# Thread dial indicator.



## Suzuki4evr (Oct 9, 2018)

Hey chippers
Is there something on this site about making your own thread dial indicator for metric and imperial threading. I can't seem to find any,maybe looking in the wrong place. I have a metric Mashstroy lathe with the thread dial indicator missing. I've been threading without it for very long time now, but it is taking to long when doing long threads. Any help would be appreciated. 

Michael


----------



## 4ssss (Oct 9, 2018)

You don't need a thread dial. When you cut threads, pull the tool out at the end of the thread,  reverse the motor without disconnecting the split nut, at the beginning of the thread, reverse the motor again and cut another pass. It may sound like a pain, but it's faster than you think when you don't have a dial


----------



## RJSakowski (Oct 9, 2018)

I made a new thread dial for my Grizzly lathe but not the axle and gear.  The first step is to determine the lead of the lead screw on inches/ thread if Imperial or mm/thread if metric.  Most Imperial lead screws are either 8 tpi (.125" lead) or 16 tpi (.0625" lead).  Your mating gear has to have the same pitch to mesh with the lead screw.  Some gears are cut with helical teeth to match the helix of the lead screw but another common technique is to rotate the axis slightly to mesh so an ordinary spur gear can be used.  There is no load involved so you can get away with a less than perfect mesh.

Normally, the gear would have four times as many teeth as as are in one inch of the lead screw for and Imperial setup.  This means that the thread dial makes on complete revolution for four inches of carriage travel.  The dial then has four numbered marks and four in-between marks.  My Grizzly is an exception as the lead screw has 12 threads/inch and 36 teeth on the gear, making a complete revolution in three inches.  It has 12 markes on the dial.  Metric lead screws & thread dials work in a similar fashion.

The difficult part would be finding/making the gear.  A little searching, once you know the diametral pitch, should turn up a suitable gear.  An axle and housing would have to be made as well as a thread dial.   It is possible that you might be able to find an assembly from another lathe that could be modified to fit yours.

edit: re-reading your post, I see that the lathe is metric.  The procedure is the same though.  SPI has low cost metric gears which will work for you. http://www.sdp-si.com/products/Gears/Index.php


----------



## Suzuki4evr (Oct 9, 2018)

4ssss said:


> You don't need a thread dial. When you cut threads, pull the tool out at the end of the thread,  reverse the motor without disconnecting the split nut, at the beginning of the thread, reverse the motor again and cut another pass. It may sound like a pain, but it's faster than you think when you don't have a dial


Thank you,but I know this and this is how I've been doing it,but like I said,when I do long threads it takes to long for my taste, but thanks for the input


----------



## plunger (Oct 9, 2018)

I dont think it would be too difficult to knock up a brass gear for your leadscrew. As has been pointed out it doesnt have to be exact. Im sure a flycutter could do it.


----------



## BaronJ (Oct 9, 2018)

Hi Guys,

I've rescued loads of gears, most of them plastic, from old printers, photocopiers etc.  Its possible you might get a suitable gear that way.


----------



## P. Waller (Oct 9, 2018)

Suzuki4evr said:


> Thank you,but I know this and this is how I've been doing it,but like I said,when I do long threads it takes to long for my taste, but thanks for the input


If speed is your #1 CONCERN then buy a NC lathe, input the start Z and the end Z, start diameter and finish diameter and the lead, this can be either metric or inch, it does not matter as lead is lead regardless of units.


----------



## 9t8z28 (Oct 9, 2018)

I have thought about doing this as well and wondered what was involved.  Great info RJSakowski.  I don’t see an NC lathe as a solution.  Sorry but its not what he’s wanting or asking.


----------



## 9t8z28 (Oct 9, 2018)

Me too.  I’ve got buckets full of printer gears!  I am amazed at the quality and design of some of them, especially the brass worm gears.  One day I’ll make up a powerfeed or something cool with some of these gears.





BaronJ said:


> Hi Guys,
> 
> I've rescued loads of gears, most of them plastic, from old printers, photocopiers etc.  Its possible you might get a suitable gear that way.


