Thread Dial Indicator imperial and metric

[@bogdan_n]

"Keep in mind that you'll never get along with only one TDI on a metric lathe cutting metric threads"... Well, that explains why the 6mm pitch lead screw lathe i found myself in front of through a twist of fate (i'm not a machinist), has 3 TDIs, and what the indicator table on the front panel of the lathe is all about. THANK YOU!

[@gangleweed]

Wow.........what a crafty way to get a TDI for a lathe not fitted with one....so simple, I must add this to my favorites listing.

[@prof-rieg]

Thank you very much!

[@robertqueberg4612]

It is interesting to see how other people accomplish the same tasks, in other nations. I have found that in most cases, a manual engine lathe does not allow a high enough surface speed to justify carbide inserts. I have been fortunate enough to have cut a wide array of different threads over fifty four years. Around forty five years ago, I made a grinding fixture, to form, and re-sharpen a standard 60 degree high speed tool bit on a surface grinder. It forms the left cutting edge, the right side to provide a 59 degree included angle for a bit of clearance, and the top cutting face, with a five degree rake, perpendicular to the left edge. This creates a better cutting action, and a much improved surface finish on the thread flanks. I would encourage you to at least try cutting a few threads, with the compound rest/ top slide, rotated clockwise 60 degrees, to form the right thread flank. You return the cross slide to 0 each time, and get the infeed from the compound rest. To cut a left hand thread, the cutting tool would need to be mirrored. Also, I have found a benefit in grinding the left cutting edge, only slightly longer than needed to reach the finished thread depth. This will allow working closer to a shoulder. I will review your numbers again, and likely have a few “dumb” questions.

[@prof-rieg]

Thank you for your hint!

[@renetr6771]

That may be right on small diameters. But the surface speed depends on the diameter of your part. If you cut threads on Ø250, u have to go extremely slow with hss.

[@stephensarkany3577]

The casenuve hbx360 lathe has a system where you can re- engage the threading at will in both imperial and metric pitches.

[@prof-rieg]

Thank you for your hint!

[@aurelianmunteanu7680]

I have 28mm x 6mm pitch lead screw. What gear should i use for making a dial indicator? On my lathe i saw 24 teeth image but tool is missing. i wanna make TDI , laser cut or buy if available.

[@johannriedlberger4390]

should work just fine with 3D prindted gears. Use as an TDI there is very little load on them. Great video.

[@prof-rieg]

Good idea - thank you for your feedback!

[@Antegrav]

Nice. Just a suggestion that an old-timer taught me: run the lathe in reverse and bring the tool around the back side. That way, if you can't disengage the half-nut (I've had some that grab hard under loads) or if you want to run faster, you will be feeding away from the work piece instead of at the chuck.

[@prof-rieg]

Antegrav Tank you for your tip. You are welcome!

[@billyrebcollins9615]

I have a Mingxi (Vevor) 8x16 lathe but it didn't come with a TDI, What is the lead screw pitch so I can try and make a TDI for this machine. I tried a 16T TDI but it will not mesh with the lead screw, If it is metric what tooth gear would I need to mesh with the lead screw in order to build a TDI for this? Thanks in advance,, much appreciated.

[@prof-rieg]

I beg your pardon but I do not know the pitch of your leadscrew. Please measure it: for an imperial pitch count the threads for one inch. Metric leadscrew: measure the length for 10 threads and divide by 10.

[@freemanfreed1581]

I really do not understand how the lead screw make a thread . what makes the lead screw to make these thread shapes ??? plus @ 8:33, when moving backward to the starting point by the hand wheel , is there no a probability that the teeth of the TDI will break?? because the hand wheel movement is kind of fast !! why the compound is @ 0 degree ??

[@prof-rieg]

I would recommend a good book upon turning regarding thread cutting.

[@alessandroandrenacci2372]

freeman freed - can i help you ? The thread is cutted by the cutting-tool, which moves with the saddle, moved in turn by the lead-screw ( through the half-nut ). In many passes you can advance the cutting-tool a bit more every time to get the shape of your thread, been it metric or imperial ( a different shape tool is to be used for each of them, 60 degrees for metric, 55 degrees for imperial ). The wanted pitch is then got inserting some gears between the chuck and the lead screw, unless you have a professional lathe so that you only have to choose the right position on some knobs ( this depending on the type and brand of the lathe ). In simplest lathes you can get the right pitch using the following ( simple ) rule : PITCH = ( Z1/ Z2 ) • ( Z3 / Z4 ) • ( PITCH_of_the_lead-screw ) Where - Z1 is the gear running with the chuck ( or indirectly connected with the chuck, but revolving at the same speed of the chuck itself ) - Z4 is a gear directly installed at the beginning of the lead-screw - Z2 and Z3 are two coaxial gear ... ( Z2 connected to Z1 ; and Z3 connected to Z4 ) They are not only coaxial, but also latched each other with a key ... Generally the simplest lathe has a label where you can find the necessary gear teeth Z ( Z1 to Z4 ) to cut a specific pitch. Those gears ( of course ) are different in teeth so that the lead screw moves as a fraction ( or even multiple ! ) of the chuck turns, pushing the saddle ( and the cutting tool ) to cut the expected thread. About breaking the teeth of the TDI, ok, it can run fast, also very fast, but it doesn't make any work no any force against anything ... unless it couldn't freely spin on it's seat ... For compound position at zero degrees, i think there are several types of cutting threads, for metric threads i set my compound at 30 degrees ( 27,5 for imperial ), but you can also go on with radial cutting, or alternative cuttings ( a bit in left an a bit in right ). Alessandro from Italy ( i'm just an hobbist ... )

