years ago I picked up a full cobalt set on sale, very happy with them, very sharp, durable. I too use the numbered set most, alpha least, though nearly every one has been used at one time or another.

[b.lindsey]

Maybe you should post an audio file Zee...some scene from Dances With Wolves or Starman and let us decide. It's poll time 

Bill

[Kim]

Zee,
I'm not the most experienced person on the list, but I can tell you that there is a WORLD of difference between the Chicago Latrobe and Precision Twist drill bits and the HF stuff.

Several years ago when I realized I was hooked on this hobby, I upgraded from my $30 set of 119 HF bits (1/16-1/2 by 64ths, 1-60, and A-Z) and purchased the same sets of screw machine length bits from Little Machine Shop.  These cost $50-$70 each, and I thought they were great.  A whole class ahead of the HF bits (they were even straight! And sharp(ish)).

But then, on my current project, I was having a world of hurt drilling the little holes in 3/16" wall DOM steel tubing.  It was very slow going and I was breaking bits like they were pretzels.  It was at this point that people told me I needed to use good drill bits.

On the advice from several people on the forum I purchased some Chicago Latrobe, screw machine length, 135 degree, split point, Cobalt bits, and WOW!  What a difference!  It cut like a hot knife through butter!  I kid you not.   I did the entire rest of the holes with a single bit, in 1/10 the time it was taking me before.  I'm a believer now.

Based on my new found belief in good drill bits, I decided I would replace my bits over time.  The thing is, to buy one bit is hard.  You usually have to by 10 or 12 at one go.  So its not $2-3 each size its $20-$30 each size.  So, I decided to wait for a sale.  And I did.  Last month when Enco had their 30% off everything in sight sale, they also had their Precision Twist sets on sale.  So I got these sets for almost 50% off!  I'm ever so happy that I did.  It hurt up front, but was well worth the investment!

And I got the cobalt, screw machine length, 135 degree, split point bits, and am quite happy.

Others can give you better input. But this is my story and I'm sticking with it.

I saw the light
Kim

[Dave Otto]

Wow I checked in this evening and had to wade through 3 pages; Impressive!

I would recommend 135 degree split point cobalt screw machine length drills; 99% of the work you do doesn't require the length of a jobber's length drill. The split point drills are not easy to resharpen but I'm not sure that you are re-sharpening your drills anyway. Look a Kim's thread on his traction engine and see what a difference they made in his drilling. Also I would stick with a good American brand like Chicago Latrobe or Precision Twist Drill; PTD is my favorite.

There are lots of other high performance drills out there but for general purpose use I have been very happy withe these. 

Dave

[Flyboy Jim]

Speaking of drill bits, here's something I'm wondering about:  I used Marv's formula to figure the DOT at 65% for a 4-40 tap. If my figures were right, it came out to about .0910. So a #43 @ .0890 was about .0020 (corrected) to small and a #42 @ .0935 was about .0015 (corrected) to big. However, a 2.3 mm @ .0906 was "just right". So that begs the question of whether mm bits are sometimes used to bridge the gap between numbered bits or am I tuned into my own "fairytale" here?

Jim

PS: I just came back from the future and corrected my math error that was pointed out in a later post. 

[philjoe5]

Geez Louise Zee,
While I sat around thinking of a fix for your tapping woes you received about $1000 worth of machinist consultation.  I can't add to it except, buy the best taps, drill bits and dies that you can, use oil for everything, WD-40 or Tapmagic for ally, thread cutting oil for everything else.  I made this simple ally fixture 8 years ago, use it all the time and have broken 1 or 2 taps in all that time.  If I break one tomorrow I'll be really ticked off 



Fixture in the drill chuck, constant light pressure on the quill and voila



Cheers,
Phil

[zeeprogrammer]

Audio? Not so sure. I don't do spontaneous very well. Much to my wife's complaint. I'll try in the next video. You'll have 4 choices in the poll...Jeff, Kevin, Kermit, or we'll do a "What's My Line?".

I've not bought drill bits from HF. Most of what I got was LMS. Not sure about pedigree but I figure Chinese. Then again, I suspect much of the 'good' stuff is Chinese...it's all about what quality procedures they put in.

If you can get a good deal on really good bits versus same price on regular...yeah...why wouldn't you?