----------



## plunger (Oct 10, 2018)

Michael I once asked the very same question that you asked . I recieved a pm and a guy in JHB who is very talented had the same lathe as me EMCO v13. He built me one for free .But looking at it ,theres not much to it.
Do you have a manual for this lathe because it may take the guesswork out of the size and teeth on the gear.
Heres mine. He didnt have no stamps so just colour coded the dial.


----------



## plunger (Oct 10, 2018)




----------



## hman (Oct 10, 2018)

Issue #271 of Model Engineers' Workshop (September 2018) includes an article entitled "Making a Threading Indicator for a Lathe."  It's on pages 58 thru 63 and continues/concludes in issue #272 (Autumn Special 2018), pages 67 thru 69.  It goes into great detail, including the required parameters for both Imperial and metric (2 thru 6mm pitch) leadscrews.  I have no idea how easy it it for you to get publications from the UK where you are.  If need be, PM me and I can scan and email the pages to you.


----------



## ttabbal (Oct 10, 2018)

If you scan them, I'd be interested in reading it.


----------



## Tozguy (Oct 10, 2018)

plunger, re the picture above, just curious about how you get the gear to mesh with the lead screw.


----------



## Suzuki4evr (Oct 10, 2018)

P. Waller said:


> If speed is your #1 CONCERN then buy a NC lathe, input the start Z and the end Z, start diameter and finish diameter and the lead, this can be either metric or inch, it does not matter as lead is lead regardless of units.


I don't really have money laying around to go and buy new lathes to solve one problem. But if I did have the money, that is probably an option, but I want to  solve my problem the cheapest way possible and that is to make an indicator, because buying is also an issue, because I can't get one for my model lathe.


----------



## Suzuki4evr (Oct 10, 2018)

D


plunger said:


> Michael I once asked the very same question that you asked . I recieved a pm and a guy in JHB who is very talented had the same lathe as me EMCO v13. He built me one for free .But looking at it ,theres not much to it.
> Do you have a manual for this lathe because it may take the guesswork out of the size and teeth on the gear.
> Heres mine. He didnt have no stamps so just colour coded the dial.


I don't see it in my manual,some pages nissing and you can't find this lathe model on the Internet.


----------



## Suzuki4evr (Oct 10, 2018)

Tozguy said:


> plunger, re the picture above, just curious about how you get the gear to mesh with the lead screw.


So am I,it looks kinda out of alignment.


----------



## plunger (Oct 10, 2018)

The photo is taken from underneath.It simply rotates untill it makes contact.I only use it for odd threads like 1,25 and 1,75 mm. My pitch is 6mm and for imperial of which I do alot I never disingauge the half nut.


----------



## bhigdog (Oct 10, 2018)

I made a new gear out of brass for my LeBlond. Pretty easy with a spin fixture and a home made cutter. You could even use a one tooth fly cutter type cutter. Click on the pix for full size........Bob


----------



## KMoffett (Oct 11, 2018)

I had a South Bend lathe without a thread dial. I was lucky enough to order and receive a thread dial gear from South Bend...just as they were closing the door.  Body out of aluminum tube. Mount from a slit steel pipe, with a pin that fit the apron welded to it.

Ken


----------



## Tozguy (Oct 11, 2018)

Suzuki4evr said:


> D
> 
> I don't see it in my manual,some pages nissing and you can't find this lathe model on the Internet.



Suzuki, if you provide us with the exact thread spec of your lead screw, then the thread dial gear from any lathe with the same lead screw should work. Maybe we could provide you with the part number and source for a gear only and you could make the other parts to use that gear on your lathe. Unfortunately my lead screw is inchy or I would provide you with that information.

And as RJ mentioned above in all likelihood it would be rather simple to fit a whole thread dial from another metric lathe with the same lead screw.


----------



## Suzuki4evr (Oct 11, 2018)

Tozguy said:


> Suzuki, if you provide us with the exact thread spec of your lead screw, then the thread dial gear from any lathe with the same lead screw should work. Maybe we could provide you with the part number and source for a gear only and you could make the other parts to use that gear on your lathe. Unfortunately my lead screw is inchy or I would provide you with that information.
> 
> And as RJ mentioned above in all likelihood it would be rather simple to fit a whole thread dial from another metric lathe with the same lead screw.