[@RH-dz9oc]

Se le puede adaptar a cualquier torno? Yo tengo un Meuser. Tornillo diámetro 32mm paso 6mm

[@twkolejofil]

You don't need a skewed gear. You could mount it at the angle...

[@prof-rieg]

Yes, you are right.

[@nicosiebers1530]

Hallo, wie machst du das? Mein Lehrer sagte mir dass man pro 1mm zustellung beim gewinde 1/3mm das werkzeug nach links oder rechts macht, um nur eine flanke jeweils zu treffen. Aber gerade habe ich in einem youtube Video von ThisOldTony die Technik gesehen, den werkzeughalterschlitten einfach 30° zu drehen und das werkzeug wieder 30°, so dass das gewinde geschnitten werden kann. Ist diese Technik empfehlenswert? Ich denke ich muss dann halt die Zustellung immer umrechnen, aber das sollte sich doch lohnen alleine dafür dass man dann immer nur links schneidet.

[@prof-rieg]

Ja, das ist ein alter Hut mit der Schiefstellung des Oberschlittens. Macht man hierzulande irgendwie nicht, machen gerne die Englaender. Viel einfacher geht es so, wie ich es gelernt habe: Ab und zu dem Oberschlitten eine minimale Zustellung geben, damit hauptsaechlich die linke Schneide des Gewindemeissels schneidet.

[@nicosiebers1530]

@@prof-rieg genau so meinte mein Lehrer das auch aber ich finde das irgendwie nicht so schön, wenn die Engländer das machen dann werde ich das auch mal testen.

[@phuc9425]

Can you please confirm that you used gears with all module?

[@prof-rieg]

I used gears with metric module m=1.25.

[@microscheme1222]

hello my brother congratulation I loved your TDI class as I understand your lathe's lead spindle is M4 pitch I ask: Would you help me calculate diameter and amount of teeth for gears so I can make a TDI for my lathe that has an M3 feed spindle ???

[@tobyw9573]

Thanks for the excellent demonstration.

[@prof-rieg]

You are welcome!

[@HPD1171]

actually you can disengage the half nut even if you are cutting an imperial thread on a metric leadscrew or vice versa so long as you have a TDI and you re-engage the nut at the same position you started in without letting the dial perform a full rotation. It requires a bit of hand coordination but is critical if threading up to a shoulder and your lathe does not have a break. The "metric method" I have been taught was to pick a number on the TDI run forward as normal and disengage halfnut when you reach the end (just like you normally would) but then after you pull the tool out instead of bringing the carriage back you stop and reverse then reengage the half nut at the same number you disengaged it from without letting the dial make a full rotation (quite easy as it takes a few seconds for it to spin around completely which is ample time to stop the machine and reverse) just don't ever loose track of where you first engaged the half nut because then you will be in trouble. this is actually the method I first learned since my first threading operation was a metric thread, I was not up against a shoulder as it was my first threading operation but I wanted to start with learning this method is it better prepared me for when I did need to thread right up to a shoulder with only 1.5mm of thread relief. As long as you have decent coordination between your left and right hands which I have from playing piano it is actually a very fluid operation.

[@prof-rieg]

Very good feedback. Thank you.

[@thosoz3431]

A terrible comment. Put in some punctuation.

[@donniee1934]

​@@thosoz3431 WOW!

[@ARTEEMMETAL]

top das galáxias meu amigo

[@prof-rieg]

Muito obrigado!

[@phillipperry7927]

Author should learn the proper use of the compound slide in cutting threads at a 29.5 or 30 degree angle thus lessening tool overloading and subsequent failure. In this way only one side of the tool cuts thus halving cutter friction. Many videos out there illustrating same.

[@prof-rieg]

Never mind. Of course we know this procedure wird the slanted top slide- but we don 't like it.

[@microscheme1222]

Hello I'm trying to get gear information (number of teeth and modulus) to build a TDI to make metric and imperial threads on my lathe and I'm not getting it My lathe is a BV20L with M3 leadscrew There is not enough information on the internet Can you help me ??? I appreciate all the help you can get.

[@prof-rieg]

It is difficult to make a TDI for both imperial and metric threads. My suggestion: Make different DTIs.

[@deliosantos5943]

Hi! I have the same problem with the BV20. Apparently the helical gears module will be 1. The problem is that I still haven't been able to find out what number of teeth the gears must have to make a metric thread.

[@jerzyszczepanski9792]

Hi. Can you please confirm that you used gears with Module 1.25. Thank you.