But going back to it...135 degree vs 118. What makes you choose one over the other?

I remember Kim's thread. I also remember the occasion where I bought a single bit size (either 1 or a pack) and noticed the difference in drilling.

Like I said, the drill sets can be a decent start but quality suffers. Any time I bought a replacement the difference was huge. I have to think about my end-mills too. A good case where I have to question why I bought a kit of 20 end-mills and really have only needed less than a half dozen.

One zee is all one needs. I'm sure we all agree on that. 
Well okay...we can argue 'needs'...but there is no replacement.

Just saw your post Phil. Don't call me Louise.  And yes, the consultation here is priceless...yet free!

[10KPete]

Except for dedicated screw machine use I've used jobber drills forever. Until about 35 years ago when I acquired my 10K lathe and
the bed turret for it. Then I started using screw machine drills at home for the turret. And since the drill press was home size I
started using them there as well. I never bought a drill set, ever. I did buy Huot boxes and added drills as needed. Of course it
only took about 15 years to fill a few boxes, of all three types. Very early on I fell in love with 135* splits but they weren't that
common except for the screw machines. Not available in sets or on sale! So I never had a complete set of screw machine drills.
Mid last year, late last year, ?????, ENCO had some discounts that flanged up just right so I jumped on a fractional set from PTD.
Came in a Huot box and I was surprised to see the drill were made in Brazil. And they are just great!! Top quality all round. Which
I expected from PTD but I didn't know they were making them in Brazil. I jumped on the set 'cause SM drills are 90% of what I
use anymore.

Oh. Zee. I love the 135* splits 'cause they penetrate with so much less pressure than 118* non-splits. I believe they cut
straighter than 118 in either jobber or SM length. Free hand in the drill press or drill motor they don't skate around.

Did I say I like 'em??  Plain high grade HSS, black oxide finish.

So there, that's my two cents.....

Pete

[PStechPaul]

I am well satisfied with my 115 piece set of HF TiN coated drills that I got for about $50 maybe 12 years ago. Quality may have changed since then. If you want to see some really cheap ugly drills, here are some I bought in a set when I was just a young teen, in the early '60s. They were made in Japan, when that meant junk, and you can see that they are very roughly made and don't even have any margins, so they jam up if drilling anything harder than white pine:



When I checked my recollection of drill terminology, I found a pretty good reference:
http://neme-s.org/2005%20May%20Meeting/drills.pdf

Here's another bad drill:



I recently bought a set of "Trinado" drills from Enco. They seem well made, and have a triangular shank which is easy to grip tightly with keyless chucks:





I agree, to some extent, that buying quality tools is important, but I think there is a point of diminishing returns where twice the cost might only get you 20% better performance. It may be better to invest in a good grinder and learn how to use it, or maybe a "Drill Doctor". All drills will get dull, and there is a sense of pride and accomplishment to sharpening a drill and experiencing the improvement. Most run-of-the-mill drills, including many from HF, are perfectly fine for aluminum and mild steel and even 4140. For brass and copper, special sharpening is more critical than the drill material and quality.

[Jasonb]

So that begs the question of whether mm bits are sometimes used to bridge the gap between numbered bits or am I tuned into my own "fairytale" here?

No number drills in my workshop, I have a set of fractional and then two metric sets 1.0-5.9 and 6.0-10.0 both in 0.1mm steps which do all I need. The commonly used or any blunt ones have been replaced with split point and I also have a range of screw length in the commonly used sizes.

If my figures were right, it came out to about .0910. So a #43 @ .0890 was about .020 to small and a #42 @ .0935 was about .015 to big. However, a 2.3 mm @ .0906 was "just right".

Think those differences should be 0.002" and 0.0015" so allowing for your drill being unlikely to cut spot on it makes very little difference

[Stuart]

Love the crayons - is there a chapter in the Machinists Handbook on proper colors to use for different materials, tap vs clearance drilling, that sort of thing?!   

Goes with this plaque:

Crueby

Infact the third screw on the top row is a real screw they are called carrot bolts and are used to fasten the cylinder block to the boiler on a traction engine   



About half way down The page
 http://beamishtransportonline.co.uk/2015/01/ti-news-week-1-2015/

Stuart