I am trying to figure that out now. I have a thread gauge, but it only goes up to 5.5mm. This leadscrew has a very strang pitch. My caliper is set on 25.4mm (1'), as you can see,but the thread does not seem to be imperial.


The nominal size is 40mm and the minor size is 27mm. So does this mean it is a 40×13 leadscrew or do I have it totally wrong?




I found the diagram in the manual.This is the diagram out of the manual,but it does not say anywhere the leadscrew pitch or the size of the gear and other thingI do not understand is the clock section on when to engage the halfnut on wich number for wich pitch. Can you declare this maybe.


----------



## Tozguy (Oct 11, 2018)

Another way to measure the pitch is with a metric ruler. Measure the length of 10 threads and divide by 10.
That is a strange thread tho.


----------



## plunger (Oct 11, 2018)

Its a bulgarian lathe?Would it not be metric.2,5mm?


----------



## bhigdog (Oct 11, 2018)

Something wrong here. I can see a half nut engaging with that shaft but I can't see a smallish thread dial gear doing it. One tooth would almost be disengaged before the next engaged...........Bob


----------



## Tozguy (Oct 11, 2018)

Suzuki4evr said:


> So does this mean it is a 40×13 leadscrew or do I have it totally wrong?



I agree and would call it a 40x13mm thread also.
Based on the drawing of the thread dial that you provided above, the gear looks rather large and the lead screw threads are deep. Just eyeballing it, a gear with 25 teeth would mesh with the lead screw and would only be approx. 100 mm or 4'' in diameter. Hopefully sharper minds will be along to shed more light.


----------



## Tozguy (Oct 11, 2018)

The latter part of this video shows a neat homemade metric thread dial.


----------



## Suzuki4evr (Oct 12, 2018)

plunger said:


> Its a bulgarian lathe?Would it not be metric.2,5mm?


It looks to big for 2.5mn,but I am going out to the shop in a while and try to figure it out again.


----------



## Suzuki4evr (Oct 12, 2018)

Ok guys I have looked it up now. When measuring metric threads,you measure it in threads per millimeter from credt to crest,but on the ACME thread or trapezoidal thread,you woul measure and what I have concluded now,it seems that the leadscrew I have is then a 40×12mm leadscrew. I think this looks like a reasonable conclusion. But like Tozguy said,it is a large and very deep pitch. What do you guys think of my conclusion and the big question is what size OD must the gear be for this? I know now I must have a 15T and 14T gear to cover the metric spectrum.


----------



## Tozguy (Oct 12, 2018)

To get a more accurate reading with your caliper, open the caliper out and measure as many threads as possible. Then divide that length by the number of threads in your measurement. Be aware that the result does not have to be a round number, it could be 12.5mm for example.
 I am no gear expert but to get the circumference of a 15T gear to match your lead screw just measure the length of 15 threads on the screw, then divide that number by pi (3.1416). For the 14T gear measure 14 threads on the screw. That will give you a ballpark diameter for the gear. 
How did you determine that a 14 and 15 tooth gear is required?


----------



## Suzuki4evr (Oct 12, 2018)

T


Tozguy said:


> To get a more accurate reading with your caliper, open the caliper out and measure as many threads as possible. Then divide that length by the number of threads in your measurement. Be aware that the result does not have to be a round number, it could be 12.5mm for example.
> I am no gear expert but to get the circumference of a 15T gear to match your lead screw just measure the length of 15 threads on the screw, then divide that number by pi (3.1416). For the 14T gear measure 14 threads on the screw. That will give you a ballpark diameter for the gear.
> How did you determine that a 14 and 15 tooth gear is required?


Thanks for the info. I browsed around and found it on another machinist site,I think it was "practical machist". It was discussed there on wich gear to use for a metric leadscrew.


