I loved this video, the back ground music, the static, the lines and hairs, you went to a lot of effort to make it. Your British humour is wonderful. My mother used a "modern labour saving device" the washing mangle. I am from a now "dire metrical" country but grew up with trig tables ("with fewer mistakes"!) and the imperial system. I very much appreciate the full calculations are given. Well done, bravo.

I have been machining parts for over 50 years I never cut a gear in my life a while back a friend brought a 50 to 1 gearbox that was damaged needed a new worm. So some quiet time with my machinery handbook I was not able to find a pitch in metric Or inch, looking for that box of change gears I've never used nothing, I have faced such dilemmas trying to cut multiple start threads when you're already at the maximum thread pitch provided on the machine. That's when I realized what that one lever I've never used in my life was for. "The Magic Lever" π (pi) and Mod (module) inch and metric worms yay. Sure wish I had known about that a long time ago. Never too old to learn. Also I wish to thank you for your latest video on building the controller that makes it all work. Did something similar like 40 some odd years ago with a digital read out on a manual Mill to make roots blower rotors so as I moved the table in the X axis it rotated the rotor to the correct position. A friend of mine and myself prototyped what became a PSI blower they work great with methanol not so good with nitromethane it tends to go off in the blower with catastrophic results. Unlike a Roots style blower a rotary screw compressor actually compresses the air inside the blower way more efficient than a Roots blower that just beats the air to death bringing atmospheric pressure air into a pressurized manifold. Turning one of those massive pumps at about 10,000 RPM or more things start to go wrong the slow Helix on a roots rotor looked at linearly it's going the speed of sound making it difficult to the right amount of fuel in the cylinders fuel blobs bouncing all through the manifold rotary screw compressor takes what little air and a massive amount of fuel and attempts to compress that leading to a massive explosion as there is way more fuel than air and the nitro explodes in the blower you have the same issue inside the engine as more nitro exists than air as it is being compressed fortunately you have two spark plugs firing roughly 65°, before top dead center that begins the decomposition of the nitromethane molecule while still compressing it that is why top fuel cars make so much horsepower you're turning a cylinder filled with liquid into hot gas. Heat pressure 44 amps of spark times two each cylinder makes a thousand horsepower. My land speed car uses 500 lb nitromethane in under a minute to go 4 miles under power.

Golly Andy, I didn't know you had been in business so long! Well done old chap, good info for us younger blokes.

I'm still laughing "to put it in plain English 8 & 1/2 128ths"

When I seen black & white. I already knew it would be educational... Can't wait to go home from work

Seriously Andy I actually laughed out loud, informative and very entertaining buddy 👏 I must get me one of those bench grinders too

8½ 128th just killed me! Your channel is a gem.

Greetings from America, this was absolutely hilarious! The hand grinder was the part I lost it. I wish we'd just switch to metric, man.

Excellent video. I appreciate your sense of humor.

An otherwise boring topic made enjoyable and educational, great job.

My hat is off to you not only for a literate demonstration of the process but also for all the little details; this one hit me square in the sense of ha-ha and I am glad for it!

Someone has been watching Pathé Films. 😆 I have plans to make my steam engine build in a similar manner. Fantastic job on the editing, voice and soundtrack.

Fabulous, I just watched your metric video, and was about to ask for the calculations for DP gears, as I want to cut some for a 1" minnie traction engine. I'm so glad that I scrolled down a bit, before I did. This video is brilliant, had me laughing my socks off! I think I finally understand gear cutting now. Now just to get my head around trig and I'm all set 😄

Brilliant video production! You really nailed all the quirks of a vintage training video, also verry amusing.

A superb pastiche of an old time newsreel style, to use an expression from the future, luv it!

I have been laughing out loud through this whole video. Thank you! I needed the info, being a newbie, but in a more digestible form. Your humorous approach is perfect!

This is the best produced video I have ever seen on KZread. Two thumbs up! 👍 👍

"Or in plain English, eight and a half one-twenty-eighths."

Just found the channel today and did a good deal of binge watching. Keep up the great work!

This was absolutely delightful! I burst out laughing when I saw the subtitle on the cover of the book of trig tables. I am old enough to remember learning to use trig and logarithm tables -- shortly before inexpensive electronic calculators became available.

Outstanding ! I love watching old instructional videos and your replication of one made a fantastic video even better

This was hilarious! You nailed the mid Atlantic accent. It's very obvious you've watched an absolute ton of old instructional films :)

Very creative way to explain things! Thanks Andy!!

Love the traditional presentation, takes me back to all those chemistry & physics films they showed us for ‘O’ & ‘A’ level in the good old days!

absolutely barbaric! No wait, absolutely imperial! Laughed so hard whilst enjoying this piece of art

Your wit, sir, is singular.⚙

I enjoyed the novelty of your imitation old video. The information on making the hob was very interesting as well. Thanks for the video.

Eight and a half one hundred and twenty eighths … had me laughing in my chair!

'modern labor saving devices'??? Brilliant, many thanks!