[@prof-rieg]

Yes -- Module 1.25.

[@jerzyszczepanski9792]

Great. Thank you.

[@marioborg4154]

Hello,why doesn't dial turn when engaged,I am having same problem,

[@prof-rieg]

When the leadscrew is engaged, leadscrew and pinion of the TDI work like sprocket and rack because they move with the same speed --> there is no relative movement i.e. no revolution of the TDI.

[@Hereford1642]

You might like to read a book called - Screwcutting in the lathe - in the workshop practice series. Very cheap. It will explain to you some things that I think you are not properly either understanding or explaining. Neither of which is good for an educational establishment. For example it will give you 14 different gear ratio options to approximate the inch to mm conversion and includes the Myford approximation using the 21 tooth gear.

[@prof-rieg]

@@Hereford1642 I have this book - anyway, thank you for your response.

[@SeryjL]

Excellent!

[@prof-rieg]

Thank you very much -- we'll continue with such videos.

[@SeryjL]

Ок!

[@Sketch1994]

You didn't say how you calculate how many numbers you should have and which numbers you can engage on.

[@prof-rieg]

Sketch1994 The 30 teeth gearbeitet hast 4 numbers, the 28 teeth gear has 2 numbers. You may engage on any number, each.

[@MWSRD]

is you lead screw metric or imperial cos 8 tpi seems like the standard across a lot of different lathes and i was told 24 teeth (toothed).... gear wheel to use on a 8 tpi lead screw any info is appreciated

[@prof-rieg]

The lead screw of the Myford is imperial with 8 TPI, and the lead screw of the later shown Wabeco is metric.

[@prof-rieg]

Of course, you can cut a metric thread by the use of an imperial lead screw (or vice versa ) if you have the appropriate change wheels ... In fact you'll make a very small error because inches and metres do not match exactly.

[@HPD1171]

@@prof-rieg What do you mean they do not match exactly? 1 inch is defined is exactly 127/5 mm or 25.4000000... mm so as long as you have a 127 tooth gear you should be able to make the threads just as accurately is making threads using the "native units" of the lead screw. any error that you would get would simply be a result of error in the leadscrew which you would experience no matter what unit system you were using.

[@prof-rieg]

@@HPD1171 you are right, but, indeed you need a pinion with 127 teeth:a very big gearwheel which is difficult to mount on a Myford Lathe.

[@HPD1171]

@@prof-rieg True it is a rather large gear to have for such a small machine. I can relate to that, my smallest machine (the one I started with) is a chinesium G4000 which "barely" has enough room for a 127 tooth conversion gear and it is only a module 1 gear-train. unfortunately because of this there is no room for additional change gears to adjust the range of the thread size so it has a very limited cutting range, if memory serves me it is something like 0.5 to 3mm or 40TPI to 8TPI. but that is good enough for the small jobs it receives. It is certainly a problem if the machine was never initially design to incorporate such a large change gear. Curse you imperial system and your insistence on using such large prime numbers for your definition! why couldn't an inch be 128/5 mm.🤣

[@mitrenaskovski3794]

Hallo, excellent video!!! This is lathe with leadscrew with pitch 4mm, and you use (fit) gear with module 1,25.I have lathe with leadscrew with pitch 2mm, which module gear i have to use? Can you help me pls?

[@Spark-Hole]

The formula is Pitch = Module X 3.1416 which in his case pitch transfer to module 1.273 and he choose 1.25 because availability to industrial standard. In you case module would be 0.6366 and has to be special made.

[@WRFUSINAGENS]

Muito bom

[@RoughAndWretchedRAW]

Watched a video of threading metric on an imperial screw and thread gauge. They showed you could disengage the nut. It's a matter of how you do it. Here is the video that show the sequence. kzbin.info/www/bejne/fonXZYeNlphraLM

[@charleskutrufis9612]

ugly comments guys, listen to the pretty music

[@boitumelomoseki8101]

😢

[@jaanisarkishtwari8179]

اصل

[@johnwoodhead9789]

8

[@bobridge5271]

Now do it again without the totally irrelevant music.

[@billshiff2060]

This shows how the metric system is clunky, ill fitting and out of scale with reality. Horrible units of illogical size.

[@markuscamenzind5510]

fractions of some dudes foot are so much better. LOL

[@billshiff2060]

@@markuscamenzind5510 Ignoramus. Maybe try keeping your yap shut until after you learn something.

[@markuscamenzind5510]

@@billshiff2060 Sure,dumb dumb. You found one part where the metric system is less than perfect and that validates your ignorance.

[@billshiff2060]

@@markuscamenzind5510 The metric sissydom is for dolts who need to count on their fingers. It went straight from their azz right into your head. Now you're just another clone.

[@markuscamenzind5510]

@@billshiff2060 every scientist in the world , even in ipm countries use metric. Imps even need clarification on British or US. And yes you can use your fingers " because" it's so easy. No looking up lists and conversions and still needing a calculator. But i get it. Many imps don't understand the metric system and rather make silly comments than bother to learn it.