----------



## Tozguy (Oct 12, 2018)

Suzuki4evr said:


> I found the diagram in the manual.This is the diagram out of the manual,but it does not say anywhere the leadscrew pitch or the size of the gear and other thingI do not understand is the clock section on when to engage the halfnut on wich number for wich pitch. Can you declare this maybe.



Normally a diagram like you have shown in post 22 is accompanied by a parts list that provides the specs on the part. Often the parts list is on the next page following the diagram. For the dial gear shown as part 01 in the diagram I would expect that the parts list would show the number of teeth. The chart shown mounted on the dial body would only work with a gear of that size.


----------



## Suzuki4evr (Oct 12, 2018)

Tozguy said:


> To get a more accurate reading with your caliper, open the caliper out and measure as many threads as possible. Then divide that length by the number of threads in your measurement. Be aware that the result does not have to be a round number, it could be 12.5mm for example.
> I am no gear expert but to get the circumference of a 15T gear to match your lead screw just measure the length of 15 threads on the screw, then divide that number by pi (3.1416). For the 14T gear measure 14 threads on the screw. That will give you a ballpark diameter for the gear.
> How did you determine that a 14 and 15 tooth gear is required?


The fully opened calliper method gave me 11.57mm and for the 15T gear OD I got around 54.75mm.


----------



## Suzuki4evr (Oct 12, 2018)

Tozguy said:


> Normally a diagram like you have shown in post 22 is accompanied by a parts list that provides the specs on the part. Often the parts list is on the next page following the diagram. For the dial gear shown as part 01 in the diagram I would expect that the parts list would show the number of teeth. The chart shown mounted on the dial body would only work with a gear of that size.


This is all that is on the next page.Sadly I don't see anything I need.


----------



## Tozguy (Oct 12, 2018)

I can not even read the page but we tried


----------



## Tozguy (Oct 12, 2018)

Suzuki4evr said:


> The fully opened calliper method gave me 11.57mm and for the 15T gear OD I got around 54.75mm.



How many threads were included in your measurement to arrive at a pitch of 11.57mm? 
15 threads of a 11.57mm pitch should give around 173.55mm. Divide that by pi and the result is 55.24mm diameter gear. Close enough to your number but the 11.57 result still looks funny to me.

Trying to imagine what the gear teeth would look like....and figure that they must look something like these.


----------



## Suzuki4evr (Oct 12, 2018)

Good Heavens but that is one ugly gear.Over the length of 220mm,I have 19 full threads


----------



## Tozguy (Oct 12, 2018)

Thanks for the details. Never heard of a 11.57mm pitch. I'm stumped.
Sometimes it takes an ugly gear to mesh with an ugly lead screw. 

If the diagram in post 22 above is to scale, which I think it must be, is there a way that you can scale the diameter of the gear from a known dimension to arrive at its diameter? 

And I am starting to wonder why there was no thread dial that came with your lathe.


----------



## Suzuki4evr (Oct 12, 2018)

Neither have I. I will have to do something,just don't know what yet. There is a tapped hole where it is supposed to fit so I guess there was one,just got lost somehow


----------



## Tozguy (Oct 12, 2018)

On a big lathe like that maybe they did not need a thread dial and cut the threads all in one pass. 
Seriously I hope that you can work something out.


----------



## Suzuki4evr (Oct 12, 2018)

I doubt that very much,but yes I don't know how yet,but something's got to give


----------



## pstemari (Oct 12, 2018)

8 TPI leadscrews I'm familiar with, but certainly not 16 TPI. My lathe has a 4 TPI leadscrew.

Inch threads, in the worst case, sync every four inches, and that case is very rare—usually it's every inch (odd TPI, any number on the dial) or even 1/2” (even TPI, any number or line) or 1/4" (no dial needed).

Metric thread dials are much more complex than inch ones. Metric threads are specified by length, so they only sync for the least common multiple of the thread pitch and the leadscrew pitch. For example, if you have a 2.5mm thread and a 6mm leadscrew, it will sync every 30mm (12×2.5 and 5×6). A 0.35mm thread will sync every 42mm, etc. You need something like 4–6 gears to account for all the common pitches.