This is the best. I love a good laugh. And good info at the same time. Nice work!

I love how this is basically a nonstop bash on the inferial system :D

@AndysMachines

2 жыл бұрын

'Inferial system'! I like it!

This video earned an instasub. I laughed my ass off and learned a ton. Time for a dive into the back catalogue.

I was waiting for Graham Chapman to come out and slap somebody with a fish

this was clearly a lot of effort and i really appreciated it :-)

Thanks for sharing 👍 I enjoyed your old school industrial format.

not only do you make dope gear hobs, you make mad laughs too! xD thanks for the info _and_ entertainment.

I am now dead. Hilarious and very accurate

Oh mate....very very fine work. Not just the Hobbs but this is just brilliant buddy 🤪 maximum effort well delivered. 🤪 I'll be laughing about this for weeks but very few people I know will get it. Great stuff.

So informative thanks for teaching about such complicated things in such a simple format. I might pick up the required equiptment soon

Love it. Well done and excellent production work.

Very well done, looking forward to the next!!

Brilliant in so many ways! Made my day.

Andy, this was wonderful! ;D About the only thing you missed was showing a steam-engine-powered, overhead-line-shaft/leather-belt machine shop doing the work for the lathe & mill work. ;) (And _I_ live in the US too!)

@AndysMachines

2 жыл бұрын

Yes, that would have been a bit too much for me to try and replicate! Though I did try to reproduce the sound of the belts and shafts.

Bloody marvellous video!

Utterly brilliant !!! 👏👏👏👏👏

Excellent video 👍

Fantastic, modern metals, iron and cast iron. Hahaha

I like that video 😂😂😂 Keep doing great things 😁❤

Ah , ah , Funny video, I enjoyed the ability to grind the tool freehand ;-)

Freakin' hilarious! 😄

Bloody good. Informative and Funny. I love it.

Ha ha, really enjoyed that one, thanks!

Great work

Really nice!

Amazing! Even with my lame English, I understood most of what was said by ear. And I really liked the style of the video, fun and smart😆👍

Very good reminds me of my time in the navy. Make one about your controller so I can turn my mill into a hobbling machine too

A little sarcasm on imperial precision of things but what missing in this imperial version is that the compound slide should be set to 14.5 degrees when cutting the hob.

@AndysMachines

2 жыл бұрын

True! I actually just reused footage from the metric version, I hardly ever cut DP gears myself, but nowadays they are mostly cut to 20° like metric ones rather than 14.5°

Excellent

Great info

Enjoyed the tongue-in-check approach but in your earlier videos on building the Dividing Head "Gear Hobbilng Attachment" parts 1 & 2. You show the dimensions for the raw material but I'd really appreciate a set of dimensioned drawings. I am trying to work them out by watching the videos again and pulling screen shots and scaling them but a set of plans would make it a whole bunch easier. Keep up the good work.

@AndysMachines

2 жыл бұрын

Thanks! The dimensions are not really critical, you can build it any size to suit your needs. If you want it to tilt all the way to 90° you just need to allow enough space between the supports and height above the base for it to rotate all the way. I only did rough drawings myself when building this, but when I get time I will upload some dimensioned drawings to Patreon.

Utterly brilliant 😀 And people say I'm crazy lol

Excellent video as always :D can I get a question? I don't have access to O1 steel where I live so do you think vc131 or VND steel would work?

HAHAHA. This is wonderful!!!!

I guess you had as much fun making this as I had watching it. Very well done all round. You demonstrated that neither a ruler nor a thumb can measure the cutter width (which by itself makes this whole process cutting edge technology), but surely these old imperial geezers would have done it with cigarette papers, they seem to use those for nearly everything that needs measuring? Do you think there will ever come a day when a woman could make an imperial gear hob?

Brilliant! 😄😄

Quite good! Open questions: (Before having "rewatched" metric version :-) ) Did you grind relief on the teeth, or can you get away without it? How many teeth/gashes are you suggesting? Is a special assymetric relief for the cutter advisable to account for the helix angle? Do you mark the hob helix angle, pressure angle and pitch on the hob to remember all this?

@AndysMachines

2 жыл бұрын

I don't actually put any relief on the sides of the hob teeth and I keep them quite short because of this. It is possible to add this relief but it's a lot of extra work and doesn't seem to affect the cutting at least at the slow feedrates used in hobbing. I usually cut as many teeth as I can fit using one endmill to cut both the face of the teeth and the back relief of the next row of teeth at the same time. I find it easier to store small cutters in plastic bags with the information written on rather than try and put it on the cutter itself.

@timogross8191

2 жыл бұрын

@@AndysMachines Thank you very much for taking the time to answer.

Best ever video for imperial addict. Probably a little lack of reference on a well known brand of tools "made proudly in USA"? 👌👍🖖

hola Y acá estamos... excelente video está Genial muy bueno 🤜🤛👍👏👊

Thanks!

@AndysMachines

2 жыл бұрын

Thank you! I'm glad you enjoyed it, and maybe learnt something useful too!

🤣🤣🤣🤣 Brilliant, absolutely brilliant.

Brilliant 🤣

Really enjoyed the explanation - having just made a hob successfully for cutting worm wheels. I am a bit fuzzy on setting the helix angle of the hob relative to the worm wheel blank as the worm gear in use is smaller in diameter than the hob (both worm gear and hob were screw-cut at 12 t.p.i. with the same tool). The helix angle of the worm gear is 6.8degrees and that of the hob is 3.7degrees, so the hob was set relative to the worm wheel for hobbing at 3.1degrees, being the difference. The gears mesh well - but is this the correct way to do it?

@AndysMachines

2 жыл бұрын

If the hob is bigger than the worm I would probably do the same as you did and tilt it to make up the difference in the angles. Strictly speaking this will introduce a cosine error which will affect the cut, but at ~3° it will only be around 0.15% pitch error which is probably negligible. Obviously the worm won't make full contact with the teeth of the wheel, but probably not a problem, I have seen worms run with straight cut helical gears many times.

Cool!! :-)

Buen aporte!

Yeah, we *are* that backwards.

"iron and cast iron" lolol ok

Next could you explain knerling and how rubbing against the piece in the lathe cuts the pattern. To me it just looks like the tool is pressing into the metal.

The hob is cut as a thread with a pitch of 0.196". I.e., 5mm!

@AndysMachines

2 жыл бұрын

For a 16DP gear the pitch is pi/16, =0.1963" or 4.987mm, but yes close enough that you could get away with using 5mm, the total pitch error along the length of the hob would only be around 50 microns.

How would you calculate the flat distance for grinding a hss tool for making a worm wheel hob? Also when cutting the hob the OD should be bigger than the worm gear for clearance how much bigger? When making a hob to a cut worm wheel wouldn't the hob match many dimensions of the worm gear. There for the hob is only used to cut worm wheels for that specific worm gear. If the worm gear is 2 start would the hob have to be 2 start or would single start hob work?

@AndysMachines

2 жыл бұрын

You would do it in a very similar way. Yes, the worm hob should be similar to the worm except that the addendum and dedendum are swapped over, so the OD of the hob is greater than that of the worm (by 0.5-0.8 x module). People often make two identical worms, cut teeth into one and use that as a hob to make the worm wheel, though this does work it is not technically correct as there will be no clearance. I actually made a worm, matching hob and then cut a worm wheel with it recently. I took video footage of the process and this will most likely be in an upcoming video where I'll try and explain the whole process.

@machinist123

2 жыл бұрын

@@AndysMachines Thanks, love you lol

Question: When using the "New Fangled Ball Bearing Trick": I'm guessing the cutter has no rake angle and is raised half the ball diameter on a 0.125 gauge block so the helix clearance angle does not affect the new fangled measurement? How do we calculate the helix clearance angle for any given hob diameter? Thanks again

@AndysMachines

2 жыл бұрын

Yes, and yes. I glossed over a few details in this version. I covered both of these points in the metric version.

I love this old version. So if i understand your modern version is a copy of this old one!😂

Can You make pipe extruder ?

Andy do you have any notes on the electronics you could share?

@AndysMachines

2 жыл бұрын

I have this video on the controller I built for this: kzread.info/dash/bejne/lJmImpVqYs6Zqaw.html

What angle from the vertical do you run the hob and why ?

@AndysMachines

2 жыл бұрын

At the helical angle of it's spiral cut teeth so that they cut in the horizontal plane (the direction of feed). There's more detail about this in my other videos on building the hobbing attachment.

What, no banana references?

I'm not a specialist of english language nor a good english speaker for sure .. But am i right, that you are trying to sound much less birtish than normally, of course to fit those chevrolet educational documetaries?

@AndysMachines

2 жыл бұрын

I wasn't really aiming for any particular accent/dialect, just trying to recreate that 'vintage newsreel' type of sound.

I am disappointed! I bought that same bench grinder to try to follow this tutorial but they sent me a metric one and does not work for grinding imperial.😔 All jokes aside this video is funny as heck.

0:40 anyone else noticed that one oversized tooth?

Hardware emporium. haha

Why these accuracy measurement is measured by inches not mm🤔

@rickwest9904

2 жыл бұрын

he did the metric version in the previous video

@NickStallman

2 жыл бұрын

Ah but they were measured in mm since the inch's definition is backed by the metric system. :)

@Rechenmaschine9752

2 жыл бұрын

mm did not exist back then

@onkelhenning

2 жыл бұрын

Because he has done a video in metric. there is a link in the discription

@AndysMachines

2 жыл бұрын

That's actually correct. Since 1959 the inch has been defined in mm. Before that there were different sized inches sometimes in use at the same time, such as the bigger Scottish Inch. Even today there is still the US Survey Inch which is fractionally different to the 'regular' inch (1/8" per mile difference), but it's being phased out in 2023.

Imperial A.K.A. stupid version.