Sent from my Pixel XL using Tapatalk


----------



## plunger (Oct 14, 2018)

Ive found this thread quite interesting and frustrating. It has reminded me how weak my knowledge of things is. (maths).I love being a hobby machinest but not having anyone to share ideas I guess you learn by yourself and just get the job done. 
In terms of thread cutting I cut ninety percent of the time a single pitch. That is 14 tpi. It is for plumbing fittings (bsp )as I am a plumber.I seldom cut threads.

But it got me thinking .My leadscrew is 6mm and most of my threads are short so I just leave the half nut closed.If Im doing metric threads I still keep the half nut closed but if its  a pitch like 1mm or 1,5 or 2mm I sometimes loosen the half nut and and wind the carriage back .
So it got me thinking. I have to admit that I havnt used the thread dial for ages. So I thought I would try use it and no matter what I do I cant get it to work. I tried it on the metric setting and tried a 1,75 mm setting. It just doesnt follow the chase. This is where my maths becomes a problem. I just dont understand it. 

So are there any emco owners out there who own an emco v13 with a 6mm metric leadscrew and who have a thread dial who can help me out on how to use it.


----------



## Suzuki4evr (Oct 15, 2018)

plunger said:


> Ive found this thread quite interesting and frustrating. It has reminded me how weak my knowledge of things is. (maths).I love being a hobby machinest but not having anyone to share ideas I guess you learn by yourself and just get the job done.
> In terms of thread cutting I cut ninety percent of the time a single pitch. That is 14 tpi. It is for plumbing fittings (bsp )as I am a plumber.I seldom cut threads.
> 
> But it got me thinking .My leadscrew is 6mm and most of my threads are short so I just leave the half nut closed.If Im doing metric threads I still keep the half nut closed but if its  a pitch like 1mm or 1,5 or 2mm I sometimes loosen the half nut and and wind the carriage back .
> ...


I hope someone can help you. I must put this project on ice for now,because I have a few jobs that came in and that must be done first. Although I really want to get to cutting some gears. Good luck to you plumber man.


----------



## RickT (Oct 17, 2018)

hman said:


> Issue #271 of Model Engineers' Workshop (September 2018) includes an article entitled "Making a Threading Indicator for a Lathe."  It's on pages 58 thru 63 and continues/concludes in issue #272 (Autumn Special 2018), pages 67 thru 69.  It goes into great detail, including the required parameters for both Imperial and metric (2 thru 6mm pitch) leadscrews.  I have no idea how easy it it for you to get publications from the UK where you are.  If need be, PM me and I can scan and email the pages to you.



If you are scanning these, I would really like a copy as well! I have been considering marking one for my Chinese lathe.


----------



## crazypj (Oct 18, 2018)

It is a single start thread and not multi start? Either way, you would be far better off making a direct copy from drill rod/silver steel  then cut teeth to make a gear hob. (expensive in 40mm)  For a one off to cut bronze or brass, a cheaper alternative would be use mild steel and case harden it. Because of the diameter of gear blank you will almost certainly need a worm wheel type gear that fits 'around' lead-screw (I forget correct name at present, it's concave). There are plenty of instructions and video's about making gear hobs for 'softer' materials. With a 40mm lead-screw you obviously have a pretty large machine. As for the comment about buying a NC machine, I don't know how anyone can be so asinine?????.


----------



## Suzuki4evr (Oct 18, 2018)

crazypj said:


> It is a single start thread and not multi start? Either way, you would be far better off making a direct copy from drill rod/silver steel  then cut teeth to make a gear hob. (expensive in 40mm)  For a one off to cut bronze or brass, a cheaper alternative would be use mild steel and case harden it. Because of the diameter of gear blank you will almost certainly need a worm wheel type gear that fits 'around' lead-screw (I forget correct name at present, it's concave). There are plenty of instructions and video's about making gear hobs for 'softer' materials. With a 40mm lead-screw you obviously have a pretty large machine. As for the comment about buying a NC machine, I don't know how anyone can be so asinine?????.


I have a 1.5m between centres lathe. Yes, I don't know why I should buy another lathe to solve a problem, but I don't have any ill feelings towards the member,but it was a strange reply to my problem.


----------



## Suzuki4evr (Oct 30, 2018)

So here it is. Firstly, thanks to all the members for your help and advise,in particular Tozguy,you helped alot.

I made an arbor and started making the gear blank.


I then made a toolbit fitting the leadscrew on suggestion by Plunger and Bob Corves. It is not perfect but it will do the job.


After picking the right indexing plate for the dividing head,I just double checked and marked where the teeth should be just to play safe. O I forgot to mention that I made the gear out of teflon first just to see if everything works. 


Then I started winging it by setting my dividing head at 8degrees to get the angle (approximately) to my leadscrew, because I want my dial to sit straight  not angled,and I must say it worked out. I the proceeded to cut the gear.




It's not pretty or perfect, but like Bob said,it doesn't have to be. It mesh and that'sall that matters.


My question is. Is there any reason to NOT use this plastic gear as the final gear rathet than brass?

I will post again during the build of the body.

Michael


----------



## pstemari (Oct 30, 2018)

Not really. The gear only has to turn the threading dial, and Teflon will not wear on the leadscrew as much.

I assume you have an inch leadscrew—metric leadscrews require additional gears.

Sent from my Pixel XL using Tapatalk


----------



## Suzuki4evr (Oct 30, 2018)

I guess you haven't followed the whole thread if you ask the question. No it is a metric leadscrew,this is only the first gear, I am only starting to build the dial. For the commen threads I usually cut,I will be needing a T15 & T14 gear,but I will make them as I go. About the Teflon gear, I am tending to agree with you. Thank you for your input.

Michael


----------



## plunger (Oct 30, 2018)

Michael thats something I was asking myself the other day.When you look at the thread dial in action its weird because the gear almost looks still when the carriage is going forward.If it rotates and you can pin or key the gear to the shaft properly I cant see much going wrong with it. I think delrin would work well for this . I ask cause teflon is expensive..When I made my gear for my bandsaw I made a hob but pretty much did exactly what you have done. I guessed the angle and then pre gashed it with a slitting saw. Then I used the same hss piece I used to machine the worm and hob..Then I hardened the hob and just let it run into the p bronze gear. It cut a pretty neat gear for a hacker like myself.

Not knowing much about gears I wonder if plastic may be a better choice.How do they flycut gears for spur gears ? Do they try get a more true shape to the piece of hss.?I am referring to the teeth on the perimeter. A hob sorts this out even though its not cutting a true gear. 

Cant you show a fellow s african what your mill and and dividing head look like. As Ive said before its lonely being hobby machinest in S. A


----------



## plunger (Oct 30, 2018)

Havent learnt the picture thing yet.This is the hob


----------



## Suzuki4evr (Oct 30, 2018)

Here you go. All in one










I am going to make bigger change gears for my lathe that did not come with my lathe and for fun make a hob for a 12mm pitch leadscrew gear. But that will be in the distant future.


----------



## Suzuki4evr (Oct 30, 2018)

Nice work plunger


----------



## Suzuki4evr (Oct 30, 2018)

This gives a better idea of size


----------



## Tozguy (Oct 30, 2018)

Nice work by the both of you and great pictures.
I would use the teflon gear. As already mentioned it does not work hard.
Just need to find a way to keep it from spinning on the shaft as plunger said.


----------



## plunger (Oct 30, 2018)

Sorr


Suzuki4evr said:


> Nice work plunger


Thanks. The dividing head looks brand spanking new.Its a nice to have accessory. Pity our Rand is so weak and we dont have stores like harbour freight.And where I live there are never auctions or bargains on second hand stuff.


----------



## Suzuki4evr (Oct 30, 2018)

You


Tozguy said:


> Nice work by the both of you.
> I would use the teflon gear. As already mentioned it does not work hard.
> Just need to find a way to keep it from spinning on the shaft as plunger said.


 Thank you. You can't see it but I've put a key slot in the gear and will do so on the shaft.


----------



## Suzuki4evr (Oct 30, 2018)

plunger said:


> Sorr
> 
> Thanks. The dividing head looks brand spanking new.Its a nice to have accessory. Pity our Rand is so weak and we dont have stores like harbour freight.And where I live there are never auctions or bargains on second hand stuff.


It is about a year old and I had to twist my wifes arm alot to buy it. One of our previous members,Mr Mark Frazier, wanted to GIVE me one he restored,but it would have cost me over R12 000 just to ship it here. Pitty. So I bought one here for almost that.


----------



## plunger (Oct 30, 2018)

Suzuki4evr said:


> It is about a year old and I had to twist my wifes arm alot to buy it. One of our previous members,Mr Mark Frazier, wanted to GIVE me one he restored,but it would have cost me over R12 000 just to ship it here. Pitty. So I bought one here for almost that.


I bought a second hand one .Its spanish called metachecnica. Doubt there are spares for it and doubt if they are still in business.


----------



## Tozguy (Oct 30, 2018)

Just a thought but if there is going to be a dial with hash marks on it, at some point you are going to want to time the dial with the half nuts engagement which requires some adjustability somewhere.
Like an adjustable index mark or a dial with a set screw.


----------



## Suzuki4evr (Oct 30, 2018)

Tozguy said:


> Just a thought but if there is going to be a dial with hash marks on it, at some point you are going to want to time the dial with the half nuts engagement which requires some adjustability somewhere.
> Like an adjustable index mark or a dial with a set screw.


Maybe I am a bit slow,and forgive me,but I don't quite understand.


----------



## Tozguy (Oct 30, 2018)

You are not slow, at least not slower than I am. 
When using the thread dial, you have your hand on the half nut lever and wait for the target dial mark to arrive on the index mark. When it arrives on the mark you slam the lever down. But it does not go down at the mark because the half nuts do not mesh with the lead screw at that point. So you keep pressure on the lever and the nuts will close somewhere past the mark. My thread dial gear can be loosened on the shaft and turned so the half nuts will close exactly on the hash mark.   Thats what I call timing the dial to the half nuts.
I may not have explained it too well so fire away if you need more info.


----------



## Suzuki4evr (Oct 30, 2018)

Ok,I sped up,I'm with you now. Off to bed with me now. 

Thanks Tozguy


----------



## bhigdog (Oct 30, 2018)

When I made my gear I timed it by attaching the gear to the shaft with a set screw. With the set screw just snug I engaged the gear in the lead screw and moved the carriage until the index marks aligned then tightened the set screw. I cut several different pitch threads to confirm the  timing then pinned the gear to the shaft with a roll pin. It's worked very well and lasted a long time............Bob


----------



## pstemari (Oct 30, 2018)

Suzuki4evr said:


> I guess you haven't followed the whole thread if you ask the question. No it is a metric leadscrew,this is only the first gear,



Ah, wasn't certain this was the same thread. Well, fwiw, I worked out the repeat distance for the standard metric pitches up to M36 or thereabouts and came up with 1.26 meters  By way of comparison, inch threads all repeat every 4", and there are only a few oddballs that don't repeat every 1" or less: xx-1/2 TPI threads repeat every two inches and xx-1/4 and xx-3/4 TPI threads repeat every four inches. Unfortunately, the troublesome metric threads are really common (M2.5, M4, and M5) unlike the troublesome inch threads which are really rare.

Did you have a 6mm or a 3mm pitch on your leadscrew? At any rate, finding the right set of gears is going to be tedious.

Sent from my Pixel XL using Tapatalk


----------



## Suzuki4evr (Jul 16, 2020)

Hallo guys. 
I have successfully made a thread chasing dial for my 12mm pitch leadscrew lathe wich I will post about when the time comes,but now I have a question I could solve on my own. Is it possible to make a gear for the the leadscrew so I can make imperial threads too using the dial,but with the imperial dial face? I tried a 12 tooth gear,but it doesn't work. Again.....is it possible. Any advice?  Thanks guys.

Michael


----------



## Tozguy (Jul 16, 2020)

My prediction is no, it is not. The problem is that basic metric pitches and imperial pitches do not correspond. Some come close but are never really equivalent.


----------

